JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Xiaofei Wu,Jun Nan,Jimin Shen,Jing Kang,Dapeng Li,Pengwei Yan,Weiqiang Wang,Binyuan Wang,Shengxin Zhao,Zhonglin Chen
The regrowth of chlorine-resistant bacteria in drinking water can deteriorate water quality. The study evaluated the relationship between organic carbon and the regrowth potential of chlorine-resistant bacteria remaining in chloraminated water samples. The results showed that the community structure of bacteria changed with the increase of chloramine dosage. The order in which organic carbon utilized by bacteria was affected by the composition of bacterial community. The biodegradable dissolved organic carbon (BDOC), assimilable organic carbon (AOC), bacterial regrowth potential (BRP) and total cell concentration (TCC) in cultivated water sample after disinfection with 1.8 mg/L chloramine increased form 0.22 mg/L, 33.68 µg/L, 2.70 × 10 5 cells/mL and 3.48 × 10 4 cells/mL before cultivation to 1.20 mg/L, 193.90 µg/L, 4.74 × 10 5 cells/mL and 1.46 × 10 5 cells/mL, respectively. The increase of TCC did not result in the decrease of BDOC, AOC and BRP in the cultivated water samples. The results showed that other biodegradable organic carbon in chloraminated water samples assimilated by residual chlorine-resistant bacteria besides AOC, BDOC, and organic carbon assimilated by indigenous bacteria. AOC, BDOC, and BRP indicators used to characterize the biostability of drinking water were not enough to accurately assess the regrowth potential of chlorine-resistant bacteria remaining in drinking water. It is suggested to supplement the index of TCC in cultivated water samples, which might be able to more accurately evaluate the regrowth potential of chlorine-resistant bacteria remaining in drinking water.
研究领域:
环境科学
·
微生物学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL GEOLOGY
·
2025
·
IF 3.6
FengTing Wu,ChunYan Luo,YueHan Lu,XueYan Li,KuanYi Li,YingXun Du
The co-precipitation of dissolved organic matter (DOM) and phosphate with Fe(III) at the sediment-water interface plays a crucial role in the biogeochemical cycling of organic carbon (OC) and phosphate (P) in aquatic ecosystems. The fluxes of organic matter and phosphate may occur in a sequential manner. This study investigated how phosphate affected pre-equilibrated Fe(III)-humic acid (HA) co-precipitates and how HA influenced pre-equilibrated Fe(III)-phosphate co-precipitates under varying pH and Fe(III) concentrations. The results revealed that the addition of phosphate to the Fe-HA co-precipitation system generally promoted further precipitation of dissolved Fe(III) with phosphate, resulting in about 9.48–33.15 % of the phosphate being precipitated. This addition had minimal impact on the percentage of pre-immobilized HA but facilitated the release of high-aromaticity HA from the Fe-HA co-precipitate. Conversely, adding HA to the Fe P co-precipitation system increased the concentrations of soluble Fe(III) and phosphate, likely due to the strong complexation ability of HA with Fe(III). The percentage of HA remaining dissolved was lower at lower pH levels and higher initial Fe(III) concentrations. These findings highlight how the timing of phosphate or DOM inputs influences their sequestration. This has important implications for carbon and nutrient storage in aquatic sediments, where fluxes of organic carbon and phosphate may occur in a sequential manner.
