Publications by authors named "Balal Yousaf"

50 Publications

Formation of nitrogen functionalities in biochar materials and their role in the mitigation of hazardous emerging organic pollutants from wastewater.

J Hazard Mater 2021 08 24;416:126131. Epub 2021 May 24.

University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Seoul, South Korea.

Emerging organic pollutants (EOPs) are serious environmental concerns known for their prominent adverse and hazardous ecological effects, and persistence in nature. Their detrimental impacts have inspired researchers to develop the strategic tools that reduce and overcome the challenges caused by EOPs' rising concentration. As such, biochar becomes as a promising class of biomass-derived functional materials that can be used as low-cost and environmentally-friendly emerging catalysts to remove EOPs. Herein, in-depth synthetic strategies and formation mechanisms of biochar-based nitrogen functionalities during thermochemical conversion are presented. Most prominently, the factors affecting N-surface functionalities in biochar are discussed, emphasizing the most effective N-doping approach, including intrinsic N-doping from biomass feedstock and extrinsic N-doping from exogenous sources. Moreover, biochar-assisted EOPs removal in line with interactions of nitrogen functionalities and contaminants are discussed. The possible reaction mechanisms, i.e., radical and non-radical degradation, physical adsorption, Lewis acid-base interaction, and chemisorption, driven by N-functionalities, are addressed. The unresolved challenges of the potential applications of biochar-mediated functionalities for EOPs removal are emphasized and the outlooks of future research directions are proposed at the end.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126131DOI Listing
August 2021

Health impacts of indoor air pollution from household solid fuel on children and women.

J Hazard Mater 2021 08 17;416:126127. Epub 2021 May 17.

Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, and State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China; Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong, China. Electronic address:

The inefficient and incomplete combustion of solid fuel (SF) is associated with high levels of indoor air pollutants leading to 3.55 million deaths annually. The risk is higher in women and children, due to their higher exposure duration and unique physical properties. The current article aims to provide a critical overview regarding the use of solid fuel, its associated pollutants, their toxicity mechanisms and, most importantly the associated health impacts, especially in women and children. Pollutants associated with SF mostly include polycyclic aromatic hydrocarbons, particulate matter, nitrous oxide, carbon monoxide and sulfur dioxide, and their concentrations are two- to threefold higher in indoor environments. These pollutants can lead to a variety of health risks by inducing different toxicity mechanisms, such as oxidative stress, DNA methylation, and gene activation. Exposed children have an increased prevalence of low birth weight, acute lower respiratory tract infections, anemia and premature mortality. On the other hand, lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases are the major causes of disability and premature death in women. Indoor air pollution resulting from SF combustion is a major public health threat globally. To reduce the risks, it is important to identify future research gaps and implement effective interventions and policies.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126127DOI Listing
August 2021

Environmental emission, fate and transformation of microplastics in biotic and abiotic compartments: Global status, recent advances and future perspectives.

Sci Total Environ 2021 Oct 10;791:148422. Epub 2021 Jun 10.

Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China; Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China. Electronic address:

The intensive use and wide-ranging application of plastic- and plastic-derived products have resulted in alarming levels of plastic pollution in different environmental compartments worldwide. As a result of various biogeochemical mechanisms, this plastic litter is converted into small, ubiquitous and persistent fragments called microplastics (<5 mm), which are of significant and increasing concern to the scientific community. Microplastics have spread across the globe and now exist in virtually all environmental compartments (the soil, atmosphere, and water). Although these compartments are often considered to be independent environments, in reality, they are very closely linked. Ample research has been done on microplastics, but there are still questions and knowledge gaps regarding the emission, occurrence, distribution, detection, environmental fate and transport of MPs in different environmental compartments. The current article is intended to provide a systematic overview of MP emissions, pollution conditions, sampling and analytical approaches, transport, fates and transformation mechanisms in different environmental compartments. It also identifies research gaps and future research directions and perspectives.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148422DOI Listing
October 2021

Enthralling the impact of engineered nanoparticles on soil microbiome: A concentric approach towards environmental risks and cogitation.

Ecotoxicol Environ Saf 2021 Oct 30;222:112459. Epub 2021 Jun 30.

Botany and Microbiology Department, King Saud University, Riyadh, Saudi Arabia. Electronic address:

Nanotechnology is an avant-garde field of scientific research that revolutionizes technological advancements in the present world. It is a cutting-edge scientific approach that has undoubtedly a plethora of functions in controlling environmental pollutants for the welfare of the ecosystem. However, their unprecedented utilization and hysterical release led to a huge threat to the soil microbiome. Nanoparticles(NPs) hamper physicochemical properties of soil along with microbial metabolic activities within rhizospheric soils.Here in this review shed light on concentric aspects of NP-biosynthesis, types, toxicity mechanisms, accumulation within the ecosystem. However, the accrual of tiny NPs into the soil system has dramatically influenced rhizospheric activities in terms of soil properties and biogeochemical cycles. We have focussed on mechanistic pathways engrossed by microbes to deal with NPs.Also, we have elaborated the fate and behavior of NPs within soils. Besides, a piece of very scarce information on NPs-toxicity towards environment and rhizosphere communities is available. Therefore, the present review highlights ecological perspectives of nanotechnology and solutions to such implications. We have comprehend certain strategies such as avant-garde engineering methods, sustainable procedures for NP synthesis along with vatious regulatory actions to manage NP within environment. Moreover, we have devised risk management sustainable and novel strategies to utilize it in a rationalized and integrated manner. With this background, we can develop a comprehensive plan about NPs with novel insights to understand the resistance and toxicity mechanisms of NPs towards microbes. Henceforth, the orientation towards these issues would enhance the understanding of researchers for proper recommendation and promotion of nanotechnology in an optimized and sustainable manner.
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http://dx.doi.org/10.1016/j.ecoenv.2021.112459DOI Listing
October 2021

Nickel in soil and water: Sources, biogeochemistry, and remediation using biochar.

J Hazard Mater 2021 Oct 16;419:126421. Epub 2021 Jun 16.

