| 基于负压抽滤的畜禽养殖污水过滤试验 |
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| 引用本文： | 关正军,贾兴江,金东波,王秋雁,熊丕荣,束勇,杨仁强.基于负压抽滤的畜禽养殖污水过滤试验[J].农业工程学报,2023,39(21):196-204. |
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| 作者姓名： | 关正军 贾兴江 金东波 王秋雁 熊丕荣 束勇 杨仁强 |
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| 作者单位： | 西南大学工程技术学院, 重庆 400715 |
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| 基金项目： | 重庆市科技局农高新专项项目《水禽养殖污水资源化利用关键技术研究与应用示范》（CSTC2019ngzx0017） |
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| 摘 要： | 降低畜禽养殖污水处理成本是促进养殖业健康发展的重要因素，介质过滤能截留污水中的悬浮性固体，是养殖污水预处理的有效途径之一。其中，以作物秸秆为滤料的自然过滤装置结构简单、能耗低，能有效去除养殖污水中的固体污染物，但仍存在易堵塞、过滤速度慢、秸秆利用率低等问题。对此，该研究提出负压抽滤方案并进行了相关试验：首先通过单因素试验确定了各试验参数的边界条件，再利用二次回归组合试验，优化了负压抽滤的运行参数，试验结果表明当滤层厚度、压实密度、过滤压差分别为10 cm、130 kg/m3、30 kPa时综合过滤效果最佳，此时总固体（total solid，TS）、挥发性固体（volatile solid，VS)、化学需氧量（chemical oxygen demand，COD)、氨氮（NH4+-N）的去除率分别为40.47%、45.07%、13.56%、11.75%；经过自然过滤和负压抽滤的对比试验，相同滤层条件负压抽滤的污水处理量是自然过滤的4倍，而用时仅占自然过滤的1/5，负压抽滤能有效提高过滤速率和秸秆利用率。最后利用厌氧发酵试验，负压抽滤污水较未处理污水发酵周期缩短30%，产气量平稳且波动较小，负压抽滤能显著提升后续生化处理效率。研究结果可为改进现有畜禽养殖污水处理工艺提供了技术支撑。
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| 关 键 词： | 污水 处理 过滤畜禽养殖污水 玉米秸秆 负压抽滤 |
| 收稿时间： | 2023/7/18 0:00:00 |
| 修稿时间： | 2023/9/23 0:00:00 |
Experiments on livestock and poultry farming wastewater filtered by negative pressure |
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| GUAN Zhengjun,JIA Xingjiang,JIN Dongbo,WANG Qiuyan,XIONG Pirong,SHU Yong,YANG Renqiang.Experiments on livestock and poultry farming wastewater filtered by negative pressure[J].Transactions of the Chinese Society of Agricultural Engineering,2023,39(21):196-204. |
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| Authors: | GUAN Zhengjun JIA Xingjiang JIN Dongbo WANG Qiuyan XIONG Pirong SHU Yong YANG Renqiang |
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| Institution: | Department of Engineering and Technology, Southwest University, Chongqing 400715, China |
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| Abstract: | Wastewater treatment has been one of the restricting factors in the development of livestock and poultry industry, due to the difficulty and high cost. Furthermore, there is serious pollution to soil, air and groundwater, if the farming wastewater is discharged without any treatment. Current biogas engineering can cause a heavy load and high blocking of wastewater. Fortunately, crop straw can serve as filter material for the filtration pre-treatment of livestock and poultry farming wastewater. The suspended solids can also be removed to effectively improve wastewater treatment. However, it is very necessary to promote the filtering speed and utilization rate of straw at present. In this study, the filtering project was proposed to solve these challenges using negative pressure. A series of tests were also carried out on the livestock and poultry farming wastewater. Firstly, the test platform was constructed to filter the farming wastewater using negative pressure, which was mainly composed of a filtration device, control box, sewage pump, vacuum pump, and pressure sensor. Specifically, the filter device was used to form the filter layer built by crop straw and the enclosed space required for filtration; The sewage pump was to pump the wastewater into the filter device; The vacuum pump was to form a vacuum degree in the filter device; The pressure sensor was to detect the air pressure in the filter device, and then control the vacuum pump on (or off) together with the PLC controller in the control box, in order to ensure the pressure stable within the set range. Secondly, the test factors were selected as the thickness and compaction density of the filtration layer, as well as the filtration pressure. The test range of each factor was then determined by the single-factor experiments. Moreover, the quadratic regression experiment was implemented to determine the filtration parameters of the optimal performance on filtering by negative pressure. The thickness and compaction density of the filtration layer and the filtration pressure were 10 cm, 130 kg/m3, and 30 kPa, respectively. Design-Expert 12 software was used to analyze the influence of the interaction among factors on the removal performance of wastewater. It was found that the removal rates of Total Solid (TS), Volatile Solid (VS), Chemical Oxygen Demand (COD), and NH4+-N were 40.47%, 45.07, 13.56%, and 11.75%, respectively, indicating effective removal of solid pollutants in wastewater. Then, comparative tests were conducted on filtration between negative pressure and gravity under the same conditions. It was found that the amount of treated wastewater filtering by negative pressure was four times that of gravity, and the duration was only 1/5, indicating the higher filtration speed and utilization rate of straw. Finally, a comparative test was carried out on the anaerobic fermentation of wastewater. The wastewater filtering by negative pressure and gravity shortened the fermentation period by 30%, compared with the untreated wastewater. Gas production was stable without any fluctuation, indicating the reduction of the load during anaerobic fermentation. In summary, it is feasible for the crop straw as filter material to filter the livestock and poultry farming wastewater by negative pressure. The finding can provide technical support to the filtration equipment for the livestock and poultry wastewater. |
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| Keywords: | wastewater treatment filter livestock and poultry farming wastewater crop stalk filtration by negative pressure |
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