Study On The Simulation Research Of Effect Of Waste Water Discharging Ways On Water Quality Nearby In Upper Yangtze River

With the experiment water storage of the depth175m in three gorges the upperYangtze River, the water velocity gets slowly in the reservoir region. In this condition,the discharge of saline wastewater of pickle industry the dominant industry of thereservoir region bring the phenomenon of salinity rise affect the release of pollutant insediment and change the water quality characteristic in the discharge outlet nearbyresult in series of water environmental issues which are become hot issues of socialconcerns. The objective of the research is to develop the discharging way which has aminimal impact on salinity rise and to reveal the effect of the distribution of salinity riseon the change of water quality in the discharge outlet nearby.The article builds four three-dimensional mathematical models of salinity risedistribution on four tail water discharge ways in the condition of subcritical flow baseon FLUENT software. And obtain the regularities of salinity rise distribution nearby theoutlet on four discharging ways and choose the optimal discharging way which has aminimal impact on aquatic environment. This article also studies the effect ofdistribution of salinity rise and disturbance in water on the release of pollutant insediment nearby the outlet and reveals the regularities of pollutant release in sediment.The conclusions of the study are as follow:The regularities of salinity rise distribution nearby the outlet was obtained in thecondition of four discharging ways which are single-port and double-portsubmerged-type discharging ways and single-port and double-port unsubmerged-typedischarging ways. The results shows that double-port submerged-type discharging wayis better than single-port submerged-type discharging way, the maximum concentrationvalue and average concentration value of each section both are lower than single-portsubmerged-type discharging way; double-port unsubmerged-type discharging way isbetter than single-port unsubmerged-type discharging way, the maximum concentrationvalue and average concentration value of each section both are lower than single-portunsubmerged-type discharging way. In order to select the optimal discharging waybetween double-port submerged-type and double-port unsubmerged-type dischargingways, x=4m、5m、7m，y=4m、3.5m、3m，z=1.9m、2.1m、2.3m are chosen as monitoring sections. The value of the maximum concentration and average concentration on x and zmonitoring sections of double-port unsubmerged-type discharging way is lower thandouble-port submerged-type discharging way; the value of the maximum concentrationis higher and the value of average concentration is lower than double-portsubmerged-type discharging way on y monitoring section. There are few points’ valueof salinity on y monitoring section of double-port unsubmerged-type discharging wayhigher than that of double-port submerged-type discharging way, while most points’value are lower than double-port submerged-type discharging way. Meanwhile theamount of salinity on y monitoring section of double-port unsubmerged-typedischarging way are lower than that of double-port submerged-type discharging way.The optimal discharging way is double-port unsubmerged-type.The regularities of the effect of salinity rise distribution and disturbance in water onthe release of pollutant in sediment nearby the outlet was found by static simulationexperiment. It is found that salinity rise distribution can increase the release of pollutantin sediment. And the average release of total phosphorus was influenced most, the valueof which is4.08higher than that of tap water only as overlying water, COD comessecond which is1.57higher, the last is NH3which is1.08higher. Disturbance in watercan increase the release of pollutant in sediment. And the average release of totalphosphorus was influenced most, the value of which is3.67higher than that in staticcondition, COD comes second which is3.17higher, the last is NH3which is1.32higher.Salinity rise distribution can decrease the release of pollutant in sediment in thecondition of disturbance. And the average release of total phosphorus was influencedmost, the value in disturbance condition and using tap water as overlying water is2.27higher than that in static condition and using brackish water as overlying water. CODcomes second which is1.17higher, the last is NH3which is1.05higher. Thecombination of salinity rise and disturbance can increase the release of pollutant insediment. And the average release of COD was influenced most, the value of which is2.84higher than that in static condition and using tap water as overlying water, the totalphosphorus comes second which is1.61higher, the last is NH3which is1.26higher.The content of this study have the characteristic of high pertinence, it can provide scientific basis for the discharging of saline wastewater in three gorges the upperYangtze River. And it can also support the sustainable development of waterenvironment in reservoir region. The results of this study have important using valueand realistic significance.