| With the micro-pollution of water source intensifies,The microcystins produced by the outbreak of algae threatens the healthy life of people.The microcystins can cause skin allergies,respiratory failure,even a liver tumor promoter,has a highly pathogenic.However the effect of conventional water treatment process is very limited.In order to reduce the concentration of microcystins in water,exploring new treatment is very necessaryFirst,the removal of MC-LR by Ozone-Powdered Activated Carbon process is studied.Considering the removal of MC-LR,organic matter and turbidity by ozone,it determined that the optimum dosage of ozone is 1.5mg/L.When the1.5mg/L ozone in combination with 35mg/L Powder Activated Carbon,the removal rates of MC-LR,UV254 and turbidity are 84.86%,63.36% and 67.46%.respectively.Comparing Ozone-Powdered Activated Carbon process with Potassium Permanganate-Powdered Activated Carbon process for removal capacity of micro-polluted water.The experiments have determined the optimum dosage of Potassium Permanganate is 1.0mg/L.When combined with 35mg/L Powdered Activated Carbon,The removal rate of MC-LR is 33.17%,turbidity is only 7.84%,UV254 is just 33.4%.This shows that the Ozone-Powdered Activated Carbon process for treatment of micro-polluted water is better than Potassium Permanganate-Powdered Activated Carbon process.Secondly,modification experiment on Powdered Activated Carbon by 20%phosphate and 20% ammonia,respectively.Scanning electron microscopic observation of morphology and determine the surface functional groups by Bohem titration method.Different modification changes the chemical structure of activated carbon,modified with phosphoric acid oxidation,reducing the surface area,increasing surface acidic groups,reduce the zero point of charge;After the modification of ammonia,increases the surface area,alkaline surface functional groups,and zero point of charge.Experimental study on the static adsorption of different adsorption time,temperature and pH conditions,the adsorption capacity of organic matter.by three kinds of activated carbon.Results showed that the best activated carbon organic adsorption time is 120min;Higher temperatures enhance the adsorption capacity of activated carbon,activated carbon for the adsorption process is an endothermic process of organic matter;alkaline conditions more suitable for activated carbon adsorption.Then,study the removal of MC-LR,turbidity and organic matter by three kinds of activated carbon.The results show that,three types of activated carbon for removal capacity of MC-LR and organic matterin is: ammonia modified carbon superior than unmodified carbon than phosphate modified charcoal;On the turbidity removal effects,no modified carbon is similar to phosphate modified charcoal,but less than the turbidity in ammonia-water modified carbon.On this basis,combined 1.5mg/L ozone with different d dosage of PAC modified by ammonia.When the dosage of PAC modified by ammonia is 45mg/L,the removal rate of MC-LR up to 90.54%.The turbidity is only 0.56 NTU,removalrate is 86.7%,The removal rate of UV254,TOC and CODMn is 63.16%,60.91%and 42.86%.When treatment of micro-polluted water,ozone combined with ammonia modified PAC is better than unmodified PAC.Finally,modeling MC-LR multiple linear regression model by using MATLAB software with the research data.Making MC-LR as explanatory variables,dosage,turbidity,UV254 as explanatory variables.The results show that,the multiple linear regression models to predict MC-LR is effective,R2 values is between 0.9847 and 1.0000. |
