Research On The Control Technology Of Urine On The Sulfide In Sewer

As an important urban infrastructure,the urban drainage pipe system guarantees the drainage safety of urban roads and shoulders the key functions of flood prevention.However,the problem of corrosion and odor caused by sulfide generation in the drainage pipe network is a serious challenge which all countries in the world are facing.At present,the main control strategy is the expensive dosing.In this study,based on the field monitoring data of the sewer,reactors was built in the laboratory to study the generation of sulfide,and it was proposed to use high-concentration free ammonia in urine to control the sulfide in sewer.In a northern city,two well located on the sewage main pipe and branch pipe were selected to monitor multiple biochemical indicators of sewage,the time and space changes of each indicator were analyzed.On this basis,three experimental reactors were built : the biofilm reactor,the sediment reactor and the sewer simulation reactor,all of them were operated continuously for 150 days.The sulfide in the effluent and the sulfur production rate was monitored daily and batch experiments were carried out regularly.By comparing the sulfide production of the three reactors,it was found that the average sulfur production concentrations of the biofilm reactor and the sediment reactor were 9-11 mg-S/L and 12-15mg-S/,respectively,the contribution of them to sulfide is equivalent,but both are less than which in sewer simulation reactor(18-23mg-S/L),so two sewer simulation reactors provide sulfide for control and experiment in the follow-up experiment.The study further examined the inhibitory effect of dosing raw urine on the sulfide production in the sewer reactor,the results showed that after the raw urine was added,the biofilm was severely damaged and the sulfide concentration was greatly suppressed,and it took about two weeks for the sulfide in the experimental reactor to return to half the level of the control reactor.Then it was determined that it’s more suitable to achieve pipeline sulfide control for long-term with treatment for 24 hours and ten-times dilution of raw urine,and based on this control strategy,multiple rounds of experiments were carried out,the experimental results showed that the method was efficient,the sulfide content in the effluent of the experimental reactor was reduced to 50% of the control reactor for a long time.It takes10 days for the sulfide production to reach a 50% recovery rate,which indicates that a sulfidecontrol system has been established and greatly reduced the reactor’s sulfur production rate.This strategy can also reduce the methane productivity,thereby reducing the risk of greenhouse gas(GHG)emissions from the drainage pipes.By comparing the high-throughput sequencing results of the biofilm in the reactor before and after the urine wastewater treatment,it was found that compared with the control reactor,the biofilm population after multiple rounds of diluted urine wastewater treatment was reduced by half.Among the disappearing genera,the microbacteria Parvibaculum,Methylocystis and Thiomonas are the main genus,while Proteocatella and Desulfobulbus are the main genus in the experimental reactor biofilm,accounting for more than 50%,and also introduced 26 new genera including Jeotgalibaca and Atopostipes,etc.Desulfococcus has adaptability to pipeline environment and urine wastewater treatment,which may weaken the effect of sulfide control in long-term applications.This study fully proves that the use of urine wastewater for sulfide control strategies in sewage pipelines is feasible,and the results provide technical support for the control of corrosion and malodor in sewer.