WATER SCIENCE AND TECHNOLOGY
·
2015
·Vol. 73
·期 2
·260-266
·
IF 1.106
Zha F. G.,Yao D. X.,Hu Y. B.,Gao L. M.,Wang X. M.
The landfill leachate treated by sonication in presence of Fe 2+ (US/Fe 2+ ) and then by photo-Fenton achieved the highest total organic carbon (TOC) removal efficiency among the screened processes. The lower initial pH, dosage of Fe 2+ and initial concentration of leachate were helpful in raising TOC removal efficiency of leachate by US/Fe 2+ . The optimal conditions for the US-photo-Fenton process were as follows: initial pH at 3.0, [H 2 O 2 ]/[TOC 0 ] at 2, [H 2 O 2 ]/[Fe 2+ ] at 5 and initial concentration of landfill leachate at 600 mg/L. The removal efficiency of TOC, chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD 5 ) were 68.3, 79.6 and 58.2%, while the BOD 5 /COD rose from 0.20 to 0.43 at optimum condition. Based on gas chromatography–mass spectrometry (GC-MS) results, 36 of a total of 56 pollutants were completely degraded by US-photo-Fenton treatment.
研究领域:
环境工程
·
水处理技术
·
高级氧化过程
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污染控制化学
·
环境化学
✓ 已验证
DOI
高影响因子
Water
·
2025
·Vol. 17
·期 2
·179
·
IF 3
Wei Xu,Xiaoping Zhang,Guichang Zhang,Xin Zhang
The treatment of wastewater using microalgae is regarded as a green and potential technology. However, its engineering application has been largely hindered because of the limitation of microalgae separation and harvesting. Therefore, immobilization technology has been widely used to embed microalgae for wastewater treatment. In this paper, sodium alginate (SA) and polyvinyl alcohol (PVA) as the common immobilized carriers were used to immobilizeankistrodesmus falcatusfor simulated slaughtering wastewater (SSW) treatment. The experimental results of the mass transfer and adsorption of immobilized carriers were found to show that the mass transfer of SA-SiO2gel balls (SS-GB) was better than PVA-SA gel balls (PS-GB) and that the adsorption of PS-GB was better than SS-GB. When immobilizing microalgae with the two kinds of carriers, it was found that SA-SiO2microalgal spheres (SS-MS) were better than PVA-SA microalgal spheres (PS-MS) for the maintenance of microalgal cell activity and that PS-MS were better than SS-MS for the resistance to biodegradation. This is because the carrier of PS-MS had a thick shell and dense structure, while the carrier of SS-MS had a thin shell and loose structure. The results of SSW treatment by PS-MS and SS-MS were found to show that the total phosphorus (TP) removal rates of PS-MS and SS-MS were 90.31% and 86.60%, respectively. This indicates that the TP removal effect of PS-MS was superior to that of SS-MS. The adsorption kinetics simulation showed that the adsorption of TP onto PS-GB was controlled by chemisorption and that the adsorption of TP onto SS-GB was controlled by physical adsorption. The chemical oxygen demand (COD) and ammonium nitrogen (NH4+-N) removal of PS-MS were 9.30% and 10.70%, respectively, and the COD and NH4+-N removal of SS-MS were 54.60% and 62.08%, respectively. This indicates that the COD and NH4+-N removal effect of SS-MS were superior to PS-MS. This is the result of the combined action of the degradation by microalgal cells and adsorption by the carrier.
