Study of heavy metals biosorption on native and alkali-treated apricot shells and its application in wastewater treatment
Study of heavy metals biosorption on native and alkali-treated apricot shells and its application in wastewater treatment
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DOI：
10.1016/j.molliq.2018.03.055
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发表时间：
2018-06
影响因子：
6
通讯作者：
T. Šoštarić;M. Petrović;F. Pastor;D. Lončarević;J. Petrović;J. Milojković;M. Stojanović
中科院分区：
文献类型：
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作者：
T. Šoštarić;M. Petrović;F. Pastor;D. Lončarević;J. Petrović;J. Milojković;M. Stojanović
当地可用的杏 (Prunus ameniacaL.) 壳被归类为水果加工的废物，经过碱活化，以开发一种用于水净化的有效重金属离子吸附剂。为了检查碱处理后发生的变化，对生杏壳 (SH) 和改性杏壳 (SHM) 的化学成分和表面特性进行了彻底的表征。化学分析表明，碱处理导致半纤维素分解（其含量从19.2％下降到3.5％），这与FTIR结果一致。 SEM 显微照片和压汞孔隙率测定法显示 SHM 具有更大的表面积和孔隙率。 Bohem酸碱滴定法表明，SHM表面羧基大部分为钠盐形式，与零电荷点的pH值一起表明改性后表面碱度增加。 NaOH处理对Cu2+、Zn2+和Pb2+的吸附能力分别提高了154%、61%和90%。 SHM 释放的阳离子量几乎等于吸附的金属离子的量，表明存在离子交换机制。准二级动力学表明，重金属阳离子主要通过络合结合。为了确定生物吸附剂在实际废水样品中的有效性，采用SHM对原子吸附分光光度计排出的废水进行净化。 SHM 对多种金属离子表现出较高的去除效率。 Fe、Pb、Cu 和 Cr 离子的量分别减少了 97%、87%、81% 和 80%，而 Ni 和 Zn 的量分别减少了 33% 和 14%。用过的生物吸附剂 SHM 可以用 HCl 成功再生（解吸 > 95%），再生后生物吸附剂可以重复使用或可以安全处置。
Locally available apricot (Prunus armeniacaL.) shells classified as a waste product from fruit processing, were alkali activated in order to develop an efficient heavy metal ions sorbent for water purification. To examine the changes occurred after alkali treatment, raw (SH) and modified apricot shells (SHM) were thoroughly characterized in terms of their chemical composition and surface properties. Chemical analysis revealed that alkaline treatment causes the disintegration of hemicellulose (its content decreased from 19.2 to 3.5%), which was in accordance with FTIR results. SEM micrographs and the mercury intrusion porosimetry revealed a larger surface area and porosity of SHM. Bohem's acid-base titration method indicated that the most of the SHM surface carboxylic groups were in sodium salt form and together with the pH of points of zero charge showed increase of surface alkalinity after modification. Treatment with NaOH enhanced the adsorption capacity by 154, 61 and 90% for Cu2+, Zn2+and Pb2+, respectively. The amount of cations released from SHM was almost equal to the amount of adsorbed metal ions, suggesting ion exchange mechanism. The pseudo-second order kinetic indicated that the heavy metals cations were bound predominantly by complexation.In order to establish the effectiveness of the biosorbent in real wastewater sample, SHM was employed for cleaning-up of drain water emanating from atomic adsorption spectrophotometer. The SHM showed high removal efficiency towards multiple metal ions. The amounts of Fe, Pb, Cu and Cr ions were reduced by 97, 87, 81 and 80%, respectively, while Ni and Zn amounts were reduced for 33 and 14%.Used biosorbent SHM can be successfully regenerated with HCl (desorption > 95%) and after regeneration biosorbent can be reused or it can be safely disposed.