Study On Purified Efficiency Of Domestic Sewage By Wetland Plants In Constructed Wetland

Over the last two decades, Constructed wetland systems are increasingly used to treat domestic sewage, industrial wastewater, and agricultural runoff. because it has particular mechanism and function in treatment of wastewater. This wetland treatment process has been gaining international interests and applications due to its low-energy cost low maintenance and operational cost, and high removal capacity. The advantages of constructed wetland also include correspondingly low investment, multiformity and pertinence of treatment systems, efficient purification capability and especial environment function. It is suitable for China, especiably for the rural areas and small cities. Constructed wetlands system is an ecoligical technique by using natural purifying functions of soil, vegetation and microorganisms. Constructed wetlands remove wastwater N and P by precipitation, soil adsorption, plant uptake with organic matter accumulation, and microbial immobilization.This paper provided a brief review on the definition, composition, design, mechanism of sewage disposal and the application of constructed wetlands. At the same time, the paper specified various factors and restrain conditions affecting purification efficiency and discussed the interrelations among them. Aquatic plants have an important functions in the ecological restoration of a polluted water body . In this paper, the roles of Wetland plants are discussed in order to disclose the importance of wetland plants in congstructed wetland for wastewater treatment..The most two important functions include: 1) Uptake the nutrients, absorb and accumulate heavy metal and poisonous substances from wastewater. 2) Transfer oxygen to rhizophere for the growth, reproduction and decompositions of microorganisms.The technical design of small-scale plots of constructed wetland was described along with details of some associated wastewater purification effects. The system were comprised of two chambers. One chamber induced downward-flow, the other created upward-flow. We transplanted six kinds of wetland plants include Phragmites communis, Typha orientalis, Scirpus tabernaemontani,Zizania caduciflora,Sagittaria sagittifolia and Acorus calamus.Its purification efficiencies for domestic sewage were analyzed under different operating...