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Tang S, Huang S, Chen P, Wu Z, Zhao T. Comprehensive assessment of enhancing dewaterability of dredged sediments by starch-based flocculant. RSC Adv 2024; 14:17547-17556. [PMID: 38828273 PMCID: PMC11140457 DOI: 10.1039/d4ra02189d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/25/2024] [Indexed: 06/05/2024] Open
Abstract
Dredged sediment poses significant challenges for transportation and subsequent treatment due to its high water content and large volume. Coagulation, a common method of dewatering, can significantly enhance the dewatering performance of dredged sediment. This study synthesized a cationic starch-based flocculant [starch-3-chloro-2-hydroxypropyl trimethylammonium chloride (St-CTA)] through etherification for the flocculation dewatering of dredged sediment. The effectiveness and mechanism of St-CTA as a dewatering flocculant for dredged sediment were investigated. The results demonstrated that when the dosage of St-CTA was 12 mg g-1 TSS (total suspended solids), the dehydration property of dredged sediment substantially improved, with the specific resistance to filtration (SRF) decreasing by 93.3%, the capillary suction time (CST) by 93.5%, and the water content of the filter cake (WC) by 9.7%. The removal rate of turbidity of the supernatant from the conditioned dredged sediment reached 99.6%, accelerating the settling speed and effectively capturing and separating fine particles from the sediment. St-CTA significantly increased the median particle size (D50), altered the microstructure and extracellular polymeric substances (EPS) of the flocs, and increased the fractal dimension of the flocs, making them more compact and conducive to the formation of drainage channels. These findings confirm the feasibility of using potentially environmentally friendly St-CTA as a rapid dewatering conditioning agent for sediment.
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Affiliation(s)
- Shilei Tang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Shaobin Huang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Pengfei Chen
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Zhipeng Wu
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Tianyu Zhao
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
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Wei Y, Jiao Y, Chen H. Polydimethyldiallylammonium chloride inhibits dark fermentative hydrogen production from waste activated sludge. BIORESOURCE TECHNOLOGY 2024; 393:130003. [PMID: 37977493 DOI: 10.1016/j.biortech.2023.130003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023]
Abstract
Polydimethyldiallylammonium chloride (PDDA) is an excellent flocculant for wastewater purification and sludge dewatering, but whether it poses a threat to hydrogen production from waste activated sludge is not known. In this study, the effect and underlying mechanism of PDDA on the dark fermentation of sludge was investigated. The results showed that PDDA reduced cumulative hydrogen production from 3.8±0.1 to 2.4±0.1 mL/g volatile suspended solids at 40 g/kg total suspended solids. PDDA impeded the dark fermentation process by inhibiting the activity of key enzymes, presenting a stronger inhibitory effect on the hydrogen production process than the hydrogen consumption process. Additionally, PDDA inhibited Firmicutes by enriching other microorganisms, thereby impeding hydrogen production via the acetate pathway. This study deepens the understanding of the potential effects of PDDA on sludge treatment and provides a theoretical basis for alleviating the negative effects of quaternary ammonium-based cationic flocculants.
