Publications by authors named "Jingchun Tang"

77 Publications

Toxic effects of acetone, 2-pentanone, and 2-hexanone on physiological indices of wheat (Triticum aestivum L.) germination and seedlings.

Environ Sci Pollut Res Int 2021 Jul 26. Epub 2021 Jul 26.

School of Environmental Science and Engineering, China-America CRC for Environment & Health, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, People's Republic of China.

Petroleum hydrocarbons are important characteristic pollutants in the process of oil exploitation in the Yellow River Delta (China), and they cause a potential hazard to the surrounding ecological environment. The research on eco-toxicological effects of petroleum-derived products still needs to be studied in depth. This paper describes the physiological indices of wheat (Triticum aestivum L.) seeds and seedlings under independent stresses of acetone, 2-pentanone, and 2-hexanone to determine the toxicological effects of ketones derived from petroleum products on typical crops. The experimental results indicated that ketones with concentrations lower than 0.4 mg·cm and 800 mg·kg the germination of wheat seeds and the growth of seedlings were promoted to 113.32-127.27% and 105.41-126.39%, respectively, thus exhibiting low-dose excitatory effects. However, when the concentration was higher than 0.4 mg·cm and 800 mg·kg, germination and seedlings' growth were significantly reduced to 7.14-2.12% and 35.09-13.33%, respectively. At the same time, acetone had a greater impact on the growth of wheat seed roots, the malondialdehyde (MDA), and chlorophyll contents in leaf tissues. The low concentration of acetone had a significant promoting effect on the activity of α-amylase in wheat seeds. 2-Pentanone reduced the electrical conductivity of wheat seed extract, and it significantly promoted the catalase (CAT) activity at low concentrations. 2-Hexanone had a strong inhibitory effect on wheat germination and growth. This study provided new research results to determine the toxic effects of petroleum-derived products and provided a basis for the environmental management of such substances.
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http://dx.doi.org/10.1007/s11356-021-15496-9DOI Listing
July 2021

Effect of dissolved biochar on the transfer of antibiotic resistance genes between bacteria.

Environ Pollut 2021 Jul 5;288:117718. Epub 2021 Jul 5.

Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.

The spread of antibiotic resistance genes (ARGs) is a global environmental issue. Dissolved biochar is more likely to contact bacteria in water, producing ecological risks. This study explored the effects of dissolved biochar on ARGs transfer in bacteria. Conjugative transfer efficiency was significantly different following treatment with different types of dissolved biochar. Typically, humic acid-like substance in dissolved biochar can significantly improve the transfer efficiency of ARGs between bacteria. When the concentration of dissolved biochar was ≤10 mg biochar/mL, humic acid-like substance substantially promoted ARGs transfer. An increase in dissolved biochar concentration weakened the ARGs transfer from humic acid-like substance. The inhibitory effects of small-molecule matters dominated, decreasing conjugative transfer frequency. At a concentration of 100 mg biochar/mL, the conjugative transfer efficiency of all treatments was lower than that of control. Compared with corn straw dissolved biochar, there were more transconjugants in pine sawdust dissolved biochar. Following treatment with 10 mg biochar/mL pine sawdust dissolved biochar, the number of transconjugants was at its maximum; approximately 7.3 folds higher than the control. We also explored mechanisms by which dissolved biochar impacts conjugative transfer. Due to the complex composition of dissolved biochar, its effects on the expression of conjugative transfer-related genes were also dynamic. This study investigates the ecological risk of biochar and guides its scientific application.
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http://dx.doi.org/10.1016/j.envpol.2021.117718DOI Listing
July 2021

Green synthesized nanosilver-biochar photocatalyst for persulfate activation under visible-light illumination.

Chemosphere 2021 Jun 15;284:131237. Epub 2021 Jun 15.

School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0372, USA. Electronic address:

This paper presents a novel eco-sustainable wastewater treatment using silver nanoparticles and biochar ([email protected]) synthesized from an Eriobotryra japonica leaf. A simple green pyrolysis method was chosen to activate peroxydisulfate (PDS) for organic pollutant degradation under the action of visible light. Rhodamine B (RhB) was chosen as a typical containment to assess the photocatalytic performance of the [email protected]/PDS system with visible-light illumination ([email protected]/PDS-vis). When [email protected] (referring to the [email protected] pyrolyzed at 750 °C) was added, the photocatalytic activity of PDS for RhB degradation was enhanced (from k = 0.165-2.984 min). The result confirmed that 99.9% of the RhB was degraded in the [email protected]/PDS-vis system within 10 min and with a 2.0 g/L photocatalyst, 10 mM PDS and under pH 9.03 (k = 6.723 min). Over 100 mg/L of RhB could be degraded completely in the [email protected]/PDS-vis system within 30 min mainly attributed to various free radicals. The possible degradation pathways of RhB were illustrated and the recyclability of the [email protected] photocatalyst was confirmed. The findings in this study reveal the virtue of using the [email protected]/PDS-vis process for advanced water disinfection and its provision as an alternative solution in addressing the green way for further water treatment.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131237DOI Listing
June 2021

Toxic mechanism on phenanthrene-induced cytotoxicity, oxidative stress and activity changes of superoxide dismutase and catalase in earthworm (Eisenia foetida): A combined molecular and cellular study.

