畜禽养殖废水沼液生物脱氮的影响因素研究

畜禽养殖废水中的抗生素会影响生物脱氮过程,加剧水体富营养化。采用SBR法处理模拟畜禽废水厌氧消化液探究金霉素、碱度和温度对生物脱氮的限速步骤硝化过程的影响。6个相同的SBR反应器分别在25,30℃、不同金霉素浓度和碱度条件下运行166个周期。结果表明:不同温度和碱度下,金霉素质量浓度依次为0,5,20 mg/L时,随着金霉素浓度升高,氨氧化率降低,亚硝态氮积累率升高。不同温度和金霉素浓度下,氨氧化率随碱度的减少(ALK/N分别为9.28、7.14、4.76、3.57、2.38、0)而降低;而亚硝态氮积累率随温度变化而改变。由此可见,金霉素对AOB和NOB均有抑制作用,致使氨氧化率降低;其中,金霉素对NOB的抑制作用大于AOB,造成亚硝态氮累积。金霉素和温度的共同作用可致使亚硝态氮积累率增加。

STUDY ON THE INFLUENCE FACTORS OF BIOLOGICAL NITROGEN REMOVAL FROM LIVESTOCK WASTEWATER DIGESTED EFFLUENT

Antibiotics in livestock wastewater will affect biological nitrogen removal， exacerbating the problem of eutrophication． The effect of chlortetracycline、alkalinity and temperature on nitification which was rate-limiting step of biological nitrogen removal was investigated in sequencing batch reactor． Adopting synthetic digested livestock wastewater as the influent，six SBＲ reactors were operated at different chlortetracycline concentration and alkalinity under the condition of 25 ℃ and 30 ℃． The duration of experiments was 166 cycles． With the increase of chlortetracycline，ammonia oxidation rate decreased and nitrite accumulation rate increased when chlortetracycline were 0，5，20 mg /L at different temperature and alkalinity． Under the different temperature and chlortetracycline，ammonia oxidation rate decreased with the reduction of alkalinity( ALK/N was 9. 28、7. 14、4. 76、3. 57、2. 38、0，respectively) ; and a different trend of nitrite accumulation rate was emerged at the different temperature． The results showed that both of AOB and NOB were inhibited by chlortetracycline， resulting in the reduction of ammonia oxidation rate． NOB was more sensitive than AOB，leading to the accumulation of nitrite． The combination of chlortetracycline and temperature could increase nitrite accumulation rate．