Research On Urban Black And Odorous Water Treatment

In recent years,our country’s economic and social development has made significant progress.However,environmental pollution,especially water pollution,has become increasingly prominent due to the dense urban population.Therefore,it is of great significance to explore the treatment of urban black and odorous water bodies to improve the living environment,implement the concept of ecological civilization and the people-centered development idea.This thesis took the opportunity of serving the housing construction,ecological environment,urban management and other departments in the Xuyi County Government Office and actually participating in the implementation of black and odorous water body remediation.Taking the urban water environment management in Xuyi County as an example,the research of this project has carried out with the two black and odorous water bodies of Tiantai Mountain Intercepting Ditch and Chengdong Great Ditch as the research objects.First,12 monitoring points were set up along the black and odorous water body,and indicators such as transparency,dissolved oxygen,redox potential and ammonia nitrogen were regularly measured to determine the black and odorous water body.Secondly,along the black and odorous water body,surveyed,investigated,and mapped out its geographical location,starting and ending points,buildings on both sides,communities,vegetation,revetment,construction of rain and sewage pipe network,etc.,and evaluated the current water body and surrounding environment to determine the pollution source.Then analyzed the causes of black and odorous water bodies.After that,according to the current water quality and pollution of the water body characteristics and composition,comprehensively used the black and odorous water treatment technologies such as source control and interception,dredging,ecological restoration,etc.,putt forward the planning and design of pollution control and treatment,and conducted water treatment experiments.Finally,the public evaluation method and other methods were used to evaluate the effect of the water body after remediation and to propose long-term management ideas.The main findings of the thesis are as follows:(1)Through regular monitoring of water body characteristic indicators,including water transparency,dissolved oxygen,redox potential,ammonia nitrogen,etc.,the transparency of Tiantai Mountain Intercepting Ditch was 18.94 cm,dissolved oxygen 2.94 mg/L,redox potential186.74 m V,and ammonia nitrogen 32.14 mg /L.According to the grading standard of black and odorous water body,the Tiantai Mountain Intercepting Ditch was determined to be a severe black and odorous water body.The transparency of Chengdong Great Ditch was 12.00 cm,dissolved oxygen 3.08 mg/L,redox potential 269.63 m V,ammonia nitrogen 10.07 mg/L.It was determined that Chengdong Great Ditch was a mildly black and odorous water body.(2)Through on-the-spot investigation,data review,data analysis and other methods,the causes of black and odor water body were analyzed,it was found that Tiantai Mountain Intercepting Ditch and Chengdong Great Ditch had different degrees of point source pollution,non-point source pollution and endogenous pollution.Among them,the point source pollution was mainly caused by the domestic sewage of the residents on both sides of the water body,the non-point source pollution was mainly caused by the inflow of sewage from production,domestic waste and aquaculture,and the endogenous pollution was mainly due to the deposition of a lot of oxygen-consuming substances and nutrient salts in the sediment,which were slowly and permanently released to the water body,resulting in secondary pollution.(3)In 6 consecutive months after the completion of the treatment of Tiantai Mountain Intercepting Ditch,the treatment effect was comprehensively evaluated.At the level of mass evaluation,questionnaires were issued to the residents around the water body and passers-by to ask them about their satisfaction with the treatment of the water body.At the level of data analysis,indicators including transparency,dissolved oxygen,redox potential,ammonia nitrogen,etc.were measured and compared with those before treatment.At the level of intuitive feeling,photos,images and other data before and after treatment were analyzed and compared,so as to comprehensively evaluate the treatment effect of Tiantai Mountain Intercepting Ditch.The result was that the public satisfaction was 94%,the water transparency was 41 cm,the redox potential was 96 m V,the dissolved oxygen was 8.54 mg/L,and the ammonia nitrogen was 1.62 mg/L.After the treatment,the organic pollutants in the Tiantai Mountain Intercepting Ditch had been greatly reduced,the treatment effect was obvious,and the treatment goal had been achieved.(4)In order to prevent the water bodies of Tiantai Mountain Intercepting Ditch and Chengdong Great Ditch from returning to black and odorous,through the establishment of a management agency,setting up a water quality monitoring system,carrying out normalized management and protection,implementing the "River Chief System",and raising public awareness of water environmental protection,etc,a long-term management and protection mechanism for urban black and odorous water bodies was proposed.(5)The "three stages and six steps" of urban black and odorous water treatment was summarized,that was the judgment of black and odor levels before the treatment,the investigation of the current environment and the cause analysis of black and odor,the application of comprehensive technologies in the treatment,and the evaluation of the treatment effect and normal long-term management mechanism after the treatment.