Membranes
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2024
·Vol. 14
·期 6
·125
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IF 3.3
Qingao Li,Lixin Xie,Shichang Xu,Wen Zhang
The removal of dissolved organic matter (DOM) from seawater before the reverse osmosis (RO) processes is crucial for alleviating organic fouling of RO membranes. However, research is still insufficiently developed in the comparison of the effectiveness of integrating coagulation with ultrafiltration (UF) or sand filtration (SF) in the pretreatment stage of seawater reverse osmosis (SWRO) for the removal of DOM. In this study, we investigated the effect of pretreatment technologies on RO fouling caused by DOM in seawater, including the integration of coagulation and sand filtration (C-S pretreatment) and the integration of coagulation and ultrafiltration (C-U pretreatment). Both integrated pretreatments achieved comparable DOM removal rates (70.2% for C-U and 69.6% for C-S), and C-S exhibited enhanced removal of UV-absorbing compounds. Although C-U was more proficient in reducing the silt density index (below 2) compared to C-S (above 3) and improved the elimination of humic acid-like organics, it left a higher proportion of tyrosine-protein-like organics, soluble microbial by-product-like organics, and finer organics in the effluent, leading to the formation of a dense cake layer on RO membrane and a higher flux decline. Therefore, suitable technologies should be selected according to specific water conditions to efficiently mitigate RO membrane fouling.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2023
·
IF 7
Hai-Ling Liu,Xing Li,Na Li
Bio-slow sand filters (BSSFs) are widely employed in rural drinking water treatment ascribing to its economic applicability, easy operation and high efficiency. This study investigated the influence of particle size, filter thickness, water quality and filtration rate on decontamination performance, bacterial community and metabolic function of BSSFs. The effluent ammonia nitrogen during stable operation period basically met the standards for drinking water quality in China (0.5 mg/L). The average removal efficiencies of fine sand were about 4 % higher than those of coarse sand, and thick filter layer showed more stable performance. Schmutzdecke removed most turbidity and organic pollutants , playing an overwhelming role in water purification . Filtration rate was a key factor in shaping bacterial community structure. Proteobacteria and Cyanobacteria were dominant phyla, whose relative abundance significantly decreased and increased as filtration rate increasing, respectively. Co-occurrence patterns were dominant within bacterial communities. Function bacteria (e.g. Hyphomicrobium and Methylophilus ) and rare genera ( Curvibacter and Simplicispira ) were identified as hub genera in the networks. The bacterial communities exhibited a metabolic versatility. Several pathways for secondary metabolism significantly shifted under different conditions, such as xenobiotics biodegradation and metabolism. Moreover, filtration rate and dominant genera greatly affected pollutant removal performance. Many species of Proteobacteria and Bacteroidota were closely related to carbohydrate metabolism , energy metabolism and nucleotide metabolism, and metabolic functions corresponded more cohesively to conditional abundant taxa, conditional rare or abundant taxa, conditional rare taxa. This study highlights the adaptability and bacterial community characteristics of BSSFs, and provides references for their practical application.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Zhilin Xia,Chenchen Zhu,Zhenling Shen,Mingmeng Liu,Zhaopeng Zhang,Ting Wang,Xin Yang,Xianjia Peng
Sand filtration was innovatively used to separate metal sulfide particles from acidic wastewater. CuS particles were efficiently separated by sand filtration, and the turbidity in the effluent maintained less than 1.00 NTU. However, the filter column was easily penetrated after 25 min filtration of As 2 S 3 particles. CdS particles had poor sand filtration performance and the turbidity in the effluent was higher than 121.00 NTU. UV light irradiation greatly increased the zeta potential of CdS and As 2 S 3 particles from −26.79 to −8.46 mV and −38.45 to −11.20 mV, respectively, and also improved the hydrophobicity, making the water contact angels of CdS and As 2 S 3 particles increased from 22.79° to 61.70° and 64.50° to 87.80°, respectively. After UV irradiation, the particle size distribution of CdS and As 2 S 3 particles was transferred to a range with larger particle sizes. The sand filtration performance of the UV light irradiated As 2 S 3 and CdS particles was significantly enhanced, and the turbidity in the effluent was less than 1.00 NTU under a flow rate of 6.0–12.0 m/h. The calculated XDLVO energies ( Δ E d 0 Tot ) between the UV irradiated metal sulfide particles as well as between these particles and quartz sand greatly decreased, implies the self-aggregation and attachment on the surface of quartz sands of these particles were markable enhanced, resulting the improvement of sand filtration performance of these particles. This study presents an efficient and economical method to separate metal sulfide particles produced by sulfidation precipitation from acidic wastewater.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Shan Wang,Yingxin Xu,Shufen Chen,Baoyou Shi,Haoming Xu,Wande Ding,Xin Huang,Kefeng Zhang
