Research On The Treatment Of Sediment Phosphorus By The Environmental Ceramic Filter Balls Combining With Submerged Plants

As the outside source phosphorus pollution has been basically under control, the endogenous phosphorus pollution of the lake eutrophication has become increasingly important. The recovery of submerged plants is a quite effective method to control sediment phosphorus pollution of lakes. The new environmentally friendly ceramic filter also has certain adsorption effect on sediment phosphorus.Combined with the national "Eleventh Five-Year" water special demonstration project-West Lake in Hangzhou West Lake aquatic plant communities optimization, the test investigated the effects of the environmentally friendly ceramic filter and submerged plants (Potamogeton crispus, Vallisneria, Ceratophyllum demersum) on sediment phosphorus removal respectively, and tried to get the two combined to enhance removal efficiency, but the test results showed that the sediment phosphorus removal rate was significantly declined with laying filter.The test results are as follows:1. Temperature, pH, stirring time had a certain influence on the static release of sediment phosphorus. Emission increased as the temperature increased; under neutral conditions, the emission was the least, whether the pH value is raised or lowered, the removal rate increased rapidly, the reason might be that more stable Fe/Al-P was transformed into occluded phosphorus and organic phosphorus which were easily released; sediment was fully mixed with water by stirring, which was conducive to the release of phosphorus.2. The adsorption amount of new environmentally friendly ceramic filter of sediment phosphorus was positively related to the dosage of the filter. The adsorption process was also affected by temperature, pH and stirring time, in which the impact of pH is the greatest. When the temperature is about40℃, adsorption effect is the best; the elevation of temperature would make the filter suppress adsorption of Ca-P, but promote the adsorption of Fe/Al-P; the adsorption effect under acidic conditions was significantly better than alkaline conditions, when the pH was1, the removal rate of TP was up to66.88%.The acidic conditions were conducive to the release of the Ca-P, it because that the solubility of the Ca-P would increase at the time, however Fe Al-P emission would increase under alkaline conditions;Sediment can fully contacted with water and filter by stirring, which was conducive to the filter of phosphorus adsorption and its own release.3.Submerged plants need to absorb phosphorus from the sediments due to its growth but also by changing environmental factors (such as dissolved oxygen. pH, etc.) to influence the sediment phosphorus removal. Due to photosynthesis in plants, planting submerged plants could result in the increasing of dissolved oxygen and then the pH value increased.4. Potamogeton crispus, Vallisneria, Ceratophyllum demersum can effectively remove phosphorus from sediments. Ceratophyllum demersum had the best removal effect and its ability to adapt to the environment was the strongest.Potamogeton crispus and Vallisneria had higher utilization of the Ca-P, and part of the Ca-P could be converted to Fe/Al-P under the affection of Potamogeton crispus and Vallisneria, however Ceratophyllum demersum had relatively high utilization of Fe/Al-P.5. As laying2cm,4cm thick filter, the removal rate of sediment phosphorus of the three kinds of plants obviously decreased, the removal rate of Ceratophyllum demersum was slightly higher.lt possible because:the filter had little adsorption of phosphorus when the overlying water was alkaline; the laying of filter inhibited the growth of submerged plants, then reduced the phosphorus absorption of plants; the laying of filter also hindered phosphorus in the sediments transferred into the overlying water.6. The laying of filter media could not increase the release of sediment phosphorus; however it played an inhibitory effect on sediment phosphorus release by inhibiting the growth of submerged plants and hindering phosphorus transferred into the overlying water.So planting Ceratophyllum demersum to remove phosphorus from the sediments is a good choice, the adaptability of Ceratophyllum demersum is strong and its removal efficiency is high, it also has a good landscape effects.