Study On Rbcs Combined With Multistage Ecological Treatment System Treating Surface Water

Liangtan River is located in the main urban area of Chongqing,but with the expansion of the city scale and the progress of living and production activities,the water body of Liangtan River has been seriously polluted.In response to the pollution problem of the Liangtan River,the Liangtan River Comprehensive Treatment Project combines the RBCs with a multi-level ecosystem to treat the Liangtan River.Comprehensive evaluation and analysis of the treatment effect of the process can provide valuable reference and reference for future engineering projects.In this paper,the RBCs+multi-level ecosystem are taken as the research object,mainly exploring the three different ways of hanging the membrane of the RBCs in winter,the removal effect of the key pollutants in the Liangtan River during the film hanging period and the film hanging condition;In the spring,summer,autumn and winter,the effect of pollutant removal and the removal of pollutants along the path;the kinetic model of ammonia nitrogen degradation in summer was established;the microbial biofilm microbial situation after stable operation was analyzed and compared;The operation effect and influencing factors of the ecosystem;finally,the comprehensive effect of the combined operation of the RBCs+multi-level ecosystem combined process were analyzed.At the same time,the improvement suggestions and the applicable conditions of the process were proposed.The results show:?1?In the winter,the RBCs are started at a low temperature,and RBCs can be started most quickly by using the inoculated nitrifying bacteria method.The inactivated activated sludge method has the second starting speed,while the natural hanging film method starts the slowest,but in terms of long-term operation,three different hanging methods are used.The RBCs processing ability tends to be consistent.The removal rate of bio-rotary inoculation of nitrifying bacteria after running for 25 days can reach88.78%.After 100 days,the removal rate of NH₄⁺-N and COD by biological turntable can reach 90%and 23%,respectively.?2?The water quality of the Liangtan River is characterized by poor spring and winter fluctuations,large fluctuations in summer and autumn,and small fluctuations.When the COD,NH₄⁺-N,TN,and TP water loading loads are 2.61⁸.33 g/?m²·d??0.36¹.45 g/?m²·d??0.99².27 g/?m²·d??0.07⁰.27 g/?m²·d?,the removal rate of RBCs increase with the increase of the influent load.The RBCs have a good removal effect on COD and NH₄⁺-N,and the removal effect on TN and TP is not good,up to 54.55%,91.10%,21.33%and 14.74%?3?The pollutant removal of the seven-stage RBCs at three different temperatures of low temperature,medium temperature and high temperature are as follows:the first stage turntable has the highest contribution rate to the removal of pollutants,and the subsequent six-stage removal contribution rate decreases in turn.The average contribution rate of COD,NH₄⁺-N,TN and TP in the first stage was 46%,72%,24%and 39%,respectively.The average removal rate of COD,NH₄⁺-N and TN in the latter six stages decreased from 15%,9%and 19%,respectively.The removal rate of TP in the latter six stages was less than 10%,and the phenomenon of phosphorus release has appeared to varying degrees.?4?Based on the Monod equation and material balance,the utilization model of NH₄⁺-N and the NH₄⁺-N degradation kinetics model of the first and subsequent single-stage turntables of the summer bio-rotary turntable were established,and the degradation reaction of NH₄⁺-N was determined to be the first-order reaction.The model can reflect the law and condition of the degradation and utilization of the RBCs NH₄⁺-N to a certain extent.At the same time,the equation also has a certain mathematical relationship with the microbial saturation constant and concentration,which can provide a certain reference for engineering design.?5?The RBCs after stable operation generally show the trend of biodiversity and uniformity of the rear end of the turntable is higher than that of the front end;after three years of long-term operation,the RBCs of different start-up modes have little difference in microbial composition.It has become the dominant species,but the RBCs inoculated with activated sludge as a whole have relatively high microbial richness and uniformity.?6?The removal of COD,NH₄⁺-N,TN and TP from surface wetlands,distribution ponds,subsurface wetlands,sedimentation ponds and outlet ponds is more affected by the load,and the overall removal rate decreases with the increase of area load.The area removal increases as the area load increases and gradually stabilizes.At the same time,the removal effect of NH₄⁺-N and TN on surface wetland and subsurface wetland is mainly affected by temperature,and the removal rate increases with the increase of temperature.Surface removal wetland,subsurface wetland,sedimentation pond+exit pond have relatively good COD removal effect.The water storage capacity of the water distribution pond is relatively poor due to the large hydraulic load;the subsurface wetland has the best effect on the removal of TP,the surface wetland and The removal effect of TP on the pond system is general;the removal effect of NH₄⁺-N on the surface wetland is better than that on the subsurface wetland,and the removal effect on TN is reversed.?7?The combined process has obvious effects on the removal of COD,NH₄⁺-N,TN and TP.The RBCs have better and more stable COD and NH₄⁺-N removal effects than the ecological system,but the reduction effect on TN and TP is small.The multi-level ecosystem has better TN and TP removal effects,and the two effectively complement each other.The monthly average removal rates of COD,NH₄⁺-N,TN and TP were 60.69%⁷6.61%,79.06%⁹6.36%,59.15%⁸6.00%and 52.05%⁵5.26%.In general,RBCs have excellent NH₄⁺-N and COD reduction effects,while the multi-level ecosystem has a significant effect on TN and TP removal.The combined process compensates for the deficiencies of the individual processes on the basis of strengthening their respective advantages.The combined process provides an important guarantee for the long-lasting Qingliang of Liangtan River,and also provides valuable practical engineering reference and reference for river management in China,which is of great significance to the development of surface water treatment.