Publications by authors named "Binoy Sarkar"

82 Publications

Petroleum hydrocarbon rhizoremediation and soil microbial activity improvement via cluster root formation by wild proteaceae plant species.

Chemosphere 2021 Jul 26;275:130135. Epub 2021 Feb 26.

Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), The University of Newcastle, PO Box 18, Callaghan, NSW, 2308, Australia. Electronic address:

Rhizoremediation potential of different wild plant species for total (aliphatic) petroleum hydrocarbon (TPH)-contaminated soils was investigated. Three-week-old seedlings of Acacia inaequilatera, Acacia pyrifolia, Acacia stellaticeps, Banksia seminuda, Chloris truncata, Hakea prostrata, Hardenbergia violacea, and Triodia wiseana were transplanted in a soil contaminated with diesel and engine oil as TPH at pollution levels of 4,370 (TPH1) and 7,500 (TPH2) mg kg, and an uncontaminated control (TPH0). After 150 days, the presence of TPH negatively affected the plant growth, but the growth inhibition effect varied between the plant species. Plant growth and associated root biomass influenced the activity of rhizo-microbiome. The presence of B. seminuda, C. truncata, and H. prostrata significantly increased the TPH removal rate (up to 30% compared to the unplanted treatment) due to the stimulation of rhizosphere microorganisms. No significant difference was observed between TPH1 and TPH2 regarding the plant tolerance and rhizoremediation potentials of the three plant species. The presence of TPH stimulated cluster root formation in B. seminuda and H. prostrata which was associated with enhanced TPH remediation of these two members of Proteaceae family. These results indicated that B. seminuda, C. truncata, and H. prostrata wild plant species could be suitable candidates for the rhizoremediation of TPH-contaminated soil.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130135DOI Listing
July 2021

Co-hydrothermal carbonization of swine and chicken manure: Influence of cross-interaction on hydrochar and liquid characteristics.

Sci Total Environ 2021 Sep 27;786:147381. Epub 2021 Apr 27.

Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea. Electronic address:

Swine and chicken manures are abundant solid wastes that can be converted into carbonaceous materials through hydrothermal carbonization (HTC). Owing to their unique biochemical compositions, co-HTC of these two types of manures may have significant implications for the generated products. We investigated the co-HTC of swine manure and chicken manure to understand the influence of the interaction between contrasting manures on the properties of the derived products. The results indicated that co-HTC treatment enhanced the formation of solid product and improved the C and N contents, heating value, and energy yield of the resulting hydrochar. Regarding the ignition temperature and comprehensive combustion index, the combustion properties of the hydrochar were enhanced owing to the mutual effect of the HTC intermediates. Additionally, the interaction of the intermediates significantly impacted the transfer of nitrogenous species and generation of organic acids and organic polymers with fused-ring structures. Therefore, co-HTC processing of animal manures could potentially provide a sustainable pathway for the conversion of animal waste into solid products with improved characteristics compared to those produced by treating the two feedstocks separately.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147381DOI Listing
September 2021

Distribution, behaviour, bioavailability and remediation of poly- and per-fluoroalkyl substances (PFAS) in solid biowastes and biowaste-treated soil.

Environ Int 2021 May 5;155:106600. Epub 2021 May 5.

Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA; Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.

Aqueous film-forming foam, used in firefighting, and biowastes, including biosolids, animal and poultry manures, and composts, provide a major source of poly- and perfluoroalkyl substances (PFAS) input to soil. Large amounts of biowastes are added to soil as a source of nutrients and carbon. They also are added as soil amendments to improve soil health and crop productivity. Plant uptake of PFAS through soil application of biowastes is a pathway for animal and human exposure to PFAS. The complexity of PFAS mixtures, and their chemical and thermal stability, make remediation of PFAS in both solid and aqueous matrices challenging. Remediation of PFAS in biowastes, as well as soils treated with these biowastes, can be achieved through preventing and decreasing the concentration of PFAS in biowaste sources (i.e., prevention through source control), mobilization of PFAS in contaminated soil and subsequent removal through leaching (i.e., soil washing) and plant uptake (i.e., phytoremediation), sorption of PFAS, thereby decreasing their mobility and bioavailability (i.e., immobilization), and complete removal through thermal and chemical oxidation (i.e., destruction). In this review, the distribution, bioavailability, and remediation of PFAS in soil receiving solid biowastes, which include biosolids, composts, and manure, are presented.
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http://dx.doi.org/10.1016/j.envint.2021.106600DOI Listing
May 2021

Unravelling the mechanism of amitriptyline removal from water by natural montmorillonite through batch adsorption, molecular simulation and adsorbent characterization studies.

J Colloid Interface Sci 2021 Sep 26;598:379-387. Epub 2021 Apr 26.

Environmental Contaminants Group, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.

Amitriptyline (AMI) is one of the most common tricyclic antidepressant personal care medications. Due to its environmental persistence and bioaccumulation, release of AMI into the environment via wastewater streams in elevated levels could lead to significant ecological and human health impacts. In this study, the adsorption of AMI by montmorillonite (SWy-2), a naturally abundant smectite clay with sodium ions as the main interlayer cations, was investigated. Maximum AMI adsorption (276 mg/g) occurred at pH 7-8. After adsorption, examination of the adsorbent's X-ray diffraction pattern indicated that interlayer expansion had occurred, where chemical stoichiometry confirmed cation exchange as the principal adsorption mechanism. AMI adsorption reached equilibrium within 4 h, with kinetic data best fitting the pseudo-second order kinetic model (R = 0.98). AMI adsorption was unaffected by solution pH in the range 2-11, where adsorption was endothermic, and molecular simulations substantiated by Fourier transform infrared spectroscopy and thermogravimetric investigations indicated that the orientation of AMI molecules in the interlayer was via an amine group and a benzene ring. Overall this research shows that SWy-2 has significant potential as a low cost, effective, and geologically derived natural material for AMI removal in wastewater systems.
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http://dx.doi.org/10.1016/j.jcis.2021.04.033DOI Listing
September 2021

Mitigation of petroleum-hydrocarbon-contaminated hazardous soils using organic amendments: A review.