研究领域:
环境科学
·
生物技术
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产品关联
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Xinyue Jiang,Defu Liu,Guodong Jiang,Yuqun Xie
A technique for monitoring chemical oxygen demand (COD), total nitrogen (TN), ammonia (N-NH4), and phosphate (P-PO4) in surface water with a targeted signal multielectrode system (Cu, Ir, Rh, Co(OH)2, and Zr(OH)4 electrodes) is proposed for the first time. Each water quality index is specifically detected by at least two electrodes with distinct selectivity sensing mechanisms. Cyclic voltammetry and electrochemical impedance measurements are employed for multidimensional signal acquisition, complemented by normalization and Least Absolute Shrinkage and Selection Operator (LASSO) for principal feature extraction and dimension reduction. Multiple linear regression (MLR), partial least-squares (PLS), and eXtreme Gradient Boosting (XGBoost) were employed to evaluate the established prediction model. The precisions of the multielectrode system are ±10%/±5 ppm of COD, ±10%/±0.2 ppm of TN, ±5%/±0.1 ppm of N-NH4, and ±5%/±0.01 ppm of P-PO4. The analysis time of the multielectrode system is reduced from hours to minutes compared with traditional analysis, without any sample pretreatment, facilitating continuous online monitoring in the field. The developed multielectrode system offers a feasible strategy for online in situ monitoring of surface water quality.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2023
·
IF 4.8
Gaogui Jing,Xiangsong Meng,Jing Chen,Wei Sun,Przemyslaw Boguslaw Kowalczuk,Zhiyong Gao
Efficient treatment and purification of mineral processing wastewater (MPW) have not been sufficiently investigated in the past though they are of great importance for sustainable mineral processing. Herein, a unique electrocoagulation (EC) reactor with aluminium scraps as anode material was developed for the treatment of real industrial MPW containing residual flotation reagents (major contributor to chemical oxygen demand, COD) and suspended particles. It was found that the active coagulants produced from the dissolution of aluminium scraps can play a key role in the purification of MPW. Under the conditions of initial pH 9, current 1 A, and processing time 90 min, the removal rate of COD was 74% while the turbidity can be almost completely removed. The mechanism lies in that most of the flotation reagents was adsorbed on the surfaces of suspended mineral particles, namely, montmorillonite, quartz, garnet, chlorite and mica, and then precipitated with the mineral particles. This innovative technology of utilizing wasted aluminium scraps to treat MPW is in line with the green development.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2018
·Vol. 10
·期 16
·1902-1910
·
IF 2.073
Xiaojuan Cao,Min Zhou,Yongjun Ma,Fen Liu,Ning Yang,Yun Xie
In this work, we have developed a rapid determination method for the low-level chemical oxygen demand (COD) index in dye-containing wastewater samples, which is based on a novel sample treatment technique that combines the advantages of microwave-assisted digestion and two-step wet-chemical oxidation with two oxidants such as KMnO4 and Ce(SO4)2. By using methylene blue (MB) as the model dye molecule, we have optimized the determination conditions and affirmed the validity of the COD assay for dye-containing wastewater. In particular, specific molar proportion relationships have been found between the added amounts of oxidants and catalysts in two kinds of digestion solutions, which exist as n(KMnO4) : n(MnSO4) = 6 : 1 and n(Ce(SO4)2) : n(Cu2+ + Ag+) = 4 : 3. Additionally, potassium tungstate as a specific reagent is introduced into the wet-chemical digestion reaction of water samples for the first time, and its positive influence on COD determination is investigated. Under optimized operating conditions, the average digestion efficiency of the MB molecule in a standard dye sample is up to 99.5%. The COD quantitative range of the MB dye is 1.0–75.0 mg O2 L−1 with a correlation coefficient (R2) of 0.9996 and a lower limit of detection (LOD) of 0.33 mg O2 per L (3σ). Moreover, the application of the method to another three types of phenothiazine dyes has also achieved satisfactory results.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
JiaJia Xue,Dandan Lei,Xiumei Zhao,Yaru Hu,Shijie Yao,Kuangfei Lin,Zejian Wang,Changzheng Cui
Various pollutants are released during pharmaceutical production processes, which is of great concern. Most studies have focused on the terminal treatment results of mixed pharmaceutical wastewater, and further research on wastewater from the production processes is required. This study investigated the wastewater quality indicators, residual antibiotics, and biological toxicity of the wastewater during the production process in a large pharmaceutical producing factory in Northern China. The wastewater contained numerous organic pollutants, with the chemical oxygen demand (COD) values ranging from 2.0 × 10 3 to 2.6 × 10 5 mg L −1 and the total nitrogen (TN) values ranging from 1.3 × 10 3 to 2.0 × 10 4 mg L −1 . High concentrations of cephalexin and cefradine remained in the wastewater of the production workshop, with the highest concentration of cefradine reaching 1328 mg L −1 . The wastewater from the oxidation and solvent recovery workshops was more toxic to Vibrio fischeri and Daphnia magna than that of other workshops. Moreover, the biological acute toxicity of wastewater was significantly correlated with the concentration of COD and TN ( p < 0.01). This study provides new insights into the treatment of antibiotic production wastewater, illuminating the incomplete extraction of products and the significant risk posed by pharmaceutical wastewater to the environment.
