CARBOHYDRATE POLYMERS
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2015
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IF 4.074
Hangcheng Zhu,Yong Zhang,Xiaogang Yang,Lan Shao,Xiumei Zhang,Juming Yao
The discharge of effluents from surfactant manufacturers is giving rise to increasingly serious environmental problems. In order to develop the eco-friendly flocculation materials to achieve effective removal of pollutants from the surfactant effluents, the bamboo pulp cellulose from Phyllostachys heterocycla is employed as the skeleton material to synthesize an eco-friendly bamboo pulp cellulose-g-polyacrylamide (BPC-g-PAM) for flocculation. The BPC-g-PAM is used with the metal ions as the coagulant to treat the effluent from a surfactant manufacturer. The response surface methodology coupled with Box–behnken design is employed to optimize the key factors of coagulation–flocculation. The results show that the combination of Fe 3+ with BPC-g-PAM achieves the best coagulation–flocculation performance like, the fast treatment time, minimum coagulant and BPC-g-PAM dosages compared with the other two combinations of Al 3+ with BPC-g-PAM and Ca 2+ with BPC-g-PAM. Therefore, the combination of Fe 3+ with BPC-g-PAM is expected to promote its application for the pollution control in the surfactant manufacturers.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
Journal of Cleaner Production
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2025
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IF 10
Yufeng Liao,Leyi Wang,Yechao Tian,Jun Li,Qing Zhou,Aimin Li,Ming Hua,Yang Pan
Ozonation is a commonly used method to enhance coagulation during reclaimed water treatment, which can significantly reduce the formation of disinfection byproducts (DBPs) due to the removal of dissolved organic matter. However, effects of different combination sequences and operation conditions of ozonation-enhanced coagulation on effluent organic matter (EfOM), especially dissolved organic nitrogen (DON), as well as the subsequent DBP formation and toxicity are not well investigated. In this study, the coagulation effects of polyaluminum chloride (PAC) and polyferric sulfate (PFS), as well as the optimal coagulation conditions were determined. The effects of the ozone dose and combination sequence of ozonation-enhanced coagulation on EfOM properties, DBPs, and acute toxicity were investigated. The results showed that the optimal coagulation conditions were achieved by PFS at a dose of 80 mg/L, and removal efficiencies of dissolved organic carbon (DOC), DON, and acute toxicity were 36%, 40%, and 21%, respectively. For ozonation-enhanced coagulation, the optimal removal efficiencies were achieved at a 1 mg/L ozone dose. Among the three combination sequences, the hybrid ozonation-coagulation process had the highest removal efficiencies for DON (43.8%), carbonaceous DBPs (34.5%), nitrogenous DBPs (33.8%), and total organic halogen (38.0%), respectively. For DOC and acute toxicity, the highest removal efficiencies were achieved by the post-ozonation process (20.9%) and pre-ozonation process (16.4%), respectively. The formation of •OH and the increasing Fe c content led to the enhancement of the hybrid ozonation-coagulation process, and the decreasing Fe b content led to the negative impact on the removal of DOC by the hybrid ozonation-coagulation process.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
AQUA-Water Infrastructure Ecosystems and Society
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2024
·Vol. 73
·期 5
·930-944
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IF 2.1
Ye Miaomiao,Song Lei,Chen Peng,Li Kexin,Zheng Kai,Zhang Tuqiao,Liu Xiaowei
View large Download slide View large Download slide Close modal The S(IV)–Fe(II)/PM pretreatment has demonstrated preliminary potential as an effective ultrafiltration (UF) pretreatment technology. However, a comprehensive understanding of its impact on UF membrane fouling control and the dynamic evolution of membrane fouling during prolonged operation is still lacking. In this study, a relatively prolonged fouling experiment was conducted. Results revealed that the S(IV)–Fe(II)/PM pretreatment exhibited superior performance over Al(III) coagulation pretreatment in mitigating the transmembrane pressure difference and addressing both reversible and irreversible membrane fouling. The application of a cluster analysis method to