J Hazard Mater 2021 Mar 22;416:125702. Epub 2021 Mar 22.

Global Centre for Environmental Remediation, The University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address:

The term "Total petroleum hydrocarbons" (TPH) is used to describe a complex mixture of petroleum-based hydrocarbons primarily derived from crude oil. Those compounds are considered as persistent organic pollutants in the terrestrial environment. A wide array of organic amendments is increasingly used for the remediation of TPH-contaminated soils. Organic amendments not only supply a source of carbon and nutrients but also add exogenous beneficial microorganisms to enhance the TPH degradation rate, thereby improving the soil health. Two fundamental approaches can be contemplated within the context of remediation of TPH-contaminated soils using organic amendments: (i) enhanced TPH sorption to the exogenous organic matter (immobilization) as it reduces the bioavailability of the contaminants, and (ii) increasing the solubility of the contaminants by supplying desorbing agents (mobilization) for enhancing the subsequent biodegradation. Net immobilization and mobilization of TPH have both been observed following the application of organic amendments to contaminated soils. This review examines the mechanisms for the enhanced remediation of TPH-contaminated soils by organic amendments and discusses the influencing factors in relation to sequestration, bioavailability, and subsequent biodegradation of TPH in soils. The uncertainty of mechanisms for various organic amendments in TPH remediation processes remains a critical area of future research.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125702DOI Listing
March 2021

Carbon-based adsorbents for fluoroquinolone removal from water and wastewater: A critical review.

Environ Res 2021 Jun 29;197:111091. Epub 2021 Mar 29.

Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, South Korea. Electronic address:

This review summarizes the adsorptive removal of Fluoroquinolones (FQ) from water and wastewater. The influence of different physicochemical parameters on the adsorptive removal of FQ-based compounds is detailed. Further, the mechanisms involved in the adsorption of FQ-based antibiotics on various adsorbents are succinctly described. As the first of its kind, this paper emphasizes the performance of each adsorbent for FQ-type antibiotic removal based on partition coefficients of the adsorbents that is a more sensitive parameter than adsorption capacity for comparing the performances of adsorbents under various adsorbate concentrations and heterogeneous environmental conditions. It was found that π-π electron donor-acceptor interactions, electrostatic interactions, and pore-filling were the most prominent mechanisms for FQ adsorption by carbon and clay-based adsorbents. Among all the categories of adsorbents reviewed, graphene showed the highest performance for the removal of FQ antibiotics from water and wastewater. Based on the current state of knowledge, this review fills the gap through methodolically understanding the mechanism for further improvement of FQ antibiotics adsorption performance from water and wastewater.
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http://dx.doi.org/10.1016/j.envres.2021.111091DOI Listing
June 2021

Weathering of microplastics and interaction with other coexisting constituents in terrestrial and aquatic environments.

Water Res 2021 May 5;196:117011. Epub 2021 Mar 5.

Department of Agronomy, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, Kansas 66506, United States.

Weathering of microplastics (MPs, < 5 mm) in terrestrial and aquatic environments affects MP transport and distribution. This paper first summarizes the sources of MPs, including refuse in landfills, biowastes, plastic films, and wastewater discharge. Once MPs enter water and soil, they undergo different weathering processes. MPs can be converted into small molecules (e.g., oligomers and monomers), and may be completely mineralized under the action of free radicals or microorganisms. The rate and extent of weathering of MPs depend on their physicochemical properties and environmental conditions of the media to which they are exposed. In general, water dissipates heat better, and has a lower temperature, than land; thus, the weathering rate of MPs in the aquatic environment is slower than in the terrestrial environment. These weathering processes increase oxygen-containing functional groups and the specific surface area of MPs, which influence the sorption and aggregation that occur between weathered MPs and their co-existing constituents. More studies are needed to investigate the various weathering processes of diverse MPs under natural field conditions in soils, sediments, and aquatic environments, to understand the impact of weathered MPs in the environment.
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http://dx.doi.org/10.1016/j.watres.2021.117011DOI Listing
May 2021

Fe(III) loaded chitosan-biochar composite fibers for the removal of phosphate from water.

J Hazard Mater 2021 08 19;415:125464. Epub 2021 Feb 19.

Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea. Electronic address:

Excess phosphorous (P) in aquatic systems causes adverse environmental impacts including eutrophication. This study fabricated Fe(III) loaded chitosan-biochar composite fibers (FBC-N and FBC-C) from paper mill sludge biochar produced under N (BC-N) and CO (BC-C) conditions at 600 °C for adsorptive removal of phosphate from water. Investigations using SEM/EDX, XPS, Raman spectroscopy, and specific surface area measurement revealed the morphological and physico-chemical characteristics of the adsorbent. The Freundlich isotherm model well described the phosphate adsorption on BC-N, while the Redlich-Peterson model best fitted the data of three other adsorbents. The maximum adsorption capacities were 9.63, 8.56, 16.43, and 19.24 mg P g for BC-N, BC-C, FBC-N, and FBC-C, respectively, indicating better adsorption by Fe(III) loaded chitosan-biochar composite fibers (FBCs) than pristine biochars. The pseudo-first-order kinetic model suitably explained the phosphate adsorption on BC-C and BC-N, while data of FBC-N and FBC-C followed the pseudo-second-order and Elovich model, respectively. Molecular level observations of the P K-edge XANES spectra confirmed that phosphate associated with iron (Fe) minerals (Fe-P) were the primary species in all the adsorbents. This study suggests that FBCs hold high potential as inexpensive and green adsorbents for remediating phosphate in contaminated water, and encourage resource recovery via bio-based management of hazardous waste.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125464DOI Listing
August 2021

Insights into upstream processing of microalgae: A review.

