Removal of Lead from Aqueous Solutions Using Rice Husk

Abstract

Rice husk, an agricultural waste, was studied as a potential scavenger of lead from various aqueous solutions. Physicochemical parameters such as selection of appropriate electrolyte, shaking time, and the concentrations of adsorbent and adsorbate were studied to optimize the conditions to be utilized on a commercial scale for the decontamination of effluents using a batch technique. Maximum adsorption was observed with 0.01 moldm" 3 acid solutions (HNO 3 , HC1, H 2 SO 4 and HC1O 4 ) using 1000 mg of adsorbent for a 4.82 X 10" 5 moldm" 3 lead concentration in less than 10 minutes equilibration time. Studies show that the adsorption decreases with an increase in the concentrations of all the acids. The adsorption data follows the Freundlich isotherm over the 9.65 X 10~5to4.83 X 10~3 moldm" 3 range of lead concentration. The characteristic Freundlich constants, i.e., \ln = 0.93 ± 0.04 and A = 19.86 ± 0.82 mmolg" 1 , have been computed for the sorption system. Thermodynamic parameters, i.e., A C , AS", and A//°, have also been calculated for the system.

[Retracted] Removal of Lead from Synthetic Solutions by Protonated Teleosts Biomass

“…It is clear from results as shown in Figure 4 [13][14][15] . The sorption characteristics indicated that surface saturation was dependent on initial metal ion concentration.…”

Pilot production of activated carbon from cotton stalks using H3PO4

“…Agricultural wastes and by-products are good candidates in that they are low-cost, renewable sources with high carbon and volatile contents, low ash, and reasonable hardness. Examples of investigations utilizing agricultural biomass sources for activated carbon production in the recent two decades include: almond shells and peach stones [3]; olive stones and pulp [4][5][6]; apricot stones [7,8]; date pits [9]; apple pulp [10]; sugarcane bagasse [11]; rice husks [12]; and nutshells and fruit stones [13,14].…”

Studies on the Removal of Ni(II) from Aqueous Solutions Using Chemically Activated Pistachios Seed Shell and Commercially Available Carbon

“…Effect of pH The increased adsorption at higher temperatures can be due to one or more of the following reasons. Acceleration of some originally slow step(s) 18 ; creation of some new activation sites on the adsorbent surface 18 and decrease in the size of the adsorbing species 19 . This could well occur due to progressive desolvation of the adsorbing ion as the solution temperature increases.…”