研究领域:
环境科学
·
生物地球化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Yang-xiao-xiao Shi,Jia-qi Cui,Feng Zhang,Ke-wei Li,Jun Jiang,Ren-kou Xu
Hexavalent chromium (Cr(VI)) is a toxic heavy metal and its mobility and bioaccessibility in soils are influenced by soil properties. In this study, the soil pH and organic carbon contents of Ultisol , Alfisol , and Inceptisol were adjusted before they were polluted with 230 mg kg −1 Cr(VI). Alkaline digestion, sequential extraction, and an in vitro experiment were conducted to study the valence state, species, and bioaccessibility of Cr in the soils. The results showed that a high soil pH was not favorable for reduction of Cr(VI); therefore the Cr(VI) and exchangeable Cr contents were positively related to soil pH. Soil organic carbon promoted the reduction of Cr(VI). Almost all Cr(VI) was reduced to Cr(III) when the soil organic carbon content reached 10 g kg −1 . Chromium bioaccessibility in simulated gastric and intestinal phase solutions was influenced by Cr(VI) and Cr(III) adsorption/desorption, dissolution/precipitation, and redox reactions. Chromium bioaccessibility differences between the gastric and intestinal phases were associated with the Cr(VI)/Cr(III) ratio. Acidic conditions and a high organic carbon content promoted the conversion of Cr(VI) to Cr(III). When soil pH was increased from 4.01 to 5.85, Cr(VI) in Alfisol without the addition of humic acid increased from 96.38 to 174.78 mg kg −1 , the exchangeable Cr proportion increased from 9.7% to 22.6%, and Cr bioaccessibility increased from 41.29% to 49.14% in the gastric phase and from 41.32% to 48.24% in the intestinal phase. When the organic carbon content increased from 3.95 to 9.28 g kg −1 in Alfisol, Cr(VI) content decreased from 167.66 to 20.52 mg kg −1 , which led to a decrease in Cr bioaccessibility from 49.15% to 13.8% in the gastric phase and from 45.85% to 7.67% in the intestinal phase. Therefore, acidic conditions and increasing soil organic carbon levels can reduce the health risk posed by Cr in soils.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Yulei Liu,Lu Wang,Zhuangsong Huang,Xianshi Wang,Xiaodan Zhao,Yuanyuan Ren,Shaofang Sun,Mang Xue,Jingyao Qi,Jun Ma
Indole is a typical fecal odor compound and has negative impact on water quality at low concentrations. Here, the oxidation of indole by ferrate [Fe(VI)] was investigated, in terms of the reaction kinetics, the oxidation products, and the variation of assimilable organic carbon (AOC). The oxidation of indole was pH-dependent (6.0–9.5), and the pH-dependent profile could be well explained by the acid-base equilibrium of Fe(VI). The apparent second-order rate constants (k app ) for indole oxidation with Fe(VI) ranged from 692 ± 26 M −1 s −1 at pH 6.0 to 3.08 ± 0.15 M −1 s −1 at pH 9.5. The results of experiments conducted under real source water background showed that indole could be effectively removed by Fe(VI) from actual polluted waters. After analyzing the reaction pathway, it was found that the initial steps in the oxidation of indole were the hydroxylation of indole to 2,3-dihydroxyindole, followed by the cleavage of N-heterocyclic ring. Formanilide was a major oxidation product in this process, and it is less reactive with Fe(VI) than that of indole. High concentrations of Fe(VI) could effectively oxidize indole in the water and has little impact on the microbiological stability of the treated water. Based on the results, Fe(VI) can be an effective agent for the control of indole in water treatment.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Zezhou Zhao,Wei Lou,Delai Zhong,Yao Shi,Fengjiao Zhang,Linling Wang,Xiaohui Wu,Anxu Sheng,Jing Chen
Engineering black carbon (e.g. biochar) has been widely found in natural environments due to natural processes and extensive applications in engineering systems, and could influence the geochemical processes of coexisting arsenic (As V ) and Fe II , especially when they are exposed to oxic conditions. Here, we studied time-varying kinetics and efficiencies of As V immobilization by solid-phase Fe II (Fe II solid ) and Fe III (Fe III solid ) in Fe II -As V -biochar systems under both anoxic and oxic conditions at pH 7.0, with focuses on the effects of biochar surface and biochar-derived dissolved organic carbon (DOC). Under anoxic conditions, Fe II could rapidly immobilize As V via co-adsorption onto biochar surfaces, which also serves as the dominant pathway of As V immobilization at the initial stage of reaction (0–5 min) under oxic conditions at high biochar concentrations. Subsequently, with increasing biochar concentrations, Fe III solid precipitation from aqueous Fe II (Fe II aq ) oxidation (5–60 min) starts to play an important role in As V immobilization but in decreased efficiencies of As V immobilization per unit iron. In the following stage (60–300 min), Fe II solid oxidation is suppressed and leads to As V release into solutions at >1.0 g·L −1 biochar. The decreasing efficiency of As V immobilization over time is attributed to the gradual release of DOC into solution from biochar particles, which significantly inhibit As V immobilization when Fe III solid is generated from Fe II solid oxidation in the vicinity of biochar surfaces. Specifically, 4.06 mg·L of biochar-derived DOC can completely inhibit the immobilization of As V in the 100 μM Fe II system under oxic conditions. The findings are crucial to comprehensively understand and predict the behavior of Fe II and As V with coexisting engineering black carbon in natural environments.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Haowen Zhang,Mengjie Pu,Ming Zheng,Bentuo Xu,Jason T. Magnuson,Qiqing Chen,Xiangrong Xu,Xiangyong Zheng,Min Zhao,Wenhui Qiu
Microplastics (MPs) are gaining attention for their widespread presence and toxicity in ecosystems. However, their role as a carbon source in urban wetland carbon sinks is still unclear. In this study, the microplastic-carbon (MP-C) was firstly quantified based on the abundance and occurrence characteristics, including MP morphology, size and type in the Sanyang Wetland, a typical urban wetland of China. MP abundances ranged from 2.4 ± 0.6–14.9 ± 1.5 items/L in surface water and 6.6 ± 1.2 × 10 3 to 46.3 ± 5.9 × 10 3 items/kg in sediment. The predominant morphological characterization of MPs was fragments smaller than 200 μm in size, consisting of PP, PE, and PET, which suggests that the main source was domestic wastewater discharge nearby. Notably, in the Sanyang wetland, the contribution of MP-C to total organic carbon (TOC) was estimated to be 0.023 0.20 % in water and 0.026 0.28 % in sediment. With the continuous production of plastics globally, these values were predicted to increase to 0.12 0.71 % and 0.83 4.12 % by 2100, respectively. Although the estimations relied on simplified geometric assumptions for MP volume and theoretical carbon content, these approaches provide a reasonable basis for understanding MP-C dynamics in wetlands under current analytical constraints. The integration of MP-C characterization during environmental monitoring and management strategies would enhance our understanding of MP pollution's role in the carbon cycle.