Bioresour Technol 2021 Jun 18;329:124870. Epub 2021 Feb 18.

Department of Separation Science, LUT School of Engineering Science, LUT University, Sammonkatu 12, FI-50130 Mikkeli, Finland. Electronic address:

The aim of this review is to provide insights into the upstream processing of microalgae, and to highlight the advantages of each step. This review discusses the most important steps of the upstream processing in microalgae research such as cultivation modes, photobioreactors design, preparation of culture medium, control of environmental factors, supply of microalgae seeds and monitoring of microalgal growth. An extensive list of bioreactors and their working volumes used, elemental composition of some well-known formulated cultivation media, different types of wastewater used for microalgal cultivation and environmental variables studied in microalgae research has been compiled in this review from the vast literature. This review also highlights existing challenges and knowledge gaps in upstream processing of microalgae and future research needs are suggested.
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http://dx.doi.org/10.1016/j.biortech.2021.124870DOI Listing
June 2021

Pristine and iron-engineered animal- and plant-derived biochars enhanced bacterial abundance and immobilized arsenic and lead in a contaminated soil.

Sci Total Environ 2021 Apr 25;763:144218. Epub 2020 Dec 25.

Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou 311300, China; Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China. Electronic address:

In this study, typical animal- and plant-derived biochars derived from pig carcass (PB) and green waste (GWB), and their iron-engineered products (Fe-PB and Fe-GWB) were added at the dose of 3% (w/w) to an acidic (pH = 5.8) soil, and incubated to test their efficacy in improving soil quality and immobilizing arsenic (As = 141.3 mg kg) and lead (Pb = 736.2 mg kg). Soil properties, microbial activities, and the geochemical fractions and potential availabilities of As and Pb were determined in the non-treated (control) and biochar-treated soil. Modification of PB (pH = 10.6) and GWB (pH = 9.3) with Fe caused a decrease in their pH to 4.4 and 3.4, respectively. The application of PB and GWB significantly increased soil pH, while Fe-PB and Fe-GWB decreased soil pH, as compared to the control. Application of Fe-GWB and Fe-PB decreased the NHHPO-extractable As by 32.8 and 35.9%, which was more effective than addition of GWB and PB. However, PB and GWB were more effective than Fe-PB and Fe-GWB in Pb immobilization. Compared to the control, the DTPA-extractable Pb decreased by 20.6 and 21.7%, respectively, following PB and GWB application. Both biochars, particularly PB significantly increased the 16S rRNA bacterial gene copy numbers, indicating that biochar amendments enhanced the bacterial abundance, implying an alleviation of As and Pb bio-toxicity to soil bacteria. The results demonstrated that pristine pig carcass and green waste biochars were more effective in immobilizing Pb, while their Fe-engineered biochars were more effective in As immobilization in co-contaminated soils.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144218DOI Listing
April 2021

Soil salinity under climate change: Challenges for sustainable agriculture and food security.

J Environ Manage 2021 Feb 6;280:111736. Epub 2020 Dec 6.

Global Centre for Environmental Remediation, University of Newcastle, Callaghan, NSW, 2308, Australia; Cooperative Research Centre for High Performance Soils, Callaghan, NSW, 2308, Australia.

Soil salinity is one of the major and widespread challenges in the recent era that hinders global food security and environmental sustainability. Worsening the situation, the harmful impacts of climate change accelerate the development of soil salinity, potentially spreading the problem in the near future to currently unaffected regions. This paper aims to synthesise information from published literature about the extent, development mechanisms, and current mitigation strategies for tackling soil salinity, highlighting the opportunities and challenges under climate change situations. Mitigation approaches such as application of amendments, cultivation of tolerant genotypes, suitable irrigation, drainage and land use strategies, conservation agriculture, phytoremediation, and bioremediation techniques have successfully tackled the soil salinity issue, and offered associated benefits of soil carbon sequestration, and conservation and recycling of natural resources. These management practices further improve the socio-economic conditions of the rural farming community in salt-affected areas. We also discuss emerging reclamation strategies such as saline aquaculture integrated with sub surface drainage, tolerant microorganisms integrated with tolerant plant genotypes, integrated agro-farming systems that warrant future research attention to restore the agricultural sustainability and global food security under climate change scenarios.
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http://dx.doi.org/10.1016/j.jenvman.2020.111736DOI Listing
February 2021

Efficient and selective removal of Se and As mixed contaminants from aqueous media by montmorillonite-nanoscale zero valent iron nanocomposite.

J Hazard Mater 2021 02 15;403:123639. Epub 2020 Aug 15.

