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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Tengfei Ma,Tong Li,Qiuhua Chen,Xiangyou Yue,Xin Mao,Bing Zhang
The pre-coagulation process significantly affects the operational efficiency and membrane fouling behavior of membrane bioreactors (MBRs). Nevertheless, the underlying mechanisms remain inadequately elucidated with the development of innovative MBRs. This study evaluated the operational performance of aerobic granular sludge membrane bioreactor (AGMBR) and algal-bacterial aerobic granular sludge membrane bioreactor (ABGMBR) following the application of polymeric aluminum chloride (PAC) and modified microbial flocculant (MMF). The ABGMBR exhibited superior pollutant removal rates and permeate flux compared to the AGMBR owing to its excellent bacteria-algal symbiosis system. PAC/MMF exhibited exceptional flocculation performance, effectively inhibiting foulant adhesion on the membrane surface. Moreover, the extended Derjaguin–Landau–Verwey–Overbeek theory elucidated that the PAC/MMF system hindered the combination of membrane-foulant and foulant-foulant, confirming its efficacy in controlling membrane fouling in AGMBR and ABGMBR. Correlation analysis revealed that PAC/MMF significantly removed the chemical oxygen demand and suspended solids content in raw sewage, which was the primary reason for the alleviation of membrane fouling. This study elucidates the antifouling mechanisms of dual coagulation in granular sludge-membrane systems and offers an economical, efficient, and sustainable strategy for wastewater treatment.
研究领域:
环境工程
·
水处理技术
·
生物化学工程
·
膜科学技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xiao Ma,Jian-Yi Chen,Ji-Wen Xu,Xiao-Jian Wu,Hao-Di Chi,Yao-Dong Wei
The increasing environmental burden of drilling wastewater calls for more efficient and mechanistically informed treatment strategies to support the sustainable development of oil and gas operations. This study systematically compares the performance of three flocculants—polyaluminum chloride (PAC), polyaluminum ferric silicate (PSAF), and aluminum sulfate (Al 2 (SO 4 ) 3 )—in the flocculation-flotation treatment of drilling wastewater, with an emphasis on elucidating floc–bubble interaction mechanisms. Flotation experiments demonstrated that PAC achieved the highest suspended solids (SS) removal efficiency (80.58 % at 1.0 g/L), followed by PSAF and Al 2 (SO 4 ) 3 . Comprehensive characterization, including FTIR, zeta potential, contact angle analysis, and floc size measurement, revealed that PAC formed large, moderately hydrophobic flocs with strong structural integrity and stable bubble adhesion. In contrast, Al 2 (SO 4 ) 3 generated smaller, highly hydrophobic flocs with low interfacial energy barriers, leading to poor aggregate stability. The EDLVO theory was applied to calculate interaction energy profiles, demonstrating that floc–bubble adhesion is governed by the combined effects of van der Waals, electrostatic, and hydrophobic interactions. PAC presented the most balanced profile, combining high adhesion potential with strong post-attachment stability. These findings provide novel mechanistic insights for optimizing flocculation-flotation processes in complex wastewater systems, offering a theoretical basis for practical engineering applications.
研究领域:
环境科学
·
化学工程
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Jiajia Fan,Jinyuan Hu,Shengchi Bai,Xifan Li,Guijing Chen,Jia Chen,Sheng Chen,Baicang Liu
Developing high-performance anti-fouling ultrafiltration membranes is essential for treating shale gas wastewater (SGW), addressing its severe membrane fouling issues. This study reports the fabrication of polyvinylidene fluoride (PVDF)/PVDF-graft-poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) blended hollow fiber membranes via non-solvent induced phase separation for direct treatment of SGW. The influences of the copolymer doping ratio on microstructure, chemical composition, and hydrophilicity were systematically investigated. The addition of PVDF-g-PEGMA contributed to a favorable membrane morphology and significantly improved hydrophilicity. The 20 wt% PVDF-g-PEGMA modified membrane achieved a 64.4% increase in pure water flux while retaining over 95.9% rejection for both humic acid and bovine serum albumin. More importantly, in long-term filtration of SGW, the modified membrane demonstrated a stable permeation flux of ~30.4 L·m −2 ·h −1 , surpassing the performance of the unmodified membrane by 300% and reducing the cost of water treatment for unit flux by 17.6%. Analysis based on the extended Dragun-Landau-Verwey-Overbeek theory indicated that the incorporation of PVDF-g-PEGMA effectively reduced the attractive interaction energy between the membrane and pollutants. These results demonstrate that the PVDF-g-PEGMA blending modification not only significantly enhanced membrane permeability and anti-fouling performance under challenging real wastewater conditions but also achieved sustained flux and superior anti-fouling behavior during lab-scale SGW operation, thereby enabling water reuse with reduced maintenance demand.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Pengcheng Zhao,Shihu Liu,Wei Huang,Lei He,Jiao Li,Jiong Zhou,Jian Zhou