研究领域:
环境科学
·
生态学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 33
·12799-12806
·
IF 8.262
Xintong Zhang,Wei Wang,Wenxin Shi,Jiaojie He,Hui Feng,Yongpeng Xu,Fuyi Cui,Ce Wang
Microbial growth in water poses a growing threat to humans. Nutrient starvation is an effective and green manner to control microbial growth in water. The general coexisting phosphate and organic carbon in water can both serve as nutrients for microbial metabolism, and thus one can take a heavy toll on the performance of a nutrient-starvation antibacterial approach based on the other. Herein, carbon nanofibers with embedded LaCO3OH nanoparticles (LCNFs) were rationally synthesized by carbonizing electrospun polyacrylonitrile nanofibers containing La-species. The LCNFs served as a capture agent for both phosphate and organic matter to realize more effective nutrient-starvation antibacterial activity for water security. The LCNFs rendered high phosphate removal efficiency through the strong chemical bond between LaCO3OH and phosphate, even for trace phosphate concentrations. At the same time, organic nutrients could be synchronously cut down by LCNFs, which resulted in more stringent nutrient-deficient conditions to control microbial growth in water effectively.
研究领域:
环境科学
·
材料科学
·
生物学
✓ 已验证
DOI
高影响因子
APPLIED SOIL ECOLOGY
·
2024
·
IF 4.8
Jiahui Liao,Yuanyuan Li,Juanping Ni,Tingting Ren,Ke Shi,Xiaoming Zou,Han Y.H. Chen,Manuel Delgado-Baquerizo,Honghua Ruan
Soil microbial extracellular polymeric substances (EPS) are important components of soil organic carbon (SOC), which are thought to promote the formation of soil structures and induce the stabilization of SOC. Earthworms may not only stimulate the production of EPS through the promotion of microbial activity and microbial biomass, but might also accelerate the decomposition of EPS via ingestion, resulting in SOC sequestration or loss. However, the exact impacts of earthworms on EPS in soils have never been evaluated. Here, a pioneering experiment involving two species of endogeic earthworms ( Drawida gisti and Metaphire guillelmi ) with different body sizes was conducted to investigate their impacts on soil EPS. It was found that the D. gisti and M. guillelmi earthworms reduced the soil EPS-protein concentrations by 12.6 % and 17.6 %, respectively; however, they did not affect the EPS-polysaccharide concentration. Moreover, the presence of these endogeic earthworms increased soil microbial biomass, and elevated microbial respiration, microbial metabolic quotient, dissolved organic carbon, and soil pH. The results of this study provide the first evidence for the decoupling effects of earthworms on extracellular residual components. This suggests that earthworms may alter the molecular composition of SOM, thereby influencing its persistence and soil-atmosphere carbon exchange.