Facultad de Química y Biología, Universidad de Santiago de Chile, Av. B. O'Higgins, 3363, Santiago, Chile; Center for the Development of Nanoscience and Nanotechnology, CEDENNA, 9170124, Santiago, Chile. Electronic address:

Nanoscale zero-valent iron (NZVI) and NZVI supported onto montmorillonite (NZVI-Mt) were synthetized and used in this study to remove Se and As from water in mono- and binary-adsorbate systems. The adsorption kinetics and isotherm data for Se and As were adequately described by the pseudo-second-order (PSO) (r>0.94) and Freundlich (r>0.93) equations. Results from scanning electron microscopy showed that the dimension of the NZVI immobilized on the Mt was smaller than pure NZVI. Using 0.05 g of adsorbent and an initial 200 mg L As and Se concentration, the maximum adsorption capacity (q) and partition coefficient (PC) for As on NZVI-Mt in monocomponent system were 54.75 mg g and 0.065 mg g·μM, which dropped respectively to 49.91 mg g and 0.055 mg g·μM under competitive system. For Se adsorption on NZVI-Mt in monocomponent system, q and PC were 28.63 mg g and 0.024 mg g·μM, respectively. Values of q and PC were higher for NZVI-Mt than NZVI and montmorillonite, indicating that the nanocomposite contained greater adsorption sites for removing both oxyanions, but with a marked preference for As. Future research should evaluate the effect of different operational variables on the removal efficiency of both oxyanions by NZVI-Mt.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123639DOI Listing
February 2021

Comparative removal of As(V) and Sb(V) from aqueous solution by sulfide-modified α-FeOOH.

Environ Pollut 2020 Dec 16;267:115658. Epub 2020 Sep 16.

Global Centre for Environmental Remediation, University of Newcastle, Callaghan Campus, NSW, 2308, Australia.

Efficient elimination of As(V) and Sb(V) from wastewater streams has long been a major challenge. Herein, sulfide-modified α-FeOOH adsorbent was fabricated via a simple sulfidation reaction for removing As(V) and Sb(V) from aqueous media. Compared with the pristine α-FeOOH, sulfide-modified α-FeOOH increased the adsorption of As(V) from 153.8 to 384.6 mg/g, and Sb(V) adsorption from 277.8 to 1111.1 mg/g. The enhanced adsorption of both As(V) and Sb(V) was maintained at the pH range from 2 to 11, and was not interfered by various coexisting anions such as Cl, SO, NO, SiO and PO. The adsorption affinity increased from 0.0047 to 0.0915 and 0.0053 to 0.4091 for As(V) and Sb(V), respectively. X-ray photoelectron spectroscopic investigation demonstrated a reductive conversion of As(V) to As(III) during the adsorption process with sulfide-modified α-FeOOH, but with no obvious variation of Sb(V) speciation. While the removal mechanism for As(V) was reduction followed by adsorption via hydroxyl groups, mainly surface complexation was involved in the removal of Sb(V). This study presented a simple strategy to enhance the adsorption capacity and adsorption affinity of α-FeOOH toward As(V)/Sb(V) via sulfide-modification.
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http://dx.doi.org/10.1016/j.envpol.2020.115658DOI Listing
December 2020

Repurposing distillation waste biomass and low-value mineral resources through biochar-mineral-complex for sustainable production of high-value medicinal plants and soil quality improvement.

Sci Total Environ 2021 Mar 4;760:143319. Epub 2020 Nov 4.

Dr. K C Patel Research & Development Centre, Charotar University of Science and Technology, Changa, Anand 388421, India.

High cost of synthetic fertilizers and their hazardous effects catapult the exploration of alternative nutrient formulations and soil amendments. This study aimed to synthesize a novel biochar-mineral-complex (BMC), and evaluate its nutrient supplying and soil improvement performances. In a hydrothermal reaction, the BMC was prepared using a biochar derived from distillation waste of Lemongrass (Cymbopogon flexuosus) and farmyard manure, for the first time via fortification with low-grade rock phosphate and waste mica. The BMC showed improved physico-chemical properties and nutrient availability than the pristine biochar. When applied to a deeply weathered acidic soil, the BMC significantly (P < 0.05) improved the herbage and bioactive compound (sennoside) yields of a medicinal plant (senna; Cassia angustifolia Vahl.) compared to the pristine biochar, farmyard manure, vermicompost, and chemical fertilizers. The BMC also improved the soil quality by increasing nutrient and carbon contents, and microbial activities. Soil quality improvement facilitated greater nutrient uptake in senna plants under BMC compared to the pristine biochar, and conventional organic and chemical fertilizer treatments. This study thus encourages the development of BMC formulations not only to overcome the limitation of sole biochar application to soils, but also to phaseout chemical fertilizers in agriculture. Moreover, BMC could bestow resilience and sustainability to crop production via value-added recycling of waste biomass and low-grade mineral resources.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143319DOI Listing
March 2021

Mechanistic insights into ethidium bromide removal by palygorskite from contaminated water.

J Environ Manage 2021 Jan 7;278(Pt 2):111586. Epub 2020 Nov 7.

Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom. Electronic address:

Ethidium bromide (EtBr)-containing wastewater can be hazardous to biodiversity when released into the soil and water bodies without treatment. EtBr can mutate living microbial cells and pose toxicity to even higher organisms. This work investigated the removal of EtBr from aqueous solutions by a naturally occurring palygorskite (PFl-1) clay mineral via systematic batch adsorption experiments under different physicochemical conditions. EtBr existed in an undissociated form at pH ~7, and was adsorbed on PFl-1 obeying the Freundlich isotherm model. The maximum EtBr adsorption capacity was 285 mmol/kg. The best fitted kinetic model for EtBr adsorption was the pseudo-second order model. The amounts of exchangeable cations desorbed from PFl-1 during EtBr adsorption was linearly correlated to the amounts of EtBr adsorbed, with a slope of 0.97, implying that a cation exchange-based adsorption mechanism was dominating. Additionally, dimerization of EtBr molecules via bromide release assisted an increased EtBr removal by PFl-1 at high adsorbate concentrations. Detailed x-ray diffraction, Fourier transform infrared, scanning electron imaging and energy dispersive x-ray analyses confirmed that EtBr adsorption occurred dominantly on the surface of palygorskite which mineralogically constituted 80% of the bulk PFl-1 adsorbent. A small portion of EtBr was also adsorbed by PFl-1 through intercalation onto the smectite impurity (10%) in PFl-1. This study suggested that PFl-1 could be an excellent natural material for removing EtBr from pharmaceutical and laboratory wastewater.
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http://dx.doi.org/10.1016/j.jenvman.2020.111586DOI Listing
January 2021

Iron-modified biochar and water management regime-induced changes in plant growth, enzyme activities, and phytoavailability of arsenic, cadmium and lead in a paddy soil.

