曝气吹脱法用于牛场沼液污染物的去除

Pollutants removal characteristics by air stripping with aeration treating biogas slurry of cattle manure

氨吹脱是一种有效的污水脱氮处理技术,其中曝气吹脱法又简单易行。为了探究曝气吹脱法用于牛场沼液污染物去除的最优条件,实验研究了温度、曝气量、初始p H等参数对氨氮去除效果的影响,并探讨了投加Ca（OH）2及曝气吹脱对COD、TP的去除作用。结果显示：温度、曝气量是影响氨氮去除效果的关键因素,30℃、4 000曝气量条件下氨氮去除率最高;由于沼液本身p H会受吹脱影响升高,因此,调节初始p H在8～9.5范围内对氨氮去除效果无显著影响;Ca（OH）_2能去除少量COD及TP,吹脱也能对COD去除有一定影响,投加7.7 g/L Ca（OH）_2吹脱后,沼液COD、TP去除率分别为9.7%、14.8%。最优条件30℃、4 000曝气量下,不加Ca（OH）2吹脱能得到70%以上的的氨氮去除率。一般情况下建议不加Ca（OH）_2进行沼液氨吹脱。

Ammonia stripping is an effective technology used to remove nitrogen from sewage,including aeration,which is simple and feasible. In order to obtain the air stripping optimal conditions,the influences of temperature,aeration quantity and initial p H on ammonium（ NH＋4-N） removal efficiencies were investigated respectively,and the effects of Ca（ OH）_2usage and aeration on chemical oxygen demand（ COD） and total phosphrous（ TP） removal were also studied. The results showed that the temperature and aeration were key factors,and the NH＋4-N removal rate reached to the highest with 30 ℃ and 4 000. Because the p H of biogas slurry could increase with aeration,the effect of p H on NH＋4-N removal was insignificant with the initial p H of 8to 9. 5. Ca（ OH）_2could be useful for removing COD and TP,and aeration was helpful to remove COD. The removal rates of COD and TP were 9. 7% and 14. 8% respectively,when the Ca（ OH）_2usage was 7. 7 g / L. The NH＋4-N removal rate could be more than 70% with 30 ℃,aeration 4 000,and no Ca（ OH）_2addition. Normally,aeration without alkaline agents was the suggested way to remove nitrogen in the ammonia stripping process.