Study On Denitrification Of Secondary Effluent Of Acrylic Fiber Wastewater And Biological Diversity

The waste water pollutants of Acrylic wastewater have been degradation after biochemical treatment, and the rest of effluent cannot be biochemical degradated, but the ammonia nitrogen concentration remained at the higher level, the reason is that some nitrogen organic was transformed to ammonia nitrogen by microorganism. Ammonia nitrogen is the important pollution material due to the water-body eutrophication and biological denitrification technology is one of the economic and effective denitrification technical to degradate ammonia nitrogen widely used at present.To resolve the shortage of carbon source during Traditional denitrification used to treat Secondary Effluent of Acrylic Fiber Wastewater, Tri-stage biofilm reactor was used to treat it, influence of the pH of influent, HRT, and NH4+-N concentration in raw water on NH4+-N removal was investigated. Efficiency of TN removal was also investigated. Test by pumping in wastewater enter into the water tank, into the water tank to NaHCO3dosing adjust pH, the peristaltic pump up to level3biofilm reactor. Through the control peristaltic pump flow adjusting HRT, with constant temperature element control reaction T to keep it at30℃, the oxygen in air pump, adjust the subsystem with flowmeter to control the reactor DO. The reactor startup successful namely NH4+-N removal rate reached a plateau, reaction parameters to adjust, Firstly at the experimental conditions (HRT for12h, DO for0.5～1.0mg·L-1)to adjust pH, respectively, choose pH for6,7,7.5,7.8,8.3,8.8conditions to test, each pH conditions down except stable effect, after the next pH value adjustment, to search the best water were pH value; Secondly at the experimental conditions (HRT for12h, DO for0.5～1.0mg·L-1) to adjust HRT, respectively, choose HRT for24,18,12h conditions to test, each HRT down except stable effect, after the next HRT adjustment, to search the best HRT; And then at the feed water pH7.8, HRT24h, DO0.5～1.0mg·L-1experimental conditions, to research NH4+-N removal influenced by the concentration of ammonia nitrogen when it changes from13to94mg·L-1; Finally in the best operation were under the condition of research TN removal efficiency.It was demonstrated that the optimal hydraulic residence time and pH were24hours and7.8-8.0respectively. Under these conditions the removal efficiencies of NH4+-N and TN were94.6%and53%respectively. And the removal efficiencies of NH4+-N had no relationship with the concentration of the inflow water. When no carbon source throw in reactor, efficiency of TN removal was obvious, the average and highest removal efficiencies of TN was53%and66%respectively, efficiency of Secondary Effluent of Acrylic Fiber Wastewater nitrogen removal was obvious when used Tri-stage biofilm reactor treated.Use PCR-DGGE molecular biology technology to detecte the microbial community structure in the reactor, take the carrier from the reator at different stages of reactor, when the reactor discharging water stablely, then to preserve it at-20. After the whole reaction phase ended, unified to DGGE deformation gradient gel electrophoresis experiment, because DGGE experiments need to compear the abundance and change of diversity at the same time, different period of biological membrane microbes must do the experiment in the same time. This study of biological membrane samples taken from1-the inoculation respectively mud (2011.4.12),2-reactor operation during the start (2011.5.4),3-hang membrane reactor success (2011.5.14),4-reactor best pH runtime (2011.5.28),5-reactor remove the best effect (2011.7.4). The results show that, within reactor microbial diversity is rich, and different period of storage on the packing with different active sludge of microorganism community structure obviously, five different periods rich microbial diversity, were detected article65different bands and five different processing time of the sample for the sample of the time close similarity similarity is high, the greater the time interval similarity is smaller, samples and sample similar1and5of small, only52.8%. Microbes mainly for:bacili, vice coccus, deformation bacteria, bud form afterbirth fungus and not cultivate microorganisms.