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Affiliation(s)
- Yafei Wei
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Yimeng Jiao
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
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3
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Xiao Y, Feng J, Zhang L, Yang Y, Zhou X, Xu D, Gong M, Yin H, Yuan S. Purification of dredged water by magnetic coagulation: Response surface optimization and dissolved organic matter removal characteristics. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e10996. [PMID: 38369707 DOI: 10.1002/wer.10996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/07/2024] [Accepted: 01/25/2024] [Indexed: 02/20/2024]
Abstract
In the present study, magnetic coagulation was used to treat dredged water and the response surface method was used to optimize process parameters. The dissolved organic matter (DOM) removal characteristics were characterized by three-dimensional fluorescence spectrometry and ultra-high resolution mass spectrometry. During the magnetic coagulation process, the suspended solids (SS) removal rate increased initially and then decreased under conditions of increasing magnetic powder dosage and stirring rate. After magnetic coagulation and precipitation for 20 min, the contents of SS, ammonia nitrogen, chemical oxygen demand, and total phosphorus in the treated dredged water met the requirements of the discharge standard (GB8978-1996, China). Three-dimensional fluorescence results showed that magnetic coagulation selectively removed fulvic acids and humic acid substances. After magnetic coagulation with precipitation for 10 min and 20 min, the total relative content of lignins, tannins, proteins, lipids, aminosugars, unsaturated hydrocarbons, condensed aromatic structures, and carbohydrates decreased by 26.3% and 39.4%, respectively. After magnetic coagulation, the distribution range of small molecule DOM shifted to the low H/C and high O/C regions. This study provides a novel perspective for studies on the removal of DOM in dredged water by magnetic coagulation. PRACTITIONER POINTS: SS and DOM removal were significantly enhanced by the use of magnetic coagulation. SS removal efficiency was affected by stirring rate and magnetic powder dosage. Magnetic coagulation selectively removed fulvic acids and humic acid substances. DOM molecule shifted to low H/C and high O/C regions after magnetic coagulation.
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Affiliation(s)
- Yuanting Xiao
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Jingwei Feng
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Liu Zhang
- Anhui Provincial Academy of Eco-Environmental Science Research, Hefei, China
| | - Yulin Yang
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Xuyang Zhou
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Deqian Xu
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Miao Gong
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
| | - Hao Yin
- CAS Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
- Mass Spectrometry Lab, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, China
| | - Shoujun Yuan
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, China
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4
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Li L, Liang T, Qiu S, Zhang Y, Qu J, Liu T, Ma F. A rapid and simplified method for evaluating the performance of fungi-algae pellets: A hierarchical analysis model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160442. [PMID: 36435261 DOI: 10.1016/j.scitotenv.2022.160442] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/08/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Microbial pellets technology has undergone extensive research recently and has increasingly matured, showing significant promise. However, the performance of microbial pellets cannot be predicted quickly by the current evaluating methods because they are complicated to operate, take a long time, and pose a risk to the environment. In this study, a representative microbial pellet, fungi-algae pellet, was selected as the research object. Eight evaluation parameters and four evaluation indices were chosen to construct the performance evaluation system of the fungal-algal pellets using the analytic hierarchy process (AHP) and weighting method. Combining the correlation analysis and expert opinion, we found that among the eight parameters selected, the adsorption saturation rate of mycelial pellets on algae had the most significant influence weight on the performance of fungi-algae pellet, followed by algal culture time and fungal incubation time. This research proposes and validates the Performance Evaluation Value (PEV) of fungi-algae pellet and its calculation method. We also discuss the effectiveness of this new evaluation system in saving time, cost, and emission reductions. The results of this paper enable the rapid evaluation of fungi-algae pellets and promote the better development of fungi-algae pellets technology and even other multi-microbial symbiotic pellet technologies.
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Affiliation(s)
- Lixin Li
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China.
| | - Taojie Liang
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China; School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Shan Qiu
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yanlong Zhang
- Department of Environmental Science and Engineering, Nankai University Binhai College, Tianjin 300270, China
| | - Jiwei Qu
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China
| | - Tiantian Liu
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China
| | - Fang Ma
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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Li J, Ru S, Yuan C, Wu B, Ji Y, Dai Z, Lei Z, Zhang Z, Yuan T, Li F, Liu M. An all-organic conditioning method to achieve deep dewatering of waste activated sludge and the underlying mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 327:116923. [PMID: 36470188 DOI: 10.1016/j.jenvman.2022.116923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/04/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Among the common treatment/disposal routes of excessive activated sludge from municipal wastewater treatment plant, dewatering process functions as an essential pre-/post-treatment for volume minimization and transportation facilitation. Since inorganic coagulants have long been criticized for their high dosage and solid residue in sludge cake, there is an urgent need for investigations regarding the potential of applying organic chemicals as the conditioner. In this study, combined use of poly dimethyldiallylammonium chloride (PDMD) and tannic acid (TA) were investigated as an all-organic co-conditioning method for sewage sludge pre-treatment. Results showed that this all-organic conditioning strategy can effectively improve the dewaterability of sewage sludge. The capillary suction time reduced from 128.8 s to 23.1 s, and the filtration resistance reduced from 1.24 × 1012 cm/g to 7.38 × 1010 cm/g. The moisture content of dewatered sludge cake decreased to as low as 55.83%, showing the highest dewatering efficiency reported so far. In addition, the combination of PDMD and TA maximized the treating efficiency with very limited consumption of conditioners (added up to 4% of total solid). Based on the physic-chemical and rheological property investigation, it was proposed that the intermediate molecular weight polymer-based flocculation process and the TA agent-based protein precipitation process, could remarkably strengthen the compactness and structure robustness of sludge. In all, this PDMD-TA-based conditioning method suggested practical significance in consideration of its cost-effectiveness and disposal convenience of sludge cake.
