Research On A/O+A/O Process Products Wastewater Treatment

As advance occurred in combined-soda process industry and scale-up application of chemical fertilizer in agriculture, the treatment of wastewater with high concentration ammonia nitrogen becomes worse and worse. High ammonia wastewater characterised with wide variety of sources, the high concentration, difficult to handle, among, high ammonia nitrogen wastewater containing a large number of different forms of nitrogen ammonia nitrogen, nitrite nitrogen and cyanide to the traditional denitrification process has brought great processing difficulties. In this study, focused on the characteristics of high ammonia wastewater, a highly efficient system for treating high concentrations of organic matter and high concentration of ammonia nitrogen was built in this study. The traditional A/O process on the basis of full consideration to the target high ammonia concentration in wastewater characteristics, summed up the basis of existing wastewater treatment process on the design, building efficient denitrification A/O+A/O process.Construction for the design of the new A/O+A/O wastewater treatment process, the separate experiments consist of investigate anaerobic and aerobic reactor was built for the treatment of wastewater. Explore the anaerobic reactor start-up conditions and ways to accelerate, it turns out to use granular sludge as inoculum source can shorten reactor start-up time, and add methanol as a co-substrate can benefit for performance. The study researched the effect brought from different conditions of methanol dosage, in terms of treatment efficiency of anaerobic reactor, according to the experimental results, when methanol dosage reached 1000mg/L, this means anaerobic COD removal can reach 88.9%.Moreover, C/N ratio and nitrification liquid reflux ratios were 7 and 150% respectively, the maximum COD removal efficiency was obtained. In the aerobic reactor, coupling with biological contact oxidation pond, vectors filler, porous aeration systems, in order to accelerate the aerobic reactor start-up time, operating the reactor after front anaerobic reactor. The final optimal pH and DO concentration were 7 and 3-5mg/L range, the maximum COD removal efficiency was achieved with the optimum sludge reflux ratio of 2:1.In separate experiments consist of aerobic and anaerobic process technology research, based on a systematic process couplet with design and construction, using the actual production of wastewater as wastewater to investigate the effect of the entire process. According to the study results, in the start-up phase, couplet process showed better adaptability to combined-soda wastewater. When the influent load reached 3.12kgCOD/m³, COD removal efficiency of the reactor can be relatively stable at 60%. The effects of nitrogen removal efficiency of the process were investigated, the results showed that under the conditions of the unsegmented water, ammonia nitrogen removal efficiency of the process was not ideal, the removal rate is relatively low, while after using the segmented water, the ammonia removal rate changed with more substantial increase, and the final equality of effluent met the emission standards of GB8978-1996 required level. We can see from the nitrate removal, with the water segment, high nitrate removal efficiency can reach 80% or more, it is possible to promote the overall efficiency of the system to step feed into the system in favor of nitrification and denitrification.Based on the above experimental results, multiport A/O process can achieve the high performance in the treatment of high concentration of ammonia nitrogen wastewater, so in this study, the pilot scale was operated in the final part with enterprises gasification wastewater, cooling water, soda water recycling, oily wastewater ammonium chloride, soda water and other miscellaneous wastewater. According to the pilot study results, the overall process of COD removal rate can remain stable at 98% above and NH₃-N removal rate can remain stable at 97% above, COD and NH₃-N value of the effluent can meet the national wastewater discharge standards of emission standards level. We also calculated the cost of the treatment process, pharmaceutical costs per ton of about 4.66 yuan, compared to other process cost price, the prices are fairly competitive, indicating that the process has a good economic applicability.