| The problem of rural sewage in the suburbs is a very serious challenge that we face at this stage.In the suburbs and rural areas,because the economic level is relatively backward compared with the urban economy,it is obviously too costly to copy the system of handling urban sewage.Therefore,a low-energy,high-efficiency treatment system is needed to selectively remove rural sewage in the suburbs.In this paper,we use the drop-water contact oxidation ecological ditch developed by the research group to explore the effect of treating the domestic sewage in the suburbs,and carry out research on the effects of various parameters on the efficiency of water-reducing oxygenation,and under the optimal conditions,the device is refluxed.And the research on the effect of actual domestic sewage treatment before the reflux,the research on the treatment effect of each component of the device,and the research on the microbial colony inside the device.Influencing factors of water infusion and oxygenation:In the range of test height 40cm≤H≤100cm,when the test flow rate is 180mL/min ≤Q ≤420mL/min,the standard oxygen total transfer coefficient KLas of the test group with the water puncture perforated strip component is significantiy larger than The blank test group of the water-free perforated strip assembly proves that the water-filled perforated strip assembly can enhance the oxygenation capacity of the device;the flow rate and height have a greater influence on the oxygenation efficiency of the water,and the oxygenation efficiency and the water drop The height H is proportional to the falling water flow Q;when the flow rate and height are increased,the difference between the KLas of the perforated plate assembly and the non-perforated plate assembly is getting smaller and smaller;the pore diameter and the falling water oxygenation are found to be less regular,and the analysis may be In the study,the number of pore size variables is small,and it is found that when the pore diameter is 5mm,the water-filling oxygenation efficiency is the highest.At this time,when the flow rate Q is 240mL/min,the water-supply oxygenation efficiency increases fastest.The empirical formula for calculating the drop oxygenation efficiency when there are components is:KLas(Q,H)=1.32×(0.0065251n(Q)-0.0262)(4.4×10-4H0.2968);The empirical formula for calculating the drop oxygenation efficiency without components is:KLas(Q,H)=2.5×(0.00541n(Q)-0.0217)(8×10-7H0.6479)。The actual sewage water drop oxygenation test study,the COD in water has a significant effect on the standard oxygen total transfer coefficient KLas.It can be seen from the test that the higher the COD concentration in the sewage,the lower the standard oxygen total transfer coefficient KLas.However,the effect on saturated dissolved oxygen Cs is not obvious.Therefore,the COD concentration has a great influence on the total oxygen transfer correction coefficient a of the sewage.The total oxygen transfer correction coefficient a decreases with the increase of COD concentration,while the saturated dissolved oxygen correction coefficient p changes almost unchanged with the COD concentration.It is indicated that the difference in COD concentration under the same test conditions will affect the alpha value,but has almost no effect on the saturated dissolved oxygen correction coefficient β value.The drop height affects the oxygenation efficiency in the sewage,but its growth rate is relatively slow.When H is 55cm,its oxygen total transfer correction coefficient a and oxygen transfer growth efficiency are the largest.Experimental study on actual sewage treatment by falling water contact oxidation ecological ditch.The effluent concentrations of target pollutants BOD,,COD,NH4+-N,TN,TP,and SS were 14.1 mg/L,42.35 mg/L,2.51 mg/L,12.17 mg/L,and 0.9 mg/L,respectively.The removal rates were 86%,75%,89%,55%,51%,86%.The effluent concentrations of COD,BODS,NH4+-N and TN all reached the first-class A treatment standard of "Emission Standards for Pollutants in Urban Sewage Treatment Plants" GB18918-2002,and the effluent concentrations of TP and SS reached the "Emission Standards for Pollutants in Urban Sewage Treatment Plants" GB18918-2002 Level 1 B processing standard.After reflux,the ammonia nitrogen removal rate was significantly higher than that before reflux.The drop oxygenation has a high contribution rate to the total oxygen demand of the system.When the drop height is 55cm,it accounts for 70%of the total gas supply.The bacterial colony structure study,the population and abundance of the anoxic pool sample and the aerobic pool sample were significantly larger than the microbial samples in the membrane stage.And the three functional bacteria are distinct.This research further strengthens the oxygenation efficiency in the research results of this research group,and conducts the pilot test on the actual sewage,which is important for ensuring the quality of sewage treatment effluent and the rural natural environment in the suburbs,comprehensively rectifying the rural environment in the suburbs,and building ecological civilization in China.significance. |
