WATER RESEARCH
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2019
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IF 7.913
Jiajian Xing,Heng Liang,Siqi Xu,Chong Joon Chuah,Xinsheng Luo,Tianyu Wang,Jinlong Wang,Guibai Li,Shane A. Snyder
In this work, UV and UV/chlorine (UV/Cl) were employed to enhance powdered activated carbon (PAC) adsorption pretreatment prior to ultrafiltration process for algae-contaminated surface water treatment . Their performance on membrane fouling mitigation and organic pollutant rejection was systematically evaluated. A comparative experiment was conducted under varying pollution degrees of algal extracellular organic matter (EOM) contamination in surface river water. The results indicated that UV/PAC and UV/Cl/PAC pretreatment effectively enhanced the removal of dissolved organic carbon (DOC) and UV-absorbing at 254 nm (UV 254 ). The characteristics of feed water after pretreatments were investigated through apparent molecular-weight (MW) distribution and fluorescence parallel factor analysis (PARAFAC). In regard to membrane fouling mitigation, UV/Cl/PAC noticeably decreased reversible and irreversible fouling resistance simultaneously and UV/PAC preferred reducing reversible membrane fouling. Combined fouling modeling was operated to scrutinize the fouling mitigation mechanisms and standard pore blocking was proved to be dominant during the filtration process. Moreover, the UV/Cl and UV/Cl/PAC pretreatments were proved positive for emerging micropollutants degradation and disinfection by-products formation potential reduction. The results suggested that UV and UV/Cl are likely strategies to enhance the efficiency of PAC adsorption pretreatments prior to ultrafiltration during algae-contaminated water treatment.
研究领域:
环境科学
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水处理工程
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PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2019
·
IF 4.865
Juan Tang,Jie Wang,Hui Jia,Haitao Wen,Juan Li,Wenbin Liu,Jingyu Li
For the low-concentration oily micro-polluted water formed by the leakage of refined oil products, an unexpensive and high-efficiency magnetic enhanced flocculation method was introduced in this study. First, the performance of magnetic flocculation(MF) to remove oily contaminants was discussed. The results indicated that it achieved more than 95% removal in only 1min with 50mg/L-Polyaluminum chloride(PAC), 50mg/L-Fe 3 O 4 and10mg/L- Polyacrylamide (PAM). The novel indexs R δ and S i were proposed to evaluate the oil removal with UV-Abs in-situ method. According to the adsorption kinetics of oil contaminants, the adsorption kinetics changed from pseudo-first-order to pseudo-second-order kinetics after the addition of Fe 3 O 4 on the basis of conventional coagulation (CF). It was transformed into intraparticle diffusion kinetics when the PAM continued to be added. Combined with the Fe–O–Al bond in the FTIR spectrum of flocs, the main mechanism of MF is enhanced charge neutralization and hydrogen bond adsorption. In addition, it was shown that satisfactory oil removal after recover, which indicated the great potential of a sustainable way by reusing low-cost magnetic seeds.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
PLoS One
·
2021
·Vol. 16
·期 3
·e0247948
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IF 3.24
Shiliang Xu,Mengke Cui,Renjie Chen,Qiaoqing Qiu,Jiacai Xie,Yuxin Fan,Xiaohu Dai,Bin Dong
With the increasing demand for energy, fracturing technology is widely used in oilfield operations over the last decades. Typically, fracturing fluids contain various additives such as cross linkers, thickeners and proppants, and so forth, which makes it possess the properties of considerably complicated components and difficult processing procedure. There are still some difficult points needing to be explored and resolved in the hydroxypropyl guar gum (HPG) removal process, e.g., high viscosity and removal of macromolecular organic compounds. Our works provided a facile and economical HPG removal technology for fracturing fluids by designing a series of processes including gel-breaking, coagulation and precipitation according to the diffusion double layer theory. After this treatment process, the fracturing fluid can meet the requirements of reinjection, and the whole process was environment friendly without secondary pollution characteristics. In this work, the fracturing fluid were characterized by scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy technologies, etc. Further, the micro-stabilization and destabilization mechanisms of HPG in fracturing fluid were carefully investigated. This study maybe opens up new perspective for HPG removal technologies, exhibiting a low cost and strong applicability in both fundamental research and practical applications.
