Utilization of peanut shells as adsorbents for selected metals

Abstract

Peanut shells of mesh size 10±20 were modi®ed by combinations of treatments following a 3 2 factorial design. Treatments consisted of either no wash, water wash or base wash followed by no modi®cation or modi®cation with 0.6 M citric acid or 0.6 M phosphoric acid. The nine samples were evaluated for their uptake of ®ve metal ions (Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II)) from solution. The results were compared with metal ion adsorption by three commercial cation exchange resins, namely, Amberlite 1 200, Amberlite 1 IRC 718 and Duolite 1 GT-73. The percent of metal ions adsorbed per gram of adsorbent was signi®cantly increased by each of the acid treatments, average values ranged from 19 to 34% compared with non-acid treated samples at 5.7%. The percent of metal ions adsorbed for base-washed samples were higher than water-washed or unwashed shells. Interaction between wash and acid treatment was not signi®cant for most of the experimental conditions used. Acid-treated samples were as effective as Duolite 1 GT-73 in the adsorption of Cd(II) and almost twice as effective in the adsorption of Zn(II) from solutions containing a single metal ion. In solutions containing multiple metal ions, citric acid samples were found to be most effective and selective for Cu(II) compared with Cd(II), Ni(II), and Zn(II). In general, phosphoric acid-modi®ed shells removed the most metals from solution for the experimental samples and were more effective in removing Cd(II) and Zn(II) than two of the three commercial resins. Acid-modi®ed peanut shells are promising as metal ion adsorbents.

Sesame Husk as Adsorbent for Copper(II) Ions Removal from Aqueous Solution

“…Recently, agricultural by-products have been widely studied for sequestering of metals from water including peat [29], wood [30], pine bark [31], banana pith [32], rice bran, soybean and cottonseed hulls [33], peanut shells [34], hazelnut shell [35], rice husk [36], sawdust [37], wool [38], orange peel and compost [39] and leaves [40]. Most of this work has approved that natural products could be perfect adsorbents for heavy metals [26].…”

A study on cations and color removal from thin sugar juice by modified sugar beet pulp

“…at mildly elevated temperatures enhance their sorption capacity for metal ions and basic dyes (Lehrfeld 1997;Wafwoyo et al 1999;Marshall et al 1999Marshall et al , 2000Vaughan et al 2001;Wong et al 2003;Altundogan et al 2007;Gong et al 2006Gong et al , 2007Gong et al , 2008. It has been reported that an estimated production cost for citric acid-modified soybean hull is $1.17/kg versus typical retail costs $4-40/kg for commercial, petroleum-based cation exchange resins when purchased in bulk quantities .…”

Comparative Study of Physical Properties of Polymer Composites Reinforced with Uncarbonised and Carbonised Coir

“…For instance, by-products from agricultural sources have been used-maize cobs, rubber seed shell, ground nut husk, cassava peeling, plantain peel, coir fibre, rubber seed shell carbon, etc. [7] [10] [19]- [21]. In this study, coir and its carbonised product were analysed as fillers in rubber composites.…”