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Affiliation(s)
- Jie Li
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China.
| | - Shaoqin Ru
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Chenwei Yuan
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Bo Wu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Yiwen Ji
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Zijun Dai
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Zhongfang Lei
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Zhenya Zhang
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Tian Yuan
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Fengting Li
- College of Environmental Science & Engineering, State Key Laboratory of Pollution Control and Resource Reuse Study, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Misha Liu
- National Engineering Research Center of Dredging Technology and Equipment, 10 Gucui Road, Shanghai, 201314, China; Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
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6
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Zhang W, Han S, Zhang D, Yuan S, Jin X, Shan B. Evaluation of water quality at national scale from 2011 to 2021: Advances and challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 849:157803. [PMID: 35934028 DOI: 10.1016/j.scitotenv.2022.157803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 06/15/2023]
Abstract
More environmental policies and larger investments in protecting the aquatic environment in China have been made in the last decade than previously. It is important to assess how this will affect river water quality. Here, changes in water quality in China between 2011 and 2021 are assessed. Water bodies meeting class III or better defined in the Chinese Environmental Quality Standards for Surface Water (GB3838-2002) were labeled WQI, water bodies meeting class V or better but below class III were labeled WQII, and water bodies below class V were labeled WQIII. The percentage of WQI water bodies increased from 66.1 % in 2011 to 81.0 % in 2021, and the percentages of WQII and WQIII water bodies decreased between 2011 and 2021. The percentage of WQI water bodies increased more quickly and the percentage WQIII water bodies decreased more quickly after 2017 than between 2011 and 2016. The percentages of WQI water bodies in the Northwest River Basin (RB), Pearl RB, Southeast RB, Southwest RB, and Yangtze RB were >80 %, and were higher than the percentages of WQI water bodies in the other five RBs. The percentages of WQI and WQII water bodies increased but the percentage of WQIII water bodies decreased in the Hai RB. The percentage of WQI water bodies increased but the percentages of WQII and WQIII water bodies decreased in the Huai RB, Liao RB, Yangtze RB, and Yellow RB. The river monitoring capacity increased and pollution sources, particularly point sources, became more controlled, and this improved river water quality. River management in China has passed the first stage of controlling pollution sources after 10 years of centralized management. The next stage should be focused on strengthening control of non-point sources of pollution and rehabilitating ecological systems to improve river health.
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Affiliation(s)
- Wenqiang Zhang
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, PR China.
