Experimental Study And Engineering Application For Purification And Remediation Of Black-color And Odorous Urban River

Currently water environment pollution has become one of the most important issues in the world, and river pollution in city is more flinty. The urban river is playing an important role in the city water environment, is an essential source in the formation and development of the city. With the development of economy and the increase of population, the discharge of industrial wastewater and domestic wastewater have constantly increased, large amount of ineffectively treated sewage has discharged directly into city water area, especially the middle and small-scale urban rivers.All that results in the black and odorous water body and have a bad effect on citizen daily life and environment, and have already deeply affected the urban ecological construction and the sustainable development of city economy. The treatment for black and odorous water body is an urgent problem to delay in city.On the basis of appraisement of the familiar engineering measurement at home and abroad such as sediment dredging, disposal and integrated low-flow augmentation. This dissertation point that bioremediation is the indispensable measurement. At the same time, this paper compares and analyzes the theory and technique of various treatments for the black and odorous rivers in city, summarizes their advantages and disadvantages, and studies the key technique of bioremediation.This subject aimed at developing an effective and combined with city natural ecosystem water environment treatment technology for the black and odorous rivers in city. The research was about biological trough system treating the black and odorous water in Gongye river. Results showed:1. Biological trough system had better purifying effect to landscape water polluted while testing, could improve its water quality at little. The purification efficiency varied in line with temperature and seasons hydraulic loading values and the growth of plant and microorganisms. The purification effect of the combination trough of filling and aquatic plant were better than the filling trough. The former's removal rates of BOD₅,COD_Cr,NH₃-N,and TP are 37.0%, 34.8%, 34.7%, 26.7%.At the same condition, the plant's absorption to the soluble pollutant and the rhizosphere microorganism's metabolism function strengthened the purification effect of the system in the certain degree.2. Whether adding microorganisms or not, the changes, however, was not obvious. No adding microorganisms were suggested in the same situation to decrease the cost of operation, regarding to the similar water quality condition. Moreover, the experiment system are influenced by external environment, because the pollution loading changed by the rain fall will cause the impact to the system, which will affect directly the system's stability and the purification efficiency to all kinds of pollutant. The plants contributed less for the removal of nitrogen pollutants (8.92%), but played an important role (25.24%) for the removal of phosphorus pollutants. The Concentration of DO experienced a changed process, which increased first and then declined, and arrived at the maximum value from14:00 to16:00.3. The hydraulics resident time can influence obviously the removal rates of BOD₅ and TP and the combination trough were better than that of the filling trough. The treatment performance of 24h (HRT) was better than that of 8h(HRT).But The influence of the hydraulics resident time to remove the ammonia was not obvious for the filling group, however, is remarkable for the combination group. Aeration can enhance obviously the removal rates of the ammonia in the system. In the same type trough, the effect of aeration was better than that of no aeration. At the same aeration condition, the purification effect of the combination trough of filling and aquatic plant were better than that of the filling trough except the removal to TP.4. Some measures such as sewage truncation, sediment dredging , disposal and aeration could improve its water quality. The concentration of oxygen increase evidently, and the organic content, nitrogen and phosphorus content of the sediment has reduced, which suggest that there is a change with tendency from anaerobic condition to aerobic condition in sediment.Because of the truncation dirt incompletely , there were all kinds of pollutants dumped into the river, which could create a remarkable increasing in the concentration of the pollutant for the short time, and caused certain impact of pollutant load. We should strengthen the control of the extraneous source pollutant input and carry on effective supervisal and management for a long time.