Study On The Anthracite-sand Dual Media Filter Aimed At High Concentrations Of Algae And Organic Yellow Reservoir Water

The study took Dongying Hekou water treatment plant as the research object,analyzed the water quality of Gu He reservoir which is water source of water plant,summarized the limitations of the ordinary sand filter in the water treatment plant of our country,and combined the actual investigation and monitoring of the Dongying Hekou water treatment plant,and made the corresponding test plan according to the problems of the existing filter in the water plant.A pilot test device has been built near the sedimentation tank of west water treatment plant,and a series of experiments have been carried out.The research conclusions can provide an optimal proposal for the limitations of the existing filter for high algae and high organic water in the actual water plant,and provide a theoretical basis and technical support for the selection of filter.The research content mainly includes three aspects:?1?the evaluation of the filter operation effect of the Hekou water treatment plant;?2?the experimental study on the removal of organic matter by the double layer filter material of the coal sand;?3?the experimental study on the removal of algae by the double layer filter material of the coal sand;?4?the design of the reform scheme of the filter pool in the Hekou water treatment plant.In the study of the performance evaluation of the filter pool in the Hekou water treatment plant,the water quality of the reservoir was collected and analyzed,and the water quality of the reservoir was clearly characterized by high algae and high organic pollution.During the field investigation of the Hekou water treatment plant,the effluent indexes of the existing processes in the water plant were collected and calculated.The effluent turbidity,ammonia,COD_Mn,total algae and chlorophyll a were found to meet the requirements of drinking water sanitation standards,but the treatment ability of high algae and high organic pollution water quality in the reservoir of the reservoir was found.Limited,the removal effect is unstable.Faced with this situation,we should consider the following two ways:first,strengthen the management and protection of water sources,and control the eutrophication of water bodies.The two is to transform the filter which has limited effect on organic matter and algae removal in water works.Through researched the study of the filtration treatment technology of high algae and high organic pollution at home and abroad,and the development status of anthracite and quartz sand double filter filter,it is found that the anthracite and quartz sand filter filter has the advantages of strong pollution capacity,good removal effect on organic matter and algae,and it is very suitable for the transformation of Hekou water treatment plant existing filter types.Therefore,the experiment selected the type of filter pool of double filter material of coal sand,combined with the actual conditions of the water plant and the operating parameters of the existing technology,through the comparison with the ordinary sand filter,the removal effect of the conventional water quality index and the organic matter index and the algae index was studied.Pilot test was adopted in the experiment.A pilot scale filter column was set up in the gallery of the sedimentation tank unit of the west water treatment plant.In the experiment of removing organic matter from the double filter material of coal sand,the experiment was carried out on the conventional water quality index and the organic matter index of the experimental filter column with different filter material.The results show that the removal rate of the turbidity and ammonia in the double layer filter material of the coal sand is 88.4%and 75.47%,which are obviously higher than that of the single sand filter material for the turbidity and ammonia nitrogen removal rate of 80.47%and 46.27%.And the turbidity of coal sand filter column drops below 0.3NTU,and the removal effect is very obvious.During the test,the pH value of the water and water in the coal sand filter is in the7.5⁸.0 range,which provides a suitable environment for the nitrification of the microbes on the anthracite coal and improves the water quality of the effluent.Compared with ordinary sand filtration,coal sand filter can effectively remove organic matter in water,especially for small molecule organic matter.During the test period,the average removal rates of COD_Mn,UV₂₅₄ and TOC were 47.58%,64.18%and 65.13%respectively.The COD_Mn concentration,UV₂₅₄54 and TOC of coal sand filter effluent decreased to 2.5mg/L,0.02cm^-1 and 4mg/L below.By studying the mechanism of organic matter removal from coal and sand double layer filter,it is found that it mainly removes organic matter by filter interception,anthracite adsorption and bio degradation.The study of algae removal by coal and sand double layer filter showed that the total number of algae in the raw water was 10⁷ orders of magnitude during the experiment,and it was always at eutrophication level all the year round.After the treatment of raw water,the total number of algae decreased significantly,and the sedimentation pond removed most of the algae.Filtration played a key role in the removal of algae.The removal rate of total algae and chlorophyll a in coal sand filter is 88.4%and 75.47%,which is better than that of Single layer sand filtration,and the removal rate of turbidity and ammonia nitrogen is 80.47%and 46.27%respectively.The effect of coal sand double layer filter material on algae removal is better and more stable than that of single sand filter media.The distribution rule of algae in filter layer of anthracite is as follows:with the continuous operation of filtration,the distribution of algae in filter layer is increasing.The algae content in the surface layer is the largest.With the deepening of filter layer,the number of algae is less.The study on removal of algae by double filter material of coal sand found that the removal of organic matter and algae could be effectively enhanced by the filtration of double layer filter material of coal sand on the basis of effective removal of turbidity.At last,the plan was designed to transform the tilting plate filter into a coal sand double-layer filter material filter.Through the design of water,filter speed and backwash strength,the area,size,height of filter pool and water distribution system of the filter pool of the coal sand double filter are designed and calculated,and the plane and section drawings of the filter are also drawn.It provides a reference for the reconstruction of the filter in the water plant.