研究领域:
环境科学
·
药学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Hui-Wen Huo,Xiao-Qiong Wu,Jia-Fang Xie,Ding Li,Quan-Bao Zhao,Yu-Ming Zheng
Chemical oxygen demand (COD) indicates the relative content of organics in water. The electrochemical measurement of COD is a promising ecofriendly alternative method for rapidly, automatically, and highly accurately determining the content of organics in water. However, the key anodes must possess high catalytic efficiency and long-term stability, be easy to prepare, and be free of heavy metal leaching. Therefore, in this study, a SnO2–Sb-based porous anode was prepared using simple coating and calcination. Because of its porous, conductive, and robust Ti felt/Pt (TF/Pt) substrate, the anode (TF/Pt/SnO2–Sb) possessed stable current responses that were highly correlated (R2 = 0.999) with COD measurements in the range of 20–6000 mg L–1. The detection limit was 3.03 mg L–1 (at a signal-to-noise ratio of 3), and the relative standard deviation was within 3.2% (n = 10), which is superior to those of the standard dichromate detection method. The further assembly of a flow-through system with the proposed anode exhibited a wider linear range of up to 8000 mg L–1 at a lower sample injection volume of 50 μL. These results suggest the application potential of the electrochemical method with the porous TF/Pt/SnO2–Sb anode as a reliable alternative for sustainable COD determination.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Xiong Ke,Huiling He,Zhi Qin,Tuo Wei,Acong Chen,Qing Wang,Guanglei Qiu,Chaohai Wei
Zero-discharge industrial wastewater treatment is an inevitable goal that enterprises seek for the green and sustainable development. However, the generation and treatment of mixed salt present an enormous challenge. This study, taking the practical case of coking wastewater treatment, analyzes the influencing factors of salt and proposes a load salt reduction strategy. The results show that chemical oxygen demand (COD) is the main factor for the change in salt content. When the influent COD of coking wastewater is 3863.93 ± 466.61 mg/L, the relationship between salt reduction (y) and the COD change rate (x) in the treatment process follows the ExpGro1 natural exponential function: y = −2.2378 × exp (-x/17.0839) + 2.2570, with a fitting degree of 0.9938. In the case where the economic and environmental benefits of this strategy are positive (with a maximum COD reduction of 0.5796 kg/m 3 ), every 1.0 kg/m 3 reduction in COD will result in a reduction of 2.5002 ± 0.2980 mS/cm·m 3 in salinity, 3.7391 ± 0.9245 CNY/m 3 in operating costs, and 1.4989 ± 0.6509 kg CO 2 /m 3 in carbon emissions. Moreover, this study proves that the adsorption - oxic/hydrolytic & heterotrophic denitrification/oxic (A-OHO) process can effectively reduce the load salt. Other salt reduction strategies (technology salt reduction and cycle salt reduction) and the concept of strategic cooperative operation are also further explored.
研究领域:
环境科学
·
污水处理
✓ 已验证
DOI
高影响因子
ACS Sensors
·
2020
·
IF 7.333
Huiyun Jiang,Bing Sun,Yan Jin,Junjie Feng,Hongwei Zhu,Lin Wang,Shucai Zhang,Zhe Yang
On-site simultaneous quantification of multiple contaminants in a water body is challenging, especially for parameters requiring complicated chemical reactions to measure such as Chemical Oxygen Demand (COD), ammonia nitrogen, and phosphate. A novel disposable multiplexed microfluidic device has been developed herein that allows the quantitative detection of up to five parameters at once. Solid reagent rather than commonly used liquid reagent was used to ensure long shelf life, and a “flow to dissolve” mechanism was provided accordingly for the thorough dissolution and mixing of a solid reagent on chip. Samples from river water and industrial wastewater were tested using the microfluidic chip, showing less than 15% deviation from results acquired with the traditional standard method. The test time though was only 1/6 of that required by the traditional method. In addition, the feasibility of using a smartphone to collect the colorimetric signal was discussed, and a data analysis method was provided for quantification purposes. The combination of the multiplexed chip and smartphone imaging provides a convenient and practical way to obtain accurate information on the water quality within a short period of time without the use of any sophisticated instruments.
