Abstract: In order to solve the problem of environmental pollution caused by the end of intensive farming unorganized air emissions, combined with the principles of pickling and washing spray method, a PLC-based compound air purification platform for livestock and poultry breeding was designed. The platform can view data information and set control parameters through humancomputer interaction interface, automatically complete pickling, washing, waste discharge, adding acid and other work; Ultrasonic atomization dilution of ammonia solution was used to simulate ammonia emissions from livestock and poultry breeding. The distribution of gas concentration in the chamber of the test platform was analyzed with the aid of intelligent environmental monitoring instrument, and the influence of different pH values and organic acids on ammonia purification efficiency was explored. The test results showed that the pH value of the pickling solution had a significant effect on the purification efficiency, the lower the pH value of the solution and the higher the purification efficiency, but when the pH was less than 1.9, the effect was not significant, the purification efficiency was basically constant at about 90%. The average purification efficiency of concentrated sulfuric acid solution (8944%) > the average purification efficiency of acetic acid solution (82.03%) > the average purification efficiency of oxalic acid solution (8104%) > the average purification efficiency of citric acid solution (79.17%) > the average purification efficiency of lactic acid solution (78.73%) > the average purification efficiency of pure water solution (4396%). And with the purification reaction, the pH of concentrated sulfuric acid, oxalic acid and citric acid were more stable, while the pH of acetic acid and lactic acid changed more.

Key words: scale farming, terminal purification, programmable logic controller, pH purification characteristics

摘要： 为解决集约化养殖末端空气无组织排放造成的环境污染问题。结合酸洗、水洗喷淋法原理，设计基于PLC控制的畜禽养殖末端空气复合净化平台。该平台通过人机交互界面查看数据信息并设置控制参数，自动完成酸洗、水洗、排废、加酸等工作；采用超声波雾化稀释氨水溶液模拟畜禽养殖末端氨气排放，借助智能环境监测仪分析试验平台腔体内气体浓度分布规律，并探索研究不同pH值与有机酸对氨气净化效率的影响。试验结果表明：酸洗液pH值对净化效率具有显著影响，溶液pH值越低净化效率越高，但当pH小于1.9后影响不大，净化效率基本恒定在90%左右。不同酸洗液对净化效率及pH稳定性有一定影响，浓硫酸溶液的平均净化效率（89.44%）＞乙酸溶液的平均净化效率（82.03%）＞草酸溶液的平均净化效率（81.04%）＞柠檬酸溶液的平均净化效率（79.17%）＞乳酸溶液的平均净化效率（78.73%）＞纯水溶液的平均净化效率（43.96%）；且随着净化反应进行，浓硫酸、草酸及柠檬酸pH较稳定，乙酸与乳酸pH变化较大。

关键词: 规模化养殖, 末端净化, 可编程逻辑控制器, pH净化特性