State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an 311300, China; Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2H1, Canada. Electronic address:

Nickel (Ni) is a potentially toxic element that contaminates soil and water, threatens food and water security, and hinders sustainable development globally. Biochar has emerged as a promising novel material for remediating Ni-contaminated environments. However, the potential for pristine and functionalized biochars to immobilize/adsorb Ni in soil and water, and the mechanisms involved have not been systematically reviewed. Here, we critically review the different dimensions of Ni contamination and remediation in soil and water, including its occurrence and biogeochemical behavior under different environmental conditions and ecotoxicological hazards, and its remediation using biochar. Biochar is effective in immobilizing Ni in soil and water via ion exchange, electrostatic attraction, surface complexation, (co)precipitation, physical adsorption, and reduction due to the biogeochemistry of Ni and the interaction of Ni with surface functional groups and organic/inorganic compounds contained in biochar. The efficiency for Ni removal is consistently greater with functionalized than pristine biochars. Physical (e.g., ball milling) and chemical (e.g., alkali/acidic treatment) activation achieve higher surface area, porosity, and active surface groups on biochar that enhance Ni immobilization. This review highlights possible risks and challenges of biochar application in Ni remediation, suggests future research directions, and discusses implications for environmental agencies and decision-makers.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126421DOI Listing
October 2021

Interactive assessment of lignite and bamboo-biochar for geochemical speciation, modulation and uptake of Cu and other heavy metals in the copper mine tailing.

Sci Total Environ 2021 Jul 18;779:146536. Epub 2021 Mar 18.

Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Zijingang Campus, Yuhangtang Road 866, Hangzhou 310058, China. Electronic address:

This study was designed to examine the combined effect of bamboo-biochar (BC) and water-washed lignite (LGT) at copper mine tailings (CuMT) sites on the concentration of Cu and other metals in pore water (PW), their bioavailability, and change in geochemical speciation. Rapeseed (first cropping-season) and wheat (second cropping-season) were grown for 40-days each and the influence of applied-amendments on both cropping seasons was observed and compared. A significant increase in pH, water holding capacity (WHC), and soil organic carbon (SOC) was observed after the applied amendments in second cropping-seasons. The BC-LGT significantly reduced the concentration of Cu in PW after second cropping seasons; however, the concentration of Pb and Zn were increased with the individual application of biochar and LGT, respectively. BC-LGT and BC-2% significantly reduced the bioavailability of Cu and other HMs in both cropping seasons. The treated-CuMT was subjected to spectroscopic investigation through X-ray photoelectron spectroscopy (XPS), Fourier transform Infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD). The results showed that Cu sorption mainly involved the coordination with hydroxyl and carboxyl functional groups, as well as the co-precipitation or complexation on mineral surfaces, which vary with the applied amendment and bulk amount of Mg, Mn, and Fe released during sorption-process. The co-application of BC-LGT exerted significant effectiveness in immobilizing Cu and other HMs in CuMT. The outcomes of the study indicated that co-application of BC-LGT is an efficacious combination of organic and inorganic materials for Cu adsorption which may provide some new information for the sustainable remediation of copper mine tailing.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146536DOI Listing
July 2021

Geochemical fractionation and spectroscopic fingerprinting for evaluation of the environmental transformation of potentially toxic metal(oid)s in surface-subsurface soils.

Environ Geochem Health 2021 Apr 15. Epub 2021 Apr 15.

Sustainable Development Study Centre, Government College University, Lahore, Pakistan.

The contamination of soil by toxic metal(oid)s has emerged as a major concern worldwide, particularly in developing countries. A metals behavior in the soil environment is influenced by organic matter, mineral phases, and oxidation states in which a particular metal exists. However, the spectroscopic evidence of metal(oid)s interactions in soil with organic matter and mineral phases can induce an extensive understanding. The surface and sub-surface soils (0-50 cm) from four sites of upper Indus basin, Pakistan, were collected and analyzed by using FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy) in addition to ICP-MS (inductively coupled plasma mass spectrometry) and geochemical fractionation. Geochemical fractionation of metal(oid)s indicated that As, Cu, Ni, Pb, and Zn were mostly found in the potentially bioavailable fractions. However, an increase in the residual fraction was observed from top to bottom. The absorption bands of FTIR spectra were divided into three spectral regions 700-400, 1700-800, and 3700-2800 cm. The soil was found rich in organic matter and capable of retaining metals as abundant peaks were observed in the mid-infrared region. The mineralogical analysis of soil samples testified silicon oxides and zeolite as major mineral phases. The XPS spectra showed broad peaks of As(III), AsO, AsS, PbO, and PbCo. The study concludes that the source identification of metal(oid)s in the upper Indus is crucial to find out the particular source of contamination in the soil.
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http://dx.doi.org/10.1007/s10653-021-00932-zDOI Listing
April 2021

Identification of the featured-element in fine road dust of cities with coal contamination by geochemical investigation and isotopic monitoring.

Environ Int 2021 07 12;152:106499. Epub 2021 Mar 12.

School of Ecology and Environment, Anhui Normal University, Wuhu 241000, Anhui, China.

The exploitation of coal releases large amounts of contaminants into the environment. However, the featured pollutants of coal utilization as well as the scope and degree of their impact remain to be revealed. To identify the featured-element of coal contamination in a complex environment, a typical coal resource city was selected, and the major elements, 18 trace elements, as well as δC, δN, and δS in the fine road dust and certain source materials were analyzed. Through multiple analysis methods, the featured-element was determined step-by-step: firstly, elements with enrichment coefficients greater than two in road dust were focused: Zn, Hg, Pb, Cu, Cd, and Cr; secondly, difference analysis showed a significant difference (p < 0.05) of Hg and Cu concentration at different distance from the coal-fired power plant, making Hg and Cu the only candidates for the featured-element; finally, through coal-related source materials determination, Cu was not qualified as a featured-element. Therefore, Hg was the only left element to be considered as the featured-element. To be more convincing, more analyses were performed to support Hg as the featured-element: cluster analysis and isotope monitoring indicated Hg in road dust could originate from coal combustion; X-ray photoelectron spectroscopy was also conducted, where the forms of Hg in road dust with possible source materials were compared, and the presence of HgO and Hg only in the road dust near the power plant indicated the impact of the power plant on the surrounding dust. Through the health risk assessment, it was found that Hg in the road dust had no health risk, though the study area still had Pb, Cr, and As risks, which were not closely related to the pollutants released by coal-related sources.
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http://dx.doi.org/10.1016/j.envint.2021.106499DOI Listing
July 2021

Recent trends in advanced oxidation process-based degradation of erythromycin: Pollution status, eco-toxicity and degradation mechanism in aquatic ecosystems.

Sci Total Environ 2021 Jun 27;772:145389. Epub 2021 Jan 27.

Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610 Bandar Seri Iskander, Perak, Malaysia.

