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Wang S, Xu Z, Xu X, Gao F, Zhang K, Zhang X, Zhang X, Yang G, Zhang Z, Li R, Quan F. Effects of two strains of thermophilic nitrogen-fixing bacteria on nitrogen loss mitigation in cow dung compost. BIORESOURCE TECHNOLOGY 2024; 400:130681. [PMID: 38599350 DOI: 10.1016/j.biortech.2024.130681] [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: 12/18/2023] [Revised: 04/06/2024] [Accepted: 04/06/2024] [Indexed: 04/12/2024]
Abstract
Excavating nitrogen-fixing bacteria with high-temperature tolerance is essential for the efficient composting of animal dung. In this study, two strains of thermophilic nitrogen-fixing bacteria, NF1 (Bacillus subtilis) and NF2 (Azotobacter chroococcum), were added to cow dung compost both individually (NF1, NF2) and mixed together (NF3; mixing NF1 and NF2 at a ratio of 1:1). The results showed that NF1, NF2, and NF3 inoculants increased the total Kjeldahl nitrogen level by 38.43%-55.35%, prolonged the thermophilic period by 1-13 d, increased the seed germination index by 17.81%, and the emissions of NH3 and N2O were reduced by 25.11% and 42.75%, respectively. Microbial analysis showed that Firmicutes were the predominant bacteria at the thermophilic stage, whereas Chloroflexi, Proteobacteria, and Bacteroidetes were the predominant bacteria at the mature stage. These results confirmed that the addition of the isolated strains to cow dung composting improved the bacterial community structure and benefited nitrogen retention.
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Affiliation(s)
- Shaowen Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Zhiming Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Xuerui Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Feng Gao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Kang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Xin Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China
| | - Xiu Zhang
- North Minzu University Ningxia Key Laboratory for the Development and Application of Microbial Resources in Extreme Environments, Yinchuan 750021, PR China
| | - Guoping Yang
- North Minzu University Ningxia Key Laboratory for the Development and Application of Microbial Resources in Extreme Environments, Yinchuan 750021, PR China
| | - Zengqiang Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling Shaanxi, 712100, PR China
| | - Ronghua Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling Shaanxi, 712100, PR China
| | - Fusheng Quan
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, 712100, PR China.
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Bicalho SF, Pegoraro RF, Almeida Neta MN, Barroso AMF, França LO, Santos LS, Silva RR, Rodrigues MN, Sampaio RA, Viana LB. Biochemical changes, metal content, and spectroscopic analysis in sewage sludge composted with lignocellulosic residue using FTIR-MIR and FTIR-NIR. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:35727-35743. [PMID: 38740679 DOI: 10.1007/s11356-024-33652-9] [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: 03/07/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024]
Abstract
The use of lignocellulosic residues, originating from sawdust, in composting sewage sludge for organic fertilizer production, is a practice of growing interest. However, few studies have explored the effect of the proportion of sawdust and sewage sludge raw materials on composting performance in the humification process. This study assessed the addition of sawdust in the sewage sludge composting process, regarding carbon content, presence of heavy metals, and humification of the organic compost. The experimental design employed was a randomized complete block design with five treatments featuring different proportions of organic residues to achieve C/N ratios between 30-1 (T1: 100% sewage sludge and 0% sawdust, T2: 86% sewage sludge and 14.0% sawdust, T3: 67% sewage sludge and 33% sawdust, T4: 55% sewage sludge and 45% sawdust, and T5: 46.5% sewage sludge and 53.5% sawdust) and five replications, totaling 25 experimental units. The addition of lignocellulosic residue in sewage sludge composting increased the levels of TOC and the C/N ratio, reduced the levels of pH, P, N, Na, Ba, and Cr, and did not interfere with the levels of K, Ca, Mg, S, CEC, labile carbon, and metals Fe, Zn, Cu, Mn, Ni, and Pb. The increase in the proportion of sawdust residue favored the degradation of aliphatic groups, increasing the presence of aromatic structures and reducing humification at the end of composting. The use of sawdust as a lignocellulosic residue in sewage sludge composting is a viable and efficient alternative to produce high-quality organomineral fertilizers.
