臭氧氧化处理养猪场厌氧沼液

Treatment of swine farm anaerobic biogas slurry by ozone oxidation

实验在MAP沉淀处理的基础上,采用臭氧氧化技术对养猪场厌氧沼液进行处理。研究了氧化过程中臭氧的投加量、反应时间对沼液pH、COD和UV254的去除效果、沼液可生化性、氮形态转化的影响。结果表明,在臭氧氧化过程中,随着反应时间的延长,沼液pH呈逐渐下降的趋势。在臭氧投加量为6 mg/L、反应时间为40 min时,COD和UV254去除率达到最大,分别为21.7%和60%。此外,臭氧氧化能把BOD5/COD的比值从0.24提高为0.41,有效提高了沼液的可生化性。在臭氧投加量为6 mg/L、反应时间为2 h时,TN的浓度基本维持在370~410 mg/L之间,氨氮浓度随时间呈现先升高后降低的变化趋势,且最终维持在132.7 mg/L,然而,硝态氮浓度反而升高了近一倍,由此可见,臭氧氧化不能完全脱氮,只能使氮从一种形态转化为另一种形态。

The treatment of swine farm anaerobic biogas slurry by ozone oxidation followed magnesium ammonium phosphate precipitation（MAP） was carried out in this study.The effects of ozone adding dosages and reaction time of ozone oxidation on pH,COD and UV254 removal,biodegradability,nitrogen transformation were investigated.The results showed that the pH value decreased gradually with the extension of reaction time.In addition,the ozone oxidation was able to remove 21.7% of COD,60% of UV254 and increased the BOD5 to COD ratio from 0.24 to 0.41 with the ozone adding dosages at 6 mg/L and the reaction time at 40 min.In fact,when the ozone adding dosage was 6 mg/L,the TN concentration maintained between 370 and 410 mg/L over the whole reaction time,but the ammonia nitrogen concentration increased first and then decreased,and the final ammonia nitrogen concentration was remained at 132.7 mg/L,however,the nitrate nitrogen concentration increased nearly doubled.It was suggested that the ozone oxidation could not perform denitrification and only transform nitrogen from one form to another form.