Study On Water Quality Control Technology Of Urban Landscape Water Based On Pond System

Taking reclaimed water as supplementary water for landscape water has become a common pattern for saving water resource and improving the utilization rate of water resource.However,it is easily to cause eutrophication because the landscape water have bad self-purification ability and the nitrogen and phosphorus concentration is high in reclaimed water.This study was based on the eco-restoration technologies to test different purification abilities of different aquatic plant ponds.After previous experiments,a tandem circulation flow plants pond system was built up for stimulating the treatment efficiency of different aquatic plants combination for reclaimed water.And tested the treatment effect of the ozonation for eutrophication landscape water.At the same time,water quality monitoring and optimal operation factors analysis were conducted in Kunming Xihua park landscape water as an application case.This research will apply technical support and guidance for water quality control of other similar landscape water.Total results of this research are as follows:(1)Different aquatic plant ponds all had different purification abilities for nitrogen,phosphorus and COD.It was suggested that Hydrilla verticillata pond had the highest efficiency for total nitrogen removal,the removal rate was 87.17%.The removal rate for ammonia nitrogen was over 40%and the removal rate for total phosphorus was over 80%in every aquatic plant pond.The tandem circulation flow plants pond system had good treatment in three different influent concentrations,the total removal rate was over 90%for ammonia nitrogen and total phosphorus,and over 50%for total nitrogen and COD.(2)The ozonation had good effect on removing COD and chlorophyll a of landscape water,but it couldn't remove nitrogen and phosphorus directly.It had better removal rate for total nitrogen,ammonia nitrogen,total phosphorus,COD and chlorophyll a by ozonation combined with submerged plants,the removal rate was 78.65%,86.96%,95.29%,61.60%and 88.86%separately.(3)Studies on Xihua park landscape water as an application case showed that pond system has effectively controlled the concentration of nitrogen and phosphorus in landscape water.The average removal rates of ammonia nitrogen,total nitrogen and total phosphorus were 44.43%,72.13%and 57.80%separately.And the concentrations of total nitrogen,ammonia nitrogen,total phosphorus and COD should be controlled within 3mg/L,0.5mg/L,0.05mg/L and 30mg/L in order to maintain the stability of landscape water.Above all,nitrogen and phosphorus is the most important factors.What's more,the water transparency should be over 50cm,and the concentration of chlorophyll a should be controlled within 20?g/L.Submerged plants play an important role in treating polluted water so the coverage should be kept over 50%.By the way,it is also important to strengthen water circulation and maintenance management of pond system for better purification effect.