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Affiliation(s)
| | - Rodinei Facco Pegoraro
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
| | - Maria Nilfa Almeida Neta
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil.
| | - Aline Martins Ferreira Barroso
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
| | - Letícia Oliveira França
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
| | - Leandro Soares Santos
- Universidade Estadual Do Sudoeste da Bahia, UESB. BR 415, Itapetinga, BA, 45700-000, Brazil
| | | | - Márcio Neves Rodrigues
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
| | - Regynaldo Arruda Sampaio
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
| | - Lucas Barbosa Viana
- Universidade Federal de Minas Gerais, Instituto de Ciências Agrárias, Av. Universitária 1000, Montes Claros, MG, 39400-090, Brazil
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Li Y, Chen Y, Sun F, He L, Zhao Y. Study on the effect of biochar combined with Fenton oxidation on the aerobic composting of sludge. ENVIRONMENTAL TECHNOLOGY 2024; 45:1374-1387. [PMID: 36322505 DOI: 10.1080/09593330.2022.2143289] [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: 06/15/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Biochar was derived from rice straw pyrolyzed at 400°C, and biochar was added to the excess sludge at the ratio of 10% DS, 25% DS, and 50% DS as a supplementary skeleton for sludge Fenton pre-treatment. Rice husk biochar mixed with fungus residue as compost conditioner. In this study, we explored the effects of seven groups of composting materials on the composting effect and fertilizer quality under different pre-treatment methods of Fenton-pretreated sludge cake and conventional dewatered sludge cake, and different biochar additions. Specifically, we conducted a 22-day composting experiment using a composting reactor to investigate the effect of rice husk biochar combined with Fenton oxidation on the physicochemical properties of sludge composting. The results of this study showed that the FB50 group significantly increased the composting rate. Nutrient analysis showed that the FB50 group was rich in fertilizer nutrients, such as available phosphorus, and alkali-hydrolyzable nitrogen content increased. Heavy metals (Cu, Cd, Cr, Pb, Zn, Ni) met China's 'Agricultural Sludge Pollutant Control Standard' GB 4284-2018 Grade A standard, with obvious passivation and significantly reduced bioavailability. All these results suggested that biochar coupled with Fenton oxidation was more beneficial to sludge composting.
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Affiliation(s)
- Yanjun Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China
| | - Yu Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China
| | - Fei Sun
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China
| | - Liwenze He
- School of Civil Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China
| | - Yuting Zhao
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China
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Wang M, Duan L, Bai Y, Peng J, Wang Y, Zheng B. Improved export coefficient model for identification of watershed environmental risk areas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:34649-34668. [PMID: 36515872 DOI: 10.1007/s11356-022-24499-z] [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] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
As a complex system under the joint action of man and nature, land use/cover directly or indirectly affects the environmental quality of the freshwater ecosystem. Studying the response of water environment quality to land use/cover change was significant to accurately simulate lake water quality and effectively enhance the management level. As an empirical model, the classical export coefficient model has been widely used and developed in agricultural non-point source pollution research because of its simple structure and convenient application. However, it assumes that the export coefficient of a particular type of land use/cover was constant, ignoring the influence of surface runoff and interception on the output intensity of pollutants in pollutant migration. This study improved the classical export coefficient model by adding factors such as precipitation, surface cover, and topography, evaluated the contribution of land use/cover to total nitrogen load into the lake in Dianchi Lake Basin, and applied the pollution assessment results to the identification of watershed environmental risk areas. The results showed that the improved export coefficient model could better simulate the relationship between land use/cover and total nitrogen load into Dianchi Lake from the basin. At the same time, spatial characteristics of the total nitrogen load contribution of the terrestrial could be represented. The high-risk areas in the basin were mainly cultivated land and construction areas with low vegetation coverage around lakes or downstream. The contribution per unit area to the TN load into the lake from areas with a high risk was 14.28 t/km2, which was 3.47 times that of medium-high-risk areas and 52.28 times that of the medium-risk area. Land use control measures in high-risk areas in the basin should be further strengthened, especially in the lakeside zone.
