Removal Of The Organic Matter In Water By Coagulation

In this paper, the optimum coagulation condition for the raw water was studied. We also discussed the coagulation behavior and mechanism. Different coagulants,temperatures,pH values,dosages,added ions were the main influence factors. Organic matter in the natural water and water treatment process could complex on the colloid surface, along with colloid migrating, depositing, precipitating, and filtering Therefore considering the different dosages of kaoline to the coagulation process has the practical significance. Filtering and precipitation time were also important in the coagulation. Further the mechanism in coagulation process was studied. Residual humic acid and residual aluminium in waer with enhanced coagulation was controlled. The topic will raise the competitive technology to different quality water and source, and theoretically analysis coagulation behavior and mechanism of natural organic matter. It will have the certain theory value and the application prospect. Moreover locating in the Xiangjiang water,has a good practical significance.Control of residual humic acid and residual aluminium in water with enhanced coagulation was investigated. The influence of various factors on the coagulation was studied,in order to reach the maximum humic acid removal and the minimum aluminium residue simultaneously. Results showed that residual humic acid was controlled below 0.04 cm-1 and residual aluminium kept at about 0.1 mg/L in water with pH value between 6 and 6.5,the AlCl3 dosage of 0.5×10^-3 mol/L,under the temperature of 20℃. Addition 0.01 mol/L of CaCl2 could improve the enhanced coagulation effect. Because the suspended granule concentration changes with seasons,the influence of the kaoline dosage on the humic acid removal process was studied.In the paper, the removal of organic matter in Xiangjiang River by enhanced coagulation was studied. Results show that when adding 3×10^-4 mol·L^-1 PAC and pH was between 5 and 6, TOC removal could reach to 53%. Turbidity and UV-254 could also be removed effectively, reaching to 96.4% and 83.2% separately. The relations between TOC and UV-254 was UV-254 = 0.0485 * TOC - 0.0738.