classify membrane fouling evolution stages further confirmed that S(IV)–Fe(II)/PM pretreatment effectively decelerated the rate of membrane fouling evolution. The surface cake layer of UF membranes pretreated with S(IV)–Fe(II)/PM exhibited greater looseness and smoothness. It also showed better results than Al(III) coagulation pretreatment in reducing the accumulation of organic foulants, controlling the Si content and reducing the total microorganisms and live microorganisms in the UF feed water. Variance Partitioning Analysis indicated that the combined contribution of organic, inorganic, and biological foulants was the most significant for UF membranes after S(IV)–Fe(II)/PM pretreatment (50.4%) and UF membranes after Al(III) coagulation pretreatment (70.2%). These findings underscore the efficacy of S(IV)–Fe(II)/PM pretreatment in controlling UF membrane fouling under prolonged operation. S(IV)/Fe(II)/PM pretreatment efficiently mitigated UF membrane fouling during long-term operation. S(IV)/Fe(II)/PM pretreatment yielded a long uncontaminated stage and accelerated contaminated stage. S(IV)/Fe(II)/PM pretreatment suppressed the contribution of organic–inorganic–biological composite fouling.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2025
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IF 9
Xiwen Jia,Dong Liu,Jiajie Xu,Hui Zhang,Luoyang Liu,Lujia Han,Weihua Xiao,Suan Shi
In this study, caproate was synthesized from corn stover through sequential fermentation, and biochar was prepared from unhydrolyzable corn stover by pyrolysis to utilize full-component of corn stover. The results indicate that the caproate concentration in the unhydrolyzable corn stover biochar (UCSB) group was 2.2 times higher than that of the control group, and the fermentation start-up time was shortened by 18 days. Mechanistic analysis suggested that the rough surface of UCSB facilitated microbial colonization and reduced product inhibition. Genes expression analysis further demonstrated that UCSB significantly upregulated crucial functional genes responsible for ethanol oxidation and the reverse β -oxidation pathway, ultimately resulting in enhanced caproate production. The successful utilization of UCSB derived from unhydrolyzable solid residue effectively boosted fermentation, leading to a 37 % increase in the carbon utilization efficiency of corn stover. This study offering valuable insights for the high-value and full-component utilization of lignocellulosic biomass.
研究领域:
生物技术
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环境科学
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能源科学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2024
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IF 8.2
Bing Zhang,Xin Mao,Yu Shen,Tengfei Ma,Bing Zhang,Bin Liu,Wenxin Shi
The structural variances of adsorbents play a crucial role in determining the number of effective adsorption sites and pretreatment performance. However, there is still a gap in comprehending the impact of different carbon structural adsorbents on membrane fouling . Therefore, this study aimed to compare the efficacy of granular activated carbon (GAC), powdered activated carbon (PAC), and activated carbon fiber (ACF) in mitigating membrane fouling during municipal sewage reclamation using an aerobic granular sludge membrane bioreactor (AGMBR). The results demonstrated that the utilization of PAC significantly enhanced the normalized flux and reduced fouling resistance in comparison to GAC and ACF systems. PAC effectively adsorbed low and medium-molecular-weight pollutants present in raw sewage, resulting in an increase in average particle size and a decrease in foulant content on the membrane surface. The Hermia model indicated that adsorption pretreatment minimized standard blocking while promoting the formation of a sparse and porous cake layer. Moreover, according to the extended Derjaguin–Landau–Verwey–Overbeek theory, PAC has been demonstrated as the optimal antifouling system owing to its enhanced repulsion between membrane-foulant and foulant-foulant interactions. Correlation analysis revealed that the exceptional antifouling performance of the PAC system was due to its high removal rates of chemical oxygen demand (~78 %) and suspended solids (~97 %). This research offers valuable insights into the mitigation of membrane fouling through the utilization of adsorbents featuring diverse carbon structures .
