Field study on improvement of river water quality by riparian mixed plant zone
河岸混合植物带改善河水水质的现场研究

Water from polluted river had been treated with riparian mixed plant zone in the field for one year. Water quality indexes such as COD, NHf-N, TP, turbidity, and water temperature were tested. Results were compared by seasons. The results showed that the mixed plants give better water quality in summer and autumn than in winter and spring. In summer, the mixed plant zone removes 37.01% of the COD, 69.21% of the ammonia, 62. 45% of the phosphorous, and 99.17% of the turbidity. It can also improve water quality to some extent in winter. The mixed plant zone can reduce effluent temperature and effluent temperature difference between evening and morning and then improve water microenvironment locally. Comparisons between riparian zones with mixed plant and without aquatic plant showed that the mixed plants act importantly on removing pollutants, improving local microenvironment of water.