WATER RESEARCH
·
2024
·
IF 11.4
Suhua Gu,Fangshu Qu,Dan Qu,Zhongsen Yan,Yuchuan Meng,Ying Liang,Haiqing Chang,Heng Liang
Membrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.54 % and 54.52 %, respectively. The hydrophobic fraction decreased from 52.75 % in raw SGPW to 37.70 % and 27.20 % for SPC and Fe(II)/SPC, respectively, and the MD normalized flux increased from 0.19 in treating raw SGPW to 0.65 and 0.81, respectively. The superiority of SPC oxidation in reducing the deposited membrane foulants and restoring membrane properties was further confirmed through scanning electron microscopy observation, attenuated total reflection fourier transform infrared, water contact angle and surface tension analyses of fouled membranes. Correlation analysis revealed that hydrophobic/hydrophilic matters and fluorescent organics in SGPW took a crucial role in MD fouling. The mechanism of MD fouling mitigation by Fe(II)/SPC oxidation was attributed to the decrease in concentrations and hydrophobicity of organic by synergistic oxidation, coagulation and adsorption.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Arabian Journal of Chemistry
·
2020
·
IF 4.762
Zijun Dong,Feng Wang,Xiulan Song,Miao Zhang,Chengchun Jiang,Feiyun Sun,Mu Li
Iodoform (CHI 3 ) is one of the disinfection by-products (DBPs) that is formed in the pre-oxidation and disinfection processes of drinking water treatment. In this study, Fe(II)-activated persulfate oxidation (Fe 2+ /PS) was employed to degrade iodoform, the effects of initial reactants concentration, reaction parameters, kinetics model were investigated, and the underlying mechanisms of CHI 3 degradation in Fe 2+ /PS oxidation process was unveiled. The results showed that the mole ratio Fe 2+ /PS of 1:5, initial PS concentration of 15 μmmol/L, and pH of 3.0 were identified as the optimum operating parameters. In addition, a relatively higher temperature could enhance CHI 3 removal and deiodination. The kinetic model has two different reaction steps: a fast one during the first ten minutes of reaction; then followed by a much slower one. Suppression of the reaction by TBA and MeOH showed that the combined effects of SO 4 − · and ·OH contributed to the degradation of CHI 3 , but ·OH played a dominant role. The degradation pathways and the products of total liberated iodine species demonstrate that the applicability of the Fe 2+ /PS oxidation process for CHI 3 degradation. These results indicated that the Fe 2+ /PS oxidation process is an effective advanced oxidation process for CHI 3 removal in 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
AQUA-Water Infrastructure Ecosystems and Society
·
2024
·Vol. 73
·期 5
·930-944
·
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
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Zhaobin Liu,Shiliang Heng,Qicai Dai,Yijing Gao,Yule Han,Lingtian Hu,Yisheng Liu,Xueqin Lu,Guangyin Zhen
Waste activated sludge properties vary widely with different regions due to the difference in living standards and geographical distribution, making a big challenge to developing a universally effective sludge dewatering technique. The Fe(II)-activated persulfate (S 2 O 8 2− ) oxidation process shows excellent ability to disrupt sludge cells and extracellular polymeric substances (EPS), and release bound water from sludge flocs. In this study, the discrepancies in the physicochemical characteristics of sludge samples from seven representative cities in China (e.g., dewaterability, EPS composition, surface charge, microbial community, relative abundance of antibiotic resistance genes (ARGs), etc.) were investigated, and the role of Fe(II)-S 2 O 8 2− oxidation in enhancing removal of antibiotic resistance genes and dewatering ability were explored. The results showed significant differences between the EPS distribution and chemical composition of sludge samples due to different treatment processes, effluent sources, and regions. The Fe(II)-S 2 O 8 2− oxidation pretreatment had a good enhancement of sludge dewatering capacity (up to 76 %). Microbial analysis showed that the microbial community in each sludge varied significantly depending on the types of wastewater, the wastewater treatment processes, and the regions, but Fe(II)-S 2 O 8 2− oxidation was able to attack and rupture the sludge zoogloea indiscriminately. Genetic analysis further showed that a considerable number of ARGs were detected in all of these sludge samples and that Fe(II)-S 2 O 8 2− oxidation was effective in removing ARGs by higher than 90 %. The highly active radicals (e.g., SO 4 − ·, ·OH) produced in this process caused drastic damage to sludge microbial cells and DNA stability while liberating the EPS/cell-bound water. Co-occurrence network analysis highlighted a positive correlation between population distribution and ARGs abundance, while variations in microbial communities were linked to regional differences in living standards and level of economic development. Despite these variations, the Fe(II)-S 2 O 8 2− oxidation consistently achieved excellent performance in both ARGs removal and sludge dewatering. The significant modularity of associations between different microbial communities also confirms its ability to reduce horizontal gene transfer (HGT) by scavenging microbes.
研究领域:
环境工程
·
微生物学
·
污水处理
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Zijun Dong,Chengchun Jiang,Jingxin Yang,Xi Zhang,Weili Dai,Pengwei Cai
This work investigates the transformation of iodide (I − ) by Fe(II)-activated peroxydisulfate (PDS). The transformation of I − into iodate (IO 3 − ) is a two-step process, involving reactive iodine species, such as hypoiodous acid (HOI), as a key intermediate, and IO 3 − as the final product. In the first step, SO 4 •- produced by Fe(II)-activated PDS is mainly responsible for the transformation of I − into HOI. In the second step, Fe(IV) formed by the reaction of Fe(III) with PDS is required, to facilitate the further oxidation of HOI to IO 3 − . The disproportionation of HOI and the oxidation by PDS alone contribute negligibly to IO 3 − formation. The IO 3 − yield increases to a maximum, before decreasing gradually, with increased PDS and Fe(II) dosages. The transformation of I − into IO 3 − is favored by lower pH and higher temperature, due to the greater SO 4 •- production by the reaction of Fe(II) with PDS under these conditions. Humic acid , as a representative natural organic matter, scavenges the formed HOI to form iodinated disinfection byproducts , which largely inhibit the transformation of I − into IO 3 − . In addition, the transformation of I − into IO 3 − and iodinated disinfection byproducts by Fe(II) activated PDS was confirmed in the natural waters.
研究领域:
环境化学
·
水处理
·
高级氧化过程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）