净水污泥柠檬酸钠改性焙烧制备陶粒吸附剂及其对废水中氨氮吸附性能的研究  

Preparation of Ceramsite Adsorbent by Trisodium Citrate Dihydrate Modified and Baking Drinking Water Treatment Sludge for Ammonia Nitrogen Removal from Wastewater

作　　者：罗书舟 王东田[1,2] LUO Shuzhou;WANG Dongtian(School of Environmental Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China;School of Chemistry,Biology and Materials Engineering9Suzhou University of Science and Technology,Suzhou 215009,China)

机构地区：[1]苏州科技大学环境科学与工程学院,江苏苏州215009 [2]苏州科技大学化学生物与材料工程学院,江苏苏州215009

出　　处：《安全与环境工程》2021年第5期230-239,共10页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(51778392)。

摘　　要：以净水污泥为原料,选用盐酸、氢氧化钾、柠檬酸钠为改性剂,通过研磨-改性-造粒-焙烧等工艺制备改性净水污泥陶粒吸附剂(以下简称改性陶粒吸附剂),测定其对水中氨氮的吸附量,筛选出最佳改性陶粒吸附剂和最佳改性陶粒吸附剂浓度,并在相同条件下制备原净水污泥陶粒吸附剂(简称原泥陶粒吸附剂)作为对比;采用XRD、BET、FTIR、SEM/EDX分析手段对改性陶粒吸附剂和原泥陶粒吸附剂两种吸附剂进行了表征,并通过静态吸附对比实验,探讨了两种吸附剂对废水中氨氮吸附效果的影响因素;对试验数据进行了吸附等温线和吸附动力学模型拟合研究,并探讨了饱和改性陶粒吸附剂对氨氮的解吸和重复再生效果。结果表明:(1)净水污泥的最佳改性条件为采用0.5 mol/L的柠檬酸钠搅拌混合并在65℃水浴温度下浸泡5 h;(2)改性陶粒吸附剂对氨氮的去除效果与原泥陶粒吸附剂相比有显著提高,当溶液最佳pH为7、饱和吸附时间为6 h、吸附剂投加量为20 g/L、氨氮初始浓度为50 mg/L时,改性陶粒吸附剂的最大吸附量为1.938 mg/g,为原泥陶粒吸附剂的2.46倍;(3)吸附等温线和吸附动力学的拟合结果表明,改性陶粒吸附剂和原泥陶粒吸附剂对氨氮的吸附过程均符合Langmuir模型和准二级动力学模型;(4)饱和改性陶粒吸附剂的最佳再生液为0.1 mol/L的NaOH溶液,经过5次解吸再生后,对氨氮的解吸率仅下降6.53%。By using drinking water treatment sludge as raw material and HCl、KOH、trisodium citrate dihydrate as modifier,the modified ceramsite adsorbent for drinking water treatment sludge(hereinafter referred to asmodified ceramsite absorbent)was prepared through grinding-modification-granulation-baking,and the adsorption capacity of ammonia nitrogen in water was measured to screen out the optimal modified ceramsite adsorbent and the optimal concentration of modified ceramsite adsorbent.Under the same conditions,the drinking water treatment sludge ceramsite adsorbent(hereinafter referred to as raw sludge ceramsite adsorbent)was prepared for comparison.XRD,BET,FTIR and SEM/EDX were used to characterize the modified ceramsite adsorbent and raw sludge ceramsite adsorbent,and the influencing factors of the adsorption effect of the two adsorbents on ammonia nitrogen in wastewater were discussed through static adsorption contrast experiments.The adsorption isotherms and adsorption kinetics models were fitted to the experimental data,and the desorption and regeneration effects of saturated modified ceramsite adsorbent on ammonia nitrogen were discussed.Experiments indicate that:(1)The optimal modification condition of drinking water treatment sludge was mixing with 0.5 mol/L trisodium citrate dihydrate and soaking for 5 h at 65℃water bath temperature.(2)The modified ceramsite absorbent has significant improvement in ammonia-nitrogen removal rate compared with the raw sludge ceramsite adsorbent.On conditions of the optimal solution pH value 7,saturation absorption time 6 h,absorbent dosage 20 g/L and the initial ammonia-nitrogen concentration 50 mg/L,the modified ceramsite absorbent shows the largest absorption capacity of 1.938 mg/g,2.46 times that of the raw sludge ceramsite adsorbent.(3)According to the fitting results of absorption isotherm and absorption kinetics,the ammonia-nitrogen absorption process by both the modified and raw sludge ceramsite adsorbent accords with Langmuir model and pseudo second-order kinetics mo

关 键 词：净水污泥 柠檬酸钠改性 陶粒吸附剂 氨氮 吸附 

分 类 号：X703[环境科学与工程—环境工程]