Study On The Application Of High-density Clarification Process In Seawater Treatment

To solve bottleneck problem of poor ability to against the load impact、the cost of infrastructure and operation is high、cleaning frequently and microbial pollution, this test took the nearshore seawater of Caofeidian as the research object, applied high-density clarification process to seawater purification, mainly carried out the research and explore the following three aspects:(1) According to perform relevant tests for raw water quality, we found that: the amount of particulate matter is less, turbidity is low, particle size is small, and water quality fluctuation is opposite bigger, all these make the process of purification process more difficult.(2) After the exploration on the optimum conditions of process operation, we found:①Types of coagulants、dosing quantity, stirring speed, the amount of sludge return, dosing quantity of NaClO and mud cycle conditions on water quality have an influence on treatment effect;②The best operating conditions:Choose FeCl3as the coagulant, dosage is15mg/L, the stirring speed is400r/min (G is586.6s-1), the sludge reflux ratio is15%, dosing amount of NaClO is1mg/L and mud cycle is8h.(3) After monitoring and analysis of the high-density clarification process treatment effect, we concluded that the Densadeg’s removal effect is different for pollution indicators, dose NaClO can promote it, Specific as follows:①In the removal of turbidity, high-density clarification process showed a very strong stable ability of peak clipping, effluent turbidity remained at around4-5NTU;②In the removal of algae, under the condition of not adding NaClO, the treatment effect of high-density clarification process is not ideal, when raw water’s chl-a average amount was13.83μ g/L, after adding NaClO, the amount of chl-a in water could be reduced from11.36μ g/L to6.94μ g/L;③In the removal of organic matter, after adding NaClO, the removal rate of CODMn and UV254has improved considerably, CODMn removal rates promoted from30%to50%, the removal rate of UV254promoted from around26%to45%;④In the removal of iron, because of the iron coagulant dosing, the water content of iron has increased, but after adding NaClO, situation eased; ⑤In the removal of activated silica, adding NaClO can improve the removal effect, when we add NaClO, average water activated silica can be reduced from1.73mg/L to1.59mg/L.