Enhancement of the Adsorption of Co(II) and Ni(II) Ions onto Peanut Hulls through Esterification Using Citric Acid

Abstract

Peanut hulls were modified chemically by esterification with citric acid under conditions which yielded hulls rich in carboxyl content. The esterified products thus obtained were used in the removal of Co(II) and Ni(II) ions from aqueous solutions. The factors affecting the esterification reaction and the adsorption of the metal cations onto the peanut hulls before and after esterification were thoroughly investigated. The results obtained highlighted the following conclusions. The optimum conditions for esterification involve the treatment of peanut hulls (1 g) with 12.4 mmol citric acid in the presence of a very small amount of water for 2 h at 140°C. Similarly, the optimum pH for the adsorption of cobalt(II) ions onto the peanut hulls citrate was 7.0. The adsorption capacity, qe (mg/g), of Co(II) ions onto the peanut hulls citrate increased on increasing the extent of esterification, expressed as mequiv. —COOH/100 g sample. The maximum values for the adsorption capacity, qmax, were 28.7 mg/g and 270.3 mg/g on native and peanut hulls citrate, respectively. The qmax values for of Ni(II) ion adsorption were 5 mg/g and 175.4 mg/g on native and peanut hulls citrate, respectively. The equilibrium data were well fitted by the Langmuir and Freundlich adsorption models and showed the large capacity of peanut hulls citrate in the removal of Co(II) and Ni(II) ions from aqueous solutions.

Heavy metal adsorption onto agro-based waste materials: A review

“…More recently, great effort has been contributed to develop new adsorbents and improve existing adsorbents. Many investigators have studied the feasibility of using low-cost agro-based waste materials [21][22][23][24][25][26][27][28][29].…”

“…The removal of heavy metal ions using low-cost abundantly available adsorbents: agricultural wastes such as tea waste and coffee [55], hazelnut shells [56][57][58], peanut hull [59,21], red fir [60] and maple [61] sawdusts [62,63], pinus bark [64][65][66][67] and different bark samples [68][69][70][71][72][73][74][75][76][77], palm kernel husk [78] and coconut husk [79,80], peanut skins [81], modified cellulosic materials [82,83], chemically modified cotton [84], corncobs [85] and modified corncob [86], rice hulls [87], apple wastes [88], coffee grounds [89], bark [90,91], modified bark [37], wool fibers [92], tea leaves [93], and wool, olive cake, pine needles, almond shells, cactus leaves, charcoal [94], modified lignin [48,95,96], banana and orange peels …”

Removal of lead and cobalt using lignocellulosic fiber derived from Citrus reticulata waste biomass

“…The use of biomaterials, such as agricultural wastes, for the removal of heavy metals from wastewater and industrial effluents has emerged as a potential alternative method to conventional methods [9]. The agricultural waste materials, particularly those containing cellulose, show potential metal biosorption capacity due to the presence of a variety of functional groups that facilitate metal complexation [10].…”

Biosorption Studies of Copper, Chromium, Lead and Zinc Using Fins of Catla Catla Fish

“…Several researchers have reported the removal of heavy metal through algae, marine algae, bacteria, yeast and higher plants in immobilized as well as in free state [8]. Agricultural residues are usually composed of lignin and cellulose as the major constituents with other polar functional groups such as alcohols, aldehydes, ketones, carboxylic acids and ethers that facilitate metal complexation resulting biosorption of heavy metal ions from wastewater [9], [10]. They are economical, eco-friendly and abundantly available and hence are viable option for heavy metal remediation [11].…”