研究领域:
环境科学
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污水处理
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PubMed
高影响因子
CHEMOSPHERE
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2024
·
IF 8.1
Xu Yin,Jie Zhang,Siru Chen,Wei Li,Hongwei Zhu,Kajia Wei,Yonghao Zhang,Haoming Chen,Weiqing Han
In this work, an electric field-enhanced heterogeneous catalytic ozonation (EHCO) was systematically investigated using a prepared FeOx/PAC catalyst. The EHCO process exhibited high sulfadiazine (SDZ) and TOC removal efficiency compared with electrocatalysis (EC) and heterogeneous catalytic ozonation (HCO) process. Almost 100% of SDZ was removed within 2 min, and the TOC removal reached approximately 85% within 60 min. Quenching experiments and EPR analysis suggested that the prominent SDZ and TOC removal performance is supported by the enhanced ·OH generation ability. Further study proved that H 2 O 2 formed by O 2 electrochemical reduction, peroxone reaction and electrochemical reduction of ozone contributed to improving ·OH generation. Furthermore, the EHCO system showed satisfactory stability and recyclability compared to conventional HCO systems, and the SDZ and TOC removal rates were maintained at ≥95% and ≥70% in 16 consecutive recycles, respectively. Meanwhile, XPS analysis and Boehm's titration for the FeOx/PAC catalyst used in HCO and EHCO process confirmed that the external electron supply could restrain the oxidation of surface functional groups of PAC and maintain a balance of the Fe(II)/Fe(III) ratio, which proved the critical role of cathode reduction in catalyst in situ regeneration during long consecutive recycles. In addition, the EHCO system could achieve more than 80% SDZ removal within 2 min in different water matrices. These results confirmed that the EHCO process has a wide application perspective for refractory organics removal in actual wastewater.
研究领域:
环境科学
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催化化学
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水处理工程
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DOI
PubMed
高影响因子
Processes
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2024
·Vol. 12
·期 2
·322
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IF 2.8
Bo Zhang,Jiale Li,Zhizhi Xu,Xiaohong Xu,Chundu Wu
In this research, a new catalyst for activating persulfate was developed by loading iron and nickel ions onto powdered activated carbon (PAC) for treating methyl orange, and the preparation process was optimized and characterized. The efficacy of the treatment was evaluated using the Chemical Oxygen Demand (COD) removal rate, which reflects the impact of various process parameters, including catalyst dosage, sodium persulfate dosage, and reaction pH. Finally, the recovery and reuse performance of the catalyst were studied. The optimal conditions for preparing the activated sodium persulfate catalyst were determined to be as follows: a molar ratio of Fe3+and Fe2+to Ni of 4:1, a mass ratio of Fe3O4to PAC of 1:4, a calcination temperature of 700 °C, and a calcination time of 4 h. This preparation led to an increase in surface porosity and the formation of a hollow structure within the catalyst. The active material on the surface was identified as nickel ferrite, comprising the elements C, O, Fe, and Ni. The magnetic property is beneficial to recycling. With the increase in catalyst and sodium persulfate dosage, the COD removal efficiency of the oxidation system increased first, and then, decreased. The catalyst showed good catalytic performance when the pH value was in the range of 3~11. Furthermore, Gas Chromatography–Mass Spectrometry (GC-MS) analysis indicated the complete oxidation of methyl orange dye molecules in the system. This result highlights the important role of the newly developed catalyst in activating persulfate.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
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2024
