微波热裂解-KOH活化制备杏壳活性炭及其对甲基橙的吸附性能

Preparation of apricot shell AC by microwave pyrolysis-KOH activation and absorption of methyl orange

以陇东地区生物质废弃物杏壳为原料,采用微波热裂解-KOH活化联合法制备活性炭,研究了微波功率和时间,活化过程中KOH溶液的浓度、用量、浸渍时间、加热活化温度和时间对活性炭吸附性能的影响;以甲基橙为染料模拟印染废水,研究了甲基橙初始浓度、振荡吸附时间和活性炭用量对吸附效果的影响。结果表明:微波功率800W,热裂解30min,生物炭的收率为56%;KOH溶液的浓度为25%,碱/炭为2.5∶1,活化温度800℃,加热活化1.5h,所制备活性炭的碘吸附值为1332mg/g,比表面积为1223m2/g,总孔体积为0.68cm3/g,活性炭的得率为32.7%;甲基橙浓度为250mg/g,振荡吸附240min,活性炭用量为每100mL甲基橙溶液0.15g时,甲基橙去除率高达99.78%;吸附过程符合准二级动力学方程。

Activated carbon(AC)was prepared from apricot shell of biomass waste in Longdong region by microwave pyrolysis-KOH activation combination method.The effects of microwave power and time,the concentration and dosage of KOH solution,dipping time,heating activation temperature and time on the adsorption performance of AC were studied.Using methyl orange as simulated dyeing wastewater,the effects of initial concentration of methyl orange,oscillating adsorption time and AC content on the adsorption result were studied.The results showed that the yield of biochar was 56% at 800 W microwave power and 30 min pyrolysis.The concentration of KOH solution was25%,alkali/carbon was 2.5∶1,the activation temperature of 800℃,heating activation 1.5 h.The iodine adsorption value of AC prepaed was 1332 mg/g,BET specific surface area was 1223 m^2/g,total pore volume was 0.68 cm^3/g,the yield of AC was 32.7%.When the concentration of methyl orange was 250 mg/g,the adsorption time was 240 min,and the amount of AC was 0.15 g per 100 mL of methyl orange solution,the removal rate of methyl orange was up to 99.78%.The adsorption process conformed to the quasi-second order kinetic equation.