Supported liquid membrane-based simultaneous separation of cadmium and lead from wastewater
Supported liquid membrane-based simultaneous separation of cadmium and lead from wastewater
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DOI：
10.1016/j.memsci.2014.02.019
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发表时间：
2014-06-01
影响因子：
9.5
通讯作者：
Ghoshal, Aloke Kumar
中科院分区：
文献类型：
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作者：
Bhatluri, Kamal Kumar;Manna, Mriganka Sekhar;Ghoshal, Aloke Kumar
研究了椰子油平板支撑液膜(FS-SLM)同时萃取和回收水溶液中的重金属(Cd和Pb2+)。椰子油的环保性质是这项技术的主要优势。N-甲基-N，N-二辛基-1-氯化铵(Aiquat 336)是迁移上述重金属的理想载体。考虑到乙二胺四乙酸对金属的络合能力，选择乙二胺四乙酸(EDTA)作为反萃剂。最初，只研究了支持液膜(SLM)对Cd(II)的传输性能。采用聚偏氟乙烯(PVDF)为载体的多孔聚合物固体膜，在SLM结构中保持和容纳膜液。考察了膜相载体浓度、反萃剂浓度、料液pH值等操作条件对分离效果的影响。以椰子油为膜相，0.015%(v/v)的Aiquat336为膜相，乙二胺四乙酸乙二酯为反萃剂，料液pH值为6.5时，Cd(II)的迁移效果最佳。初始进料浓度为5ppm，总输送时间为10h，并在此最佳工艺条件下对另一种重金属铅(铅)进行了输送。最后，研究了饲料中不同摩尔比(Cd：Pb)时两种金属(铅和镉)的同时迁移。镉的最佳萃取率和回收率分别为79%和67%，铅的最佳萃取率和回收率分别为84%和78%。由于铅的良好电子构型，观察到铅优先通过SLM传输。(C)2014爱思唯尔B.V.保留所有权利
This work is aimed at the investigation of simultaneous extraction and recovery of heavy metals (cadmium and lead) from aqueous solutions through a coconut oil-based Flat Sheet Supported Liquid Membrane (FS-SLM). Environmentally benign nature of coconut oil is the prime advantage in this technique. N-Methyl-N,N-dioctyloctan-1-ammonium chloride (Aliquat 336) is an ideal carrier agent for the transportation of the said heavy metals. Ethylenediaminetetraacetic acid (EDTA) was selected as stripping agent keeping in view its metal chelating capacity. Initially, the performance of Supported Liquid Membrane (SLM) was investigated only for the transportation of cadmium, or precisely Cd(II). A porous polymeric solid membrane viz., polyvinylidene fluoride (PVDF) was used as a support in order to hold and contain the membrane liquid in the SLM structure. The size of the pores in the support is 02 mu m. The effects of various operating conditions viz, concentration of the carrier in membrane phase, concentration of stripping agent, pH of feed phase etc were studied. The optimum process conditions for the transportation of Cd(II) were: 0.5% (v/v) Aliquat 336 in coconut oil as membrane phase, 0.015 M EDTA as stripping agent, and pH of 6.5 in the feed phase. The initial feed concentration was 5 ppm and the total transportation time was 10 h. Transportation of another heavy metal viz., lead (Pb) was also carried out with the above optimum process conditions. Finally, simultaneous transportations of both metals (lead and cadmium) were studied with various molar ratios (Cd:Pb) in the feed. The optimum extraction and recovery of cadmium were found as 79% and 67%, respectively, and that of lead were found as 84% and 78%, respectively, in simultaneous transportation. Lead was observed to be preferentially transported through SLM due to its favorable electronic configuration. (C) 2014 Elsevier B.V. All rights reserved