研究领域:
石油工程
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环境科学
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材料科学
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PubMed
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2023
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IF 7.8
Ce Wang,Yuling Lü,Tianxu Ye,Feng Rong,Limin He
This paper demonstrates flotation separation for dispersed oil droplets and dissolved organics by preparing condensate bubble aphrons (CBA) by partially vaporizing condensate. The results show that the new CBA consists of a condensate membrane and a gas core, with a three-phase contact angle above 140° from the oil surface due to excellent wettability . At different temperatures and condensate compositions, bubbles are about 25–100 µm in size. The half-life time (140–230 s) of CBA and gas hold-up (10–25%) is much higher than nitrogen bubbles. It shows that the CBA has good stability and dispersibility . The flotation experiment of CBA found that the condensate group distribution ratio was optimally adapted to the temperature, and the optimum oil removal efficiency of up to 87% was obtained when the operating temperature was higher than the bubble point of 25–35 °C. The experimental experiment shown the recommended initial oil concentration (400 mg/L) and the mixing ratio of condensate and water (1.0%). Otherwise, CBA flotation efficiency was 10% higher than dissolved gas flotation. With the addition of flocculant , the CBA flotation efficiency can reach 97% of oil droplets and can achieve 50% removal of Acetic acid (HAc).
研究领域:
环境科学
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石油工程
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高影响因子
International Journal of Environmental Research and Public Health
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2023
·Vol. 20
·期 4
·2793
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IF 4.614
Jie He,Qixuan Song,Jian He
In order to address the growing problem of water pollution caused by the excessive discharge of contaminants and provide a better aquatic ecosystem for the public, increasing attention has been paid to the harmlessness and efficiency of coagulation. In this study, polyaluminum lanthanum silicate (PALS) was synthesized through co-polymerization as a novel coagulant to treat wastewater. FTIR, XRD, and SEM were used to analyze the morphology and structure of the material, which further confirmed that the PALS was successfully synthesized. The results indicated that PALS had a great performance in the treatment of a kaolin–humic acid suspension under the optimal synthesis conditions with Al/Si = 3, La/Si = 0.1, and basicity = 0.7. Compared with conventional coagulants, PALS exhibited a better performance at a low coagulant dose and could achieve a good removal effect for an ultraviolet wavelength less than 254 nm (UV254) (83.87%), residual turbidity (0.49 NTU), and dissolved organic carbon (DOC) (69.57%) at the optimal conditions. Additionally, the PALS showed a better effect on phosphate removal than other coagulants did, where the removal efficiency could reach 99.60%. Charge neutralization and adsorption bridging were the potential wastewater treatment mechanisms employed by the PALS, which showed varied contributions under different pH levels. The results indicated that PALS can be a promising coagulant in water treatment.Keywords:coagulant;water treatment;phosphate adsorption;polymer bridging
研究领域:
环境科学
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材料科学
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2015
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IF 4.529
Zailin Gong,Shujin Li,Jun Ma,Xiangdong Zhang
The commercial powdered activated carbon (PAC) has been selectively oxidized by two methods. The two oxidized methods are wet oxidation with ammonium persulfate and thermal treatment after acidification with hydrochloride acid, respectively. The two oxidized PAC were then functionalized with thermoresponsive poly ( N -isopropylacrylamide) (PNIPAM) in aqueous solution at ambient temperature. Comparing the two oxidized PAC products and their grafted derivatives, the oxidized PAC modified with thermal treatment after acidification shows larger surface area of 1184 m 2 /g and better adsorption of bisphenol A. Its derivative also exhibits relatively large surface area and adsorption capacity after grafted with PNIPAM. The maximum surface adsorption capacity simulated under Langmuir Models reached 156 mg/g. In addition, the grafted PAC products show self-flocculation behaviors with rapid response to temperature because of the thermal phase transition and entanglement behaviors of PNIPAM. The present study provides a new way to obtain carboxyl-rich activated carbon with large surface area and better adsorption capacity. The retrievable grafted PAC with good self-flocculation effect responsive to temperature will have high potential application in water remediation which requires pre-heating and emergency water treatment in the wild.
研究领域:
环境科学
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材料科学
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高影响因子
CHEMOSPHERE
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2017
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IF 4.208
Hu Wu,Zhouzhou Liu,Aimin Li,Hu Yang
China is a major textile manufacturer in the world; as a result, large quantities of dyeing effluents are generated every year in the country. In this study, the performances of two cationic starch-based flocculants with different chain architectures, i.e., starch- graft -poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride] (STC- g -PDMC) and starch-3-chloro-2-hydroxypropyl trimethyl ammonium chloride (STC-CTA), in flocculating dissolved organic matter (DOM) in dyeing secondary effluents were investigated and compared with that of polyaluminum chloride (PAC). In the exploration of the flocculation mechanisms, humic acid (HA) and bovine serum albumin (BSA) were selected as main representatives of DOM in textile dyeing secondary effluents, which were humic/fulvic acid-like and protein-like extracellular matters according to the studied wastewater’s characteristics based on its three-dimensional excitation–emission matrix spectrum. According to experimental results of the flocculation of both the real and synthetic wastewaters, STC- g -PDMC with cationic branches had remarkable advantages over STC-CTA and PAC because of the more efficient charge neutralization and bridging flocculation effects of STC- g -PDMC. Another interesting finding in this study was the reaggregation phenomenon after restabilization at an overdose during the flocculation of BSA effluents by STC- g -PDMC at a very narrow pH range under a nearly neutral condition. This phenomenon might be ascribed to the formation of STC- g -PDMC/BSA complexes induced by some local charge interactions between starch-based flocculant and the amino acid fragments of protein due to charge patch effects.