Wide spread documentation of antibiotic pollution is becoming a threat to aquatic environment. Erythromycin (ERY), a macrolide belonging antibiotic is at the top of this list with its concentrations ranging between ng/L to a few μg/L in various global waterbodies giving rise to ERY-resistance genes (ERY-RGs) and ERY- resistance bacteria (ERY-RBs) posing serious threat to the aquatic organisms. ERY seems resistant to various conventional water treatments, remained intact and even increased in terms of mass loads after treatment. Enhanced oxidation potential, wide pH range, elevated selectivity, adaptability and greater efficiency makes advance oxidation processes (AOPs) top priority for degrading pollutants with aromatic rings and unsaturated bonds like ERY. In this manuscript, recent developments in AOPs for ERY degradation are reported along with the factors that affect the degradation mechanism. ERY, marked as a risk prioritized macrolide antibiotic by 2015 released European Union watch list, most probably due to its protein inhibition capability considered third most widely used antibiotic. The current review provides a complete ERY overview including the environmental entry sources, concentration in global waters, ERY status in STPs, as well as factors affecting their functionality. Along with that this study presents complete outlook regarding ERY-RGs and provides an in depth detail regarding ERY's potential threats to aquatic biota. This study helps in figuring out the best possible strategy to tackle antibiotic pollution keeping ERY as a model antibiotic because of extreme toxicity records.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145389DOI Listing
June 2021

Decisive role of vacuum-assisted carbonization in valorization of lignin-enriched (Juglans regia-shell) biowaste.

Bioresour Technol 2021 Mar 14;323:124541. Epub 2020 Dec 14.

CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China.

Bioenergy is considered a sustainable substitute to fossil-fuel resources and the development of a prudent combination of renewable and innovative conversion technologies are essential for the valorization and effective conversion of biowaste to value-added commodities. Here, a negative pressure-induced carbonization process was proposed for the valorization of lignin-enriched biowaste precursor to bio-oil and environmental materials (biochar) at various temperatures. The high heating values (HHV) of the as-prepared biochars from the lignin enriched precursor under negative pressure (low-medium vacuum) were within 25.9-31.5 MJ/kg, which matched satisfactorily to the commercial charcoal. Whereas, the bio-oils produced from the lignin enriched precursor under vacuum conditions was a blend of complex aromatic and straight-chain hydro-carbons, including aldehyde, ketone, phenol, and furans, exhibiting ability as potential heating-oil with HHV within 21.2-28.2 MJ/kg. Moreover, the biochars produced under vacuum environments at higher temperature showed greater stability (22.5-35.9%) than those produced under N atmosphere.
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http://dx.doi.org/10.1016/j.biortech.2020.124541DOI Listing
March 2021

Biochar-mediated transformation of titanium dioxide nanoparticles concerning TiONPs-biochar interactions, plant traits and tissue accumulation to cell translocation.

Environ Pollut 2021 Feb 1;270:116077. Epub 2020 Dec 1.

University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285, Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Seoul, Republic of Korea.

Titanium dioxide nanoparticles (TiONPs) application in variety of commercial products would likely release these NPs into the environment. The interaction of TiONPs with terrestrial plants upon uptake can disturb plants functional traits and can also transfer to the food chain members. In this study, we investigated the impact of TiONPs on wheat (Triticum aestivum L.) plants functional traits, primary macronutrients assimilation, and change in the profile of bio-macromolecule. Moreover, the mechanism of biochar-TiONPs interaction, immobilization, and tissue accumulation to cell translocation of NPs in plants was also explored. The results indicated that the contents of Ti in wheat tissues was reduced about 3-fold and the Ti transfer rate (per day) was reduced about 2 fold at the 1000 mg L exposure level of TiONPs in biochar amended exposure medium. Transmission electron microscopy (TEM) with elemental mapping confirmed that Ti concentrated in plant tissues in nano-form. The interactive effect of TiONPs + biochar amendment on photosynthesis related and gas exchange traits was observed at relatively low TiONPs exposure level (200 mg L), which induced the positive impact on wheat plants proliferation. TiONPs alone exposure to wheat also modified the plant's bio-macromolecules profile with the reduction in the assimilation of primary macronutrients, which could affect the food crop nutritional value and quality. X-ray photoelectron spectroscopy (XPS) chemical analysis of biochar + TiONPs showed an additional peak, which indicated the binding interaction of NPs with biochar. Moreover, Fourier-transform infrared (FTIR) spectroscopy confirmed that the biochar carboxyl group is the main functionality involved in the bonding process with TiONPs. These findings will help for a mechanistic understanding of the role of biochar in the reduction of NPs bioavailability to primary producers of the terrestrial environment.
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http://dx.doi.org/10.1016/j.envpol.2020.116077DOI Listing
February 2021

Morpho-chemical characterization and source apportionment of potentially toxic metal(oid)s from school dust of second largest populous city of Pakistan.

Environ Res 2021 05 19;196:110427. Epub 2020 Nov 19.

Advanced Laboratory for Functional Agriculture, Suzhou Institute for Advanced Study, University of Science and Technology of China, Suzhou, 215123, Jiangsu, China. Electronic address:

Interior settled dust is one of the greatest threats of potentially toxic metal(oid)s (PTMs) exposure to the children, especially in the school environment. Therefore, it is more worthy of having in-depth knowledge of compositional characteristics of school dust. Forty schools were selected of Lahore city for dust sampling. The school dust was analyzed to determine the PTMs (As, Cd, Cr, Cu, Ge, Mo, Ni, Pb, Sb, Sn, Sr, V, and Zn) concentrations using ICP-MS. The morphological characteristics, PTMs speciation, and mineralogy of school dust were examined using SEM with EDS, XPS, and XRD, respectively. Moreover, the geo-accumulation index (I), potential ecological risk index (PERI), and multivariate statistical analysis were employed to assess the pollution levels, ecological risk, and source identification of PTMs, respectively. The I indicated a heavily-extreme pollution level of Cd (I = 4.92), moderate-heavy pollution of Zn (I = 3.22), and Pb (I = 2.78), and slight-moderate pollution of Cr (I = 1.62), and Cu (I = 1.53). The ecological risk has been found extremely high for Cd and moderately high for Pb and As, while potential ecological risk found extremely high posed by cumulatively all selected PTMs. Multivariate statistical analysis showed that sources of PTMs comprise of natural processes as well as several anthropogenic processes like vehicular emissions, agricultural and industrial activities. The SEM, XRD, and XPS analyses demonstrated the presence of airborne particles and PTMs containing minerals with several toxic chemical species in school dust. This study can help to develop strategies to reduce school indoor pollution and hence to establish an eco-friendly learning environment for children.
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http://dx.doi.org/10.1016/j.envres.2020.110427DOI Listing
May 2021

Carbon fractionation and stable carbon isotopic fingerprint of road dusts near coal power plant with emphases on coal-related source apportionment.

