Model Study Of Wetland Plant Rhizosphere Microorganism In The Treatment Of Sanitary Wastewater

With the growth of the urban wastewater,it has caused the serious environmental pollution to the locality,and the wastewater treatment of small town has been already very urgent.Constructed wetland wastewater treatment system is a technology developed in the seventies of the 20th century.Because purify effectually,the apparatus of craft is simple,operation and maintenance management is convenient,energy consumption is low,has a good adaptability to load change,expenses of project construction and operation is low,can realize the utilization of the wastewater etc.Wetland has obtained the widespread development and application.The mechanism of wastewater purification of the constructed wetland is very complicated,that utilizes the compounding ecosystem of matrix - microorganism - plant,purifying the wastewater by treble coordination function of physics,chemistry and biology.Constructed wetland can be classified as surface flow wetlands,subsurface flow wetlands,vertical flow wetlands.Because the sanitary condition is better,the occupation of land is small,wastewater treatment result is better;Subsurface flow wetland system has been studied and applicated most widely at present.The canna has appreciative value,is widely used in Various regions,has the better tolerance,can purify the polluted water body,.This experiment adopted the canna model of the subsurface flow wetland.The experiment studied the effect of artificial adding of rhizosphere microorganism on the degradation of sanitary wastewater COD in wetland modles.Two rhizosphere bacteria isolated from the constructed wetland were mixed with a certain proportion of waste water into the wetland.During the intermittent operation and the continuous operation, the degradation of wastewater COD was examined.The results of the intermittent operation indicated that the COD degradation ratio of the bacteria model was significantly higher than that of control model(P＜0.05),and the difference was even greater along with the time extension.The 48h COD degradation ratio for natural sanitary wastewater in control model and the two bacteria model(model 1 and model 2) were 50.6%,73.0%and 75.3%respectively;for sterilized sanitary wastewater,the 48h COD degradation ratio were 52.2%,76.3%and 80.1%respectively.The results of the continuous operation indicated that,with the time extension the quantity of bacterium of upper soil in control model and experimental model is on the rise,had gradually formed relatively stable biological communities in quantity and activity in long-term operation.There was obvious relevance between the bacterium quantity and COD degradation ratio;The control model presented the slack water phenomenon in various degree,and the experimental model runned normally.The results indicated that the wetland rhizosphere microorganism plays the very major role in the sewage treatment process,artificial adding of rhizosphere microorganism may improve the COD degradation ratio of sanitary wastewater in wetland,and has certain alleviation function to the wetland jamming.Further work should be carried to exploit the technology.The water pollution treatment project of Wuhan Liu jiashan village is the demonstration project of new rural reconstruction of Hubei Province.The existing problem is as followed:the wetland treatment system is not imperfect,the landscape of Tongyou River is bad,water quality is worse.and the wastewater treatment facilities are not imperfect,the engineering design has made corresponding transformation measures in view of the above questions.The implementation of this project will improve local living and traveling environment,and maintain the water quality of the downstream region(Jiuzui Reservoir).The environmental benefit is remarkable...