SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Jiawei Hu,Yuanhui Zuo,Bing Guo,Huancong Shi
A novel and high-efficiency sludge pretreatment method by combination of freezing and calcium hypochlorite (CH) for promoting the anaerobic fermentation performance was reported in this work. Experimental results indicated that a maximum biohydrogen production of 18.18 ± 0.43 mL/g volatile suspended solids (VSS) was realized by freezing (−5 °C) combined with CH (0.12 g/g VSS) pretreatment, which was 1.19, 4.05 and 11.36 times to that from the sole CH, sole freezing and control fermenters, respectively. Mechanism study showed that freezing + CH pretreatment efficiently disintegrated sludge flocs, producing abundant substrates for anaerobic fermentation. Model substances degradation experiment showed that the biochemical processes were all suppressed by freezing + CH method, but the suppressive degrees for hydrogen-consuming processes were greater than hydrogen-producing processes. 16S rRNA analysis revealed that the microbial community in freezing + CH treated reactor was more beneficial to hydrogen generation than that in the control, because the abundance of functional microbes was enriched from 6.81 % to 34.95 % by the co-treatment. Furthermore, sludge dewatering performance, including settleability, dewaterability and filterability, was enhanced by freezing + CH pretreatment.
研究领域:
环境工程
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微生物学
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DOI
PubMed
高影响因子
Minerals
·
2018
·Vol. 8
·期 10
·463
·
IF 1.835
Shangyong Lin,Runqing Liu,Yongjie Bu,Chen Wang,Li Wang,Wei Sun,Yuehua Hu
During smelting, arsenic in copper concentrates affects the product quality and causes environmental pollution. Removing arsenic minerals from copper concentrates requires environmental-friendly and cost-effective depressants for flotation separation. Ca(ClO)2was combined with sodium humate (SH) to improve the flotation separation of chalcopyrite from arsenopyrite. Results of single-mineral flotation indicated that combined Ca(ClO)2and SH significantly inhibited arsenopyrite and exerted a negligible effect on chalcopyrite. The arsenic content in copper concentrates significantly decreased from 63% to 11% in the absence of a depressant and in the presence of Ca(ClO)2and SH, as proven by the mixed-mineral flotation results. SH can adsorb on both mineral surfaces as indicated by the zeta potential measurements and Fourier transform infrared spectroscopy. However, the presence of Ca(ClO)2increased the adsorption of arsenopyrite compared with chalcopyrite. The arsenopyrite floatability depressed with the Ca(ClO)2oxidation and subsequent SH adsorption, as verified by X-ray photoelectron spectroscopy. Results of flotation tests confirmed that the chalcopyrite surface was slightly oxidized, but it remained hydrophobic. The combination of depressants has the potential for industrial application.Keywords:chalcopyrite;arsenopyrite;calcium hypochlorite;oxidation;sodium humate
研究领域:
矿物加工工程
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
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IF 13.3
Lian Zhang,Wei Fang,Panyue Zhang
The high water content of sewage sludge presents a significant challenge for its subsequent treatment. With activation of hypochlorite treatment hydrophilic protein in sludge could not be effectively degraded which limits the performance of sludge dewatering, meanwhile, excessive radicals could be consumed. To solve this issue, in this study a novel Fe 2+ /Ca(ClO) 2 /tannic acid (TA) process was proposed for the first time, aiming at enhancing the dewaterability of waste activated sludge (WAS). Treatment with 1.2 mmol/g total solids (TS) of Ca(ClO) 2 , 1.0 mmol/g TS of Fe 2+ and 0.15 mmol/g TS of TA resulted in the reduction of 66.58 %, 88.31 % and 9.75 % in capillary suction time (CST), specific resistance to filtration (SRF) and water content (Wc) of sludge cake, respectively. Mechanistic investigations revealed that the ·OH and ·CH 2 CH 2 OH generated within the Fe 2+ /Ca(ClO) 2 /TA system facilitated the decomposition of extracellular polymeric substances (EPS) and sludge cells, leading to the release of bound water as free water. The value of α-helix/(β-sheet + random coil) with Fe 2+ /Ca(ClO) 2 /TA conditioning decreased from 50.43 % to 38.72 %. Furthermore, the formation of multivalent ions, such as Fe 3+ and Ca 2+ , along with TA, promoted re-coagulation, resulting in an increase in sludge particle size and enhanced flocculation. Additionally, TA effectively complexed hydrophilic proteins, facilitating the interaction between calcium and sulfate ions to form additional gypsum material as skeleton in sludge cake, which led to improved permeability and compressibility of the sludge cake. This study provides a new approach for efficient improvement in sludge dewaterability.