Ecotoxicol Environ Saf 2020 Oct 22;202:110888. Epub 2020 Jun 22.

CAS Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, Anhui, China.

Road dust from coal utilization is a significant source contributing to the generation of pollutants that can affect the health of people residing within close proximity to roadways. In this study, road dust samples were collected from different directions centered around a coal-fired power plant in Huainan. Black carbon (BC), soot, char, organic carbon (OC) and total carbon (TC), as well as the δC of samples, were determined. Compared to the reference locations which were distant from the power plant, the research areas surrounding the power plant were featured by significantly higher OC/BC ratio and TC concentration. The OC/BC showed significant difference in urban vs. rural areas, and at different distances from the central power plant, which implied that the source and spread of carbonaceous species was dominantly affected by wind direction and urban/rural area differences. Surface morphology analysis showed that the road dust was mixed with spherical particles similar to fly ash. High-resolution XPS C1s spectrum revealed the existence of metal carbide, metal carbonate, and CF in the road dust samples. The speciation of carbon in road dusts was found correlated with sampling directions and urban functional areas. Based on the δC and OC/BC, it could be inferred that coal-related substances might be important sources of road dusts.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110888DOI Listing
October 2020

Bamboo-biochar and hydrothermally treated-coal mediated geochemical speciation, transformation and uptake of Cd, Cr, and Pb in a polymetal(iod)s-contaminated mine soil.

Environ Pollut 2020 Oct 16;265(Pt A):114816. Epub 2020 May 16.

CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China. Electronic address:

In this study, polymetal(iod)s-contaminated mining soil from the Huainan coalfield, Anhui, China, was used to investigate the synergistic effects of biochar (BC), raw coal (RC), and hydrothermally treated coal (HTC) on the immobilization, speciation, transformation, and accumulation of Cd, Cr, and Pb in a soil-plant system via geochemical speciation and advanced spectroscopic approaches. The results revealed that the BC-2% and BC-HTC amendments were more effective than the individual RC, and/or HTC amendments to reduce ethylene-diamine-tetraacetic acid (EDTA)-extractable Cd, Cr, and Pb concentrations by elevating soil pH and soil organic carbon content. Soil pH increased by 1.5 and 2.5 units after BC-2% and BC-HTC amendments, respectively, which reduced EDTA-extractable Cd, Cr, and Pb to more stabilized forms. Metal speciation and X-ray photoelectron spectroscopy analyses suggested that the BC-HTC amendment stimulated the transformation of reactive Cd, Cr, and Pb (exchangeable and carbonate-bound) states to less reachable (oxide and residual) states to decrease the toxicity of these heavy metals. Fourier transform infrared spectroscopy and X-ray diffraction analyses suggested that reduction and adsorption by soil colloids may be involved in the mechanism of Cd(II), Cr(VI), and Pb(II) immobilization via hydroxyl, carbonyl, carboxyl, and amide groups in the BC and HTC. Additionally, the BC-2% and BC-HTC amendments reduced Cd and Pb accumulation in maize shoots, which could mainly be ascribed to the reduction of EDTA-extractable heavy metals in the soil and more functional groups in the roots, thus inhibiting metal ion translocation by providing the electrons necessary for immobilization, compared to those in roots grown in the unamended soil. Therefore, the combined application of BC and HTC was more effective than the individual application of these amendments to minimize the leaching, availability, and exchangeable states of Cd, Cr, and Pb in polymetal(iod)s-contaminated mining soil and accumulation in maize.
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http://dx.doi.org/10.1016/j.envpol.2020.114816DOI Listing
October 2020

Transformation pathways and fate of engineered nanoparticles (ENPs) in distinct interactive environmental compartments: A review.

Environ Int 2020 05 13;138:105646. Epub 2020 Mar 13.

Department of Chemistry, College of Science, Bld#5, King Saud University, Riyadh, Saudi Arabia.

The ever increasing production and use of nano-enabled commercial products release the massive amount of engineered nanoparticles (ENPs) in the environment. An increasing number of recent studies have shown the toxic effects of ENPs on different organisms, raising concerns over the nano-pollutants behavior and fate in the various environmental compartments. After the release of ENPs in the environment, ENPs interact with various components of the environment and undergoes dynamic transformation processes. This review focus on ENPs transformations in the various environmental compartments. The transformation processes of ENPs are interrelated to multiple environmental aspects. Physical, chemical and biological processes such as the homo- or hetero-agglomeration, dissolution/sedimentation, adsorption, oxidation, reduction, sulfidation, photochemically and biologically mediated reactions mainly occur in the environment consequently changes the mobility and bioavailability of ENPs. Physico-chemical characteristics of ENPs (particle size, surface area, zeta potential/surface charge, colloidal stability, and core-shell composition) and environmental conditions (pH, ionic strength, organic and inorganic colloids, temperature, etc.) are the most important parameters which regulated the ENPs environmental transformations. Meanwhile, in the environment, organisms encountered multiple transformed ENPs rather than the pristine nanomaterials due to their interactions with various environmental materials and other pollutants. Thus it is the utmost importance to study the behavior of transformed ENPs to understand their environmental fate, bioavailability, and mode of toxicity.
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http://dx.doi.org/10.1016/j.envint.2020.105646DOI Listing
May 2020

Contrasting effects of biochar and hydrothermally treated coal gangue on leachability, bioavailability, speciation and accumulation of heavy metals by rapeseed in copper mine tailings.

Ecotoxicol Environ Saf 2020 Mar 28;191:110244. Epub 2020 Jan 28.