J Hazard Mater 2021 Jun 9;418:126302. Epub 2021 Jun 9.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China. Electronic address:

Phenanthrene (PHE) is an important organic compound, which is widespread in the soil environment and exhibits potential threats to soil organisms. Toxic effects of PHE to earthworms have been extensively studied, but toxic mechanisms on PHE-induced cytotoxicity and oxidative stress at the molecular and cellular levels have not been reported yet. Therefore, we explored the cytotoxicity and oxidative stress caused by PHE in earthworm coelomocytes and the interaction mechanism between PHE and the major antioxidant enzymes SOD/CAT. It was shown that high-dose PHE exposure induced the intracellular reactive oxygen species (ROS) generation, mediated lipid peroxidation, reduced total antioxidant capacity (T-AOC) in coelomocytes, and triggered oxidative stress, thus resulted in a strong cytotoxicity at higher concentrations (0.6-1.0 mg/L). The intracellular SOD/CAT activity in cells after PHE exposure were congruent with that in molecular levels, which the activity of SOD enhanced and CAT inhibited. Spectroscopic studies showed the SOD/CAT protein skeleton and secondary structure, as well as the micro-environment of aromatic amino acids were changed after PHE binding. Molecular docking indicated PHE preferentially docked to the surface of SOD. However, the key residues Tyr 357, His 74, and Asn 147 for activity were in the binding pocket, indicating PHE more likely to dock to the active center of CAT. In addition, H-bonding and hydrophobic force were the primary driving force in the binding interaction between PHE and SOD/CAT. This study indicates that PHE can induce cytotoxicity and oxidative damage to coelomocytes and unearthes the potential effects of PHE on earthworms.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126302DOI Listing
June 2021

Combined Effects of Microplastics and Biochar on the Removal of Polycyclic Aromatic Hydrocarbons and Phthalate Esters and Its Potential Microbial Ecological Mechanism.

Front Microbiol 2021 30;12:647766. Epub 2021 Apr 30.

Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin, China.

Microplastics (MPs) have been attracting wide attention. Biochar (BC) application could improve the soil quality in the contaminated soil. Currently, most studies focused on the effect of MPs or BC on the soil properties and microbial community, while they neglected the combined effects. This study investigated the combined effects of BC or ball-milled BC (BM) and polyethylene plastic fragments (PEPFs) and degradable plastic fragments (DPFs) on the removal of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) from the PAH-contaminated soil and the potential microbial ecological mechanisms. The results showed that BC or BM combined with PEPF could accelerate the removal of PAHs and PAEs. PEPF combined with BM had the most significant effect on the removal of PAHs. Our results indicating two potential possible reasons contribute to increasing the removal of organic pollutants: (1) the high sorption rate on the PEPF and BC and (2) the increased PAH-degrader or PAE-degrader abundance for the removal of organic pollutants.
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http://dx.doi.org/10.3389/fmicb.2021.647766DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8120302PMC
April 2021

Sulfidated zero valent iron as a persulfate activator for oxidizing organophosphorus pesticides (OPPs) in aqueous solution and aged contaminated soil columns.

Chemosphere 2021 Oct 11;281:130760. Epub 2021 May 11.

MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin, 300350, China. Electronic address:

Sulfidation treatment is an effective method of improving the catalytic performance of zero-valent iron (ZVI). Here, we prepared sulfidated, micro-sized ZVI (S-mZVI) using ball milling technology to activate persulfate (PS) with the goal of oxidizing organophosphorus pesticides (OPPs) in aqueous solution and aged OPP-contaminated soil columns. Energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS) analyses uncovered the formation of FeO, FeOOH, FeS and FeS in the S-mZVI prepared by ball milling with different proportions of elemental S powder to make micro-sized ZVI particles. The presence of sulfur can regulate the morphology of S-mZVI with a dispersed and spherical shape, and it can improve the activation performance of PS. In aqueous solution, 11.2 mg of S-mZVI activated 2.5 mM PS (S-mZVI-PS) with an S/Fe molar ratio of 0.100, and it was the best at activating PS, leading to oxidation-rate constants of 0.030 s for 10 mg/L phorate and 0.026 s for 10 mg/L terbufos, which were much greater than those of the other S-mZVI and mZVI. The results of the soil column experiment showed that the PS, which had a low consumption for the total dosage, achieved higher degradation percentages among the three OPPs in the S-mZVI-PS treatment than those in the mZVI-PS treatment over 120 h, with the best performance achieved by oxidizing 69.7% phorate, 48.0% terbufos and 60.6% aminoparathion. The effluent concentrations of the three OPPs in the S-mZVI-PS treatment were significantly lower than those in the mZVI-PS treatment, while dissolved total iron and Fe(II) displayed the opposite results. These results indicate that S-mZVI prepared by ball milling can effectively activate PS and be applied to remediate OPP-contaminated soil.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130760DOI Listing
October 2021

Graphitic carbon nitride/biochar composite synthesized by a facile ball-milling method for the adsorption and photocatalytic degradation of enrofloxacin.

J Environ Sci (China) 2021 May 6;103:93-107. Epub 2020 Nov 6.

Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address:

In order to enhance the removal performance of graphitic carbon nitride (g-CN) on organic pollutant, a simultaneous process of adsorption and photocatalysis was achieved via the compounding of biochar and g-CN. In this study, g-CN was obtained by a condensation reaction of melamine at 550°C. Then the g-CN/biochar composites were synthesized by ball milling biochar and g-CN together, which was considered as a simple, economical, and green strategy. The characterization of resulting g-CN/biochar suggested that biochar and g-CN achieved effective linkage. The adsorption and photocatalytic performance of the composites were evaluated with enrofloxacin (EFA) as a model pollutant. The result showed that all the g-CN/biochar composites displayed higher adsorption and photocatalytic performance to EFA than that of pure g-CN. The 50% g-CN/biochar performed best and removed 45.2% and 81.1% of EFA (10 mg/L) under darkness and light with a dosage of 1 mg/mL, while g-CN were 19.0% and 27.3%, respectively. Besides, 50% g-CN/biochar showed the highest total organic carbon (TOC) removal efficiency (65.9%). Radical trapping experiments suggested that superoxide radical (•O) and hole (h) were the main active species in the photocatalytic process. After 4 cycles, the composite still exhibited activity for catalytic removal of EFA.
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http://dx.doi.org/10.1016/j.jes.2020.10.006DOI Listing
May 2021

Development of a novel pyrite/biochar composite ([email protected]) by ball milling for aqueous Cr(VI) removal and its mechanisms.

J Hazard Mater 2021 07 13;413:125415. Epub 2021 Feb 13.

BCIG Environmental Remediation Co., Ltd, Tianjin 300042, China.

