Influence of low-temperature anaerobic fermentation on sedimentation characteristics of dairy wastewater

doi:10.11975/j.issn.1002-6819.2021.05.026

	Influence of low-temperature anaerobic fermentation on sedimentation characteristics of dairy wastewater
	Zhu, Ruiqing 1; Niu, Yongyan 1; Mao, Ting 1; Wang, Zhiye 1; Yang, Tao 1; Ji, Bin 1; Liu, Meiling 2; Mu, Yongsong 3; Bai, Huihui 4
	2021-03-01
发表期刊	Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
ISSN	10026819
卷号	37 期号:5 页码:224-230
摘要	Large volume of dairy wastewater has caused a great threat to the ecological environment, due to the difficulty to treat it. Traditional treatment requires more heating energy at the least temperature of 36. Alternatively, non-hazardous fertilizers are widely expected to treat wastewater, particularly easy soluble in water to transfer through dripping or spraying irrigation. However, the chemical fertilizers derived from wastewater contain many organic matters and nutrients, resulting in the blockage of spray nozzles. In this study, a feasible bio-treatment of dairy wastewater was proposed using the low-temperature anaerobic fermentation, thereby lowering energy consumption, while increasing the fluid permeability through dripping or spraying irrigation. The treated dairy wastewater was observed in the anaerobic fermentation at low temperatures (10-25 ) through an array of time points by no inoculants, as well as at a normal temperature of 36 by inoculants of granular anaerobic sludges. A full-length 16S rRNA gene sequencing was used to detect microbiological compositions. Response surface analysis was performed on fermentation parameters. The results showed that there was a significant influence of anaerobic fermentation under low temperature on the sediment characteristics of dairy wastewater. The sedimentation and layering performance of wastewater were significant under the condition of 9 days at 10 , where the turbidity of supernatant was about 5. The most energy-efficient and economical condition was at 15 in the 4 d for the low-temperature anaerobic treatment. There was an average energy saving of 2 865 kW•h/d by l5 anaerobic fermentation with ambient temperature around 7.8 , compared with fermentation at 36 . Low-temperature anaerobic fermentation changed the sedimentation characteristics of wastewater over a longer time but with equal quality, where supernatant CODCr was reduced to (2 627.8±548.1) mg/L, nitrogen to (565.2±79.5) mg/L, fecal coliforms to around 360 g/L, the residue ratio of the dry filter by mesh diameter 75 μm filters approximately to 0 %. The dry matter ratio of supernatant dropped from 18.9% to 2.3% after treatment, while a part of of wastewater was recycled as irrigation water, where the total nutrients (N+P2O5+K2O) content of supernatants were 1.744 9 g/L. The number of fecal coliforms reduced down to 360 g/L, while, the mortality ratio of ascarid egg was above 95%. Both granular and low-temperature sludges showed the treating functions of wastewater (methanogenesis and wastewater turbidity change), but with different efficiency, where 199 otu were detected in the anaerobic sludges via the full-length 16S rRNA gene sequencing, while 207 otu in the acclimatized granular anaerobic sludges, and 96 otu were common in both sludges. Candidatus Cloacimonas was a dominant species in the long-term (over 6 mon) low-temperature conditioned anaerobic sludges, while genus Sulfurovum dominated in inoculated granular anaerobic sludges. In the study site with the mean annual temperature of 4.1 , low-temperature (15 ) anaerobic fermentation saved much more energy consumption than the thermal anaerobic fermentation (36 ). The supernatant could transmit through to the nuzzle irrigation, the environmental non-hazardous proxies met with the discharge requirements of the national standard. The finding can provide a potential application for future recycling in agriculture and sustainable development. © 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
关键词	Agricultural robots Energy efficiency Energy utilization Fermentation Fertilizers Genes Hazards Irrigation Nutrients Particulate emissions RNA Sedimentation Spray nozzles Surface analysis Sustainable development Temperature Turbidity Water recycling 16S rRNA gene sequencing Anaerobic fermentation Ecological environments Mean annual temperatures Microbiological composition Response surface analysis Sediment characteristic Sedimentation characteristic
DOI	10.11975/j.issn.1002-6819.2021.05.026
收录类别	EI
语种	中文
出版者	Chinese Society of Agricultural Engineering
EI入藏号	20212010364218
EI主题词	Wastewater treatment
EI分类号	451.1 Air Pollution Sources ; 452.4 Industrial Wastes Treatment and Disposal ; 461.2 Biological Materials and Tissue Engineering ; 525.2 Energy Conservation ; 525.3 Energy Utilization ; 631.1 Fluid Flow, General ; 641.1 Thermodynamics ; 741.1 Light/Optics ; 802.3 Chemical Operations ; 804 Chemical Products Generally ; 821.3 Agricultural Methods ; 914.1 Accidents and Accident Prevention ; 951 Materials Science
引用统计	无
文献类型	期刊论文
条目标识符	https://ir.lut.edu.cn/handle/2XXMBERH/151120
专题	兰州理工大学
作者单位	1.Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou; 730000, China; 2.Northwest Institute of Ecological Environment and Resources, Chinese Academy of Sciences, Lanzhou; 730000, China; 3.Gansu Huarui Agricultural Co., Ltd., Zhangye; 734500, China; 4.School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou; 730000, China
推荐引用方式 GB/T 7714	Zhu, Ruiqing,Niu, Yongyan,Mao, Ting,et al. Influence of low-temperature anaerobic fermentation on sedimentation characteristics of dairy wastewater[J]. Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering,2021,37(5):224-230.
APA	Zhu, Ruiqing.,Niu, Yongyan.,Mao, Ting.,Wang, Zhiye.,Yang, Tao.,...&Bai, Huihui.(2021).Influence of low-temperature anaerobic fermentation on sedimentation characteristics of dairy wastewater.Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering,37(5),224-230.
MLA	Zhu, Ruiqing,et al."Influence of low-temperature anaerobic fermentation on sedimentation characteristics of dairy wastewater".Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 37.5(2021):224-230.