Experimental Study On The Water Quality Improvement And Restoration Of River Body In Baoding City

Water pollution is a main factor causing shortage of water supply. As a new, cheap and ecological sound technology, phytoremediation of eutrophicated water system attracts many scientists all over the world. Paper carried out the static simulation test according to the heavy pollution characteristics in the river of Baoding city. Paper analyzed the purifycation effects and rules of plant floating-bed technology on polluted river water.The experiment was taken on the basis of resource surveys to the aquatic plants in the north china region and Monochoria korsakowii, Lythrun salicaria, Alisma orientale, Pistia straitens L and Eichhornia crassipes were choosen for experiment. Paper studied and compared the effectiveness of different aquatic plants pecies on restoring polluted water of Fuhe river in Baoding city. All the experiments were carried out in outdoor natural condition. The study included three parts. The first part analyzed the purification ability and anti- pollution behaviour of emergent plants,the second part analyzed the purification ability and anti-pollution behaviour of floating plants,the third part analyzed purification ability and growth characteristics of aquatic plants in two types of wastewater(low concentration and high concentration). The results were summarized as follows:Firstly, Monochoria korsakowii, Lythrun salicaria and Alisma orientale can help to remove pollutant in wastewater in different extent. The purification ability was related to season and how the plants grow up. Lythrun salicaria has the best effect of depurating wastewater in three emergent plants. Its net removal rate of TP, TN, NH₃-N, CODcr were 92.00%,97.60%,99.34%,84.25%, secondly for Alisma orientale and the purification capacity of Monochoria korsakowii is worst.Secondly, Eichhornia crassipes and Pistia straitens L had strong ability to adapt wastewater and strong reproductive capacity.But the difference of purification capacity is not obvious. Their net removal rate of TP, TN, NH₃-N, CODcr were 88.93%,96.42%;96.15%,93.45%;93.91%,96.32%;37.50%,66.67%, and the removal rate of TP,TN,NH₃-N reached 60% on fourteenth days. Pistia straitens L had the fastest speed of purification of TP and TN in previous experiment, but speed of purification of NH₃-N was slower than Eichhornia crassipes.The experiments of different types of wastewater show that the purifying efficiency on the low concentrated wastewater was significantly less than the high. Pistia straitens L had the best purifying efficiency of TP and TN in two types of wastewater, and with the concentration increasing, the removal rate were increasing. Eichhornia crassipes had priority to get rid of NH₃-N, but poor purifying efficiency of other water quality index. The CODcr removal rate of Monochoria korsakowii was the highest, followed by Pistia straitens L, finally followed by Eichhornia crassipes. The experimental results show that the more abundant of nutrient in wastewater, the more beneficial to increasing the purifying efficiency.Paper studied the cause of water eutrophication of river body in Baoding City, and proposed a practical technology of eutrophication control and water self-purification. The technology would be positive for water ecological environment recovery construction and the water quality improvement of Baoding city in the future.