As a natural reduction mineral, pyrite (FeS), was combined with biochar by simply ball milling technology to synthesize [email protected] composite ([email protected]) and applied for the removal of hexavalent chromium (Cr(VI)) in aqueous solution. SEM, XRD, FTIR, and XPS characterization results showed that the FeS and biochar were successfully combined and biochar suppressed the agglomeration of FeS. Batch sorption experiments showed that the [email protected] composite (mass ratio of FeS-to-biochar = 3:1) had enhanced Cr(VI) removal capacity of 134 mg·g, which were 3-25 times higher than those of the corresponding pristine and ball-milled biochar and FeS. The removal of Cr(VI) by [email protected] was dosage and pH dependent. The addition of oxalic acid (OA) exhibited a promotion effect on the removal of Cr(VI) by increasing the removal rate of Cr(VI) from 56% to 100%. Reduction, adsorption, and surface complexation were the dominate mechanisms for Cr(VI) removal by [email protected] At the equilibrium Cr(VI) concentration of 15.7 mg·L, 92.25% of Cr(VI) was removed through reduction/precipitation and 8.75% was removed by adsorption/surface complexation. The fitting results of the Langmuir model proved that the removal of Cr(VI) by [email protected] composite was chemical surface monolayer adsorption. This work demonstrates the potential of ball milling for the preparation of [email protected] composite to remove Cr(VI) from water and wastewater.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125415DOI Listing
July 2021

Do polystyrene nanoplastics affect the toxicity of cadmium to wheat (Triticum aestivum L.)?

Environ Pollut 2020 Aug 9;263(Pt A):114498. Epub 2020 Apr 9.

MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, PR China. Electronic address:

There has been an increase on the research of microplastics (<5 mm in diameter) as carriers for toxic chemicals to evaluate their risks for human health and environment, but only few works focused on nanoplastics (1 nm-1000 nm in diameter) interacting with pre-existing contaminants such as heavy metals. It is still unclear whether polystyrene nanoplastics (PSNPs) could affect the toxicity of cadmium to wheat (Triticum aestivum L.). Here, we assessed the impact of polystyrene nanoplastics (0, 10 mg/L) on the Cd (0, 20 μM) toxicity to wheat grown in 25% Hoagland solution for three weeks. We found that the presence of PSNPs could partially reduce Cd contents in leaves and alleviate Cd toxicity to wheat, which might be due to weakened adsorption capacity of PSNPs affected by ionic strength. In addition, PSNPs have little effect on catalase (CAT), peroxidase (POD) activities, except for decreasing superoxide dismutase (SOD) activity, which suggested that antioxidant defense systems might not be the main mechanism to reduce the oxidative damage induced by Cd in wheat. Electron paramagnetic resonance (EPR) analysis showed that PSNPs could accelerate the formation of long-lived radicals in leaves after exposure to Cd. Notably, our metabolomics profiling further indicated that the simultaneously elevated carbohydrate and amino acid metabolisms induced by PSNPs could partly alleviate Cd toxicity to wheat. Nevertheless, the present study provides important implications for the toxicological interaction and future risk assessment of co-contamination of nanoplastics and heavy metals in the environment.
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http://dx.doi.org/10.1016/j.envpol.2020.114498DOI Listing
August 2020

Combined cytotoxicity of polystyrene nanoplastics and phthalate esters on human lung epithelial A549 cells and its mechanism.

Ecotoxicol Environ Saf 2021 Apr 15;213:112041. Epub 2021 Feb 15.

Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Dept. Veterinary Biomedical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada; Dept. Environmental Sciences, Baylor University, Waco, TX 76798-7266, USA.

Awareness of risks posed by widespread presence of nanoplastics (NPs) and bioavailability and potential to interact with organic pollutants has been increasing. Inhalation is one of the more important pathways of exposure of humans to NPs. In this study, combined toxicity of concentrations of polystyrene NPs and various phthalate esters (PAEs), some of the most common plasticizers, including dibutyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) on human lung epithelial A549 cells were investigated. When co-exposed, 20 μg NPs/mL increased viabilities of cells exposed to either DBP or DEHP and the modulation of toxic potency of DEHP was greater than that of DBP, while the 200 μg NPs/mL resulted in lesser viability of cells. PAEs sorbed to NPs decreased free phase concentrations (C) of PAEs, which resulted in a corresponding lesser bioavailability and joint toxicity at the lesser concentration of NPs. The opposite effect was observed at the greater concentration of NPs, which may result from the dominated role of NPs in the combined toxicity. Furthermore, our data showed that oxidative stress and inflammatory reactions were mechanisms for combined cytotoxicities of PAEs and NPs on A549 cells. Results of this study emphasized the combined toxic effects and mechanisms on human lung cells, which are helpful for assessing the risk of the co-exposure of NPs and organic contaminants in humans.
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http://dx.doi.org/10.1016/j.ecoenv.2021.112041DOI Listing
April 2021

A review of human and animals exposure to polycyclic aromatic hydrocarbons: Health risk and adverse effects, photo-induced toxicity and regulating effect of microplastics.

Sci Total Environ 2021 Jun 28;773:145403. Epub 2021 Jan 28.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China. Electronic address:

Polycyclic aromatic hydrocarbons (PAHs) are one of the most widely distributed persistent organic pollutants (POPs) in the environmental media. PAHs have been widely concerned due to their significant health risk and adverse effects to human and animals. Currently, the main sources of PAHs in the environment are the incomplete combustion of fossil fuels, as well as municipal waste incineration and agricultural non-surface source emissions. In this work, the scope of our attention includes 16 typical PAHs themselves without involving their metabolites and industrial by-products. Exposure of human and animals to PAHs can lead to a variety of adverse effects, including carcinogenicity and teratogenicity, genotoxicity, reproductive- and endocrine-disrupting effects, immunotoxicity and neurotoxicity, the type and severity of which depend on a variety of factors. On the other hand, the regulatory effect of microplastics (MPs) on the bio-toxicity and bioaccumulation capacity of PAHs has now gradually attracted attention. We critically reviewed the adsorption capacity and mechanisms of MPs on PAHs as well as the effects of MPs on PAHs toxicity, thus highlighting the importance of paying attention to the joint bio-toxicity caused by PAHs-MPs interactions. In addition, due to the extensive nature of the common exposure pathway of PAHs and ultraviolet ray, an accurate understanding of biological processes exposed to both PAHs and UV light is necessary to develop effective protective strategies. Finally, based on the above critical review, we highlighted the research gaps and pointed out the priority of further studies.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145403DOI Listing
June 2021

Carbon coating enhances single-electron oxygen reduction reaction on nZVI surface for oxidative degradation of nitrobenzene.