Department of Chemistry, College of Science, Bld#5, King Saud University, Riyadh, Saudi Arabia. Electronic address:

The purpose of this research was to examine the influence of hydrothermally treated coal gangue (HTCG) with and without biochar (BC) on the leaching, bioavailability, and redistribution of chemical fractions of heavy metals (HMs) in copper mine tailing (Cu-MT). An increase in pH, water holding capacity (WHC) and soil organic carbon (SOC) were observed due to the addition of BC in combination with raw coal gangue (RCG) and HTCG. A high Cu and other HMs concentration in pore water (PW) and amended Cu-MT were reduced by the combination of BC with RCG and/or HTCG, whereas individual application of RCG slightly increased the Cu, Cd, and Zn leaching and bioavailability, compared to the unamended Cu-MT. Sequential extractions results showed a reduction in the exchangeable fraction of Cu, Cd, Pb, and Zn and elevation in the residual fraction following the addition of BC-2% and BC-HTCG. However, individual application of RCG slightly increased the Cu, Cd, and Zn exchangeable fractions assessed by chemical extraction method. Rapeseed was grown for the following 45 days during which physiological parameters, metal uptake transfer rate (TR), bioconcentration factor (BCF), and translocation factor (TF) were measured after harvesting. In the case of plant biomass, no significant difference between applied amendments was observed for the fresh biomass (FBM) and dry biomass (DBM) of shoots and roots of rapeseed. However, BC-2% and BC-HTCG presented the lowest HMs uptake, TR, BCF (BCF and BCF), and TF for Cu, Cd, Cr, Ni, Pb, and Zn in rapeseed among the other amendments compared to the unamended Cu-MT. Overall, these findings are indicative that using biochar in combination with RCG and/or HTCG led to a larger reduction in HMs leaching and bioavailability, due to their higher sorption capacity and could be a suitable remediation strategy for heavy metals in a Cu-MT.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110244DOI Listing
March 2020

Biochar-induced immobilization and transformation of silver-nanoparticles affect growth, intracellular-radicles generation and nutrients assimilation by reducing oxidative stress in maize.

J Hazard Mater 2020 05 25;390:121976. Epub 2019 Dec 25.

University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285, Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Seoul, Republic of Korea. Electronic address:

Silver nanoparticles (AgNPs) are used in a wide range of consumer products inevitably releases in massive quantities in the natural environment, posing a potential thread to ecosystem-safety and plant health. Here, the impact of AgNPs (100-1000 mg L) without and with biochar (@2 % w/v) amendment on maize plants was assessed in hydroponics exposure medium. AgNPs exposure to plants induced dose-dependent phytotoxicity by suppressing plant growth, disturbing photosynthesis and gas exchange traits and alteration in macro- and micronutrients assimilation. At the same time, AgNPs with addition of biochar alleviated the phyto-toxic effects of AgNPs through approximately 4-8 times reduction in uptake and tissue accumulation of Ag. Moreover, activities of antioxidant enzymes in AgNPs + biochar treated plants indicated the lower oxidative stress. Electron paramagnetic resonance (EPR) spectroscopy confirmed that superoxide (O) radical was the dominant reactive oxygen species. Fourier-transform infrared spectroscopic (FTIR) and X-ray photoelectron spectroscopic (XPS) results revealed that biochar surface carboxyl and sulfur functional groups were involved in complexation process with NPs, which inhibited the oxidative dissolution and release of Ag ions besides of biochar space shield effect. Thus, the interaction of biochar with AgNPs immobilizes these NPs and can effectively reduce their bioavailability in the environmental matrix.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121976DOI Listing
May 2020

A comprehensive review of biogeochemical distribution and fractionation of lead isotopes for source tracing in distinct interactive environmental compartments.

Sci Total Environ 2020 Jun 27;719:135658. Epub 2019 Nov 27.

CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, PR China. Electronic address:

Lead (Pb) is a non-essential and extremely noxious metallic-element whose biogeochemical cycle has been influenced predominantly by increasing human activities to a great extent. The introduction and enrichment of this ubiquitous contaminant in the terrestrial-environment has a long history and getting more attention due to its adverse health effects to living organisms even at very low exposure levels. Its lethal-effects can vary widely depending on the atmospheric-depositions, fates and distribution of Pb isotopes (i.e., Pb, Pb, Pb &Pb) in the terrestrial-environment. Thus, it is essential to understand the depositional behavior and transformation mechanism of Pb and the factors affecting Pb isotopes composition in the terrestrial-compartments. Owing to the persistence nature of Pb-isotopic fractions, regardless of ongoing biogeochemical-processes taking place in soils and in other interlinked terrestrial-compartments of the biosphere makes Pb isotope ratios (Pb-IRs) more recognizable as a powerful and an efficient-tool for tracing the source(s) and helped uncover pertinent migration and transformation processes. This review discusses the ongoing developments in tracing migration pathway and distribution of lead in various terrestrial-compartments and investigates the processes regulating the Pb isotope geochemistry taking into account the source identification of lead, its transformation among miscellaneous terrestrial-compartments and detoxification mechanism in soil-plant system. Additionally, this compendium reveals that Pb-pools in various terrestrial-compartments differ in Pb isotopic fractionations. In order to improve understanding of partition behaviors and biogeochemical pathways of Pb isotope in the terrestrial environment, future works should involve investigation of changes in Pb isotopic compositions during weathering processes and atmospheric-biological sub-cycles.
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http://dx.doi.org/10.1016/j.scitotenv.2019.135658DOI Listing
June 2020

A comprehensive review of climate change impacts, adaptation, and mitigation on environmental and natural calamities in Pakistan.

Environ Monit Assess 2019 Dec 16;192(1):48. Epub 2019 Dec 16.

CAS Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, People's Republic of China.

The devastations and damages caused by climate change are apparent across the globe, specifically in the South Asian region where vulnerabilities to climate change among residents are high and climate change adaptation and mitigation awareness are extremely low. Pakistan's low adaptive capacity due to high poverty rate, limited financial resources and shortage of physical resources, and continual extreme climatic events including varying temperature, continual flooding, melting glaciers, saturation of lakes, earthquakes, hurricanes, storms, avalanches, droughts, scarcity of water, pest diseases, human healthcare issues, and seasonal and lifestyle changes have persistently threatened the ecosystem, biodiversity, human communities, animal habitations, forests, lands, and oceans with a potential to cause further damages in the future. The likely effect of climate change on common residents of Pakistan with comparison to the world and their per capita impact of climate change are terribly high with local animal species such as lions, vultures, dolphins, and tortoise facing extinction regardless of generating and contributing diminutively to global GHG emissions. The findings of the review suggested that GHG emissions cause climate change which has impacted agriculture livestock and forestry, weather trends and patterns, food water and energy security, and society of Pakistan. This review is a sectorial evaluation of climate change mitigation and adaption approaches in Pakistan in the aforementioned sectors and its economic costs which were identified to be between 7 to 14 billion USD per annum. The research suggested that governmental interference is essential for sustainable development of the country through strict accountability of resources and regulation implemented in the past for generating state-of-the-art climate policy.
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http://dx.doi.org/10.1007/s10661-019-7956-4DOI Listing
December 2019

Characterizing pollution indices and children health risk assessment of potentially toxic metal(oid)s in school dust of Lahore, Pakistan.

