Study On Start-up And Treatment Efficiency Of Contact Oxdiation Bioreactor

High strength ammonia wastewater widespread in tourism, transport, mining and other productive activities occasions, it has some characteristics as small flow rates, separate locations and treats by bio-contact oxidation. In this paper, using the bio-contact oxidation deal with high strength ammonia wastewater as an example, a contrastive study was made on the different start-up methods; the methods include Natural inoculation, wet sludge inoculation and dry sludge inoculation. It studied the restart and some effect factors, including temperature, alkalinity, and microbial equivalent. After nearly 7 months of testing, reached the following conclusions:1, Wet sludge inoculation was about 15 days to complete, in the start-up process, COD removal rate above 85% maenad the start-up complete. In the natural inoculation process, the treatment effect changed greatly, COD removal rate was 61.86% and an upward trend maenad natural inoculation was success, lasted 27 days. When the dry sludge inoculation stage was success, the treatment efficiency of COD stabilized at 80% after 10 days around;2, In the stable operation process, effluent quality achieve to water quality standard for urban miscellaneous water consumption. The first contact reactor removed the most of the COD and NH4 +-N, the second and third grid removed small parts of the COD and NHU +-N;3, COD removal rate reached 87.10%, NH4 +-N removal rate reached 57.41% after six days re-start, the process of re-start cost little time.4, The main factors of start-up are temperature, dissolved oxygen and PH value. In this paper, the temperature was an important factor in microbial growth, microbial source, dissolved oxygen and PH value did not limit the process of start-up;5, Temperature had little effect on heterotrophic bacteria, but had large effect on activity and specific growth rate of nitrifying bacteria. When the temperature was 25℃, the removal rate of COD and NH4 +-N were good. Alkalinity impacted the removal rate of NH4 +-N greatly, and in the conditions of 6 times and 8 times alkalinity, NH4 +-N conversion rate reached 99%, COD removal rate changed little in different conditions. The heterotrophic bacteria activity and COD removal efficiency decreased slightly after adding protozoan inhibitors, The NH4 +-N concentration in the effluent when the protozoan was inhibited is lower than that when protozoa were not inhibited. It turns out to be evident improvement in NH4 +-N removal. It indicated that protozoan has a strong impact on nitrifying bacteria activity.