A.K. Minocha

Biosorption optimization of nickel removal from water using Punica granatum peel waste

The present study was undertaken to evaluate the feasibility of Punica granatum (pomegranate) peel waste for the removal of nickel from water. Batch experiments were performed to study the biosorption of nickel on prepared pomegranate peel adsorbent. The sorption process was well explained with pseudo-second-order kinetic model. The maximum sorption capacity of pomegranate peel adsorbent for nickel removal was ca. 52 mg g(-1). The sorption has been found to be endothermic and data conform to the Langmuir model. The Gibbs free energy was determined to be negative, indicating the spontaneous nature of the sorption process. The results of the present study suggest that pomegranate peel waste can be used beneficially for nickel removal from aqueous solution.

Adsorptive removal of 2,4- dichlorophenol from water utilizing Punica granatum peel waste and stabilization with cement

The present study investigates the adsorption potential of Punica granatum (pomegranate) peel as an adsorbent for the removal of 2,4-dichlorophenol (2,4-DCP) from aqueous solutions. The adsorption was studied as a function of contact time, initial concentration and temperature by batch method. The adsorption capacity of pomegranate peel adsorbent for 2,4-DCP was found to be 65.7 mg g(-1). The equilibrium adsorption data was well described by the Langmuir model. Kinetic studies suggest that the present system of phenol adsorption on pomegranate peel adsorbent could be described more favorably by pseudo-first-order kinetic model. Column studies were also undertaken in order to test the practical utility of prepared adsorbent and found promising. After the adsorption studies, the phenol-laden adsorbent was stabilized in cement for its ultimate disposal. The results of the present study clearly reveal that prepared adsorbent can be used beneficially in treating industrial effluents containing phenols and safely disposed of by stabilizing into cement.

Removal of Anionic Dyes from Water using Citrus limonum (Lemon) Peel: Equilibrium Studies and Kinetic Modeling

Abstract The present study was undertaken to evaluate the adsorption potential of Citrus limonum (lemon) peel as an adsorbent for the removal of two anionic dyes, Methyl orange (MO) and Congo red (CR) from aqueous solutions. The adsorption was studied as a function of contact time, initial concentration, and temperature by batch method. The adsorption capacities of lemon peel adsorbent for dyes were found 50.3 and 34.5 mg/g for MO and CR, respectively. The equilibrium adsorption data was well described by the Langmuir model. Three simplified kinetic models viz. pseudo-first-order, pseudo-second-order, and Weber and Morris intraparticle diffusion model were tested to describe the adsorption process. Kinetic parameters, rate constants, equilibrium sorption capacities, and related correlation coefficients for each kinetic model were determined. It was found that the present system of dyes adsorption on lemon peel adsorbent could be described more favorably by the pseudo-first-order kinetic model. The results of the present study reveal that lemon peel adsorbent can be fruitfully utilized as an inexpensive adsorbent for dyes removal from effluents.

Assessment of the biosorption characteristics of lychee ( Litchi chinensis) peel waste for the removal of Acid Blue 25 dye from water

The aim of this study was to examine the adsorption potential of lychee (Litchi chinensis) peel waste for the removal of Acid Blue 25 dye from aqueous solutions. The adsorption was studied as a function of contact time, initial dye concentration and temperature by batch method. Equilibrium sorption isotherms showed that the lychee peel adsorbent possessed a high affinity and sorption capacity for Acid Blue 25, with a monolayer sorption capacity of ca. 200 mg g−1. The equilibrium adsorption data were well described by the Langmuir model. Kinetic studies revealed that the present system of dye adsorption on lychee peel adsorbent could be described more favourably by the pseudo‐second‐order kinetic model. The thermodynamic parameters, namely free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) changes, were determined for the process. The results of the present study suggest that lychee peel waste can be used beneficially as an adsorbent in treating industrial effluents containing dyes.

Adsorptive Removal of Cobalt from Aqueous Solutions by Utilizing Industrial Waste and its Cement Fixation

Abstract In the present study, the adsorption potential of battery industry waste as adsorbent has been investigated for the removal of cobalt from aqueous solutions. The results have shown that the prepared adsorbent adsorbs cobalt to a sufficient extent (35 mg/g). The adsorption of cobalt has been studied on this battery industry waste as a function of contact time, concentration, and temperature by the batch method. The adsorption has been found to be endothermic and the data conform to the Langmuir equation. The analysis of kinetic data indicates that adsorption is a first order process and pore‐diffusion controlled. Further, the metal‐laden adsorbent was immobilized into cement for ultimate disposal and no significant leaching was observed from the stabilized products. Thus, the present study clearly reveals that battery industry waste can be fruitfully employed in treating industrial effluents containing toxic metal ions. The proposed technology (utilization of industrial wastes for effluent treatment and then ultimate disposal of adsorbents laden with pollutants in cementitious materials by fixation) provides a twofold aim of wastewater treatment and solid waste management.

Removal of Lead Ions from Aqueous Solutions by Different Types of Industrial Waste Materials: Equilibrium and Kinetic Studies

Abstract A comparative study of the adsorbents prepared from several industrial wastes for the removal of Pb2+ has been carried out. Fertilizer industry waste viz. carbon slurry and steel plant wastes viz. blast furnace (B.F.) slag, dust, and sludge were investigated as low‐cost adsorbents after proper treatment in the present study. The adsorption of Pb2+ on different adsorbents has been found in the order: B.F. sludge>B.F. dust>B.F. slag>carbonaceous adsorbent. The least adsorption of Pb2+ on carbonaceous adsorbent even having high porosity and consequently greater surface area as compared to other three adsorbents, indicates that surface area and porosity are not important factors for Pb2+ removal from aqueous solutions. The adsorption of Pb2+ has been studied as a function of contact time, concentration, and temperature. The adsorption has been found to be exothermic, and the data conform to the Langmuir equation. The kinetic results reveal that the present adsorption system follows Lagergrens first order rate equation. Since all three waste products from the steel industry show higher potential to remove lead from water, therefore, it is suggested that these metallurgical wastes can be fruitfully employed as low‐cost adsorbents for effluent treatment containing toxic metal ions.

Removal of phenolic pollutants from water utilizing Mangifera indica (Mango) seed waste and cement fixation

Abstract A process for the removal of two chlorophenols (2-chlorophenol and 2,4-dichlorophenol) from water using surface modified mango seed waste by adsorption process followed by cement fixation of the phenols-laden adsorbent is investigated. The two main objectives of this study were to develop efficient adsorbent utilizing mango seed waste by physiochemical activation and to an environmentally-friendly disposal of phenols-laden adsorbent into cement by a fixation process. The results of the present study reveal that the modified mango seed adsorbent showed an efficient adsorption potential for chlorophenols removal from water. The maximum adsorption potential of modified mango seed adsorbent for 2-chlorophenol and 2,4-dichlorophenol was 40.6 and 72.3 mg g−1, respectively at 25°C. Adsorption kinetic data of chlorophenols adsorption on mango seed adsorbent could be described more favorably by a pseudo-second-order kinetic model. After the adsorption studies, the phenol-laden adsorbent was immobilized in cement for its ultimate disposal. Leachates from the fixed phenols-laden adsorbent exhibit phenols concentrations lower than the drinking water standards. Results from this study suggest the potential utility of agricultural wastes as one of the most promising activated carbon precursors for phenols removal from water and wastewater and the safe disposal of phenol-laden adsorbent into cement by fixation process.