研究领域:
环境工程
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水处理
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废水管理
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2016
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IF 5.31
Yusun Zhou,Zhenyu He,Yun Tao,Yonghua Xiao,Tingting Zhou,Tao Jing,Yikai Zhou,Surong Mei
In this study, a novel silica membrane functionalized with amino group and octyl-perfluorinated chain was prepared on the periphery of Fe 3 O 4 nanoparticle (NP). The obtained nanocomposite (Fe 3 O 4 @SiO 2 -NH 2 &F 13 ) exhibited good selectivity for perfluorinated compounds (PFCs) by electrostatic and fluorine-fluorine (F-F) interaction with the addition of size exclusion effect. In ethanol, the monolayer coverage of PFCs occurred on most of the binding sites and the adsorption capacity were in the range of 13.20–111.14 mg g −1 . In aqueous solution, due to the hydrophobicity of perfluoroalkane chain, some PFCs (C ⩾ 8) may also stick together on the composite surface, which made the sorption amounts of these PFCs greatly enhanced. Thereafter, Fe 3 O 4 @SiO 2 -NH 2 &F 13 was used for rapid and selective removal of nine PFCs from surface water sample. In 1 L of spiked water samples fortified at 0.5–50 ng L −1 levels, the composite showed a better removal efficiency (86.29%) for PFCs than that (58.61%) of powdered activated carbon (PAC). In addition, high concentrations (5–50 mg L −1 ) of humic acid (HA) had no significant influence on the removal performance of the composite for PFCs. Furthermore, Fe 3 O 4 @SiO 2 -NH 2 &F 13 could be reused for several times with no obvious decrease in the removal efficiency. Thus, the magnetic nanocomposite could be used as an effective adsorbent for PFC removal from aquatic environment.
研究领域:
环境科学
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材料科学
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2013
·Vol. 21
·期 3
·2122-2131
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IF 2.618
Ou Hua-Se,Wei Chao-Hai,Deng Yang,Gao Nai-Yun,Ren Yuan,Hu Yun
A novel dual coagulant system of polyaluminum chloride sulfate (PACS) and polydiallyldimethylammonium chloride (PDADMAC) was used to treat natural algae-laden water from Meiliang Gulf, Lake Taihu. PACS (Al n (OH) m Cl 3n-m-2k (SO 4 ) k ) has a mass ratio of 10 %, a SO 4
2− /Al 3
+ mole ratio of 0.0664, and an OH/Al mole ratio of 2. The PDADMAC ([C 8 H 16 NCl] m ) has a MW which ranges from 5 × 10 5 to 20 × 10 5 Da. The variations of contaminants in water samples during treatments were estimated in the form of principal component analysis (PCA) factor scores and conventional variables (turbidity, DOC, etc.). Parallel factor analysis determined four chromophoric dissolved organic matters (CDOM) components, and PCA identified four integrated principle factors. PCA factor 1 had significant correlations with chlorophyll-a ( r = 0.718), protein-like CDOM C1 (0.689), and C2 (0.756). Factor 2 correlated with UV 254 (0.672), humic-like CDOM component C3 (0.716), and C4 (0.758). Factors 3 and 4 had correlations with NH 3 -N (0.748) and T-P (0.769), respectively. The variations of PCA factors scores revealed that PACS contributed less aluminum dissolution than PAC to obtain equivalent removal efficiency of contaminants. This might be due to the high cationic charge and pre-hydrolyzation of PACS. Compared with PACS coagulation (20 mg L −1 ), the removal of PCA factors 1, 2, and 4 increased 45, 33, and 12 %, respectively, in combined PACS–PDADMAC treatment (0.8 mg L −1 + 20 mg L −1 ). Since PAC contained more Al (0.053 g/1 g) than PACS (0.028 g/1 g), the results indicated that PACS contributed less Al dissolution into the water to obtain equivalent removal efficiency.
