摘要
为解决当前氨氮废水污染问题,以自制核桃壳炭为吸附剂,以NH+4为模型吸附分子,考察了核桃壳预处理方式、焙烧温度、焙烧时间和铵根离子初始浓度等对氨氮废水吸附的影响,并采用多种手段对核桃壳炭进行表征。研究结果表明:经H3PO4预处理后于700℃焙烧2 h制备的核桃壳炭对低浓度的NH+4具有优异的吸附能力;当铵根离子初始质量浓度为8 mg/L,100 mL NH+4溶液中加入核桃壳炭2 g,吸附时间为240 min时,NH+4去除率达93.41%;核桃壳炭吸附氨氮符合准二级动力学模型。比表面积和孔径分析结果表明:经H3PO4预处理后制备的核桃壳炭的比表面积为269.18 m^2/g,总孔容积为0.1736 cm^3/g,微孔容积为0.125 cm^3/g,平均孔径为5.46 nm。FT-IR、XRD和SEM分析表明:经H3PO4预处理制备的核桃壳炭为石墨碳晶相,表面呈现石墨片层结构,从而使其具有良好的NH+4的吸附性能。
Aiming at the problem of ammonia-nitrogen wastewater pollution,walnut shell carbon was used as adsorbent,and the NH+4 was used as model adsorption molecules.The effects of pretreatment conditions of walnut shell,roasting temperature,roasting time and initial concentration of ammonium ion on the adsorption of ammonia-nitrogen wastewater were investigated.The results showed that walnut shell carbon modified by H3PO4(700℃,2 h)had excellent adsorption capacity for low concentration NH+4.When the initial concentration of NH+4 was 0.8 mg/L,the amount of walnut shell carbon was 2 g/L and the adsorption time was 240 min,the adsorption rate was 93.41%.Adsorption of ammonium ion by walnut shell charcoal accorded with pseudo-second-order kinetics model.The specific surface area of the walnut shell carbon obtained by H3PO4 pretreatment was 269.18 m^2/g,the total pore volume was 0.1736 cm^3/g,the micropore volume was 0.1250 cm^3/g and the average pore size was 5-46 nm.Phase characterization of walnut shell charcoal was carried out by infrared(IR),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that walnut shell carbon modified by H3PO4(700℃,2 h)was graphite-carbon crystalline phase with graphite lamellar structure on its surface which resulted in good adsorption.
作者
靳珂
陆倩
马来九
李惠娟
史正军
JIN Ke;LU Qian;MA Laijiu;LI Huijuan;SHI Zhengjun(Key Laboratory of National Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China (Southwest Forestry University),Kunming 650224,China)
出处
《生物质化学工程》
CAS
2021年第1期63-69,共7页
Biomass Chemical Engineering
基金
云南省农业联合专项基金(2018FG001-051)
西南林业大学生物质材料及化学应用精英班创新平台资助项目(无编号)。
关键词
核桃壳炭
氨氮
吸附性
废水
walnut shell carbon
ammonia-nitrogen ion
adsorption
wastewater