J Hazard Mater 2021 04 22;407:124344. Epub 2020 Oct 22.

Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Guangdong, Foshan 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Zhejiang, Hangzhou 311300, China. Electronic address:

The aim of this study was to evaluate the effect of raw (RawBC) and iron (Fe)-modified biochar (FeBC) derived from Platanus orientalis Linn branches on the plant growth, enzyme activity, and bioavailability and uptake of As, Cd, and Pb by rice in a paddy soil with continuously flooded (CF) or alternately wet and dry (AWD) irrigation in a pot experiment. Application of RawBC (3%, w/w) significantly increased soil pH, while FeBC decreased it. The FeBC was more effective in reducing As and Pb bioavailability, particularly under the AWD water regime, while RawBC was more conducive in reducing Cd bioavailability under the CF water regime. The FeBC decreased As concentration, but increased concentrations of Cd and Pb in the straw and brown rice, as compared to the untreated soil. Soil catalase and urease activities were enhanced by RawBC, but decreased by FeBC treatment. The FeBC increased the grain yield by 60% and 32% in CF and AWD treatments, respectively. The FeBC can be recommended for immobilization of As in paddy soils, but a potential human health risk from Cd and Pb in FeBC-treated soils should be considered due to increased uptake and translocation of the metals to brown rice.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124344DOI Listing
April 2021

Remediation of poly- and perfluoroalkyl substances (PFAS) contaminated soils - To mobilize or to immobilize or to degrade?

J Hazard Mater 2021 01 9;401:123892. Epub 2020 Sep 9.

Soil- and Groundwater-Management, Institute of Soil Engineering, Waste- and Water-Management, Faculty of Architecture und Civil Engineering, University of Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, Seoul 05006, South Korea.

Poly- and perfluoroalkyl substances (PFASs) are synthetic chemicals, which are introduced to the environment through anthropogenic activities. Aqueous film forming foam used in firefighting, wastewater effluent, landfill leachate, and biosolids are major sources of PFAS input to soil and groundwater. Remediation of PFAS contaminated solid and aqueous media is challenging, which is attributed to the chemical and thermal stability of PFAS and the complexity of PFAS mixtures. In this review, remediation of PFAS contaminated soils through manipulation of their bioavailability and destruction is presented. While the mobilizing amendments (e.g., surfactants) enhance the mobility and bioavailability of PFAS, the immobilizing amendments (e.g., activated carbon) decrease their bioavailability and mobility. Mobilizing amendments can be applied to facilitate the removal of PFAS though soil washing, phytoremediation, and complete destruction through thermal and chemical redox reactions. Immobilizing amendments are likely to reduce the transfer of PFAS to food chain through plant and biota (e.g., earthworm) uptake, and leaching to potable water sources. Future studies should focus on quantifying the potential leaching of the mobilized PFAS in the absence of removal by plant and biota uptake or soil washing, and regular monitoring of the long-term stability of the immobilized PFAS.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123892DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025151PMC
January 2021

Sorption mechanisms of lead on soil-derived black carbon formed under varying cultivation systems.

Chemosphere 2020 Dec 3;261:128220. Epub 2020 Sep 3.

College of Tropical Crops, Hainan University, Haikou, 570228, China. Electronic address:

The knowledge about lead (Pb) sorption on soil-derived black carbons (SBCs) under different cultivation intensities of soils is limited. In this study, chemical and spectroscopic methods were applied to investigate the Pb sorption mechanisms on SBCs in soils from a forest land, a rubber plantation area, and a vegetable farm with none, less and highly intensive cultivation, respectively, that are located in the Hainan Island of China. Results showed that the specific surface area and cation exchange capacity of the SBCs from the less and highly intensive cultivation soils were 4.5- and 2.7-fold, and 1.3- and 1.8-fold higher compared to that of SBC from the no-cultivation soil, which subsequently enhanced the Pb sorption capacities of SBCs in iron exchange fraction. Ion exchange and hydrogen bonded Pb fractions together accounted for about 80% of total Pb sorbed on all SBCs at an externally added 1000 mg L Pb solution concentration. The OC-O groups also played key roles in Pb sorption by forming complexes of OC-O-Pb-O and/or OC-O-Pb. Overall, SBCs in soils under all studied cultivation intensities showed high potential to sorb Pb (with the maximum absorbed Pb amount of 46.0-91.3 mg g), and increased Pb sorption capacities of the studied soils by 18.7-21.1 mg kg in the stable fraction (complexation). Therefore, SBC might be a potential environment-friendly material to enhance the Pb immobilization capacity of soil.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128220DOI Listing
December 2020

Conversion of biochar to sulfonated solid acid catalysts for spiramycin hydrolysis: Insights into the sulfonation process.

Environ Res 2020 09 7;188:109887. Epub 2020 Jul 7.

