Study On Control Technology For Urban Landscape Of The Lake Algae And Water Pollution

In recent years, eutrophication of rivers, lakes and landscape water is becoming serious day by day, which leads to a situation of excessive algae breed. And frequent reservoir bloom. Eutrophication has affected the environment and people’s normal life seriously, which is also the reason to the water shortage of our country. Currently, using polyaluminium chloride (PAC) as the coagulant is the main method of water purification. But the algae still can break through the filter when using routine ways, which means we may not be able to dislodge effectively.Taking water from Fuyang River as the raw water and adopting beaker coagulation to determine the best algae removal chemical and the most suitable dosage. The steps are as follows:first, take permanganate composite chemicals (PPC) as the pre-oxidation to treat the water, and then adopt biological activated carbon filtering technique to further the water purification.Through dynamic test, the paper studied the pollutant removal effect that cycle period and water temperature carried on biological cycle filtration water purification system.Through beaker experiment, we can make sure the dosage of PAC is20mg/L and0.6mg/L for PPC. Under these conditions, the average removal rates of chroma, turbidity, CODMn, UV254and algae are the best,50%,80%,25%,26%and78%, respectively.PPC-biological activated carbon filter study shows that, under conditions of5m/h for filtering velocity,12min for empty bed contact time (EBCT) and1.0for gas-water ratio, the average removal rates for CODMn,NH4+-N, TN, turbidity and algae are43.4%,87.9%,12.8%,90.6%,79.5%respectively. The average effluent concentration for CODMn, NH4+-N, TN, turbidity and algae are1.84mg/L,0.37mg/L,7.4mg/L,0.5NTU and127100/L, respectively. The running parameters are as follows:20mg/L for PAC coagulant,20min for coagulation hydraulic retention time and60min for inclined plate settling tank hydraulic retention time.Water temperature has obvious influence on pollutant removal rate after the research on the biological circulation filtration process. With the conditions of5m/h for hydraulic loading,98L/s for inflow,1:1for gas-water ratio,12min for HRT and41h for operation time when the temperature is beyond23℃,the average removal rates for chroma turbidity, CODMn,UV254,NH4+-N,TN,algae and chlorophyll a are68.4%,86.9%,48.75%,48.4%,86.52%,11.94%,92%and98%respectively.