Harbin City Net Sewage Capacity Plants In Constructed Wetland Research

Nowadays, with the rapid development of agriculture and industry, the basin innortheast of China had been polluted by the different levels. In recent years, theSonghua River which was the main source of water in Harbin had been pollutedseriously. The traditional sewage treatment technique had a lot of problems, while theartificial wetland sewage treatment system which is an excellent technology ownedeconomic value, sewage processing and landscape value. The wetland plant played animportant role in artificial wetland system. We selected nine representative wetlandplants (Alisma orinentale,Acorus calamus,Deyeuxia angustifolia,Typha orientalis,Scirpus validus,Sagittaria trifolia,Phragmites australis,Sangusisorba tenuifolia,Juncellus serotinus)in the research area of Baiyupao National Wetland Park. By usingsmall artificial wetland system, we researched the sewage purification effects of singlewetland plant species and different plant dispositions in different Hydraulic ResidenceTime(HRT)and concentration of wastewater. The research will provide a theoreticalbasis and the data for selecting excellent wetland plants and restoring the wetlandecosystem in Harbin city. The research showed that(1)Nine wetland plants had the ability to purify the sewage and Typha orientalisand Sagittaria trifolia had the better purification effect.(2)The five days was optimal hydraulic retention time. When HRT was five days,the removal efficiency of COD, TN, NH₄⁺-N and TP in the sewage was the highest forTypha orientalis, followed by the Sagittaria trifolia, Deyeuxia angustifolia, Scirpusvalidus and Acorus calamus. The worst was Phragmites australis and Sangusisorbatenuifolia(3)The purification effects of Typha orientalis was the best in the medium and lowconcentrations of sewage. The purification effects of plants were the worse and not thesignificant difference in high concentrations of sewage. The removal efficiency of COD,TN, NH₄⁺-N and TP of different plants was decreased with increasing the concentrationof sewage. There were purification significant differences of different plants in the low, medium and high concentrations of sewage(P<0.05), the removal rate of the majorityof plant were significantly higher than that of the contrast(P<0.05).(4)The purification effects of COD, TN, NH₄⁺-N and TP of different plantdispositions were significant differences in the medium concentration sewage(P<0.05),and the purification ability in the two plant dispositions were higher than the three plantdisposition. In high concentrations in sewage, the purification effects of COD and TP ofthe three plant dispositions were better than the two plant dispositions. There weresignificant differences for the purification effects of NH₄⁺-N(P<0.05)and notsignificant differences among different plant dispositions of TP. The purificationability was the highest for Scirpus validus+Sagittaria trifolia+Typha orientalis plantdisposition.In summary, the comprehensive purification effect of Typha orientalis was the bestamong a single species of wetland plants. Sagittaria trifolia, Acorus calamus andScirpus validus owned the better purification ability. The purification effect of the plantdisposition was significantly higher than the single-species.