Ecotoxicol Environ Saf 2020 Mar 11;190:110059. Epub 2019 Dec 11.

School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, PR China. Electronic address:

Toxic metal pollution is a renowned environmental concern, especially to sensitive environments like school classrooms and their association with children's health. The study was planned to determine the pollution characteristics of 13 potentially toxic metal (oid)s (PTMs) and their associated children's health risk assessment from school dust samples of considerably three land-use types (residential, roadside, and industrial areas) of Lahore, Pakistan. Geo-accumulation (I), pollution (PI), integrated pollution (IPI) and pollution load (PLI) indexes were used to determine the PTMs contamination and USEPA health risk assessment models were employed to assess the health risks in children. The mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn for three land-use types were found much higher than the permissible limits. Results of pollution indices revealed that school dust was strongly contaminated with Cd, Pb, and Zn whilst moderately contaminated with Cr and Cu. Moreover, the health risk assessment models revealed no significant non-cancerous risks in children with predominantly highest hazardous index (HI) of Cr in industrial (4.61E-01) and Pb in both roadside (4.30E-01) and residential (2.26E-01) area schools. According to cumulative HI of all PTMs and exposure routes, the land-use areas were in descending order as industrial > roadside > residential. The calculations of hazardous quotient (HQ) showed ingestion was the leading pathway of PTMs exposure through school dust. For carcinogenic health risk (CR), the most prominent PTM was Cr with values of 1.53E-06 in industrial area schools, found close to the tolerable range (1.0E-06). Hence, school dust of Lahore prominently contaminated with eminent PTMs triggering slight health risks predominantly by ingestion exposure to children.
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http://dx.doi.org/10.1016/j.ecoenv.2019.110059DOI Listing
March 2020

Efficiency of various silicon rich amendments on growth and cadmium accumulation in field grown cereals and health risk assessment.

Chemosphere 2020 Apr 28;244:125481. Epub 2019 Nov 28.

Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, 38040, Pakistan.

Cadmium (Cd) contamination of arable soils and its subsequent accumulation in food is one of the global issues which needs urgent attention. Field experiments were conducted to explore the impacts of ten silicon (Si) rich amendments on Cd bioavailability and accumulation by maize and wheat irrigated with sewage effluents. Results depicted that applied amendments decreased the total Cd accumulation in shoots and grains of both crops with and the maximum decrease was observed in rice husk biochar (RHB) treatment. The RHB was able to significantly decrease the translocation factor, Cd harvest and health risk indexes. All amendments differentially affected the soil pH, EC, CaCl-extractable Si, and decreased the AB-DTPA-extractable soil Cd. Overall, suitable Si rich amendments (like RHB and CSB etc.) can be employed to mitigate the health risks associated with dietary Cd in untreated sewage irrigated fields. However, the cost-benefit analysis such Si rich amendments should be considered before final recommendations.
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http://dx.doi.org/10.1016/j.chemosphere.2019.125481DOI Listing
April 2020

Estimating the pollution characteristics and health risks of potentially toxic metal(loid)s in urban-industrial soils in the Indus basin, Pakistan.

Environ Monit Assess 2019 Nov 14;191(12):748. Epub 2019 Nov 14.

School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, University of Wuppertal, Pauluskirchstraße 7, 42285, Wuppertal, Germany.

The Indus Basin Irrigation Network (IBIN) plays a vital role in the agricultural system of Pakistan, irrigating seventeen million hectares of cultivated areas. Rapid urbanization, industrialization, and agricultural activities along the Indus basin have influenced the soil quality and human health; it is, therefore, critical to know its pollution characteristics. Soil samples from Indus basin, i.e., Abbottabad (ABT), Haripur (HRP), Attock (ATC), and Islamabad (ISB) have been analyzed for the total contents of potentially toxic metal(loid)s (PTMs) in the top layer. The topsoil samples from 0 to 10 cm depth have been further investigated using different pollution indices and human health risk assessment models. The contamination degree of soil pollution was highest in ISB (33.75), followed by ABT (25.30) and ATC (23.57). The assessment of the daily intake of PTMs by children and adults through different pathways revealed ingestion as the significant exposure pathway. Cr was found to be the major element posing non-carcinogenic health risks to children at ATC whereas the non-carcinogenic risks posed by all other PTMs were within the safe limit. Furthermore, life-time carcinogenic risks for Ni followed by Cr and Cd were greatly exceeded at all locations and As at ATC and ISB for both age groups, but comparatively children were found to be at a higher risk of carcinogenicity. Hence, efficient remediation strategies are needed to reduce the increasing content and health risks of PTMs in the Indus basin.
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http://dx.doi.org/10.1007/s10661-019-7909-yDOI Listing
November 2019

Biochar-assisted transformation of engineered-cerium oxide nanoparticles: Effect on wheat growth, photosynthetic traits and cerium accumulation.

Ecotoxicol Environ Saf 2020 Jan 22;187:109845. Epub 2019 Oct 22.

CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China. Electronic address:

The extensive use of nano-fabricated products in daily life is releasing a large volume of engineered nanoparticles (ENPs) in the environment having unknown consequences. Meanwhile, little efforts have been paid to immobilize and prevent the entry of these emerging contaminants in the food chain through plant uptake. Herein, we investigated the biochar role in cerium oxide nanoparticles (CeONPs) bioaccumulation and subsequent translocation in wheat (Triticum aestivum L.) as well as impact on growth, photosynthesis and gas-exchange related physiological parameters. Results indicated that CeONPs up to 500 mg L level promoted the plant growth by triggering photosynthesis, transpiration and stomatal conductance. Higher NPs concentration (2000 mg CeONPs L) has negatively affected the plant growth and photosynthesis related processes. Conversely, biochar amendment with CeONPs considerably reduced (~9 folds) the plants accumulated contents of Ce even at 2000 mg L exposure level of CeONPs through surface complexation process and alleviated the phyto-toxic effects of NPs on plant growth. XPS and FTIR analysis confirmed the role of biochar-mediated carboxylate and hydroxyl groups bonding with CeONPs. These findings provides an inside mechanistic understanding about biochar interaction with nano-pollutants to inhibit their bioavailability to plant body.
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http://dx.doi.org/10.1016/j.ecoenv.2019.109845DOI Listing
January 2020

Synergistic effects of biochar and processed fly ash on bioavailability, transformation and accumulation of heavy metals by maize (Zea mays L.) in coal-mining contaminated soil.