College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, PR China. Electronic address:

Biochar has been recognized as a sustainable platform for developing functional materials including catalysts. This work demonstrated a method of converting biochar to sulfonated solid-acid catalysts, and the effectiveness of the catalysts for spiramycin hydrolysis was examined. Two biochar samples (H and X) were sulfonated with three reagents (concentrated HSO, ClSOH and p-toluenesulfonic acid (TsOH)) under hydrothermal, simple heating, ambient temperature, and CHCl-assisted treatments. The effect of elemental compositions and structural characteristics of the feeding materials (H and X) on the acidic properties of the sulfonated biochars were investigated. The results showed that the sulfonation ability of the three reagents was in the order of ClSOH > HSO > TsOH, while hydrothermal treatment provided the highest total acidity, and largest amount of acidic groups (e.g., SOH, COOH and Ar-OH). Biochar X with higher O/C and N contents, and less graphitic features showed superior acidic properties than biochar H under all the employed treatments. The hydrolytic efficiencies of the sulfonated biochars under 200 W of microwave irradiation increased with increasing total acidity, and the amount of SOH and COOH groups. After sulfonation, the O/C of biochars increased, while H/C decreased, and the aromatic and graphitic features did not change. The electromagnetic energy absorbed by the sulfonated biochars did not notably contribute to spiramycin hydrolysis. Thus, this work demonstrated an effective and promising method for maneuvering biochar-based functional solid-acid catalysts for antibiotic remediation in contaminated water.
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http://dx.doi.org/10.1016/j.envres.2020.109887DOI Listing
September 2020

Environmentally safe release of plant available potassium and micronutrients from organically amended rock mineral powder.

Environ Geochem Health 2020 Aug 25. Epub 2020 Aug 25.

Global Centre for Environmental Remediation, The University of Newcastle, Callaghan, NSW 2308, Australia.

The staggering production of rock dusts and quarry by-products of mining activities poses an immense environmental burden that warrants research for value-added recycling of these rock mineral powders (RMP). In this study, an incubation experiment was conducted to determine potassium (K) and micronutrients (Zn, Cu, Fe and Mn) release from a quarry RMP to support plant nutrition. Four different size fractions of the RMP were incubated with organic amendments (cow dung and legume straw) under controlled conditions for 90 days. Samples were collected at different intervals (7, 15, 30, 45, 60 and 90 days) for the analysis of available K and micronutrients in the mineral-OM mixtures and leachates. There was a significant (p <0.05) increase in pH of leachates from the mineral-OM mixtures. The K release was significantly higher from the finer size fraction of RMP. About 18.7% Zn added as RMP was released during the incubation period. Zn release increased from 4.7 to 23.2% as the particle size of RMP decreased. Similarly, Cu release from RMP increased from 2.9 to 21.6%, with a decrease in the particle size. Fe and Mn recovery from RMP recorded 11.2 and 6.6%, respectively. Combined application of OM and RMP showed significantly higher nutrient release than other treatments. This study indicates that effective blending of RMP with organic amendments could be a potential source of K and micronutrients in agriculture without posing a risk of toxic element contamination to the soil.
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http://dx.doi.org/10.1007/s10653-020-00677-1DOI Listing
August 2020

Mechanistic insights into simultaneous removal of copper, cadmium and arsenic from water by iron oxide-functionalized magnetic imogolite nanocomposites.

J Hazard Mater 2020 11 31;398:122940. Epub 2020 May 31.

Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. Electronic address:

Imogolite and magnetic imogolite-Fe oxide nanocomposites (Imo-Fe and Imo-Fe, at 50 and 25 % Fe loading (w/w), respectively) were synthesized and tested for the removal of aqueous copper (Cu), cadmium (Cd), and arsenic (As) pollutants. The materials were characterized by transmission electron microscopy, and specific surface area and isoelectric point measurements. The Fe-containing samples were additionally characterized by Mössbauer spectroscopy and vibrating-sample magnetometry. Significant differences were found in the morphological, electrophoretic, and magnetic characteristics between imogolite and the nanocomposites. The in-situ Fe-oxide precipitation process modified the active surface sites of the imogolite. The Fe-oxide, mainly magnetite, favored the contaminants' adsorption over the pristine imogolite. The adsorption kinetics of these pollutants were adequately described by the pseudo-second order and intraparticle diffusion models. The kinetic models showed that surface adsorption was more important than intraparticle diffusion in the removal of the pollutants by all the adsorbents. The Langmuir-Freundlich model described the experimental adsorption data, and both nanocomposites showed greater adsorption capacity than the imogolite. The adsorption of Cu and Cd was sensitive to cationic competition, showing a decrease of the adsorption capacity when the two cations coexisted, while their adsorption increased in the presence of arsenate.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122940DOI Listing
November 2020

Trace elements adsorption by natural and chemically modified humic acids.

Environ Geochem Health 2021 Jan 6;43(1):127-138. Epub 2020 Aug 6.

St. Petersburg State University, Universitetskaya Nab., 7/9, St. Petersburg, Russia, 199034.

Humic substances with or without chemical modification can serve as environmentally benign and inexpensive adsorbents of potentially toxic trace elements (PTTEs) in the environment. The present study investigated the absorption of Pb, Zn, Cu and Ni by natural and potassium persulfate (KSO) modified humic acids (HAs) isolated from a lowland peat through batch experiments. The adsorption of the studied PTTEs on the natural HA was satisfactorily described by the Langmuir isotherm model with maximum monolayer adsorption capacities of 318.2, 286.5, 225.0 and 136.8 mmol/kg for Pb, Cu, Zn and Ni, respectively. A thorough characterization of the natural and modified HA using C nuclear magnetic resonance spectroscopy demonstrated that the chemical modification of natural HA with KSO led to an increase in the content of carboxyl groups, and ketone and quinoid fragments in the HA structure. Consequently, the modified HA absorbed 16.3, 14.2, 10.6 and 6.9% more Pb, Ni, Zn and Cu, respectively, than the original natural HA. The isotherm data modeling together with adsorbent characterization suggested that the adsorption of PTTEs was controlled mainly by chemisorption mechanisms where inner-sphere complexations of metal ions with HA functional groups took place.
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http://dx.doi.org/10.1007/s10653-020-00686-0DOI Listing
January 2021

A review of microplastics aggregation in aquatic environment: Influence factors, analytical methods, and environmental implications.

