Research on the performance of modified bentonite in eliminating Cr~(6+) in water solution

This paper studies the influence of pH value,dosage of modifier and time of modification on the efficiency of polyaluminium chloride modified bentonite in eliminating Cr6+ in water solution.The experimental results indicate that(1) polyaluminium chloride modified bentonite obtained from modification under the condition of different pH values have obviously different effects on eliminating Cr6+ in water solution.Polyaluminium chloride modified bentonite obtained from reaction at 80℃ for 5 hours and the modified bentonite obtained from modification under the neutral condition with the pH value=7 has the maximum elimination rate(98.35%) for Cr6+ in water solution(treating 100ml potassium dichromate of 5mg/L with 0.5g polyaluminium chloride modified bentonite).(2) The dosage of modifier has great influence on polyaluminium chloride modified bentonite in eliminating Cr6+ in water solution.When the pH value=7 and bentonite is modified under the condition of 80℃ for 5 hours,it is preferable to select bentonite of 13mmol/g for the modifier of polyaluminium chloride.(3) The time of modification has a certain influence on polyaluminium chloride modified Xinyang bentonite in eliminating Cr6+.When the dosage of modifier is 15mmol/g and the pH value=9,the optimal reaction time of modification under the reaction temperature of is 80℃ 4 hours.