Sci Total Environ 2021 May 17;770:144680. Epub 2021 Jan 17.

College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin 300350, China.

Research on the in-situ generation of hydrogen peroxide (HO) using nano zero-valent iron (nZVI) has received more and more attention in recent years. However, the low utilization rate of nZVI, strict production conditions, and high energy consumption limit the application of this technology in actual environmental pollution remediation. In this study, carbon-coated nZVI ([email protected]) was used to synthesize HO in situ and realize the mineralization of nitrobenzene (NB). The results showed that the composite removed 91% of NB through adsorption, reduction, and oxidation within 120 min, of which oxidation accounts for 42.92%. Not only that, the composite material could achieve effective mineralization of NB under the wide pH range of 3-7. Quantitative experiments of hydroxyl radicals (HO) showed that the composite could generate 185.64 μM HO in 120 min without any extra energy consumption. The carbon-coated structure effectively inhibits the formation of the passivation layer on the surface of the nZVI, thereby ensuring the high activity of the Fe. In addition, the carbon coating strengthens the sequential single-electron transfer process by changing the oxygen reduction pathway on the surface of the nZVI, so that the Fe can efficiently generate HO through the superoxide radical (O) pathway under neutral conditions. This study provides a fundamental understanding of the in-situ synthesis of HO to mineralize NB by carbon-coated nZVI.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144680DOI Listing
May 2021

Effects of phosphorus modified nZVI-biochar composite on emission of greenhouse gases and changes of microbial community in soil.

Environ Pollut 2021 Apr 11;274:116483. Epub 2021 Jan 11.

Department of Biosystems Engineering and Soil Science, University of Tennessee - Knoxville, 2506 E. J. Chapman Drive, Knoxville, TN, 37996, USA.

The effect of modified biochar on the greenhouse gas emission in soil is not clear until now. In this study, biochar (BC) was modified by phosphoric acid (P) and further combined with nano-zero-valent iron (nZVI) to form nZVI-P-BC composite. The P modified biochar could significantly increase the available phosphorus in soil. The release of CO and NO in soil was inhibited during the initial stage of the experiment, with inhibition becoming more obvious over time. On the contrary, CH and NO emission in soil was enhanced by nZVI-P-BC composite. The proportion of Sphingomonas and Gemmatimonas were the most abundant bacterial species, which were related to the metabolism and transformation of nitrogen. The community structure of the fungus was also affected by nZVI-P-BC composite with Fusarium as the main species. PCoA analysis result suggested that bacterial community was more affected by the incubation time while fungal community was more related to the addition of different biochar and modified biochars.
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http://dx.doi.org/10.1016/j.envpol.2021.116483DOI Listing
April 2021

Sorption of brilliant green dye using soybean straw-derived biochar: characterization, kinetics, thermodynamics and toxicity studies.

Environ Geochem Health 2021 Aug 12;43(8):2913-2926. Epub 2021 Jan 12.

Department of Biotechnology, Shivaji University, Vidyanagar, Kolhapur, Maharashtra, 416004, India.

The present study was aimed to investigate brilliant green (BG) dye sorption onto soybean straw biochar (SSB) prepared at 800 °C and further understanding the sorption mechanism. Sorption kinetic models such as pseudo-first and pseudo-second order were executed for demonstrating sorption mechanism between the dye and biochar. Results of kinetics study were fitted well to pseudo-second-order kinetic model (R 0.997) indicating that the reaction followed chemisorption mechanism. Furthermore, the effect of various parameters like sorbent dose, dye concentration, incubation time, pH and temperature on dye sorption was also studied. The maximum dye removal percentage and sorption capacity for SSB (800 °C) within 60 min were found to be 99.73% and 73.50 mg g, respectively, at pH 8 and 60 °C temperature, whereas adsorption isotherm studies showed a higher correlation coefficient values for Freundlich model (R 0.990-0.996) followed by Langmuir model suggesting that sorption process was multilayer. The characterization of biomass and biochar was performed with the aid of analytical techniques like scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) theory, X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). FTIR analysis showed active groups on biochar surface. BET study revealed higher surface area of biochar (194.7 m/g) than the biomass (12.84 m/g). Besides, phyto- and cytogenotoxic studies revealed significant decrease in the toxicity of dye containing water after treating with SSB. Therefore, this study has proved the sorption potential of soybean straw biochar for BG dye and could be further considered as sustainable cost-effective strategy for treating the textile dye-contaminated wastewater.
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http://dx.doi.org/10.1007/s10653-020-00804-yDOI Listing
August 2021

Toxic mechanism of pyrene to catalase and protective effects of vitamin C: Studies at the molecular and cell levels.

Int J Biol Macromol 2021 Feb 5;171:225-233. Epub 2021 Jan 5.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China. Electronic address:

Polycyclic aromatic hydrocarbons, distributing extensively in the soil, would potentially threaten the soil organisms (Eisenia fetida) by triggering oxidative stress. As a ubiquitous antioxidant enzyme, catalase can protect organisms from oxidative damage. To reveal the potential impact of polycyclic aromatic hydrocarbon pyrene (Pyr) on catalase (CAT) and the possible protective effect of Ascorbic acid (vitamin C), multi-spectral and molecular docking techniques were used to investigate the influence of structure and function of catalase by pyrene. Fluorescence and circular dichroism analysis showed that pyrene would induce the microenvironmental changes of CAT amino acid residues and increase the α-helix in the secondary structure. Molecular simulation results indicated that the main binding force of pyrene around the active center of CAT is hydrogen bonding force. Furthermore, pyrene inhibited catalase activity to 69.9% compared with the blank group, but the degree of inhibition was significantly weakened after vitamin C added into the research group. Cell level experiments showed that pyrene can increase the level of ROS in the body cavity cell of earthworms, and put the cells under the threat of potential oxidative damage. Antioxidants-vitamin C has a protective effect on catalase and maintains the stability of intracellular ROS levels to a certain extent.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.12.169DOI Listing
February 2021

Efficient degradation of p-nitrophenol by [email protected] peel-derived biochar composites and its mechanism of simultaneous reduction and oxidation process.

