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Zhang Q, Tang T, Cui G, Wang Z, Liu Y. Pressurized electro-osmotic dewatering treatment of sludge: focusing on the influences on nutrients for agricultural application. ENVIRONMENTAL TECHNOLOGY 2024; 45:4805-4819. [PMID: 37970842 DOI: 10.1080/09593330.2023.2283090] [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: 06/15/2023] [Accepted: 09/09/2023] [Indexed: 11/19/2023]
Abstract
Sewage sludge requires effective dewatering and high nutrients retention before disposal for agricultural application. Pressurized electro-osmotic dewatering (PEOD) process with low energy consumption can effectively remove water from sludge, but the influences of PEOD process on nutrients for agricultural application still lacks in-depth research. In this study, the influences of PEOD process on nutrients for agricultural application were investigated, including organic matter, nitrogen, phosphorus, potassium and silicon contents. Layered experiments were conducted to investigate the layered variation of nutrients in sludge and to understand the potential change mechanisms. The experimental results showed that PEOD process caused small losses (<10%) of organic matter and total phosphorus (TP) in sludge, but caused 11.2-18.4% loss of total nitrogen (TN). PEOD process also caused 18.6-27.0% loss of total potassium (TK) and over 80% loss of available potassium in sludge, and could weaken the potential salt damage during the agricultural application of sludge. Furthermore, the available phosphorus content of sludge in the anode area increased significantly after the PEOD process, indicating that PEOD process could enhance the phosphorus bioavailability of sludge in the anode area. Besides, PEOD process caused a slight loss of silicon components in sludge, but improved the long-term silicon dissolution and release ability of sludge. This work could expand the knowledge about the influences of PEOD process on sludge nutrients and provide scientific guidance for the agricultural application of PEOD sludge.
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Affiliation(s)
- Qiming Zhang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Tian Tang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Guodong Cui
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Zheng Wang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Yangsheng Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
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Chen Y, Yang W, Zou Y, Wu Y, Mao W, Zhang J, Zia-Ur-Rehman M, Wang B, Wu P. Quantification of the effect of biochar application on heavy metals in paddy systems: Impact, mechanisms and future prospects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168874. [PMID: 38029988 DOI: 10.1016/j.scitotenv.2023.168874] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/31/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023]
Abstract
Biochar (BC) has shown great potential in remediating heavy metal(loid)s (HMs) contamination in paddy fields. Variation in feedstock sources, pyrolysis temperatures, modification methods, and application rates of BC can result in great changes in its effects on HM bioavailability and bioaccumulation in soil-rice systems and remediation mechanisms. Meanwhile, there is a lack of application guidelines for BC with specific properties and application rates when targeting rice fields contaminated with certain HMs. To elucidate this topic, this review focuses on i) the effects of feedstock type, pyrolysis temperature, and modification method on the properties of BC; ii) the changes in bioavailability and bioaccumulation of HMs in soil-rice systems applying BC with different feedstocks, pyrolysis temperatures, modification methods, and application rates; and iii) exploration of potential remediation mechanisms for applying BC to reduce the mobility and bioaccumulation of HMs in rice field systems. In general, the application of Fe/Mn modified organic waste (OW) derived BC for mid-temperature pyrolysis is still a well-optimized choice for the remediation of HM contamination in rice fields. From the viewpoint of remediation efficiency, the application rate of BC should be appropriately increased to immobilize Cd, Pb, and Cu in rice paddies, while the application rate of BC for immobilizing As should be <2.0 % (w/w). The mechanism of remediation of HM-contaminated rice fields by applying BC is mainly the direct adsorption of HMs by BC in soil pore water and the mediation of soil microenvironmental changes. In addition, the application of Fe/Mn modified BC induced the formation of iron plaque (IP) on the root surface of rice, which reduced the uptake of HM by the plant. Finally, this paper describes the prospects and challenges for the extension of various BCs for the remediation of HM contamination in paddy fields and makes some suggestions for future development.