Essential oils (EOs) are naturally occurring substances that have shown great prospect in the field of antimicrobial, antioxidant and pest control by nontoxic mechanisms. In this regard, EOs are considered the promising and eco-friendly approach for controlling harmful algae. In this study, the anti-cyanobacterial activity of EOs eugenol against Microcystis aeruginosa are evaluated from the perspective of photosynthetic efficiency, the behavior of extracellular organic matter (EOM), endogenous plant hormone synthesis, and nitric oxide signaling pathway. Results showed that the photosynthetic activity of M. aeruginosa decreased significantly after eugenol treatments. Eugenol treatment resulted in cells rupture and the release of EOM. Levels of endogenous plant hormones salicylic acid (SA) and jasmonic acid (JA) were enhanced separately by 2.32 and 2.01 times after 4 d of exposure to eugenol. And the inhibition of SA and JA biosynthesis further promotes the inhibitory effects of eugenol on algae. Additionally, the signaling molecule nitric oxide (NO) increased significantly by 3.78-fold. Furthermore, the influence of NO on microalgae exposed to eugenol was also determined, suggesting that the inhibitory effect of eugenol stress might be associated with NO generation in M. aeruginosa . These findings will be helpful for the understanding of the fate and potential of eugenol in harmful algae control.
研究领域:
环境科学
·
微生物学
·
植物生理学
·
生态毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2019
·
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
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
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
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
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
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Peng Yu,Xi Li,Xiao Zhang,Hui Zhou,Yanhua Xu,Yongjun Sun,Huaili Zheng
In this study, co-precipitation was used to prepare Fe 3 O 4 magnetic powder activated carbon (PAC) (Fe 3 O4-PAC) and MnFe 2 O 4 magnetic PAC (MnFe 2 O 4 -PAC) for the in-depth treatment of glyphosate pesticide wastewater. Magnetic adsorbent characterization results indicate that MnFe 2 O 4 was successfully loaded on the activated carbon powder. Adsorption experiment results show that the maximum adsorption capacity of MnFe 2 O 4 -PAC for glyphosate is two to three times that of the original PAC. The adsorption of glyphosate by using magnetic PAC conforms to the Langmuir adsorption isotherm, and the adsorption kinetics is consistent with the quasi-second adsorption kinetic model. The adsorption capacity of Fe 3 O 4 -PAC and MnFe 2 O 4 -PAC showed the same trend effect with the change in pH, temperature, and adsorbent dosage. The adsorption capacity of Fe 3 O 4 -PAC and MnFe 2 O 4 -PAC for glyphosate decreased with the increase in pH and magnetic PAC and rises with temperature. Regeneration experiment results showed that the order of the regeneration method of MnFe 2 O 4 -PAC is: microwave combined Fenton reagent regeneration > wet microwave regeneration > microwave combined hydrogen peroxide regeneration. MnFe 2 O 4 -PAC after regeneration still exhibited good magnetic properties and adsorption capacity.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 9
·9161-9173
·
IF 2.914
Zhang Tingting,Yang Yanling,Li Xing,Wang Nan,Zhou Zhiwei
Ultrasound-assisted regeneration of powdered activated carbon (PAC) saturated with 4-chlorophenol (4-CP) was investigated in this work. The variables, i.e., acoustic frequency, density levels, regenerating solution species, spent PAC mass, and the number of repeated cycle, were optimized. The UV–Vis spectra, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), and pore structure analysis were used to characterize the regenerated PAC as compared to the virgin and spent PAC. The adsorption experiments indicated that the adsorption kinetics of 4-CP fitted well with the pseudo-second-order model, and the main chemisorption process was nonlinear and heterogeneous. The desorption results showed that the optimized regenerated conditions were identified as 40 kHz of frequency, 0.18 W/mL of sonication intensity, 0.1 M NaOH and 50% ( v / v ) ethyl alcohol mixture of regeneration solution, and 1 g/L of saturated PAC mass. Under this condition, the regeneration efficiency reached up to 86.81%. Hydroxylated oxidation products especially benzoquinone and hydroquinone were formed during ultrasound regeneration. Ultrasound mainly acted on surface functionalities, mesopores, and macropores of PAC through the hydroxyl radical oxidization resulted from the cavitation effect.
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
CHEMICAL ENGINEERING JOURNAL
·
2016
·
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
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2013
·Vol. 21
·期 3
·2122-2131
·
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
·
水处理工程
✓ 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）