Chemosphere 2021 Mar 8;267:129213. Epub 2020 Dec 8.

Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin, 300350, China; MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China. Electronic address:

In this study, waste pomelo peels (PP) mixed with iron salts was treated successively with hydrothermal and pyrolyzing carbonization processes to obtain Fe(0) containing biochar composites ([email protected]) and the catalytic degradation of p-nitrophenol (PNP) using these [email protected] composites was studied. The results showed that the hydrothermal pre-treatment of the mixture of iron salts and pomelo peels was favorable for the incorporation of iron precursor within biomass network, which enabled copolymerization during the following pyrolysis. Through the pyrolysis process, the iron precursor was reduced in situ to amorphous Fe(0) dopped into the carbonaceous matrix, which conversely decreased the defect and disorder degree of pseudo-graphitic carbons and catalyzed the formation of environmental persistent free radicals (EPFRs). Degradation tests showed that the composites obtained at 600 °C with the theoretical Fe mass loading of 10% exhibited the greatest PNP degradation efficiency. Over 90% of 10 mg/L PNP was removed in 2 min under both N and air conditions with 1.0 g/L of catalyst level. The degradation kinetics of PNP were all well fitted by the pseudo-first-order kinetics model with k of [email protected] being 0.953 min. HPLC-QTOF/MS analysis demonstrated that both oxidation and reduction of PNP occurred as indicated by the detection of 4-aminophenol and ring opening compounds. The Fe(0) on the [email protected] was responsible for the reduction of PNP, while oxidation was induced by EPFRs. This study highlights the feasibility of synthesizing active heterogeneous Fe(0)-biochar composites by hydrothermal-pyrolysis route and the associated mechanisms of pollutant degradation.
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http://dx.doi.org/10.1016/j.chemosphere.2020.129213DOI Listing
March 2021

Efficient removal of volatile organic compound by ball-milled biochars from different preparing conditions.

J Hazard Mater 2021 03 26;406:124676. Epub 2020 Nov 26.

Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address:

Adsorption is an important technology to deal with volatile organic compounds (VOCs), and biochar has attracted much attention as a new type of adsorbent for VOCs. In this study, rice husk, corn stover and pine wood sawdust biochars from different pyrolysis temperatures (300 °C, 500 °C and 700 °C) were synthesized and treated by ball milling. The pristine and ball-milled biochars were used as adsorbents for acetone and toluene removal. Results showed that wood biochar had higher adsorption capacity for VOCs. After ball milling, the BET specific surface area and the oxygen functional group content of biochars increased. With these changes, all the ball-milled biochars showed higher adsorption rate than the pristine biochars. The ball-milled biochars under pyrolysis temperature of 300 °C showed the best adsorption performance for acetone (304 mg g), which was 1.7-fold greater than that of pristine biochar. Increasing the surface area by ball milling is conducive to the diffusion of hydrophobic VOCs molecules such as toluene to the adsorption sites in the biochar. However, for hydrophilic VOCs such as acetone, higher oxygen functional groups were the main reason for the enhanced adsorption by ball milling. Therefore, ball-milled biochar can be used as a potential adsorbent material in VOCs treatment.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124676DOI Listing
March 2021

High pyrolysis temperature biochar reduced the transport of petroleum degradation bacteria Corynebacterium variabile HRJ4 in porous media.

J Environ Sci (China) 2021 Feb 6;100:228-239. Epub 2020 Aug 6.

College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. E-mail: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin 300350, China; Tianjin Engineering Research Center of Environmental Diagnosis and Contamination Remediation, Tianjin 300350, China. Electronic address:

Biochar has been widely applied for the remediation of petroleum-contaminated soil. However, the effect of biochar on the transport of petroleum degradation bacteria has not been studied. A typical Gram-positive petroleum degradation bacteria-Corynebacterium variabile HRJ4 was used to study the effect of different biochars on bacterial transport and retention. Results indicated that the addition of biochar in sand was effective for reducing the transport of bacteria and poplar sawdust biochar (PSBC) had a stronger hinder effect than corn straw biochar (CSBC). The hindrance was more evident with pyrolysis temperature of biochar raised from 300°C to 600°C, which was attributed to the increase of specific surface area (309 times). The hindrance effect also enhanced with higher application rate of biochar. Furthermore, the reduction of HRJ4 transport was more obvious in higher (25 mmol/L) concentration of NaCl solution owing to electrostatic attraction enhancement. The adsorption of biochar to HRJ4 was defined to contribute to the hindrance of HRJ4 transport mainly. Combining the influence of feedstocks and pyrolysis temperature on HRJ4 transport, it suggested that specific surface area had the greatest effect on HRJ4 transport, and pore-filling, electrostatic force also contributed to HRJ4 retained in quartz sand column. At last, phenol transportation experiment indicated that the restriction of biochar on HRJ4 enhanced the phenol removal rate in the column. This study provides a theoretical basis for the interaction of biochar and bacteria, which is vital for the remediation of oil-contaminated soil and groundwater in the field.
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http://dx.doi.org/10.1016/j.jes.2020.07.012DOI Listing
February 2021

The toxicity effects of nano/microplastics on an antibiotic producing strain - Streptomyces coelicolor M145.

Sci Total Environ 2021 Apr 17;764:142804. Epub 2020 Oct 17.

Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Research Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address:

The toxic effects of nano/microplastics on microorganisms are still unclear. In this study, Streptomyces coelicolor (S. coelicolor) M145 was selected to study the toxicity and mechanism of nano/microplastics (20 nm, 100 nm, 1 μm and 1 mm) at concentration of 0.1, 1 and 10 mg/L on microorganisms. Results showed that the cytotoxicity, reactive oxygen species (ROS) level, permeability, and antibiotic production of M145 cells changed significantly after the addition of nano/microplastics, and the trends were size and concentration dependent. After M145 was exposed to 10 mg/L of 20 nm nanoplastics, its fatality rate was 64.8%, which was the highest among the particle size of 20 nm to 1 mm at a concentration of 0.1-10 mg/L. And the ROS level and cell permeability also reached their highest values, which was about 2.7 folds and 2.2 folds of control, respectively. After this treatment, the maximum yields of actinorhodin and undecylprodigiosin were 6.7 and 5.3 mg/L, respectively. Transcriptome analysis indicated that nanoplastics could inhibit the transport capacity, primary metabolism, and oxidative phosphorylation of M145, and that the inhibition extend was negatively related to the particle size. Moreover, the toxicity of microplastics to M145 was significantly less than that of nanoplastics. This study provides a new perspective for understanding the toxicity of nano/microplastics on microorganisms in nature.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142804DOI Listing
April 2021

Study of the effects of ultrafine carbon black on the structure and function of trypsin.

J Mol Recognit 2021 Feb 7;34(2):e2874. Epub 2020 Sep 7.

School of Environmental Science and Engineering, China-America CRC for Environment & Health, Shandong University, Qingdao, PR China.

Due to the rapid development of industrial society, air pollution is becoming a serious problem which has being a huge threat to human health. Ultrafine particles (UFPs), one of the major air pollutants, are often the culprits of human diseases. At present, most of the toxicological studies of UFPs focus on their biological effects on lung cells and tissues, but there are less researches taking aim at the negative effects on functional proteins within the body. Therefore, we experimentally explored the effects of ultrafine carbon black (UFCB) on the structure and function of trypsin. After a short-term exposure to UFCB, the trypsin aromatic amino acid microenvironment, protein backbone and secondary structure were changed significantly, and the enzyme activity showed a trend that rose at first, then dropped. In addition, UFCB interacts with trypsin in the form of a complex. These studies demonstrated the negative effects of UFCB on trypsin, evidencing potential effects on animals and humans.
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http://dx.doi.org/10.1002/jmr.2874DOI Listing
February 2021

Anthracene-induced DNA damage and oxidative stress: a combined study at molecular and cellular levels.

Environ Sci Pollut Res Int 2020 Nov 19;27(33):41458-41474. Epub 2020 Jul 19.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, 266237, Shandong, People's Republic of China.

At present, research progress of anthracene's toxicity lags far behind the pollution caused on its application fields such as petroleum and minerals. In this paper, anthracene-induced oxidative stress effects and genetic toxicity were investigated at both the molecular and cellular levels. The intracellular oxidative stress effect of anthracene on earthworm primary coelomocyte was confirmed by the detection of reactive oxygen species, antioxidant enzymes activity, and malondialdehyde content. Moreover, after anthracene exposure, the decrease in the mitochondrial membrane potential and cell viability also indicated the adverse effects of anthracene on earthworm coelomocyte. The comet assay proved the break in DNA strand, revealing the anthracene-induced DNA damage. On the molecular level, we revealed that anthracene caused the shrinkage of the catalase skeleton and altered the microenvironment of chromophores of catalase by multi-spectral methods. Molecular simulation results indicated that anthracene interacted with His74 by "arene-arene" force and the dominant binding site between anthracene and catalase was close to the active site of catalase. In addition, anthracene was shown to bind to the DNA molecule by groove binding mode. This study proposed a new combined analysis method for the toxicity evaluation of anthracene at the cellular and molecular levels. Graphical abstract This study creatively proposed a new combined analysis for the toxicity evaluation of ANT at the cellular and molecular levels.
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http://dx.doi.org/10.1007/s11356-020-10049-yDOI Listing
November 2020

Synthesis of cellulose carbon aerogel via combined technology of wet ball-milling and TEMPO-mediated oxidation and its supersorption performance to ionic dyes.

Bioresour Technol 2020 Nov 10;315:123815. Epub 2020 Jul 10.

MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address:

In this study, modified cellulose aerogels (CAs) were obtained via wet ball-milling and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and were further applied to prepare cellulose-derived carbon aerogels (CCAs) by pyrolyzing. The results showed that the successive treatments by ball-milling and oxidation completely opened the CA fibers and converted them into plane or wrinkle structures. CCAs contained porous and graphite-like structures and its specific surface area reached up to 2825 m/g. The maximum adsorption capacities of CCAs were 1078 mg/g for methylene blue (MB) and 644 mg/g for alizarin reds (ARS). The sorption of dyes occurred via hydrophobic partition, pore-filling, H-bonding, p/π-π electron donor-acceptor interactions. For the cationic MB, electrostatic attraction reinforced the sorption, while the electrostatic repulsion between the anionic ARS and CCAs was weakened by high salty. Besides, CCAs showed excellent salt tolerance. The present study provides an excellent CCA adsorbent by successive modification of ball-milling and oxidation of CAs.
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http://dx.doi.org/10.1016/j.biortech.2020.123815DOI Listing
November 2020

Toxicity assessment of Fluoranthene, Benz(a)anthracene and its mixed pollution in soil: Studies at the molecular and animal levels.

Ecotoxicol Environ Saf 2020 Oct 28;202:110864. Epub 2020 Jun 28.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China. Electronic address:

An increasing amount of Fluoranthene (Fla) and Benz(a)anthracene (BaA) is being produced and used, eventually entering the soil sediments. The accumulation of Fla and BaA will cause poisoning to typical enzymes (α-Amylase) and organisms (Eisenia fetida) in soil. However, the studies about exploring and comparing the different effects of Fla, BaA and their joint effect at different levels are rarely reported. In this paper, the different effects of Fla, BaA and their mixed pollutant on α-Amylase were evaluated and compared at the molecular level, and the effect of Fla-BaA to the antioxidant system of earthworm (Eisenia fetida) was investigated from the aspects of concentration and exposure time at the animal level. The results showed that Fla-BaA had the greatest influence on the skeleton structure and the microenvironment of amino acid residue of α-Amylase compared to Fla and BaA, and in the mixed pollutant system, the joint effect mode was additive mode. The inhibitory effect of Fla-BaA on the activity of α-Amylase was also stronger than that of the system alone. The assays at the animal level showed that low concentrations (below 5 mg/kg) of Fla-BaA increased the activity of GSH-Px and SOD while high concentrations inhibited their activity. The POD that was activated throughout the experiment period suggested its key role in the earthworm antioxidant system. Changes in T-AOC and MDA showed that long-term and high-dose of Fla-BaA exposure inhibited the antioxidant capacity of Eisenia fetida, causing lipid peroxidation and damage to cells.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110864DOI Listing
October 2020

Ball milled [email protected] hybrids coupled with peroxydisulfate for Cr(VI) and phenol removal: Novel surface reduction and activation mechanisms.