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Affiliation(s)
- Minghao Wang
- China Metallurgical Industry Planning and Research Institute, Beijing, 100013, China
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Lijie Duan
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Yang Bai
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jiayu Peng
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yong Wang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Binghui Zheng
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
- School of Environment, Tsinghua University, Beijing, 100084, China.
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Xing R, Yang X, Sun H, Ye X, Liao H, Qin S, Chen Z, Zhou S. Extensive production and evolution of free radicals during composting. BIORESOURCE TECHNOLOGY 2022; 359:127491. [PMID: 35724905 DOI: 10.1016/j.biortech.2022.127491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The production of free radicals has been widely documented in natural systems, where they play an important role in most organic matter and contaminants transformation. Here, the production and evolution of free radicals were systematically investigated during composting. Results indicated that multiple reactive oxygen species and environmentally persistent free radicals (G-factor 2.003-2.004) were generated with dynamic changes during composting. The ·OH yield fluctuated significantly with a maximum content of 365.7-1,262.3 μmol/kg at the thermophilic phase of composting, which was closely correlated with the changes of Fe (II) (Pearson's r = 0.928-0.932) and the electron-donating capacity of humus (Pearson's r = 0.958-0.896) during composting. Further investigation suggested that microorganisms driven iron/humus redox conversion could contribute to the production and dynamic changes of free radical during composting. These findings highlight the abiotic processes involving free radicals, and provide a new perspective for humification and contaminants removal during composting.
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Affiliation(s)
- Ruizhi Xing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xinggui Yang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Hanyue Sun
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaoyu Ye
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Hanpeng Liao
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shuping Qin
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhi Chen
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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Municipal Sewage Sludge Composting in the Two-Stage System: The Role of Different Bulking Agents and Amendments. ENERGIES 2022. [DOI: 10.3390/en15145014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study assessed the effect of different lignocellulosic amendments and bulking agents on compost stability (based on a 4 day respiration activity test, AT4, and self-heating factor, SHF) and maturity (based on the nitrification index Initr and the ratio of C in humic acids, HA, to total organic carbon, TOC, in compost, CHA/TOC). With all feedstock compositions (FCs), the share of sewage sludge was 79% (wet mass). For FC1, wood chips (13.5%) and wheat straw (7.5%) were used as bulking agents and amendments; for FC2, instead of wood chips, energy willow was added; for FC3, pine bark (13.5%) and conifer sawdust (7.5%) were used. All FCs produced stable and mature compost; however, with FC2, the thermophilic phase last 3 days longer than with the other FCs. Moreover, an AT4 value below 10 g O2/kg dry mass (d.m.) was obtained the earliest with FC2 (after 45 days, ca. 15–20 days earlier than with other FCs). With FC2, Initr below 0.5 was obtained in ca. 60 days, 10 days earlier than with FC3 and 30 days earlier than with FC1. The highest net increases in HS (86.0 mg C/g organic matter (OM)) and HA (56.3 mg C/g OM) were also noted with FC2; with other FCs, the concentrations of these compounds were from 1.3- to 1.5-fold (HS) and from 1.4- to 1.9-fold (HA) lower. With FC2, the highest CHA/TOC (15.5%) was also noted, indicating that this compost contained the largest share of the most stable form of organic carbon. The rates of OM removal in the bioreactor ranged from 7.8 to 10.1 g/(kg d.m.·day). The rates of SH and HA formation ranged from 1.63 to 4.83 mg C/(g OM·day) and from 1.23 to 1.80 mg C/(g OM·day), respectively. This means that, through the choice of the amendments and bulking agents, the length of the composting time needed to obtain a stable and mature product can be controlled.
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