Microcosm Modelling Of Landscape Water Eutrophication And Its Remediation Study

So far, the main water remediation techniques at home and abroad can be classified into 3 groups: nutrient control techniques, direct algae killing,biomanipulation and ecological restoration. In general, bio-ecological techniques show more persistent character such as less by-products, lower cost, and sound landscape.In this paper, water microcosms were used to model the course of landscape water eutrophication under natural conditions. During the course, light intensity, water temperature, pH, nitrogen, phosphorus, and Chla concentration were tested week by week. According to the testing results, the algae bloom forming mechanism was discussed. Then submerged macrophytes were investigated in microcosms, especially their inhibitory effects on phytoplankton. At last, Using natural zeolite, slag and sand as fillers, an up-and-down flow integrated biofiltration bed was constructed and applied to remediate eutrophic water in microcosms after a series of static and dynamic experiments. The removing efficiency for nitrogen and phosphorus and mechanism was the focus. It is found that water temperature and light intensity have significant influence on algae growth when original nitrogen and phosphorus are in the same level. In the limited range, the higher the water temperature and light intensity are, the faster the algae grow. In the range of 25℃~30℃, the highest growth rate of algae can be reached.The microcosm biological populations can be dominated by submerged macrophytes under weak light intensity. The research showed that Ceratophyllum demersum and Myriophyllum spicatum had good effects on algal growth inhibition, turbidity decrease and nutrition removal. It can also be concluded that submerged macrophytes could be helpful for the realization of persistent clean condition of waters.The nitrogen element, especially ammonia, could be removed efficiently in the bio-filter by physical adsorption, chemical combination and biodegradation under dynamic condition and the ammonia and phosphorus removal reached 96.44% and 46.54%, respectively. The effluent ammonia concentration was under...