Sci Total Environ 2020 Oct 28;739:139748. Epub 2020 May 28.

National Engineering Laboratory for Site Remediation Technology, College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China.

[email protected] hybrids were synthesized by ball milling and applied to couple with peroxydisulfate (PS) for Cr(VI) reduction and phenol oxidation. A synergistic effect between Fe and FeS for contaminants removal was found in experimental results. The removal rates of Cr(VI) and phenol by ball milled [email protected] hybrids coupled with PS were 97% and 88.7% (initial concentrations of Cr(VI) and phenol are 35 and 40 mg/L, respectively), indicating a successful treatment method for industrial wastewater containing metals, metalloids and organic pollutants. Concentrations of Cr(VI) lower than 45 mg/L could promote the degradation of phenol, while high concentration of Cr(VI) inhibited phenol degradation. Acidic conditions were beneficial to Cr(VI) and phenol removal. Scan electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis suggested that surface morphology and element valence of ball milled [email protected] hybrids changed after reaction. Radicals quenching experiment and EPR (electron paramagnetic resonance) results illustrated that SO• and HO• were major free radical species for phenol degradation. Fe(II) quenching experiment revealed that surface-bound Fe(II) instead of dissolved Fe(II) mainly participated in Cr(VI) reduction and PS activation. This study illustrated novel surface reduction of Cr(VI) and surface activation of PS by ball milled [email protected] hybrids, providing useful perspective for applying ball milled [email protected] hybrids for complex wastewater treatment.
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http://dx.doi.org/10.1016/j.scitotenv.2020.139748DOI Listing
October 2020

Ball milling as a mechanochemical technology for fabrication of novel biochar nanomaterials.

Bioresour Technol 2020 Sep 1;312:123613. Epub 2020 Jun 1.

Korea Biochar Research Centre & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea.

Mechanochemical synthesis of nano-biochar by ball-milling technology is gaining attention for the sake of its low-cost and eco-friendly nature. Ball milling as a non-/less-solvent technology can propel environmental sustainability and waste valorization into engineered biochar for advanced applications. Scalable production of biochar nanomaterials with superior properties (e.g., 400-500 m g surface area and 0.5-1000 nm pore sizes) enables diverse applications in the field of energy and environment. This review critically evaluates the synthesis, characterization, and application of ball-milled biochar nanomaterials based on the latest findings. Limitations such as feedstock selection, process optimization, product homogeneity and reusability, environmental risks, and sustainability assessment remain challenging for further studies. This work highlights the recent advances on mechanochemical biochar technology and offer insights into opportunities and future prospects related to sustainable and facile synthesis of biochar-based novel materials for achieving sustainable development goals.
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http://dx.doi.org/10.1016/j.biortech.2020.123613DOI Listing
September 2020

A novel stabilized carbon-coated nZVI as heterogeneous persulfate catalyst for enhanced degradation of 4-chlorophenol.

Environ Int 2020 05 13;138:105639. Epub 2020 Mar 13.

Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, United States.

Nano zero-valent iron (nZVI) and its composite materials have been extensively studied in the field of environmental remediation. However, the oxidation and agglomeration of nZVI limits the large-scale application of nZVI in environmental remediation. This study developed a two-step method to prepare stable carbon-coated nZVI ([email protected]) which combined hydrothermal carbonization and carbothermal reduction methods and used glucose and iron oxide (FeO) as precursors. When the carbothermal reduction temperature was 700 °C and the elemental molar ratio of carbon to iron was 22:1, stable [email protected] can be generated. The nZVI particles are encapsulated by mesoporous carbon and embedded in the carbon spheres. The unique structure of carbon coating not only inhibits the agglomeration of nZVI, but also makes nZVI stable in air for more than 120 days. Not only that, the as-synthesized [email protected] exhibited high catalytic activity toward the degradation of 4-chlorophenol (4-CP) by activating persulfate. Different from conventional nZVI catalysts in generation of sulfate radicals, [email protected] selectively induced hydroxyl radicals for 4-CP degradation. Moreover, [email protected] has been shown to efficiently degrade 4-CP by using the dissolved oxygen in water to form hydroxyl radicals. This study not only provides a simple, green method for the preparation of stabilized nZVI, but also provides the possibility of large-scale application of nZVI in the field of environmental remediation.
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http://dx.doi.org/10.1016/j.envint.2020.105639DOI Listing
May 2020

Thermal oxidation activation of hydrochar for tetracycline adsorption: the role of oxygen concentration and temperature.

Bioresour Technol 2020 Mar 3;306:123096. Epub 2020 Mar 3.

School of Petroleum Engineering and Environmental Engineering, Yan'an University, Yan'an 716000, Shaanxi, China.

Poplar hydrochar (RHC) was activated by thermal oxidation (TA-O) in air at 300 °C (O300) and in air + N (0.5% O) at 500 and 700 °C (O500 and O700), respectively, and in N at 300-700 °C (N300-N700) as control. Samples characterized by various methods were used to analyze their effect on tetracycline adsorption. The results showed that TA-O greatly increased adsorption capacity q (mg·g, C = 100 mg·L) from 6.29 for RHC to 33.32, 96.23 and 60.90 for O300, O500 and O700, respectively. The O300 increased carboxyl and aromaticity whereas little influenced on porosity. The O500, with the highest S and S, enhanced adsorption probably by micropore filling and π-π interactions. The O700 fused micropore into mesopore but decreased the S, S and q. Thus, thermal oxidation at 500 °C and 0.5% O is recommended for hydrochar activation to absorb tetracycline.
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http://dx.doi.org/10.1016/j.biortech.2020.123096DOI Listing
March 2020

Synergistic toxic effects of ball-milled biochar and copper oxide nanoparticles on Streptomyces coelicolor M145.