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Affiliation(s)
- Yonglin Chen
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
| | - Wentao Yang
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China.
| | - Yuzheng Zou
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
| | - Yuhong Wu
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
| | - Wenjian Mao
- Guizhou Environment and Engineering Appraisal Center, Guiyang, China
| | - Jian Zhang
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
| | - Muhammad Zia-Ur-Rehman
- Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Bing Wang
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
| | - Pan Wu
- Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, College of Resource and Environmental Engineering, Guizhou University, Guiyang, China
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Tian Y, Dong X, Fan Y, Yang D, Chen R. Hydrothermal alkaline synthesis and release properties of silicon compound fertiliser using high-ash coal slime. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:99652-99665. [PMID: 37615911 DOI: 10.1007/s11356-023-29413-9] [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: 06/25/2023] [Accepted: 08/16/2023] [Indexed: 08/25/2023]
Abstract
High-ash coal slime is difficult to utilise as a boiler fuel, and its accumulation results in environmental pollution. In this study, we describe a new method for the preparation of high-ash coal slime silica compound fertiliser (HASF) using CaO-KOH mixed hydrothermal method to optimize the utilization of this industrial waste and relieve the pressure on the fertiliser industry. The coal slime (D0) used in this study and its dry basis ash content by 1 mol/L and 4 mol/L sulfuric acid pre-activation (D1, D4) were greater than 85%. The effective silicon content of D0, D1, and D4 silica compound fertilisers reached 30.24%, 31.24%, and 17.35%, respectively, and the sums of effective silica-calcium-potassium oxides were 57.28%, 58.87%, and 48.16%, respectively, under the optimal reaction conditions of 230 °C, 15 h, and 1 mol/L KOH, which met the market requirements, as determined using single-factor experiments. We used XRD, FTIR, and SEM-EDS analysis techniques to demonstrate that tobermorite and leucite were the main mineral phases of the compound fertiliser, and activated coal slime D4, which contains only quartz single crystals, required more demanding reaction conditions in the synthesis reaction. Subsequently, the cumulative release pattern of HASF silica was well described by the power function equation via repeated extraction and dissolution experiments, with the dissolution rate following D4 > D1 ≈ D0. Furthermore, 4 mol/L sulfuric acid pre-activation resulted in the enrichment of HASF combined with organic matter and increased the slow-release rate of HASF silica. Thus, the synthesized HASF could have potential application prospects in soil improvement and fertilisation.
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Affiliation(s)
- Yanfei Tian
- Department of Mineral Processing Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
- Shanxi Engineering Research Center of Ecological Mining, Taiyuan, 030024, China
| | - Xianshu Dong
- Department of Mineral Processing Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China.
- Shanxi Engineering Research Center of Ecological Mining, Taiyuan, 030024, China.
| | - Yuping Fan
- Department of Mineral Processing Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
| | - Dong Yang
- State Center for Research and Development of Oil Shale Exploitation, Beijing, 100083, China
- Key Laboratory of In Situ Property Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Ruxia Chen
- Department of Mineral Processing Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
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Wang Q, Li JS, Poon CS. An iron-biochar composite from co-pyrolysis of incinerated sewage sludge ash and peanut shell for arsenic removal: Role of silica. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 313:120115. [PMID: 36122654 DOI: 10.1016/j.envpol.2022.120115] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/26/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Modification of biochar by low-cost iron sources has gained increasing attention to improve pollutants removal performance and reduce production costs compared to conventional chemical modifications. While such iron sources generally have complex compositions, their effects on properties of the iron-biochar composite are not well investigated. This study produced an iron-biochar (RBC) composite from co-pyrolysis of incinerated sewage sludge ash (ISSA) and peanut shell, and examined the role of silica with widespread existence in ISSA and other low-cost iron sources on properties of the iron-biochar composite relevant to As(III)/As(V) removal. Silica was found to react with iron during the pyrolysis process at 850 °C and formed iron silicon at the expense of producing zero valent iron and Fe3O4 which resulted in a poorer removal efficacy for As(III) and As(V) compared to the iron-biochar (FBC) made from pure Fe2O3 and peanut shell. Moreover, a high leaching of reactive silica from RBC was observed which affected the formation of corrosion products of ZVI and competed with arsenic for active adsorption sites. Despite this, RBC still exhibited a maximum adsorption capacity of 17.44 and 57.56 mg/g towards As(III) and As(V) respectively at pH 3.0. Overall, this study provides an interesting insight into upcycling ISSA into useful media for sorptive removal of arsenic from aqueous solutions.
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Affiliation(s)
- Qiming Wang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Hung Hom, Kowloon, Hong Kong; Research Centre for Resources Engineering Towards Carbon Neutrality, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Jiang-Shan Li
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Hung Hom, Kowloon, Hong Kong
| | - Chi Sun Poon
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Hung Hom, Kowloon, Hong Kong; Research Centre for Resources Engineering Towards Carbon Neutrality, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
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