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IF 4.5
Yang Zhang,Yixiao Shi,Chen Jin,Chuan Wu,Hong Dong,Zhirong Qu,Yanjiang Song
A series of α , ω -dimethylglycidoxypropyl-terminated PDMS oligomer (PDMS-GE) oligomers with different polymerization degrees were synthesized and used to modify the bisphenol-A diglycidyl ether E51 (DGEBA) / 4,4-diaminodiphenylmethane (DDM) epoxy resin, resulting in epoxy resins with high hydrophobicity, low dielectric constant, good impact toughness, low combustion heat release rate, and low total heat release. The combustion heat release rate and total heat release of the material decreased with the increase in the loadings of PDMS-GE. Relative to pure epoxy resin, the composite E51/D30–10, which using DGEBA as the matrix, PDMS-GE with a degree of polymerization of 30 as the modifier in an amount of 10 phr relative to the mass sum of DGEBA, PDMS-GE and DDM, exhibited the best comprehensive performance with a water contact angle of 102.42°, a dielectric strength of 6.49 kV/mm, a dielectric constant of 2.93 at 14.2 GHz, the peak rate of heat release (PRHR) and total heat release (THR) are of 378.3 kW/m 2 and 134.4 MJ/m 2 , respectively. These comprehensive performances underscore the potential of PDMS-GE oligomers in significantly improving epoxy resin properties. When the loadings of PDMS-GE oligomers are less than 5 wt%, PDMS-GE with a lower degree of polymerization can improve the toughness of epoxy resins. The impact strength of the composite E51/D24–5, which uses DGEBA as the matrix, PDMS-GE with a degree of polymerization of 24 as the modifier in an amount of 5 phr relative to the mass sum of DGEBA, PDMS-GE, and DDM, reaches 98.1 kJ/m 2 , which is about 28.9 % higher than that of pure epoxy resin. The results also indicated that the degree of polymerization of PDMS-GE oligomers has less influence on the dielectric properties and mechanical properties of composite materials.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Yongze Li,Yazhou Tang,Yuchen Yang,Wenxiang Zhou,Chujie Qi,Kai Zhou,Bo Bian
Existing cyanobacteria thickening and dewatering processes in Taihu Lake commonly use conventional inorganic flocculants to condition the cyanobacteria, which poses certain environmental risks. In this study, three different types of typical flocculants, namely polymerized aluminum chloride (PAC), cationic polyacrylamide (CPAM) and starch-based flocculant (St-CTA), were selected to investigate their flocculant effects on cyanobacteria and the mechanism of action. The analysis showed that the dosage of St-CTA was low, the flocculation efficiency was high, and it could form flocs with large particle size and high strength. The adsorption and precipitation effect of St-CTA on protein and polysaccharide in flocculated EPS was stronger than that of CPAM and PAC, and it was able to act on the protein structure of EPS favorable for flocculation, improve the hydrophilic effect of S-EPS and LB-EPS, and reduce the content of bound water in EPS from 2.08 to 1.22 g/g DS, thus improving the efficiency of algae-water separation. The free energy and energy barrier of the EPS surface in each layer of the cyanobacterial floc after flocculation by St-CTA were significantly reduced, which resulted in the tendency of the cyanobacterial particles to aggregate and thus flocculate and settle. The pilot validation of St-CTA for cyanobacteria dewatering showed that the water content of algal residue could be reduced to 93.48 %, and the removal efficiencies of total nitrogen (TN), total phosphorus (TP), ammoniacal nitrogen (NH 3 -N), and chemical oxygen demand (COD) in the air-floated water could be up to 27.3 %, 76.6 %, 27.4 %, and 56.4 %, respectively. In conclusion, this study provides scientific knowledge and demonstration for promoting the use of St-CTA to condition cyanobacterial thickening and dewatering, which is a new idea to solve the problem of cyanobacterial resourcefulness and safe utilization.