Sci Total Environ 2020 Jun 25;720:137582. Epub 2020 Feb 25.

School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao, Shandong 266237, China.

The toxic effects of multi-nanomaterial systems are receiving increasing attention owing to their inevitable release of various nanomaterials. Knowledge of the bioavailability of the new carbon material ball-milled biochar (BMB) and its synergistic toxicity with metal oxide nanoparticles in bacteria is currently limited. In this study, the interactions of BMB with copper oxide nanoparticles (CuO NPs) and their synergistic toxicity towards Streptomyces coelicolor M145 were analyzed. Results showed that the cytotoxicity, ROS level and permeability of cells changed greatly with the pyrolysis temperatures of biochar and the concentrations of CuO NPs. The greatest cytotoxicity (up to 63.1%) was achieved by adding 20 mg/L CuO NPs to BMB700. The ROS level and cell permeability of this treatment was also the highest, about 4.2 folds and 2.9 folds greater than that of control, respectively. The combination of 10 mg/L BMB700 with 10 mg/L CuO NPs can maximize production of antibiotics, with the yield of undecylprodigiosin (RED) and actinorhodin (ACT) 3.0 times and 4.2 times higher than that in the control, respectively, and the change trend of related genes was consistent with that of antibiotics production. Mechanism analysis showed that the different adsorption capacity of BMB of different pyrolysis temperatures on copper ions played a vital role in the synergistic toxicity, and the increase in cell membrane permeability caused by cell collisions with particles was also an important reason for cytotoxicity. Overall, the synergistic toxicity of BMB with other NPs varies the pyrolysis temperatures, when considering the synergistic toxicity of these materials, the preparation conditions need to be taken into account so as to assess their environmental risks more accurately. On the other hand, this research may provide a new approach for the antibiotic industry to increase its output.
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http://dx.doi.org/10.1016/j.scitotenv.2020.137582DOI Listing
June 2020

Biochar/iron (BC/Fe) composites for soil and groundwater remediation: Synthesis, applications, and mechanisms.

Chemosphere 2020 May 18;246:125609. Epub 2019 Dec 18.

Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China. Electronic address:

Biochar/iron (BC/Fe) composites, such as nano zero-valent iron (nZVI)/BC, iron sulfide/BC, and iron oxide/BC, have been developed and applied to deal with various contaminants owing to their excellent physicochemical properties. This work summarizes the progress in the preparation of BC/Fe composites, the properties and applications of BC/Fe, and the mechanism of the synergistic effect between Fe and BC in the composites. Various methods, including pyrolysis, hydrothermal carbonization, fractional precipitation, and ball milling, have been used to synthesize BC/Fe composites. In addition, the introduction of stabilizers, such as carboxymethyl cellulose (CMC), in the fractional precipitation process further prevents the agglomeration of Fe particles, which enhances the stability and fluidity of the resultant composites to facilitate the application of the composites in soil and water remediation. The application of BC/Fe composites in water and soil remediation is discussed in three aspects based on the interaction mechanisms, namely adsorption, reduction, and oxidation. Overall, the composites showed the synergistic effect of BC and Fe owing to the combination of the specific properties of Fe, such as reduction, catalysis, and magnetism, which can enhance the properties of BC with a larger surface area, abundant functional groups, and increased electron transfer efficiency. This review systemically summarizes the recent developments in BC/Fe composites to maximize the efficiency of BC/Fe application in soil and groundwater remediation. Key challenges and further research needs are also suggested.
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http://dx.doi.org/10.1016/j.chemosphere.2019.125609DOI Listing
May 2020

Aqueous Cr(VI) removal by a novel ball milled Fe-biochar composite: Role of biochar electron transfer capacity under high pyrolysis temperature.

Chemosphere 2020 Feb 4;241:125044. Epub 2019 Oct 4.

College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin, 300350, China; Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, China; Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin, 300350, China.

A novel ball milled Fe-biochar composite was synthesized by ball milling the mixture of biochar (pyrolyzed at 300 °C, 500 °C, and 700 °C) and micron grade iron powder. FTIR, SEM, TEM-EDS, XRD, and XPS were applied to characterize this composite. XRD results showed that iron carbide phase was formed during the ball milling process. The ability of this synthesized composited to remove aqueous Cr(VI) was tested. Removal rates of Cr(VI) (49.6%, 65.8%, and 97.8%, respectively) by ball milled Fe-biochar composite consisting of biochar pyrolyzed at 300 °C (300BMFe-BC), 500 °C (500BMFe-BC), and 700 °C (700BMFe-BC) were much higher than those (19%, 11%, and 4%, respectively) by pristine biochar pyrolyzed at 300 °C (300BC), 500 °C (500BC), and 700 °C (700BC). Cr(VI) removal rate by 700BMFe-BC increased from 15.4% to 97.8% when prolonging ball milling time from 6 h to 48 h. Ball milling promoted the combination of Fe and biochar as well as reduced the hydrodynamic diameter of the composite. Acidic conditions favored Cr(VI) removal. Ball milling exposed the functional groups of biochar and improved its Cr(VI) removal rate. Raman spectra showed that the degree of graphitization in 700 °C ball milled biochar (700BMBC) was the highest. Electrochemical analysis demonstrated that 700BMBC had the highest electron transfer capacity. In the presence of Fe, graphitized structure in 700BMBC acted as an electron conductor, facilitating electron transfer from Fe to Cr(VI). Ball milling also destroyed the surface iron oxide layer to regenerate the composite.
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http://dx.doi.org/10.1016/j.chemosphere.2019.125044DOI Listing
February 2020
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