| | - Songjie Han
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Dianwei Zhang
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, Hebei 056038, PR China
| | - Shengguang Yuan
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xin Jin
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, Hebei 056038, PR China
| | - Baoqing Shan
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, PR China
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7
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Jiang F, Feng X, Jiang X, Wang P. Enhanced dewaterability of lake dredged sediments by electrochemical oxidation of peroxydisulfate on BDD anode. CHEMOSPHERE 2022; 307:135832. [PMID: 35963373 DOI: 10.1016/j.chemosphere.2022.135832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Dredged sediments, as a product of mitigating endogenous pollution of rivers and lakes, cause severe environmental pollution without suitable disposal. To reduce dredged sediments, the electrochemical oxidation (EO) of peroxydisulfate (PS) on a boron-doped diamond (BDD) anode (EO/BDD-PS) was utilized to enhance the dewaterability of the dredged sediments. The soluble chemical oxygen demand increased in the EO/BDD-PS system, and more than 70.0% of the specific resistance to filtration was reduced by EO/BDD-PS within 20 min. The optimal conditions were determined to be as follows: current density, 30 mA cm-2; PS dosage 4 g L-1; and initial pH, 6.96. After treatment with EO/BDD-PS, the electronegativity of the sludge flocs was alleviated and the particle size increased from 7.61 to 10.64 μm. Furthermore, proteins and polysaccharides were degraded, and tightly bound extracellular polymeric substances (TB-EPS) and loosely bound EPS (LB-EPS) were effectively transported to soluble EPS (S-EPS). Furthermore, humification of organic matter occurred in S-EPS and LB-EPS when the dredged sediment was treated with EO/BDD-PS. Dominant hydroxyl radicals (•OH) and sulfate radicals (SO4•-) were generated in the EO/BDD-PS system. Moreover, the efficiency of the filtrate as an electrolyte decreased slightly after recycling five times. Therefore, this method may be economical for enhancing the dewaterability of dredged sediments.
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Affiliation(s)
- Feng Jiang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China
| | - Xianlu Feng
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Xia Jiang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China.
| | - Pengfei Wang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China.
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8
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Hu S, Jia Q, Dong L, Han J, Guo M, Guo W. An evaluation method for product design solutions for healthy aging companionship. Front Public Health 2022; 10:919300. [PMID: 36203692 PMCID: PMC9530995 DOI: 10.3389/fpubh.2022.919300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/23/2022] [Indexed: 01/22/2023] Open
Abstract
Background With the development trend of healthy aging and intelligent integration, escort products have become a new means of healthy aging. Healthy old-age care pays attention to the convenience and informatization of life. To meet the needs, designers often design multiple accompanying product solutions, and it is very important to use reasonable evaluation methods to decide on the optimal solution. Purposes A new comprehensive evaluation method is proposed to reduce the subjectivity and one-sidedness of the selection process of intelligent escort product design solutions, and to make the decision more objective and reasonable. Such decisions can enhance the experience and naturalness of the elderly using intelligent products. Methods First, a large number of user interviews were analyzed using the grounded theory, gradually refine through theoretical coding, and abstracted with the design scheme evaluation index. Second, the idea of game-theoretic weighting is used to optimize a linear combination of subjective and objective weights to determine the final weights of each evaluation indicator. Finally, the evaluation and selection are completed based on the solution ranking determined by the approximate ideal solution ranking method (TOPSIS). It is applied for the selection of the elderly escort robot design, and the usability test is conducted using the PSSUQ to verify the selection results. Results A new comprehensive evaluation method can better complete the preferential selection of product design solutions for healthy aging escorts, and reduce the subjectivity and one-sidedness of the evaluation. Conclusion This method compensates for the reliance on personal experience in the selection of options, and improve the subjectivity of the evaluation index determination process and the deviation of index weighting. Improving the objectivity and scientificity of decision-making reduces the blindness of design and production. It also provides a theoretical reference for the research scholars of healthy aging companion products.
