草木灰协同氨氮吹脱对牛粪沼液中污染物的去除和回收作用  

Removal and recovery of pollutants from cow dung biogas slurry by plant ash combined with ammonia nitrogen stripping

作　　者：王辰鹏 张华东[1] 曲威[1] 孙吉翠 杨守军[1] WANG Chenpeng;ZHANG Huadong;QU Wei;SUN Jicui;YANG Shoujun(Yantai Research Institute,China Agricultural University,Yantai 264670,China)

机构地区：[1]中国农业大学烟台研究院,山东烟台264670

出　　处：《黑龙江畜牧兽医》2023年第8期60-66,共7页Heilongjiang Animal Science And veterinary Medicine

基　　金：烟台市校地融合发展项目(2021XDRHXMQT19)。

摘　　要：为了研究促脱剂草木灰在沼液氨氮吹脱过程对沼液中多种污染物的去除和回收效果,试验以山东省烟台市某奶牛场沼气工程中的沼液为材料,设置氨氮吹脱工艺沼液中草木灰添加量为100,200,300 g/kg,气液比为1000,2000,3000,温度为20,30,40℃,进行不同参数组合工艺的氨氮去除效果研究,以获得氨氮吹脱工艺的较优组合参数;在较优组合参数基础上,分析氨氮吹脱过程中草木灰对沼液pH值的影响及包含氨氮、总磷、化学需氧量(COD)、总盐分、粪大肠杆菌群数的去除和回收情况;然后对草木灰协同氨氮吹脱工艺与常规氨氮吹脱工艺(NaOH为促脱剂)的经济效益进行评估。结果表明:氨氮吹脱工艺较优参数组合为气液比2000、温度30℃、吹脱时间3 h、草木灰添加量200 g/kg。与吹脱前沼液相比,吹脱3 h后沼液的pH值升高了21.12%(P<0.05),氨氮浓度下降了90.74%(P<0.05),氨氮去除率和回收率则达到了90.74%和81.66%;吹脱3 h后草木灰pH值降低了7.52%(P<0.05),而氨氮含量升高至843.04 mg/kg,草木灰协同氨氮吹脱工艺可实现沼液中89.16%的氨氮得到有效回收。与吹脱1 h相比,吹脱3 h后沼液中总磷含量下降了20.65%(P<0.05),但总磷去除率提高了17.76%(P<0.05);吹脱3 h后的草木灰中总磷含量和总磷回收率则分别比吹脱1 h增加了14.33%和16.39%。与吹脱前沼液相比,吹脱3 h后的沼液中COD含量、粪大肠杆菌群数、总盐分含量均显著下降(P<0.05),去除率分别达到33.95%、27.50%和25.96%,其中粪大肠杆菌去除率的98.80%和总盐分去除率的97.34%由草木灰吸附回收。用促脱剂草木灰替代NaOH虽然购买成本提高了41.91%,但农田利用价值提高了137.52%,实现工艺经济收益盈利。说明草木灰协同氨氮吹脱工艺对沼液中污染物的去除和回收具有明显的促进作用。In order to study the effects of removal and recovery of denitrification agent plant ash on various pollutants in the biogas slurry during ammonia nitrogen stripping process,the biogas slurry from a dairy farm biogas project in Yantai City,Shandong Province was selected as the material.The addition amount of plant ash in ammonia nitrogen blowing process biogas slurry was set as 100,200,and 300 g/kg,the gas-liquid ratio was 1000,2000,and 3000,and the temperature was 20,30,40℃.Then the ammonia nitrogen removal effect of different parameter combination processes was studied to obtain the better combination parameters of ammonia nitrogen stripping process.On the basis of better combination parameters,the effect of plant ash on the pH value and removal and recovery of ammonia nitrogen,total phosphorus,chemical oxygen demand(COD),total salt,and fecal Escherichia coli number in biogas slurry were analyzed during ammonia nitrogen stripping process.Then,the economic benefits of the plant ash combined ammonia nitrogen stripping process and the conventional ammonia nitrogen stripping process(NaOH as the removal promoter)were evaluated.The results showed that the optimum parameters of ammonia nitrogen stripping process were gas-liquid ratio 2000,temperature 30℃,stripping time 3 h,and addition of plant ash 200 g/kg.Compared with the biogas slurry before stripping,the pH value of the biogas slurry after 3 h of stripping was significantly increased by 21.12%(P<0.05);the ammonia nitrogen concentration was significantly decreased by 90.74%(P<0.05),and the ammonia nitrogen removal rate and recovery rate reached 90.74%and 81.66%.After 3 h of stripping,the pH value of plant ash was significantly decreased by 7.52%(P<0.05),while the ammonia nitrogen content increased to 843.04 mg/kg.The plant ash combined with ammonia nitrogen stripping process could effectively recover 89.16%of ammonia nitrogen in biogas slurry.Compared with 1 h of stripping,the total phosphorus content in biogas slurry decreased significantly by 20.65%(P<0.05)a

关 键 词：沼液 草木灰 氨氮吹脱 污染物 总磷 化学需氧量(COD) 粪大肠菌群数 去除 回收 

分 类 号：X713[环境科学与工程—环境工程]