研究领域:
环境科学
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生物学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
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IF 7.2
Yimu Qiao,Xue Han,Yijia Ren,Feiyong Chen,Cuizhen Sun,Jin Wang,Zhigang Yang,Linxu Xu,Xue Shen,Rupeng Liu
The extensive use of ibuprofen (IBU) and acetaminophen (APAP) has led to their accumulation in surface water, resulting in combined pollution with natural organic matter (NOM). In this study, a novel modified chitosan-based coagulant (CTS-DMDAAC) was successfully synthesized by adding ceric ammonium nitrate (CAN) to make chitosan (CTS) and dimethyldiallylammonium chloride (DMDAAC) produce free radicals for graft copolymerization. The study investigated the effects of pH, initial NOM concentration, and suspended particulates on the performance of contaminant removal and the characteristics of flocs. Through analysis of the Zeta potential and floc characteristics, the primary flocculation mechanisms were identified as: net capture and sweep, charge neutralization, and bridging effect. CTS-DMDAAC demonstrated effective removal of NOM, particularly humus, but encountered challenges in removing small-molecule pharmaceuticals such as IBU and APAP, with removal rates below 15%. To enhance the removal rate of small organic molecules, powdered activated carbon (PAC) was incorporated into the coagulation system, resulting in increased removal rates of IBU and APAP to 71.44% and 79.9%, respectively. Additionally, PAC improved the bridging capacity during coagulation, resulting in a 1.25-fold increase in the strength factor and a 2.34-fold increase in the recovery factor of the flocs. These findings suggest that the combined use of PAC and CTS-DMDAAC presents a novel approach for treating water bodies contaminated with NOM and pharmaceutical complexes.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Ping Sun,Xuan-Xin Chen,Yuan-Ping Zeng,Zhi-Yi He,Yun-Yan Gao,Raymond Jianxiong Zeng,Hou-Feng Wang
The distribution and transformation of water content critically influence sludge dewatering performance and remain central to sludge treatment research. Low-field nuclear magnetic resonance (LF-NMR), known for its non-destructive and rapid analysis, has emerged as a vital tool for characterizing water distribution in sludge, though its limitations require further investigation. This study employed LF-NMR to analyze T₂ relaxation spectra of sludge under various pretreatments and with differing water contents (97 %–62 %). Results indicated that, despite similar overall water content, sludge subjected to different pretreatments exhibited significant variations in T₂ peak counts and times. Notably, T₂₁, T₂₂, T₂₃, and T₂₄ showed significant exponential relationships with water content (p < 0.0001). The transformation and migration of adsorbed, interstitial, and free water demonstrated complex bidirectional continuity. Removal of adsorbed and interstitial water significantly altered sludge structure, diminishing the reversibility of water reabsorption, whereas removal of free water had minimal impact on microstructure. Overlapping T₂ relaxation peaks suggested continuous transitions among water states, challenging the traditional discrete categorization. Neglecting changes in T₂ peak times may lead to misinterpretation of water states and affect assessments of dewatering performance. While LF-NMR shows great potential, its limitations in resolving overlapping peaks and quantitatively assessing water states must be acknowledged. Consequently, LF-NMR should be regarded as a qualitative or semi-quantitative method rather than a purely quantitative tool as often assumed. Future research should integrate higher-resolution T₁–T₂ two-dimensional NMR techniques with advanced data processing to more accurately elucidate the mechanisms of water migration and transformation within sludge.
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PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
·
IF 8
Hang Xu,Chen Liu,Ao Wang,Baofeng Yue,Tao Lin,Mingmei Ding
Food processing wastewater presents a considerable challenge for treatment owing to its elevated nitrogen and phosphorus levels. Nonetheless, it possesses inherent value attributed to its abundant nutrients and organic content. This study presents an innovative approach for treating food processing wastewater and reusing biomass. Initially, the secondary-treated wastewater undergoes flocculation and sedimentation, followed by reverse osmosis to ensure that the effluent meets reuse standards. Subsequently, reverse osmosis concentrates, generated at varying water recovery rates, are utilized for microalgae cultivation to recover nitrogen and phosphorus. Furthermore, this study highlights the potential of reverse osmosis concentrates in reducing the water demand for microalgae cultivation and in producing commercial-grade nutrients. The findings reveal that reverse osmosis achieves removal rates exceeding 90 % for both nitrogen and phosphorus and effluent meets reuse standards. Following seven days of cultivation, microalgae cultured in reverse osmosis concentrated water with an 80 % water recovery rate demonstrate denitrification and phosphorus removal rates of 73.88 % and 80.92 % respectively, with a biomass concentration of 563 mg/L and a protein yield of 128 mg/L. Moreover, a total volumetric energy yield of 10.08 kJ/L is obtained, facilitating energy valorization. In conclusion, this study offers practical solutions for wastewater treatment and resource recovery, enabling the attainment of zero discharge of pollutants while generating valuable resources through microalgae cultivation.
研究领域:
环境科学
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生物技术
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）