研究领域:
生态学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING
·
2011
·
IF 1.107
Zhiqiao He,Angliang Zhang,Yu Li,Shuang Song,Zhiwu Liu,Jianmeng Chen,Xinhua Xu
Ozonation combined with UV irradiation (UV/O3) is an advanced oxidation technique that is very promising for the destruction of organic compounds in aqueous solution. In this study, chlorophene was chosen as a model substrate to investigate the effects of pH, initial substrate concentration, ozone dose, and UV light intensity in degradation experiments. The pseudo–first-order rate constant for total organic carbon (TOC) removal was 2.4 × 10−2, 9.8 × 10−4, and 6.4 × 10−2 min−1 for O3, UV, and UV/O3 treatment, respectively. Clearly, UV-enhanced ozonation leads to a synergetic increase in the overall degradation efficiency. Comparative experiments were performed to investigate the effect of the matrix (distilled water or sewage) on chlorophene removal. The organic compounds in sewage retarded the rate of chlorophene removal by 38%, probably by competitively reacting with the oxidizing agent and screening light. The compound 2-benzoylbenzo-1,4-quinone, benzo-1,4-quinone, hydroquinone and maleic acid were identified as primary intermediates by gas chromatography-mass spectrometry. The concentrations of acetic, formic and oxalic anions were detected by ion chromatography. A possible degradation pathway is proposed on the basis of the reaction products identified.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xi Li,Ting Luo,Yaxuan Wang,Bing Wang,Hong Liang,Jiabin Zhou,Lingli Li
Gas-phase ozone (O 3 ) can easily diffuse into soil aggregates and effectively degrade hydrocarbon compounds. However, gas channels in soil impede remediation efficiency. This study developed an enhanced ozonation by applying mechanical agitation (100 and 150 rpm) compared with conventional ozonation (0 rpm), to improve degradation of benzo[a]pyrene (BaP) and soil biodegradability. During ozonation process, O 3 consumption, BaP removal, soil carbon balance, and intermediates of BaP were investigated. Results showed that the enhanced ozonation disturbed gas channels and improved utilization of O 3 . At 90 min, more than 90% of the initial BaP (67.86 mg/kg) was degraded at 100 rpm, while it was 83.61% at conventional ozonation. Enhanced ozonation rapidly oxidized soil organic carbon (SOC), Acetone-n-hexane-extractable organic carbon (AeOC), residual organic carbon (ROC) and BaP into dissolved organic carbon (DOC), which increase of DOC was 31.97% higher than conventional ozonation. Enhanced ozonation accelerated decomposition of BaP to more biodegradable and lower molecular weight intermediates at short time mainly by increasing direct ozonation, which was conducive to the subsequent biodegradation. This work provides an enhanced ozonation to improve the degradation efficiency of BaP in soil by destroying gas channels and enhancing the utilization efficiency of O 3 and direct ozonation.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
BIOLOGY AND FERTILITY OF SOILS
·
2020
·Vol. 56
·期 5
·619-631
·
IF 5.521
Zhou Xiaoyu,Chen Lin,Xu Jianming,Brookes Philip C.
The regulatory gate hypothesis considers that soil organic C mineralization is a two-step process, where stable C is firstly transformed abiotically and is only then a microbially available substrate. The mechanisms involved in the abiotic conversion of non-microbially available to available soil organic C remain largely unknown. We conducted a perfusion experiment using a repeated fumigated-incubated soil and the corresponding fresh soil. We found that repeated fumigation-incubation significantly decreased soil microbial ATP to 0.22 nmol g −1 soil, 10% of that in the fresh soil, and significantly destroyed microbial composition and diversity. However, it had little influence on the soil CO 2 -C evolution rate after the flush of fumigant-killed dead biomass (8 μg CO 2 -C g −1 soil day −1 ) or dissolved organic C (DOC) concentration (about 7 μg C g −1 soil) and composition during long-term perfusion. We conclude that soil CO 2 evolution rate and DOC generation were not regulated by the size or composition of the soil microbial communities. This is in support of the regulatory gate hypothesis. We suggest that abiotic processes in soil organic C mineralization need to be considered more and studied further.
Graphical abstract
研究领域:
土壤学
·
微生物学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Shizong Wang,Yanan Yin,Jianlong Wang
Triclosan is an antimicrobial agent which has been frequently detected in the environment. In this paper, the biodegradation of triclosan after radiation-induced advanced oxidation was investigated. The results show that the removal efficiency of triclosan in the combined irradiation and biological treatment process ranged from 88% to 97%, depending on the absorbed dose, while it was only 54% in the single biological treatment process. The removal efficiency of total organic carbon (TOC) was in the range of 53.1%,−59.2% at dose of 1–5 kGy in the combined irradiation and biological treatment process. In comparison, the removal efficiency of TOC in the single biological treatment process was 24.5%, suggesting that irradiation can enhance the mineralization of triclosan. The dechlorination efficiency of triclosan ranged from 48.6% to 78.4% at dose of 1–5 kGy. The intermediates of triclosan degradation were tentatively identified by LC-MS analysis and the possible degradation pathway was proposed. Based on the above results, the combined irradiation and biological treatment process could be an alternative process for treating triclosan-containing wastewater.
研究领域:
环境科学
·
生物学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）