研究领域:
环境科学
·
生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2019
·
IF 4.865
Cong Wei,Hengping Wu,Qiaoping Kong,Jingyue Wei,Chunhua Feng,Guanglei Qiu,Chaohai Wei,Fusheng Li
The refractory nature of residual COD in bio-treated coking wastewater (BTCW) creates barriers for its further treatment and reclamation. It is necessary to fractionate the residual COD in BTCW associated with characterization of solution properties. In this paper, a stepwise process composed of membrane filtration , coagulation, adsorption and ozonation was proposed to fractionate residual COD in the BTCW, in which the COD was stepwise reduced to near zero. In addition, the correlation between COD and water quality indexes as well as solution properties were discussed together with a safety assessment of the water quality. Results showed that the residual COD fractionation percentage contributed by suspended solids, colloids, dissolved organics and reductive inorganic substances in the BTCW was 43.7%, 22.1%, 26.2% and 4.9%, respectively. By stepwise fractionating of these substances, the residual COD was reduced from 168.8 to 5.2 mg L −1 , and the UV 254 value decreased from 1.90 to 0.15 cm −1 . In addition, the particle size of the dominant substances contributing to the residual COD was smaller than 450 nm. Among these substances, the hydrophobic fraction accounted for 78.66% (in the term of TOC). Three-dimensional excitation-emission matrix (3D-EEM) analysis showed that hydrophobic neutral substances (HON) were the main fluorescence constituent in the BTCW, which was highly removable by adsorption. The residual COD after adsorption was mainly composed of reductive inorganic substances . Apart from pursuit of high COD removal rates, more emphasis should be given to the removal of toxic COD. Correlations were observed between the residual COD and water quality indicators as well as solution properties, providing a guideline for optimized removal of residual COD in the BTCW. In summary, these results gave a referential information about the nature of residual COD in the BTCW for the selection of advanced treatment technologies and the management of water quality safety.
研究领域:
环境科学
·
污水处理
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2021
·Vol. 130
·期 5
·1456-1465
·
IF 3.772
Zhao J.,Tao X.,Wang S.,Li J.,Shao T.
AimsThis study aimed to evaluate the feasibility of sorbic acid (SA) as a silage additive and its effects on fermentation quality and aerobic stability of high dry matter (DM) silage.Methods and ResultsHigh DM rice straw was ensiled with distilled water (C), 1 × 106 CFU per gram fresh weight (FW) Lactobacillus plantarum and 1 × 106 CFU per gram FW Lactobacillus buchneri (LP+LB) or SA for 45 days with a subsequent aerobic stability test. After ensiling, LP+LB silage had the highest lactic acid (LA) content and the lowest pH value, whereas SA silage had the highest DM and water‐soluble carbohydrate (WSC) contents, and the lowest ethanol and ammonia nitrogen (NH3‐N) contents among all silages (P < 0·001). Compared to C silage, SA significantly (P < 0·01) reduced the counts of yeasts but not lactic acid bacteria (LAB). During 6‐day aerobic exposure, the continuous pH increase and LA decrease were observed in C and LP+LB silages, and there was no significant change in pH, DM, NH3‐N and WSC contents of SA silage over the whole aerobic exposure. The SA addition slowed the decline of LA and acetic acid (AA) contents as well as the growth of yeasts and aerobic bacteria under aerobic exposure.ConclusionIn this study, L. buchneri could not function in high DM rice straw silage while SA effectively improved both the fermentation quality and aerobic stability.Significance and Impact of the StudyThe SA was more effective than dual‐purpose inoculants to improve the aerobic stability of high DM rice straw silage. Thus, SA can be served as a potential antifungal additive for silage with high DM.
研究领域:
动物科学
·
微生物学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Fangcong Hua,Zonghui Zhang,Zhibo Zhao,Xiaohong Hou,Jianhua Qu,Chongning Lv,Qi Hu
Quaternary-ammonium chitosan (CT-CTA) is a popular water treatment agent, and its electropositivity and cation strength are improved compared with chitosan. The use of CT-CTA is widely advocated to remove suspended particles and organic matter from wastewater. However, the solubility of CT-CTA is an important factor affecting the performance of CT-CTA, which is a neglected problem in previous studies. In the study, CT-CTA with different solubilities were prepared by adjusting pH from 2 to 7 in preparation, and their applications were explored in wastewater. When the pH was 2, 2.5, or 3, the obtained CT-CTA was a dissolved state. The turbidity and color removal were 95 % - 98 % and 60 % - 74 %, respectively. When the pH was 4, 5, 6, or 7, the obtained CT-CTA was a solid state. The turbidity and color removal were 30 % - 63 % and 90 % - 97 %, respectively. For domestic-wastewater treatment, CT-CTA in a dissolved state removed 92 % of turbidity and 50 % of chemical oxygen demand (COD). CT-CTA in a solid state removed 86 % of turbidity and 64 % of COD with poly aluminum chloride (PAC). The results illustrated the performance of CT-CTA with different solubilities, which can broaden its application in wastewater treatment .
研究领域:
环境科学
·
材料科学
✓ 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）