Pre-oxidation Collaborative Coagulation To Remove Organic Pollutants From The Jialing River Water

Spring and summer raw water quality in Chongqing Jialing river have differentfeatures: Because winter sedimentary organic matter is flushed into river, the spring rawwater contains high concentration of organic compounds; Summer water turbidity ishigher, the two types of water treatment is difficult. In order to solve a single watertreatment process difficulty when treatment above two kind of water, need to seekingstrengthen existing process of method. This subject based on pre-oxidation process oncoagulation of reinforcement, inspects potassium permanganate、hydrogen peroxide、ozone collaborative coagulation performance and effect when treatment the above twokinds of water sample.In three kinds of polyaluminium chloride dosing doses （5.0,7.5,10.0mg/L）, threekind of oxidant oxidation can enhanced coagulation to remove turbidity and organicmatter. otassium permanganate show best effect on coagulation removing turbidity, canmake the water residual turbidity reduction of1.0³.9NTU. For the removal of TOC,potassium permanganate have the best effect to coagulation in three kinds of oxidants,TOC removal rate is improved by7.8～8.1percentage points; For the removal of UV254,three kinds of oxidant effects are more obvious, the ozone effect is best, so that theUV₂₅₄removal rate increased by12.1～14.2percentage points.Oxidant dosage has significant influence on enhance coagulation effect. With threekinds of oxidant dosage increases, turbidity、TOC、UV254removal rate can be improved.For the experimental water, potassium permanganate optimum dosage is0.9mg/L,hydrogen peroxide optimum dosage is1.2mg/L, ozone optimum dosage is2.0mg/L.Using ultrafiltration membrane separation organic method, studies the waterorganic molecular changes. The results shows that, the Jialing River Raw Water is givenpriority to small molecule organic compounds; Molecular weight less than3k organicmatter have half in the total organic; molecular weight greater than10k have30%in thetotal organic. After pre-oxidation，molecular weight distribution of data comparisonshows, three kinds of oxidants can change the distribution of organic matter, molecularweight greater than3k organic volume is decreased, molecular weight less than3korganic volume showed a tendency to increase; especially dissolved organic matterdecreased obviously. Different oxidants on organic matter removal of differentmolecular segments have different effects in coagulation; three oxidants can increase themolecular weight greater than3k organics removal; but for molecular weight less than 3k organic matter showed different results, potassium permanganate pre-oxidation canincrease the organic matter removal, hydrogen peroxide and ozone reduce this part oforganic matter removal.According to the test results, it is suggested that using potassium permanganate asthe oxidants is relatively appropriate in the treatment of the Jialing river water;Potassium permanganate as an oxidant when the equipment is simple, the investment issmall, energy saving. When using potassium permanganate as the oxidants, potassiumpermanganate dosing quantity is0.6⁰.9mg/L, pre-oxidation time choose5min, canbetter enhanced coagulation to remove the organic pollutants. When water treatmentplant has preparation, delivery and aeration equipment and a subsequent to thebiological treatment of water, can use ozone pre-oxidation.when using ozone as oxidant,ozone dosing quantity is1.5².0mg/L, pre-oxidation time for5min.