Chemosphere 2020 Feb 18;240:124845. Epub 2019 Sep 18.

CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China. Electronic address:

In the paper, hydrothermally (HT) treated, sulfuric acid (HSO), and hydrochloric acid (HCl) washed fly ashes (FA) were used to examine the applied effects with and without biochar (BC) on the bioavailability of heavy metals (HMs) and growth of maize (Zea mays L.) plants in coal-mining contaminated soil. Addition of BC in combination with these processed fly ashes (PFA) significantly increased the soil pH, EC, and soil organic carbon (SOC). Individual application of BC and PFA increased the available contents of Mg, Mn, and Fe, while the combination of BC and PFA significantly decreased the bioavailability of HMs in soil compared to control. The BC + HT-FA and BC + HSO-FA were most efficient treatments followed by BC + HCl-FA in promoting plant growth parameters (i.e., fresh and dry biomass, root and shoot lengths), reduction in the uptake of HMs and increase in the uptake of macronutrients. The results established that the combined application of BC and PFA synergistically increased HMs immobilization and maize biomass yields. The lowest transfer rate (TR), bioconcentration factor (BCF), and translocation factor (TF) for Cr, Co, Ni, Cu, Zn, Cd, and Pb were detected in BC + HT-FA, followed by BC + HSO-FA and BC + HCl-FA treatments after 60 days of maize crop harvesting. It could be suggested that using BC along with PFA as a soil stabilizer may be a promising source to immobilize HMs in a coal-mining contaminated soil.
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http://dx.doi.org/10.1016/j.chemosphere.2019.124845DOI Listing
February 2020

Divisional disparities on climate change adaptation and mitigation in Punjab, Pakistan: local perceptions, vulnerabilities, and policy implications.

Environ Sci Pollut Res Int 2019 Oct 2;26(30):31491-31507. Epub 2019 Sep 2.

CAS Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, People's Republic of China.

Climate change is a global challenge faced by everyone, but the developing countries are highly vulnerable to variations in the environment. This research focuses on the Punjab province of Pakistan and evaluates the impacts and consequences of climate change on general public at local and divisional level. In order to cope with the impacts of climatic changes at all levels, especially divisional level, raising reliable awareness and dispersing actionable knowledge regarding mitigating and adapting measures is significantly important. Therefore, recognition of information gaps, improvements in the level of alertness, and development of preventive measures in each sector is imperative. The impacts of climate change are observed across the country through gradual increase in temperature, human health issues, pest diseases, droughts, floods, and irregular weather patterns leading to changes in lifestyles, and these issues are likely to continue in the future. The main cause of climate change in Punjab, Pakistan, can be attributed to excessive release of greenhouse gases (GHG) into the atmosphere due to human activities involving inefficient energy usage, rapid urban expansion, improper waste management, industrial development, increasing transportation, agricultural activities, and livestock mismanagement. The findings of this study revealed that transportation sector is the major source of GHG emissions in the country, followed by industrialization and waste, at national, as well as divisional, level. The extent of impacts of climate change at divisional level is distinguishable and displayed a direct relationship with climate, geography, variation of effects, and modes of production in various regions of Punjab. The study strategically investigated all nine divisions of the province for comprehensive understanding of climate change phenomenon, and the results indicated that nearly three-fourths of the respondents have never indulged in taking steps towards climate change mitigation and adaptation. The study adopted a mixed (qualitative and quantitative) approach where the findings can act as set of guidelines for governmental authorities in formulating, assisting in preparation, instructing, and guiding policies for climate change mitigation and adaptation at national, local, and divisional levels. Graphical abstract.
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http://dx.doi.org/10.1007/s11356-019-06262-zDOI Listing
October 2019

Investigating the drinking and surface water quality and associated health risks in a semi-arid multi-industrial metropolis (Faisalabad), Pakistan.

Environ Sci Pollut Res Int 2019 Jul 20;26(20):20853-20865. Epub 2019 May 20.

Chinese Academy of Science (CAS)-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, Anhui, People's Republic of China.

Urban areas under the influence of multi-industrial activities with arid and semi-arid environments witness the significant increase in environmental pollution especially in the water sector. The present study evaluated the water quality and associated health risk assessment through heavy metal pollution. Drinking (n = 48) and surface (n = 37) water samples were collected from semi-arid multi-industrial metropolis, Faisalabad, Pakistan. Physio-chemical and biological parameters and different metals (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Ni and Zn) were investigated using standard procedures and multivariate water quality assessments. Many physio-chemical and biological parameters and metals especially arsenic were exceeding the permissible limit of Punjab environmental quality standards and the World Health Organization. The results from water quality index showed that < 56% samples have poor, < 8% have very poor and < 6% have unsuitable water quality for drinking purposes. Water quality for the Gugera Branch Canal was found suitable with medium sodium (alkalinity) and salinity hazards, while it was found poor with magnesium absorption ratio. Hazard quotient (HQ) values for arsenic were found at the threshold level (HQ > 1) and carcinogenicity was found in case of arsenic and chromium (1 × 10) in adults and children. Semi-arid weather combined with different anthropogenic activities and unusual water features provoked metal contamination. Results of the present study can deliver basic information for effective management of water in the most populous and industrial areas.
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http://dx.doi.org/10.1007/s11356-019-05367-9DOI Listing
July 2019

Silicon nanoparticles enhanced the growth and reduced the cadmium accumulation in grains of wheat (Triticum aestivum L.).

Plant Physiol Biochem 2019 Jul 3;140:1-8. Epub 2019 May 3.

Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia; Department of Botany, S.P. College, Maulana Azad Road, Srinagar, Jammu and Kashmir, 190001, India. Electronic address:

The application of silicon (Si) under heavy metal stress is well known, but the use of Si nanoparticles (NPs) under metal stress in not well documented. Thus, the experiments were performed to investigate the impacts of soil and foliar applied Si NPs on wheat (Triticum aestivum L.) growth and cadmium (Cd) accumulation in grains under Cd toxicity. The plants were grown under natural environmental conditions and were harvested after physiological maturity (124 days after sowing). The results demonstrated that Si NPs significantly improved, relative to the control, the dry biomass of shoots, roots, spikes and grains by 24-69%, 14-59%, 34-87%, and 31-96% in foliar spray and by 10-51%, 11-49%, 25-69%, and 27-74% in soil applied Si NPs, respectively. The Si NPs enhanced the leaf gas exchange attributes and chlorophyll a and b concentrations, whereas diminished the oxidative stress in leaves which was indicated by the reduced electrolyte leakage and enhancement in superoxide dismutase and peroxidase activities in leaf under Si NPs treatments over the control. When compared with the control, the foliar spray of Si NPs reduced the Cd contents in shoots, roots, and grains by 16-58%, 19-64%, and 20-82%, respectively, whereas soil applied Si NPs reduced the Cd concentrations in shoots, roots, and grains by 11-53%, 10-59%, and 22-83%, respectively. In comparison with the control, Si concentrations significantly (p ≤ 0.05) increased in the shoots and roots in both foliar and soil supplementation of Si NPs. Our results suggested that Si NPs could improve the yield of wheat and more importantly, reduce the Cd concentrations in the grains. Thus, the use of Si NPs might be a feasible approach in controlling Cd entry into the human body via crops.
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http://dx.doi.org/10.1016/j.plaphy.2019.04.041DOI Listing
July 2019

Effects of biochar on uptake, acquisition and translocation of silver nanoparticles in rice (Oryza sativa L.) in relation to growth, photosynthetic traits and nutrients displacement.

Environ Pollut 2019 Jul 23;250:728-736. Epub 2019 Apr 23.

CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China. Electronic address:

Rapid development in nanotechnology and incorporation of silver nanoparticles (AgNPs) in wide range of consumer products causing the considerable release of these NPs in the environment, leading concerns for ecosystem safety and plant health. In this study, rice (Oryza sativa) was exposed to AgNPs (0, 100, 200, 500 and 1000 mg L) in biochar amended (2 %w/v) and un-amended systems. Exposure of plants to AgNPs alone reduced the root and shoot length, biomass production, chlorophyll contents, photosynthesis related physiological parameters as well as macro-and micronutrients in a dose dependent manner. However, in case of biochar amendment, physiological parameters i.e., net photosynthesis rate, maximum photosynthesis rate, CO assimilation, dark respiration and stomatal conductance reduced only 16, 6, 7, 3 and 8%, respectively under AgNPs exposure at 1000 mg L dose. Meanwhile, biochar at all exposure level of AgNPs decreased the bioaccumulation of Ag in rice root and shoot tissues, thus alleviated the phyto-toxic effects of NPs on plant growth. Moreover, results showed that biochar reduced the bioavailability of AgNPs by surface complexation, suppressing dissolution and release of toxic Ag ions in the growth medium. The presence of biochar at least decreased 2-fold tissue contents of Ag even at highest AgNPs (1000 mg L) concentration. These finding suggested that biochar derived from waste biomass resources can be used effectively to prevent the bioaccumulation and subsequent trophic level transfer of emerging Ag nano-pollutant in the environment.
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http://dx.doi.org/10.1016/j.envpol.2019.04.083DOI Listing
July 2019

One-step synthesis of N-doped metal/biochar composite using NH-ambiance pyrolysis for efficient degradation and mineralization of Methylene Blue.

J Environ Sci (China) 2019 Apr 28;78:29-41. Epub 2018 Jun 28.

CAS Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Shaanxi 710075, China.

A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles (NPs) were produced through single-step pyrolysis of FeCl-Ti(OBu) laden agar biomass under NH environment. The physiochemical properties of composites were characterized thoroughly. It has found that heating temperature and N-doping through NH-ambiance pyrolysis significantly influence the visible-light sensitivity and bandgap energy of composites. The catalytic activities of composites were measured by degradation of Methylene Blue (MB) in the presence or absence of HO and visible-light irradiation. Our best catalyst (N-TiO-FeO-biochar) exhibits rapid and high MB removal competency (99.99%) via synergism of adsorption, photodegradation, and Fenton-like reaction. Continuous production of O and OH radicles performs MB degradation and mineralization, confirmed by scavenging experiments and degradation product analysis. The local trap state Ti, FeO, and N-carbon of the catalyst acted as active sites. It has suggested that the Ti and N-doped dense carbon layer improve charge separation and shuttle that prolonged photo-Fenton like reaction. Moreover, the catalyst is highly stable, collectible, and recyclable up to 5 cycles with high MB degradation efficiency. This work provides a new insight into the synthesis of highly visible-light sensitized biochar-supported photocatalyst through NH-ambiance pyrolysis of NPs-laden biomass.
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http://dx.doi.org/10.1016/j.jes.2018.06.014DOI Listing
April 2019

Evaluation of floor-wise pollution status and deposition behavior of potentially toxic elements and nanoparticles in air conditioner dust during urbanistic development.

J Hazard Mater 2019 03 3;365:186-195. Epub 2018 Nov 3.

EcoHealth Research Group, Department of Environmental Sciences, PMAS Arid Agriculture University Rawalpindi, Pakistan. Electronic address:

The study was undertaken to investigate deposition behaviors of various size-segregated particles and indoor air quality using dust accumulated on the air conditioner filter acting as a sink for PTEs and nanoparticles that can pose a significant health risk. However, the particulate matter size and chemical composition in AC dust and its relationship with PTEs remains uncertain. Current study aims to investigate the PTEs and nanoparticles composition of AC dust using different analytical approaches including ICP-MS, XRD, XPS, SEM/TEM along with EDS and Laser Diffraction particle size analyzer. The mean concentration of PTEs like Al, As, Cd, Cu, Li, Pb, Sb, Se, Sn, Ti, V and Zn exceeded the corresponding background value. Pb, As, Sn, Sb, Cd were categorizing under geo-accumulation index class IV. Most of the particles were found to be > 100 μm and it decreased significantly with increase in floor altitude. A significantly negative correlation was found between particles size and PTEs concentration showing a significant increase in PTEs content with decrease in particles size. The XPS results showed dominant peaks for TiO, Ti-O-N, AsO, Fe, Fe, Al-OH and Al0. Additionally, As, Pb, Si and Fe were dominant metallic nanoparticles identified using SEM/TEM along with EDS.
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http://dx.doi.org/10.1016/j.jhazmat.2018.11.005DOI Listing
March 2019
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