研究领域:
环境科学
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污水处理
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Jianwei Zhao,Yuxin Wang,Dezheng Guan,Zhou Fu,Qi Zhang,Liang Guo,Yingjie Sun,Qiuzhuo Zhang,Dongbo Wang
This work investigated the effect of calcium hypochlorite (CH) coupled aged refuse (AR) treatment on the enhanced hydrogen generation from sludge anaerobic dark fermentation (SADF). The enhanced mechanism was systematically revealed through sludge disintegration, organic matter biotransformation, and microbial community characteristics, etc. The experimental data showed that CH coupled AR increased the hydrogen yield to 18.1 mL/g, significantly higher than that in the AR or CH group alone. Mechanistic analysis showed that CH-coupled AR significantly promoted sludge disintegration and hydrolysis processes, providing sufficient material for hydrogen-producing bacteria. Microbiological analysis showed that CH-coupled AR increased the relative abundance of responsible hydrogen-producing microorganisms. In addition, CH-coupled AR was very effective in reducing phosphate content in the fermentation liquid and fecal coliforms in the digestate, thus facilitating the subsequent treatment of fermentation broth and digestate. CH coupled AR is an alternative strategy to increase hydrogen production from sludge.
研究领域:
环境工程
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生物技术
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废物管理
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jialin Liang,Jinjia Huang,Siwei Zhang,Xian Yang,Shaosong Huang,Li Zheng,Maoyou Ye,Shuiyu Sun
High levels of extracellular polymeric substances (EPS) and bound water in sludge negatively impact sludge dewaterability. This study applied a novel sludge conditioning process involving calcium hypochlorite (Ca(ClO) 2 ) oxidation, ferric coagulant re-flocculation, and walnut shell (WS) skeleton construction to remove EPS and bound water and improve sludge dewaterability. The study also described the underlying mechanisms for this activity, by investigating the changes in EPS distribution, morphological structure, flocs morphology, rheological behavior, and bound water. Using single factor experiments, the optimal dosages of the composite conditioner included 10 mg/g dry solid (DS) of Ca(ClO) 2 , 60 mg/g DS of ferric chloride (FeCl 3 ) or 100 mg/g DS of polymeric ferric sulfate (PFS), and 600 mg/g DS of WS. Using a novel pressure filtration system, the moisture content of the dewatered sludge cake conditioned with Ca(ClO) 2 /ferric coagulant/WS was reduced to below 50 wt%. The study described a three-step mechanism for the composite conditioning of sludge. First, protein-like substances and polysaccharide-like materials in the EPS and bound water were degraded by Ca(ClO) 2 oxidation. Second, the porous structure and compact flocs were re-flocculated using high charge neutralization and the bridging ability of ferric coagulant. The flowability increased and the viscosity decreased compared with raw sludge. Third, a rigid networked structure was formed by adding the WS skeleton. The combined Ca(ClO) 2 /ferric coagulant/WS treatment had a significant synergistic effect supporting dewatering. The filter liquor of the combined treatment has a lower impact on the environment. The combined treatment is an appropriate was to treat sludge prior to landfilling and incineration. Furthermore, the economic analysis showed that using the Ca(ClO) 2 /FeCl 3 /WS treatment had economic advantages over other treatments.
