The Study Of Reclaimed Water Used As Water Source Of Urban Landscape Water Bodies

As water shortage has become a global problem, the supplement of reclaimed waterto landscape water body in water shortage city will become an inevitable trend.However there are many problems in this respect. This paper focused on the naturaldegradation of water quality under the condition of laboratory and field studies firstly.,Then the variance of algae species and number with time was discribled. Finally theimpact of plant purification on water quality was studied. The above work may provideimportant reference for the practical application of reclaimed water to be used forlandscape water bodies. The main results of this paper are as the followings:(1) The quality of reclaimed water degraded quickly under the higher temperature in thesummer. Thus the accumulation of the nutrient substance and the algae in the wateris rising. In this experiment, eutrophication of reclaimed water appeared and algaenumber reached more than200mg/m3within a week.(2)Water hyacinth can effectively remove ammonia nitrogen and soluble phosphorus ofthe water. The removal rate of ammonia nitrogen is92.6%, the absorption rate is2.491mg/g, the removal rate of solubility phosphorus is52.16%, the absorptionrate is0.0653mg/g.So they can control of algal blooms and eutrophication,effectively and improve the water quality significantly.(3)water lily can effectively remove ammonia nitrogen and soluble phosphorus of thewater. The removal rate of ammonia nitrogen is66.6%, the removal rate of totalphosphorus is46.4%, the removal rate of total nitrogen is74.4%, the removal rateof COD was36.25%. So water lily can control of algal blooms and eutrophication,effectively and improve the water quality significantly. (4) Precautions should be taken against the hidden algae, dimorphic scenedesmus,linear and wrap around needle closterium to prevent bloom occurring in landscapewater body when the reclaimed water is used as supply source. The algae amountand growth rate are closely related to the total phosphorus concentration, which hasgreat role in promoting the growth of algae. Thus the phosphate concentration isthe key factor to control algae growth. The optimal proportion of reclaimed waterand landscape water is40%.(5) With reclaimed water as the only supple source, nitrogen and phosphorus ofartificial lake are maintain high concentration，ammonia nitrogen concentration inthe range of0.132~2.547mg/L, the solubility of phosphorus concentration inthe range of0.02~0.204mg/L. Nitrogen and phosphorus and organic compoundconcentration are higher, if long-term operation, the possibility of eutrophication ishigher.