Artificial Wetland Treatment Of Rural Domestic Sewage Test Research And Application

Rural domestic sewage has the characteristics of small tonnage, scattered emissionand the difficulty of collecting, and it is difficult to manage in the sewage plant.However, artificial wetland treatment process completely considers the wastewaterquality and geographical features, which is one of the commonly used rural sewagetreatment. This project takes the sewage from Shaanxi Province as an example, usesHorizontal Sub-surface Flow Constructed to carry out the experimental study to studythe treatment effect of artificial wetland under different hydraulic loads and retentiontime in natural conditions, aerobic aeration and increased zeolite packing cases.On thisbasis, the actual engineering design and construction of rural domestic sewage by usingartificial wetland is carried out to deal with, and some advice is given to the local ruraldrainage system for sewage collection, processing and utilization etc.Main research results are as follows:1、Laboratory-scalesmall artificial wetland sewage processing without increasingany auxiliary measures, the results for the removal of organic matter is better, which theCOD degradation rate can reach more than90%; however, ammonia nitrogen and totalnitrogen removal is poorer, the degradation rate is only40%and20%, respectively.2、Since there is a large anaerobic zone existed in the wetland, thus aeration isincreased in the front stage, with composite processing. Under reasonable hydraulicload, the removal rate of COD, NH4+-N, TN and of TP are95%,90%,50%and90%,respectively. The removal effect of TN is poorer, which because the consumption ofwetland inaerobic zone of COD is too large, leads to denitrification because ofinsufficient carbon source in the later stage, thus more nitrate nitrogenresults inincreased TN. 3、Under different hydraulic retention time （1,2,3,4, and5d） for intermittentoperation, it is found that the longer the hydraulic retention time, the better the artificialwetland water effect. When the hydraulic retention time is5d, of the quality of artificialwetland water changes, which COD is31.01mg/L, NH₄⁺-N is5.02mg/L, TN is9.40mg/L and TP is2.29mg/L.4、The filler is an essential part of the artificial wetland, different filler can havedifferent effect on the treatment of artificial wetland. zeolite and gravel are used in thisexperimental study: the adsorption of zeolite to ammonia nitrogen is great superior togravel. In60mg/L water ammonia nitrogen concentration, zeolite adsorption capacitycan reach to0.37NH4+-N/g. With the increase of ammonia nitrogen concentration, theadsorption quantity increases.5、In combination with laboratory test results, in view of the household as the unitof rural domestic sewage as treatment object, the artificial wetland is used to deal withthe actual engineering design and construction of rural domestic sewage, the mainprocess is: the sewage-septic tank-regulating-artificial wetland-effluent.6、This project takes Ziyang village, ChaoYi town, Dali Xian of Shaanxi province,as an example, and analyzes the existing drainage way and the present situation ofsewage treatment, and provides the suggestions for the construction of new ruralinfrastructure such as the sewage collection, treatment and disposal plans.