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Bryson E, Anastasi A, Bricknell L, Kift R. Household dog fecal composting: Current issues and future directions. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024. [PMID: 38924209 DOI: 10.1002/ieam.4970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/05/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
Dog feces are a known source of nutrient, pathogen, and plastic pollution that can harm human and ecosystem health. Home composting may be a more environmentally sustainable method of managing dog feces and reducing this pollution. While composting is an established method for recycling animal manures into low-risk soil conditioners for food production, few studies have investigated whether household-scale compost methods can safely and effectively process dog feces for use in backyard edible gardens. A broad range of literature on in situ composting of dog feces is evaluated and compared according to scale, parameters tested, and compost methods used. Studies are analyzed based on key identified knowledge gaps: appropriate compost technologies to produce quality soil conditioner on small scales, potential for fecal pathogen disinfection in mesophilic compost conditions, and biodegradation of compostable plastic dog waste bags in home compost systems. This review also discusses how existing methods and quality standards for commercial compost can be adapted to dog fecal home composting. Priorities for future research are investigation of household-scale aerobic compost methods and potential compost amendments needed to effectively decompose dog feces and compostable plastic dog waste bags to produce a good-quality, sanitized, beneficial soil conditioner for use in home gardens. Integr Environ Assess Manag 2024;00:1-16. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Emily Bryson
- School of Health, Medical and Applied Sciences, Central Queensland University, Wayville, South Australia, Australia
| | - Amie Anastasi
- School of Health, Medical and Applied Sciences, Central Queensland University, North Rockhampton, Queensland, Australia
| | - Lisa Bricknell
- School of Health, Medical and Applied Sciences, Central Queensland University, North Rockhampton, Queensland, Australia
| | - Ryan Kift
- School of Health, Medical and Applied Sciences, Central Queensland University, North Rockhampton, Queensland, Australia
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Fate of Horizontal-Gene-Transfer Markers and Beta-Lactamase Genes during Thermophilic Composting of Human Excreta. Microorganisms 2023; 11:microorganisms11020308. [PMID: 36838273 PMCID: PMC9958827 DOI: 10.3390/microorganisms11020308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/17/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023] Open
Abstract
Thermophilic composting is a suitable treatment for the recycling of organic wastes for agriculture. However, using human excreta as feedstock for composting raises concerns about antibiotic resistances. We analyzed samples from the start and end of a thermophilic composting trial of human excreta, together with green cuttings and straw, with and without biochar. Beta-lactamase genes blaCTX-M, blaIMP, and blaTEM conferring resistance to broad-spectrum beta-lactam antibiotics, as well as horizontal gene transfer marker genes, intI1 and korB, were quantified using qPCR. We found low concentrations of the beta-lactamase genes in all samples, with non-significant mean decreases in blaCTX-M and blaTEM copy numbers and a mean increase in blaIMP copy numbers. The decrease in both intI1 and korB genes from start to end of composting indicated that thermophilic composting can decrease the horizontal spread of resistance genes. Thus, thermophilic composting can be a suitable treatment for the recycling of human excreta.
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Li J, Liu X, Li L, Zhu C, Luo L, Qi Y, Tian L, Chen Z, Qi J, Geng B. Performance exploration and microbial dynamics of urine diverting composting toilets in rural China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 321:115964. [PMID: 36007385 DOI: 10.1016/j.jenvman.2022.115964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
The ongoing "toilet revolution" in China provides new opportunities to improve the rural living environment and sanitation, and the introduction of new sanitation facilities such as urine diverting composting toilets (UDCTs) is conducive to the effective treatment and resource utilization of feces. This study revealed the degradation performance and microbial community dynamics of UDCTs and clarified the influence mechanism of fecal volume in aerobic composting treatment. The results showed that UDCTs could effectively decompose human feces, with an organic matter degradation rate of 25%⁓30%. The temperature, water content, NH4+-N and nutrient accumulation were higher in the high fecal volume treatment than in the low fecal volume treatment. Bacterial community composition and structure in UDCTs varied with composting stage and fecal volume. The diversity and richness of bacterial community in compost were changed with different fecal volumes, but the dominant groups were similar. Redundancy analysis (RDA) showed that nitrogen and organic carbon were the main drivers of bacterial community changes during composting. Highly nutritious and non-phytotoxic compost products were suitable for agronomic uses. Based on these results, UDCTs can be an effective way to solve the problem of fecal pollution in rural areas, and fecal dosage is a potential influencing factor in the operation and maintenance of composting systems.
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Affiliation(s)
- Jiabin Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Xue Liu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Luyao Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Changxiong Zhu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Liangguo Luo
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Yuanyi Qi
- Zhangye Lanbiao Biotechnology Co., Ltd, Zhangye, Gansu, 734000, PR China
| | - Lan Tian
- Zhangye Lanbiao Biotechnology Co., Ltd, Zhangye, Gansu, 734000, PR China
| | - Zhuobo Chen
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Jin Qi
- Zhangye Lanbiao Biotechnology Co., Ltd, Zhangye, Gansu, 734000, PR China
| | - Bing Geng
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China.
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