研究领域:
环境科学
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水处理工程
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2015
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IF 3.091
Zailin Gong,Shujin Li,Jun Ma,Xiangdong Zhang
Self-flocculated powdered activated carbon (PAC) with high recovery performance and unique adsorption performance of bisphenol A (BPA) has been synthesized. PAC was treated with acidification to increase its surface active points without influence on its surface area. The PAC after acidification was functionalized in the presence of macro-initiators and then grafted with N -isopropylacrylamide (NIPAM) in aqueous solution (PAC-PNIPAM). By controlling the grafting degrees of PNIPAM, the synthesized PAC-PNIPAM exhibited different removal efficiency of BPA, the maximum adsorption capacity simulated under Langmuir models reached 247.532 and 116.298 mg/g, respectively. Moreover, the desorption behaviors of BPA also changed significantly from two-stage desorption to minor desorption in water, suggesting the potential application of PAC-PNIPAM in removal of concerned pollutants. Additionally, PAC-PNIPAM showed a good self-flocculation effect, implying that PAC after adsorption could be easily retried and recovered to avoid the secondary pollution of the adsorbent. In all, our work demonstrated potential application of this newly synthesized PAC in water purification and micro-pollutant remediation.
研究领域:
环境科学
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材料科学
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2022
·
IF 10.53
Ruonan Zhang,Yanchao Xu,Liguo Shen,Renjie Li,Hongjun Lin
Efficient separation of oil-in-water emulsion remains a decisive step for success of oily wastewater treatment . To achieve this goal, a novel strategy regarding combining membrane separation with in situ electrocoagulation based on sacrificial anodes and cathodic hydrogen evolution via conductive metalized fabric membrane was proposed. As a key component of this novel coupling system, nickel functionalized fabric membrane with high hydrophilicity and electrical conductivity (electrical resistance of ∼2 Ω cm −1 ) was successfully prepared via a low-cost and facile route, including steps of PVA (polyvinyl alcohol)/Ni coating and autocatalytic electroless Ni plating. The optimized conductive membranes exhibited high permeate flux (19.3 × 10 5 L m −2 h −1 ·bar −1 ), separation efficiencies (99.5%), and separation stability to separate oil/water mixtures during the gravity-driven filtration process. To achieve the ideal performance to separate oil-in-water emulsion, a coupled electrocoagulation-membrane separation system was constructed with Ni@PVA membrane and Al mesh as the cathode and anode, respectively. It was shown that the coupled electrocoagulation-membrane separation system could achieve 99.4% rejection with high flux of 12.0 × 10 3 L m −2 h −1 ·bar −1 for oil/water emulsion separation, under the current density of 8 mA cm −2 and 20 min electrolysis time. This study revealed that the proposed electrocoagulation-membrane separation system based on Ni@PVA membrane is a promising technique in oil/water separation.
研究领域:
环境科学
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材料科学
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高影响因子
WATER ENVIRONMENT RESEARCH
·
2021
·Vol. 93
·期 10
·2298-2307
·
IF 1.946
Tiantian Song,Wanyi Fu,Shaohui Liu,Xihui Zhang
The performance of the integrated process of coagulation and ozonation with ceramic membrane filtration was evaluated for the treatment of shale gas hydraulic fracturing flowback wastewater (HFFW). The removal efficiencies of carbon oxygen demand (COD Cr ), dissolved organic carbon (DOC), petroleum oils, and turbidity in effluent by the combined process were 87.1%, 72.2%, 94.3%, and 99.6%, respectively. Compared with sole membrane filtration, the transmembrane pressure (TMP) of ceramic membrane filtration was reduced by >99% with the integrated process. The coagulation and ozonation can effectively remove the organics with high molecular weights in the cake layer of ceramic membrane. To the best of our knowledge, this work proposed the combined process of coagulation, ozonation, and flat-sheet ceramic membrane filtration for the treatment of HFFW for the first time. The water quality of the effluent met the discharge standard (Comprehensive Wastewater Discharge Standard GB8978-1996). The findings can provide an important technical foundation for the innovation of integrated equipment for HFFW treatment. Practitioner points An integrated process combining coagulation and ozonation with flat-sheet ceramic membrane ultrafiltration for the treatment of shale gas wastewater. The water quality of this integrated process met the discharge standard. Coagulation and ozonation effectively alleviated the membrane fouling related to organics with high molecular weights. A new avenue for on-site treatment of shale gas wastewater and an alternative of the current centralized wastewater management.
研究领域:
环境工程
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废水处理
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高影响因子
危险品化学品经营许可证（带存储）