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Luo C, Li S, Ren P, Yan F, Wang L, Guo B, Zhao Y, Yang Y, Sun J, Gao P, Ji P. Enhancing the carbon content of coal gangue for composting through sludge amendment: A feasibility study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123439. [PMID: 38325505 DOI: 10.1016/j.envpol.2024.123439] [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: 09/15/2023] [Revised: 01/03/2024] [Accepted: 01/22/2024] [Indexed: 02/09/2024]
Abstract
Cocomposting coal gangue and sludge eliminates the challenge of utilizing coal gangue. However, there is limited understanding about the feasibility of cocomposting sludge and coal gangue, as well as the composting indicators, functional microorganisms, and safety risks involved. Therefore, this study evaluated the feasibility of enhancing carbon composting in coal gangue by incorporating sludge along with sawdust as a conditioner. Three laboratory-scale reactors were designed and labeled as T1 (20 % coal gangue, 60 % sludge, and 20 % sawdust), T2 (40 % coal gangue, 40 % sludge, and 20 % sawdust), and T3 (60 % coal gangue, 20 % sludge, and 20 % sawdust). Seed germination and plant growth assessments were conducted to ensure compost stability and assess phytotoxicity to cabbage (Brassica rapa chinensis L.) in terms of growth and biomass. The results indicated that the temperature, pH, EC and ammonia nitrogen of all three reactor conditions met the requirements for product decomposition. Composting was successfully achieved when the sludge proportion was 20 % (T3). However, when the sludge proportion was markedly high (T1), the harmlessness of the compost was reduced. The germination indices of T1, T2, and T3 reached 95 %, 122 %, and 119 % at maturity, respectively. This confirmed that the harmless cycle, which involved promoting condensation and aromatization, enhancing decay, and reducing composting time, was shorter in T2 and T3 than in T1. Coal gangue can also serve as a beneficial habitat for microorganisms, promoting an increase in their population and activity. Potting experiments in sandy soil revealed that the mechanism of action of compost products in soil included not only the enhancement of soil nutrients but also the improvement of soil texture. The results of this study suggest that using coal gangue as a raw material for composting is an efficient and environmentally friendly approach for producing organic fertilizers.
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Affiliation(s)
- Chi Luo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Shaohua Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Pengyu Ren
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Fan Yan
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Lu Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Bin Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yimo Zhao
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yue Yang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jian Sun
- Institute of Agricultural Quality Standard and Testing Technology, Jilin Academy of Agricultural Sciences, Changchun, China
| | - Pengcheng Gao
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Puhui Ji
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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Syed Masoodhu S, Natarajan N, Vasudevan M. Modification of bentonite with black cotton soil and carboxyl methyl cellulose for the enhancement of hydraulic performance of geosynthetic clay liners. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2024; 89:1846-1859. [PMID: 38619907 DOI: 10.2166/wst.2024.093] [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: 01/18/2024] [Accepted: 03/13/2024] [Indexed: 04/17/2024]
Abstract
Geosynthetic clay liners (GCLs) are mostly used as flow barriers in landfills and waste containments due to their low hydraulic conductivity to prevent the leachate from reaching the environment. The self-healing and swell-shrink properties of soft clays (expansive soils) such as bentonite enable them as promising materials for the GCL core layers. However, it is important to modify their physico-chemical properties in order to overcome the functional limitations of GCL under different hydraulic conditions. In the present study, locally available black cotton soil (BCS) is introduced in the presence of an anionic polymer named carboxymethyl cellulose (CMC) as an alternative to bentonite to enhance the hydraulic properties of GCL under different compositions. The modified GCL is prepared by stitching the liner with an optimum percentage of CMC along with various percentages of BCS mixed with bentonite. Hydraulic conductivity tests were performed on the modified GCL using the flexi-wall permeameter. The results suggest that the lowest hydraulic conductivity of 4.58 × 10-10 m/s is obtained when 25% of BCS is blended with bentonite and an optimum 8% CMC and further addition of BCS results in the reduction of the hydraulic conductivity.
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Affiliation(s)
- S Syed Masoodhu
- Department of Civil Engineering, Dr Mahalingam College of Engineering and Technology, Pollachi, Tamil Nadu 642003, India
| | - N Natarajan
- Department of Civil Engineering, Dr Mahalingam College of Engineering and Technology, Pollachi, Tamil Nadu 642003, India E-mail:
| | - M Vasudevan
- Department of Agricultural Engineering, Bannari Amman Institute of Technology, Sathyamangalam, Tamil Nadu 638 401, India
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