Pilot-Scale Study On The Treatment Of Municipal Sewage With Low C/N By Hydrolysis-Denitrification+A/O Process

Hydrolysis-denitrification+anoxic-oxic (hereinafter referred to as A/O) process to improve the traditional hydrolysis+anaerobic-anoxic-oxic (A2/O) process, after the removal of oxygen in the process of paragraphs, the original A2/O device mixture internal reflux device improvement for the part of the second pond water nitration fluid backflow to the hydrolysis of denitrifying pool, and two sink back into the inner groove bottom of surplus sludge anaerobic period, for low carbon and nitrogen ratio town wastewater treatment. In this process, the denitrification function lead to hydrolyze pool close for one Bio-reactor, the hydrolysis anaerobic environment in the pool and adequate supply of organic matter is conducive to the growth of denitrifying bacteria and functional recovery, hydrolyze pool in addition to the hydrolytic acidification also have the effect of denitrification denitrification, make the system stable efficient denitrification efficiency.This test for a sewage treatment plant in northern residents living waste water processing object, focuses on the process of towns in low carbon and nitrogen ratio wastewater denitrification treatment in terms of efficiency, in order to for the scale to provide data support of hydrolysis of denitrifying process, the main work is as follows:The daily capacity of 50 m3 hydrolysis-denitrification+A/O pilot plant for installation and debugging and stable operation.Experimental start to finish in 25 days, hydrolyze pool VSS/SS is 0.65, aerobic sludge concentration pool is 5000-6000 mg/L, system to remove COD, NH4+-N, TN and TP ability increases gradually, and tends to be stable.Hydrolysis-denitrification+A/O process for wastewater treatment process, the system of indices such as COD, NH4+-N, TN removal efficiency is relatively stable, removal rate is 87.95%,99.42% and 51.84% respectively, the effluent COD and NH4+-N is superior to national level A urban sewage discharge standards, average effluent NH4+-N concentration was only 0.48 mg/L, show the excellent ability of nitrate nitrogen transformation.100% of nitrifying liquid reflux ratio under the condition of experiment can achieve the optimal condition, the water carbon nitrogen ratio were 1.2:1, under the condition of 1:1, systems of TN removal ratio was 45.43 mg/L,37.27 mg/L.In C/N as low as 0.83-2.24 under the conditions of hydrolysis+A/O denitrification process still showed higher than that of traditional biological nitrogen removal performance.The water temperature in winter is low and the low carbon nitrogen ratio (the average value of C/N is 1.2), under the condition of hydrolysis-denitrification+A/O process of TN still have relatively stable removal effect, the system of effluent TN its average concentration is 49.6 mg/L, absolute removal amount within 20.61-39.42 mg/L, the water under the condition of low temperature and low carbon and nitrogen ratio, system of TN still maintain an average of 30.9 mg/L definitely remove, visible the influent carbon source utilization in this process has reached A better state.In C/N is 4.5:1,1.5:1 condition, examination of hydrolyzed sludge and anaerobic pool sludge denitrificationproduction rate and organic carbon source utilization ability, the degradation process is divided into three phases, the first stage for denitrification stage quickly, rate is respectively 7.2 and 4.05 times of the second stage of the denitrification, basic reflect fully in the third stage, hydrolysis of mud 1 g per degradation of NO3--N need to consume COD respectively 3 g (4.5:1) under the condition of,2.7 g (1.5:1) under the condition, oxygen mud degradation per 1 g of NO3--N need to consume COD is respectively 3.5 and 4.2 g.Hydrolysis of denitrifying sludge in the denitrification rate test experiments show good denitrification ability, better than the anaerobic pool, carbon source within 180 min in plenty of situations reaction completely.The use of Miseq sequencing technology of hydrolysis in different height (0.3 m,1.5 m,2.3 m) hydrolysis of denitrifying sludge bacterial colonies and ancient bacteria colony of 16 sdna gene V3-V4 variable region gene sequencing analyses, the results show that the three different altitude environment, there exist certain differences of sludge bacteroidetes and acid bacillus door is given priority to, these bacteria are anaerobic metabolism related basic, among them, the door deformation bacteria (average 35.56%) in a variety of bacteria play an important role in the process of denitrification and phosphorus removal.Genus level, Thauera, Thiobacillus, Nitrospira, Nitrosomonas all belong to denitrification and phosphorus removal bacteria genera, hydrolysis of denitrifying denitrification play a crucial role.