Research On The Enhanced Coagulation And Sedimentation Process For Fluoric Wastewater Treatment

Overdischarging F in industrial waste water will pollute the environment, harm the normal growth of corps and livestocks and even severely affect the health of human beings, so defluorination in industrial waste water and F control in water resource become the most important research tasks in environment protection and sanitation fields home and abroad.As one of the main contaminant in color-tube factory wastewater, F-contain wastewater treatment has been paid great attention. This paper is about defluorination experiment for treatment of color-tube water. We mainly focus on the selection of coagulant. Contraposing the different F-contain sewage, we carried out tests with confected F-contain sewage and raw F-contain sewage . According to the tests, we evaluated the experiment effect of defluorination through lime-sedimentation,the combination of Ca(OH)₂+PFS+PAM and the different dosage of coagulant in sludge recirculation. Then according to the experimental results, we carry out local full-scale test and get the same results as experimental conclusions. We finally fix the combination of Ca(OH)₂+PFS+PAM with sludge circumfluence as enhanced process for F-contain wastewater treatment. With the adoption of this process, the remnant concentration of F in treated water is 4mg/L, comparing with the normal process, it get a decrease of 37%. The total cost of reagent is 1.127yuan/mP3P, comparing with PTEO process, it will save 205 thousand yuan per year. As for other 3 coagulant AlB2B(SO4)B3B,FeClB3B,and PFS, we also carry out detailed experiment in order to simulate local conditions and get the adaptation, optimum operation parameter and condition of the 3 different coagulants, analyse the defluorination mechanism of enhanced sludge circumfluence process, prove up the influence of sludge circumfluence to different process of using different coagulant. Further more we provide a valuable example for introducing sludge circumfluence into real use.Through continuing improvement to defluorination process in color-tube factory in Shenzhen, from using inorganic coagulant to adapting macromolecule coagulant and sludge circumfluence, the water quality also get better and could be reused. This process can also get a decrease of F concentration and total cost, make great contribution to both economic benefit and environment protection.