研究领域:
环境工程
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废水处理
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污泥管理
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化学工程
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DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Yang Song,Shibin Zhang,Haoxin Shen,Wen Qin,Jin Jiang,Jun Ma
In this study, calcium hypochlorite (Ca(ClO) 2 ) combined with potassium ferrate (Fe(VI)) (Ca(ClO) 2 /Fe(VI)) oxidation system was developed to enhance the stability of Fe(VI) and removal efficacy of emerging contaminants. For the removal of micropollutants with various moieties, carbamazepine (CBZ) and phenol removals (50 % and 35 %) in the initial stage were enhanced by Ca(ClO) 2 /Fe(VI) oxidation system, which were primarily attributed to the Ca(ClO) 2 enhanced micropollutant removal by stabilizing Fe(VI) through H 2 O 2 scavenging in the Ca(ClO) 2 /Fe(VI) system, increasing Fe(VI) exposure to boost direct degradation efficiency for Fe(VI)-reactive contaminants (CBZ or phenol), but showed limited efficacy for ClO − reactive pollutants (SMX), because the reaction of Ca(ClO) 2 with SMX was more favorable than that of Fe(VI) with SMX. The microplastics (MPs) removal achieved by the Ca(ClO) 2 /Fe(VI) oxidation system (86 %) was also higher than the sum values (65.69 %) achieved by each individual reactant, indicating the synergy of Ca(ClO) 2 and Fe(VI) could enhance coagulation and improve the removal efficiency of microplastics. Moreover, the UV 254 , electron-donating capacity (EDC), and turbidity removals by Ca(ClO) 2 /Fe(VI) oxidation system from simulated source water (36 %, 53 % and 32 %) and real source water (48 %, 86 % and 53 %) were higher than those by Fe(VI) alone (26 %, 43 % and 21 %). This study provided novel insights into optimizing Fe(VI)-based systems applied for pre-oxidation process in drinking water treatment.
研究领域:
环境科学
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水处理技术
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化学工程
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环境工程
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DOI
高影响因子
Journal of Cleaner Production
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2025
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IF 10
Qian Zhang,Jiawei Hu,Cheng Li
To solve the problem of low bio-hydrogen yield from anaerobic fermentation (AF) of sludge, a novel and efficient method by combining thermal hydrolysis (TH) with calcium hypochlorite (CH) for sludge pretreatment was proposed in this study. Experimental data demonstrated that TH + CH method synergistically promoted the bio-hydrogen production from sludge. The optimal condition of the combined pretreatment was TH at 70 °C plus 0.12 g/g volatile suspended solids (VSS) of CH, and relevant hydrogen yield was 22.52 mL/g VSS. Mechanism study exposed that TH + CH method effectively destructed extracellular polymeric substances (EPS) and sludge cells, causing the promotion of hydrolysis rate and generation of abundant fermentation substrates. In the several biochemical processes of sludge AF, acidogenesis and acetogenesis that responsible for hydrogen generation were not or only slightly suppressed by TH + CH pretreatment, while homoacetogenesis, sulfate-reducing and hydrogenotrophic methanogenesis that can consume hydrogen were severely inhibited under this condition, resulting in hydrogen accumulation. Microbiological analysis demonstrated that the functional bacteria (e.g. Rhodobacter , Proteiniborus and Petrimonas ) related to hydrogen generation were all enriched under TH + CH condition.