Due to seasonal algal outbreaks in source water, the sand filtration (SF) suffering high load exhibited poor performance in turbidity and organic matter (OM) removal. However, the filtration performance is highly dependent on the state of contaminants. This study aims to improve removal efficiency of turbidity, algae and DOM by coupling a novel green titanium sulfate-chitosan (TS-CTS) compound filter aids with/without ferrate (VI) pre-oxidation. The results indicated that the turbidity decreased to 0.25 NTU and chlorophyll a removal up to 73.5% with TS/CTS (0.8/0.3 mg/L) filter aids were utilized, while the filtration cycle was not significantly shortened. The introduced Fe(VI) (5 mg/L, 10 min) before micro-flocculation realized moderate pre-oxidation and formed in-situ Fe(III), improved algae cells removal and effectively controlled of 2-methylisoborneol (＜10 ng/L) as well as the disinfection by-product precursors as polysaccharides and amino acid-like proteins. Positively charged in-situ Fe(III) as a dual-coagulant facilitated Ti hydrolysis and promoted the clustering, cross-linking, formed Ti-AOM/NOM-Fe complexes. Under the adsorption bridging and adsorption electro-neutralization of TS-CTS and in-situ Fe(III), the microflocs were formed, migrated, adhered and ultimately retained in filter layer media. This study can provide guidance for technological and agent selection in algae-laden surface water treatment.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
ECOLOGICAL ENGINEERING
·
2013
·
IF 2.958
Shams Ali Baig,Tiantian Sheng,Yunjun Hu,Xiaoshu Lv,Xinhua Xu
In this study, adsorptive removal of arsenic in saturated sand filters (SSF(a) and SSF(b)) containing raw and iron-coated honeycomb briquette cinders (HBC and Fe-HBC) is presented. Operating parameters including SSF design, dissolved oxygen (DO), pH, iron leaching and the effects of co-occurring ions on arsenic removal were investigated at 23 ± 2.0 °C temperature for 24-days long treatment. Sampling times (ST) (5–120 min) during treatment days (TD) 1, 6, 12, 18 and 24 were purposively decided to assess filters’ performance from tap water with the spiked of 200 μg/L of As(V) and As(III) into SSF(a) and SSF(b), respectively. No other alteration or pH adjustment was made to the influent water. Results demonstrated that the removal efficiencies of arsenic in SSF(a) and SSF(b) were maintained >95% and >85% till TD-12 and than decreased to 78% and 60%, respectively, on TD-24. Lower arsenic removal in SSF(b) could be the result of As(III) slower oxidation at the studied influent pH under oxic conditions . Decreased in effluent DO and increased iron leaching were measured in both the filters from TD-1 to TD-24. Minor variations of effluents pH and co-occurring ions (Fluoride, Nitrate and Sulphate) were recorded, but no significant effect on arsenic removal was measured in the reported ranges. Performance of NaOH-regenerated filter-beds was evaluated and both filters removed 95% of arsenic in three-cycle treatments. This study suggests of an in situ treatment; by the oxidation of As(III) into As(V) in the presence of DO and hydroxyl radical on adsorbent surfaces, followed by subsequent adsorption through selective physical sorption and Fe-As complexation. SSF containing cost-effective adsorbents could be an effective in situ treatment option to conventional treatment for safe drinking water production .
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Jiayi Wu,Lun Lu,Rui Wang,Liuyi Pan,Baoliang Chen,Xiaoying Zhu
Microplastics and antibiotics were frequently detected in the effluent of sand filtration, while the presence of microplastics may change the interactions between the antibiotics and the quartz sands. However, the influence of microplastics on the transport of antibiotics in sand filtration has not been revealed. In this study, ciprofloxacin (CIP) and sulfamethoxazole (SMX) were respectively grafted on AFM probes to determine the adhesion forces to the representative microplastics (PS and PE) and the quartz sand. CIP and SMX exhibited low and high mobilities in the quartz sands, respectively. Compositional analysis of the adhesion forces indicated that the lower mobility of CIP in sand filtration columns could be attributed to the electrostatic attraction between the quartz sand and CIP compared with repulsion for SMX. Moreover, the significant hydrophobic interaction between the microplastics and the antibiotics could be responsible for the competitive adsorption of the antibiotics to the microplastics from the quartz sands; meanwhile, the π-π interaction further enhanced the adsorption of PS to the antibiotics. As a result of the high mobility of microplastics in the quartz sands, the carrying effect of microplastics enhanced the transport of antibiotics in the sand filtration columns regardless of their original mobilities. This study provided insights into the mechanism of the microplastics on enhancing the transport of antibiotics in sand filtration systems from the perspective of the molecular interaction.
研究领域:
环境科学
·
化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）