J Hazard Mater 2021 01 16;402:123496. Epub 2020 Jul 16.

Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China. Electronic address:

A large amount of plastic waste released into natural waters and their demonstrated toxicity have made the transformation of microplastics (MPs; < 5 mm) and nanoplastics (NPs; < 100 nm) an emerging environmental concern. Aggregation is one of the most important environmental behaviors of MPs, especially in aquatic environments, which determines the mobility, distribution and bioavailability of MPs. In this paper, the sources and inputs of MPs in aquatic environments were first summarized followed by the analytical methods for investigating MP aggregation, including the sampling, visualization, and quantification procedures of MP' particle sizes. We critically evaluated the sampling methods that still remains a methodological gap. Identification and quantification of MPs were mostly carried out by visual, spectroscopic and spectrometric techniques, and modeling analysis. Important factors affecting MP aggregation in natural waters and environmental implications of the aggregation process were also reviewed. Finally, recommendations for future research were discussed, including (1) conducting more field studies; (2) using MPs in laboratory works representing those in the environment; and (3) standardizing methods of identification and quantification. The review gives a comprehensive overview of current knowledge for MP aggregation in natural waters, identifies knowledge gaps, and provides suggestions for future research.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123496DOI Listing
January 2021

Phosphorus-rich biochar produced through bean-worm skin waste pyrolysis enhances the adsorption of aqueous lead.

Environ Pollut 2020 Nov 8;266(Pt 3):115177. Epub 2020 Jul 8.

Global Centre for Environmental Remediation, University of Newcastle, Callaghan Campus, NSW, 2308, Australia; Cooperative Research Centre for High Performance Soil (Soil CRC), Callaghan, NSW, 2308, Australia.

In China, more than 10,000 tons of bean-worm, which is rich in protein (68.5%) and essential amino acids (52.8%), is consumed annually. Thus, a large amount of bean-worm skin waste is generated, and is often indiscriminately disposed of, potentially causing environment problems. In this study, bean-worm skin (BWS) waste was pyrolyzed at 500 °C to produce biochar (BWS-BC), and the surface properties of BWS and BWS-BC were characterized using various spectroscopic techniques. Pb(II) adsorption properties of BWS and the corresponding biochar as a function of solution pH, contact time, and equilibrium concentration of Pb(II) were examined using adsorption isotherm, kinetics and thermodynamics studies. The maximum Pb(II) adsorption capacities based on the Langmuir isotherm model were calculated as 45 and 62 mg g for BWS and BWS-BC, respectively, which were comparable to the values obtained for biochars derived from other agro-wastes. The adsorption feasibility, favorability and spontaneity of Pb(II), as derived from the thermodynamic parameters, indicated that chemisorption and precipitation (e.g., hydroxypyromorphite) were the main adsorption mechanism in case of BWS and BWS-BC, respectively. Thus, conversion of BWS to biochar for Pb(II) adsorption can be considered as a feasible, promising and high value-added approach for BWS recycling.
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http://dx.doi.org/10.1016/j.envpol.2020.115177DOI Listing
November 2020

Potential for large-scale CO removal via enhanced rock weathering with croplands.

Nature 2020 07 8;583(7815):242-248. Epub 2020 Jul 8.

Global Food and Environment Institute, University of Leeds, Leeds, UK.

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO) removal (CDR), which is now necessary to mitigate anthropogenic climate change. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO) per year with extraction costs of approximately US$80-180 per tonne of CO. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.
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http://dx.doi.org/10.1038/s41586-020-2448-9DOI Listing
July 2020

Rhizoremediation as a green technology for the remediation of petroleum hydrocarbon-contaminated soils.

J Hazard Mater 2021 01 22;401:123282. Epub 2020 Jun 22.

Global Centre for Environmental Remediation (GCER), Advanced Technology Centre (ATC) Building, Faculty of Science, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia. Electronic address:

Rhizoremediation is increasingly becoming a green and sustainable alternative to physico-chemical methods for remediation of contaminated environments through the utilization of symbiotic relationship between plants and their associated soil microorganisms in the root zone. The overall efficiency can be enhanced by identifying suitable plant-microbe combinations for specific contaminants and supporting the process with the application of appropriate soil amendments. This approach not only involves promoting the existing activity of plants and soil microbes, but also introduces an adequate number of microorganisms with specific catabolic activity. Here, we reviewed recent literature on the main mechanisms and key factors in the rhizoremediation process with a particular focus on soils contaminated with total petroleum hydrocarbon (TPH). We then discuss the potential of different soil amendments to accelerate the remediation efficiency based on biostimulation and bioaugmentation processes. Notwithstanding some successes in well-controlled environments, rhizoremediation of TPH under field conditions is still not widespread and considered less attractive than physico-chemical methods. We catalogued the major pitfalls of this remediation approach at the field scale in TPH-contaminated sites and, provide some applicable situations for the future successful use of in situ rhizoremediation of TPH-contaminated soils.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123282DOI Listing
January 2021

Long-term influence of maize stover and its derived biochar on soil structure and organo-mineral complexes in Northeast China.

Environ Sci Pollut Res Int 2020 Aug 16;27(22):28374-28383. Epub 2020 May 16.

Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan, 528000, Guangdong, China.