研究领域:
环境工程
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生物能源
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废弃物管理
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微生物学
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生化过程
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产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 17
·12049-12057
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IF 3.9
Xiaofan Su,Yaqi Lin,Xingyu Hu,Xinzhi Tan,Yao Mai,Minyan Jiang,Ruitao Zhang,Fangjun Huo,Lei Liu,Weidong Tian,Li Xie
A novel sustained chlorine-releasing polydimethylsiloxane/Ca(ClO)2 (PDMS/Ca(ClO)2) material was fabricated by encapsulating Ca(ClO)2 in a PDMS matrix due to its high hydrophobicity and high chemical stability, which showed immediate-responsive and long-lasting antibacterial capabilities in aqueous conditions. Free chlorine could be released from the PDMS/Ca(ClO)2 after immersion in water for 2 min and could also be sustainedly released for 2 weeks, while the released concentration is negatively related to the duration time and positively with the initial Ca(ClO)2 contents. Additionally, Ca(ClO)2 powder as a filler significantly affects the crosslinking and pore size of PDMS. The PDMS/Ca(ClO)2 materials exhibited enduring antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in both planktonic and multispecies-biofilm status. It is expected that this PDMS/Ca(ClO)2 material and its similar composite would be promising candidates for wide sustainable disinfection applications in biomedical and industrial fields.
研究领域:
材料科学
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生物医学工程
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微生物学
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化学工程
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2026
·
IF 10.4
Xiyao Liang,Yuqing Zhang,Bihuan Ji,Xin Xu,Mengyue Zhang,Yueshuang Li,Yaqing Xiao,Yingnan Liu
A Cu–N-centered DT–Cu nanozyme enables dual-channel KSM readout. • Chromatography-free sensing enables on-site screening and FL confirmation. • For the first time, B-CDs-referenced readouts cross-validate KSM in food matrices. • The rapid method achieves a low LOD and 90.0–103.6% recoveries in food samples. Rapid screening and quantitative confirmation of kasugamycin (KSM) residues in foods remain challenging without chromatographic instruments. Herein, a low-cost colorimetric/dual-excitation ratiometric fluorescent platform was developed using 3,5-diamino-1,2,4-triazole-coordinated copper nanozymes (DT–Cu). Characterization verified Cu–N-associated active sites and homogeneous elemental distribution. DT–Cu catalyzed H 2 O 2 -mediated oxidation of Ampliflu Red to resorufin, whereas KSM inhibited its peroxidase-like activity through coordination/hydrogen-bonding-associated interactions, causing color fading and red fluorescence attenuation. Blue carbon dots were introduced as an internal reference to construct an I 435 /I 584 readout, improving resistance to matrix and instrumental fluctuations. Under optimized conditions, KSM was detected over 0.001–50 μg mL −1 with a detection limit of 2.31 pg mL −1 within 40 min. The probe showed good 7-day storage stability. Recoveries of 90.0%–103.6% with RSDs of 0.11%–5.89% were obtained in real samples, demonstrating its potential for rapid on-site screening. Download: Download high-res image (188KB) Download: Download full-size image
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PubMed
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Weihao Zhu,Lian Zhang,Peicong Li,Wei Fang,Panyue Zhang
Sewage sludge treatment remains a critical environmental challenge due to its high moisture content and heavy metal contamination. The Fe 2+ /Ca(ClO) 2 /tannic acid (TA) combined conditioning has shown great performances on sludge dewatering, but its influence on heavy metal removal and risk assessment was unclear. In this study the speciation transformation of heavy metals and related mechanisms were comprehensively investigated. The results demonstrated that the sludge conditioning simultaneously enhanced sludge dewatering and promoted heavy metal removal under optimized conditions. Notably, Zn, Cd, and Ni were effectively removed from the sludge solid phase, with removal efficiencies of 39.12 %, 52.49 %, and 30.86 %, respectively. Moreover, the conditioning significantly reduced the ecological risk posed by heavy metals, as indicated by a marked decrease in comprehensive risk index from high to medium levels. The mechanisms involved in the combined effects of oxidation, acidification, and ion binding. Oxidation disrupted extracellular polymeric substance structure, while acidification increased surface positivity, enhancing heavy metal desorption. The Fe 2+ /Ca 2+ competed with heavy metals for binding sites. Additionally, pH reduction and TA chelation further facilitated the transfer of heavy metals into the liquid phase. As a result, the potential mobility index for heavy metals Zn, Cd, Ni, Hg, and As decreased by 33.93 %, 35.98 %, 21.40 %, 26.76 %, and 50.57 %, respectively. This study provides a promising strategy for the safe and resource-efficient utilization of sewage sludge.