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9
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Lv F, Lu X, Song J, Zhu M, Wang S, Xu Y, Chang X. Enhanced Aramid/Al2O3 interfacial properties by PDDA modification for the preparation of composite insulating paper. RESEARCH ON CHEMICAL INTERMEDIATES 2022. [DOI: 10.1007/s11164-022-04825-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Tomak N, Polat TK. Risk prioritization model driven by success factor in the light of multicriteria decision making. OPEN CHEM 2022. [DOI: 10.1515/chem-2022-0188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Some factors in the product development process can increase success. Evaluating the risks and success factors is necessary for a more successful product development process. Some inadequacies arise in classical risk assessment methods due to the subjective nature of likelihood and severity ratings. Different probability and impact values can give the same risk size. Due to these inadequacies, doubts about the accuracy of risk prioritization may arise. In this study, a new risk prioritization model is proposed to eliminate these doubts and to consider their contribution to the success of the process they affect while prioritizing the risks, with a detailed literature review and the support of the experts of the applied company, the risks affecting the product development process. The importance levels of risks and success factors were calculated using the analytical hierarchy process. With the proposed model, unlike the classical method, when calculating the risk size, the risk weight and the total score from the success factors are added to the likelihood and severity values of the risk. Thus, companies will obtain more detailed and objective results, considering success factors and risk importance levels, and use the resources they allocate for risk reduction activities more efficiently.
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Affiliation(s)
- Necmiye Tomak
- Industrial Engineering Department, Engineering Faculty, Sakarya University , Sakarya , Turkiye
| | - Tulay Korkusuz Polat
- Industrial Engineering Department, Engineering Faculty, Sakarya University , Sakarya , Turkiye
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11
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Systematic Evaluation and Optimization of Unmanned Aerial Vehicle Tilt Photogrammetry Based on Analytic Hierarchy Process. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the data acquisition and processing of Unmanned Aerial Vehicle(UAV) oblique photography monomer modeling, it is hard to balance the model quality and the production efficiency. This research applied the Analytic Hierarchy Process (AHP) evaluation method in the field of systems engineering to the management and decision of UAV oblique photography monomer modeling. Firstly, the AHP model is constructed by the expert survey method, and the relative weights of 6 evaluation indicators in the first hierarchies and the comprehensive ones of 3 in the second hierarchies are calculated. Then, each index data of different photo modeling schemes were collected and processed through experiments, and the AHP model was used to systematically evaluate each modeling scheme. Finally, the quadratic function is constructed with two variables, the number of photos and the AHP system score, meanwhile obtaining the optimal scheme by calculation. This is a useful attempt to apply the scientific evaluation method in the field of systems engineering to the production management of UAV aerial surveys. In this way, the efficiency of internal and external data collection and processing can be maximally improved while guaranteeing modeling accuracy.
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12
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Jiao Y, Chen H. Polydimethyldiallylammonium chloride induces oxidative stress in anaerobic digestion of waste activated sludge. BIORESOURCE TECHNOLOGY 2022; 356:127331. [PMID: 35580788 DOI: 10.1016/j.biortech.2022.127331] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The effects and key mechanisms of polydimethyldiallylammonium chloride on anaerobic digestion of waste activated sludge were investigated. Polydimethyldiallylammonium chloride at 38.1 g/kg total solids substantially reduced cumulative methane production from 138.2 ± 5.5 to 49.4 ± 5.0 L CH4/kg volatile solids added, a reduction of 64.3 ± 0.2%. The quaternary ammonium groups on polydimethyldiallylammonium chloride agglomerated sludge flocs by neutralizing negatively charged amino groups in in extracellular polymeric substances, which hindered the release of organic matter. Quaternary ammonium groups induce oxidative stress by inducing the production of reactive oxygen species, thereby inhibiting the activity of anaerobic digestive enzymes. In addition, quaternary amine groups reduced the abundance of hydrolyzing bacteria, acidifying bacteria, and acetylotrophic methanogens. Oxidative stress could be an underappreciated mechanism that quaternary ammonium groups deteriorate anaerobic digestion, which could be transformative for understanding the potential risks of quaternary ammonium cationic flocculants in biological sludge treatment.