The influence of biochar on the soil structure and aggregate stability has been debated in previous studies. To probe the action of biochar on soil aggregates, a 5-year field experiment was implemented in the brown earth soil of northeastern China. We determined the aggregate distribution (> 2000 μm, 250-2000 μm, 53-250 μm, and < 53 μm) and organic carbon (OC) and organo-mineral complex contents both in the topsoil (0-20 cm) and within the soil aggregates. Three treatments were studied as follows: control (basal application of mineral NPK fertilizer), biochar (biochar applied at a rate of 2.625 t ha), and stover (maize stover applied at a rate of 7.5 t ha), and all treatments received the same fertilization. The biochar and stover applications decreased the soil bulk and particle densities significantly (p < 0.05) and enhanced the soil total porosity. Both amendments significantly (p < 0.05) enhanced the total OC, heavy OC fractions, and organo-mineral complex quantities in the bulk soil as well as in all the studied aggregate fractions. Biochar and stover applications promoted the formation of small macroaggregates. A greater amount of organic matter was contained in the macroaggregates, which led to the formation of more organo-mineral complexes, thereby improving soil aggregate stability. However, the different mechanisms underlying the effect of biochar and stover on organo-mineral complexes need further research. Biochar and stover applications are both effective methods of improving the soil structure in Northeast China.
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http://dx.doi.org/10.1007/s11356-020-08171-yDOI Listing
August 2020

MnO-decorated N-doped carbon nanotube with boosted activity for low-temperature oxidation of formaldehyde.

J Hazard Mater 2020 Sep 19;396:122750. Epub 2020 Apr 19.

Biochar Engineering Technology Research Center of Guangdong Province, Foshan University, Foshan, Guangdong 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China. Electronic address:

Low-temperature oxidative degradation of formaldehyde (HCHO) using non-noble metal catalysts is challenging. Herein, novel manganese dioxide (MnO)/N-doped carbon nanotubes (NCNT) composites were prepared with varying MnO content. The surface properties and morphologies were analyzed using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). Comparing with MnO/carbon nanotubes (CNTs) catalyst, the 40% MnO/NCNT exhibited much better activity and selectivity for HCHO oxidation, mineralizing 95% of HCHO (at 100 ppm) into CO at 30 °C at a gas hourly space velocity (GHSV) of 30,000 mL h  g. Density functional theory (DFT) calculation was used to analyze the difference in the catalytic activity of MnO with CNTs and NCNT carrier. It was confirmed that the oxygen on NCNT was more active than CNTs, which facilitated the regeneration of MnO. This resulted in remarkably boosted activity for HCHO oxidation. The present work thus exploited an inexpensive approach to enhance the catalytic activity of transition metal oxides via depositing them on a suitable support.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122750DOI Listing
September 2020

Increased yield and CO sequestration potential with the C cereal Sorghum bicolor cultivated in basaltic rock dust-amended agricultural soil.

Glob Chang Biol 2020 06 21;26(6):3658-3676. Epub 2020 Apr 21.

Leverhulme Centre for Climate Change Mitigation, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.

Land-based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its potential co-benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay-loam agricultural soil with a high loading (10 kg/m ) of relatively coarse-grained crushed basalt significantly increased the yield (21 ± 9.4%, SE) of the important C cereal Sorghum bicolor under controlled environmental conditions, without accumulation of potentially toxic trace elements in the seeds. Yield increases resulted from the basalt treatment after 120 days without P- and K-fertilizer addition. Shoot silicon concentrations also increased significantly (26 ± 5.4%, SE), with potential benefits for crop resistance to biotic and abiotic stress. Elemental budgets indicate substantial release of base cations important for inorganic carbon removal and their accumulation mainly in the soil exchangeable pools. Geochemical reactive transport modelling, constrained by elemental budgets, indicated CO sequestration rates of 2-4 t CO /ha, 1-5 years after a single application of basaltic rock dust, including via newly formed soil carbonate minerals whose long-term fate requires assessment through field trials. This represents an approximately fourfold increase in carbon capture compared to control plant-soil systems without basalt. Our results build support for ERW deployment as a CDR technique compatible with spreading basalt powder on acidic loamy soils common across millions of hectares of western European and North American agriculture.
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http://dx.doi.org/10.1111/gcb.15089DOI Listing
June 2020

Do arsenic levels in rice pose a health risk to the UK population?

Ecotoxicol Environ Saf 2020 Jul 14;197:110601. Epub 2020 Apr 14.

School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RF, United Kingdom.

Consumption of rice and rice products can be a significant exposure pathway to inorganic arsenic (iAs), which is a group 1 carcinogen to humans. The UK follows the current European Commission regulations so that iAs concentrations must be < 0.20 mg kg in white (polished) rice and <0.25 mg kg in brown (unpolished) rice. However, iAs concentration in rice used for infant food production or direct consumption has been set at a maximum of 0.1 mg kg. In this context, this study aimed to evaluate iAs concentrations in different types of rice sold in the UK and to quantify the health risks to the UK population. Here, we evaluated 55 different types of rice purchased from a range of retail outlets. First, we analysed all rice types for total As (tAs) concentration from which 42 rice samples with tAs > 0.1 mg kg were selected for As speciation using HPLC-ICP-MS. Based on the average concentration of iAs of our samples, we calculated values for the Lifetime Cancer Risk (LCR), Target Hazard Quotient (THQ) and Margin of Exposure (MoE). We found a statistically significant difference between organically and non-organically grown rice. We also found that brown rice contained a significantly higher concentration of iAs compared to white or wild rice. Notably, 28 rice samples exceeded the iAs maximum limit stipulated by the EU (0.1 mg kg) with an average iAs concentration of 0.13 mg kg; therefore consumption of these rice types could be riskier for infants than adults. Based on the MoE, it was found that infants up to 1 year must be restricted to a maximum of 20 g per day for the 28 rice types to avoid carcinogenic risks. We believe that consumers could be better informed whether the marketed product is fit for infants and young children, via appropriate product labelling containing information about iAs concentration.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110601DOI Listing
July 2020