研究领域:
环境科学
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化学工程
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废弃物管理
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环境毒理学
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水处理
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Tingting Cao,Qinghui Luo,Peixin Liu,Ma Ge,Liang Liu,Xiyang Fei,Yuanhang Zhao,Bin Cui,Han Cui,Dandan Zhou
To address low sludge resource utilization and high treatment costs, this study uses low-temperature hydrothermal oxidation to pretreat residual sludge, generating calcium salt sludge-induced nuclei (Ca-SC). It demonstrates Ca-SC’s dual role in heavy metal adsorption and low-temperature in-situ cultivation of aerobic granular sludge (AGS) in continuous-flow systems. Hydrothermal oxidation forms a hierarchically porous mixed-crystalline structure. Ca(ClO)₂ increases oxygen-containing groups (16.8 %) and Zeta potential (27.6 %) while preserving surface groups. Notably, Ca-SC achieves a 91.2 % adsorption rate for Pb²⁺, while its removal efficiencies for phenol (24.3 %), NH₄⁺–N (20.1 %), and NO₃⁻–N (9.0 %) are relatively low. Density functional theory attributes this to –OCH₃/–CHO/–COOH coordination and electrostatic interactions. In a 6℃ A/O system, Ca-SC promotes continuous-flow AGS (CFAGS) formation within 15 days, achieving 33.2 % mature particle size and 150-day stability under low-temperature/toxic stress. It enhances extracellular polymeric substance secretion (1.22-fold protein increase), enriches cold-adapted microbes ( Flavobacterium/Psychrobacter ) and nutrient-removing bacteria, improving COD/TN/TP removal by 6.7 %/12.5 %/5.4 %. This work proposes a sludge valorization strategy via functional material engineering, enabling sustainable low-temperature wastewater treatment with efficient pollutant removal and resource recovery.
研究领域:
环境工程
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化学工程
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水处理技术
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废弃物管理
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生物技术
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MICROBIOLOGY
·
2020
·Vol. 58
·期 8
·675-686
·
IF 2.845
Zou Peizhuo,Yang Qian,Wang Hailiang,Xie Guosi,Cao Zhi,Chen Xing,Gao Wen,Huang Jie
Acute hepatopancreatic necrosis disease (AHPND) is one of the most significant bacterial diseases in global shrimp culture, causing severe economic losses. In the present study, we carried out in vitro antimicrobial tests to investigate the disinfection efficacy of 14 common disinfectants toward different AHPND-causing Vibrio spp., including eight isolates of V. parahaemolyticus , four isolates of V. campbellii , and one isolate of V. owensii . Polyhexamethylene biguanidine hydrochloride (PHMB) was revealed to possess the strongest inhibitory activity. Through analyzing and evaluating the results of antimicrobial tests and acute toxicity test, we selected PHMB and hydrogen peroxide (H 2 O 2 ) for further clinical protection test. Clinical manifestations indicated that both PHMB (2 mg/L and 4 mg/L) and H 2 O 2 (12 mg/L) could effectively protect juvenile Penaeus vannamei from the infection of V. parahaemolyticus isolate Vp 362 at 10 6 CFU/ml, and the survival rate was over 80%. When the bacterial concentration was reduced to 10 5 CFU/ml, 10 4 CFU/ml, and 10 3 CFU/ml, the survival rate after treated by 1 mg/L PHMB was 64.44%, 93.33%, and 100%, respectively. According to the results, PHMB and H 2 O 2 showed a lower toxicity while a better protection activity, particularly against a lower concentration of the pathogens. Therefore, these two disinfectants are proved to be promising disinfectants that can be applied to prevent and control AHPND in shrimp culture. Moreover, the methods of this study also provided valuable information for the prevention of other important bacterial diseases and suggested a reliable means for screening potential drugs in aquaculture.
研究领域:
水产养殖学
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微生物学
·
病害防控
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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）