Environment Effects Study On Irrigation Green Land By Reclaimed Water

As an alternative water source, reclaim water using can effectively ease the shortage of water resources. Currently, reclaimed water is mainly used to industry, agricultural irrigation, landscape and urban utility, etc. But, the composition of urban recycled water is complex and it may carry some risk as when used as green plot sprikling. Therefore, research on the influences of the irrigation by reclaimed water as greening on soil, plants, plant rhizosphere and groundwater is necessary. According to the researching work, the following conclusions are obtained :(1) Under the set irrigation stress, the concentration of TN,TP,TDS and NO3--N in reclaimed water leachate are high than tap water leachate, and using this reclaimed water does not cause groundwater pollution.(2) There has no significant effect on the organic matter content and the available nitrogen content in the root zone(0-20 cm) soil irrigated by reclaimed water, but has significant influence on the contents of the available phosphorus and the available potassium; To the non-root zone(0-40 cm) soil, there has no significant effect on the organic matter content, but has significant influence on the contents of the available nitrogen, the available phosphorus and the available potassium. The change trend of available nitrogen is accumulated in root zone and reduced downward significantly. Besides, the organic matter, the available phosphorus and the available potassium had no apparent phenomenon of enrichment, plummeting and stratified.(3) The chlorophyll of these four plants which irrigated by reclaimed water is higher than that of by tap water, it shows that utilizing reclaimed water can increase the chlorophyll content of dwarf lilyturf, oxalis corymbosa, tall fescue and iris, so using reclaimed water could be benefit for these four plants photosynthesis.(4) Before the reclaimed water irrigation amount was 48 L, the membrane permeability of these four plants had increased, which indicated that reclaimed water can conducive to enhance the plant’s stress tolerance to some extent, but after that the effect become weakening.(5) Reclaimed water irrigation has no significant effect on root system activity of dwarf lilyturf, but it can promote the increase of oxalis corymbosa’s root system activity significantly and effectively, and increase the root system activity of tall fescue and iris to a certain extent.(6) Reclaimed water irrigation has certain influence on the population densities of bacterium, fungus and actinomycete in plant rhizosphere soil, but the impacts are not obvious.