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Affiliation(s)
- Yimeng Jiao
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
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13
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Chen J, Li Y, Li M, Shi J, Wang L, Luo S, Liu H. Chemical Flocculation-Based Green Algae Materials for Photobiological Hydrogen Production. ACS APPLIED BIO MATERIALS 2022; 5:897-903. [PMID: 35080839 DOI: 10.1021/acsabm.1c01281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Photobiological hydrogen production is among the most promising ways toward the mass production of hydrogen energy. The use of green algal aggregates to produce photobiological hydrogen has attracted much attention because it overcomes the limitations of sulfur deprivation and oxygen scavengers. However, the current preparation of green algal aggregates that are capable of hydrogen production is time-consuming and laborious, leading to a difficulty in large-scale applications. Here, we demonstrated that the chemical flocculation of green algae is able to generate aggregates for photobiological hydrogen production. We find that Chlorella pyrenoidosa can directly form aggregates in the original liquid cultures by a commercial chemical flocculant, cationic etherified starch, thereby achieving sustainable hydrogen production for 11 days under continuous light irradiation, and the average rate of photobiological production reaches 0.37 μmol H2 (mg chlorophyll·h)-1. This research provides a feasible approach for preparing a low-cost photobiological hydrogen production system helping to realize carbon neutrality.
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Affiliation(s)
- Jie Chen
- School of Chemical Science and Engineering, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Shanghai Research Institute for Intelligent Autonomous Systems, Tongji University, Shanghai 200092, China
| | - Yujie Li
- School of Chemical Science and Engineering, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Shanghai Research Institute for Intelligent Autonomous Systems, Tongji University, Shanghai 200092, China.,Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Mingrui Li
- School of Chemical Science and Engineering, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Shanghai Research Institute for Intelligent Autonomous Systems, Tongji University, Shanghai 200092, China
| | - Jiye Shi
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Lihua Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Shihua Luo
- Department of Traumatology, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Huajie Liu
- School of Chemical Science and Engineering, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Shanghai Research Institute for Intelligent Autonomous Systems, Tongji University, Shanghai 200092, China
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Song Z, Gao H, Zhang W, Wang D. Influence of flocculation conditioning on environmental risk of heavy metals in dredged sediment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113313. [PMID: 34311249 DOI: 10.1016/j.jenvman.2021.113313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 06/28/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
This study comprehensively analyzes the environmental risk of heavy metals (HMs) in the dewatering process of dredged sediment. First, the toxicity leaching capacity, total content, and chemical speciation of the HMs (As, Cd, Co, Cr, Cu, Hg, Mo, Pb, Sb, Sr, Tl, Zn) in dewatered sediment were determined using toxicity characteristic leaching procedure and modified Community Bureau of Reference sequential extraction procedure. The ecotoxicity and environmental risk of the HMs were then evaluated based on sediment quality guidelines, geo-accumulation index, enrichment factor, potential ecological risk, and risk assessment code. The results showed that flocculants reduced the ecological risk of Hg and Mo in sediment, and promoted the transformation of Mo, Sb, and Tl from the biologically active fraction to the more stable fraction. The transformation percentages of Mo, Sb, and Ti were 45.15%, 50.59% and 76.44%, respectively, after chitosan (CTS) treatment, and 64.55%, 31.75% and 99.90%, respectively, after cationic polyacrylamide (CPAM) treatment. CTS reduced the potential risks of bioavailable As, Cr, Cu, Mo, Sb, and Hg by (at most) 46.28%, 45.92%, 43.01%, 100.00%, 44.45%, and 39.69%, respectively, whereas CPAM decreased the ecotoxicity of bioavailable Cd, Co, and Zn by (at most) 27.49%, 16.10%, and 20.89%, respectively. According to the result of principal component analysis, the main factors affecting the environmental risk of HMs in sediment dewatering were nitrogenous organic compounds (mainly protein substances), fulvic acid substances, and minerals. The most essential factor was nitrogenous organic compounds, which accounted for 89.52% of the total variance. Chemical speciation was apparently more suitable for environmental risk assessment of sediment dewatering than total content. This study provides an important basis for controlling the environmental risk of HMs caused by sediment dewatering.
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Affiliation(s)
- Zhenzhen Song
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, Hubei, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Hongyu Gao
- Institute for Resources and Environmental Engineering, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Weijun Zhang
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, Hubei, China
| | - Dongsheng Wang
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, Hubei, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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