ABSTRACT
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 (deltaG degrees), enthalpy (deltaH degrees) and entropy (deltaS degrees) 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.
Subject(s)
Anthraquinones/isolation & purification , Fruit/chemistry , Litchi/chemistry , Ultrafiltration/methods , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Adsorption , Anthraquinones/chemistry , Biodegradation, Environmental , Color , Industrial Waste/prevention & controlABSTRACT
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.
Subject(s)
Lythraceae/chemistry , Nickel/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Kinetics , Models, Chemical , Nickel/isolation & purification , Surface Properties , Water Pollutants, Chemical/isolation & purificationABSTRACT
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.
Subject(s)
Chlorophenols/isolation & purification , Construction Materials , Lythraceae/chemistry , Water Pollutants, Chemical/isolation & purification , Adsorption , Chlorophenols/chemistry , Kinetics , Models, Chemical , Thermodynamics , Water Pollutants, Chemical/chemistryABSTRACT
Batch studies were conducted on degradation of anaerobically digested distillery wastewater by three bacterial strains, viz. Xanthomonas fragariae, Bacillus megaterium and Bacillus cereus in free and immobilized form, isolated from the activated sludge of a distillery wastewater treatment plant. The removal of COD and colour with all the three strains increased with time up to 48 hr and only marginal increase in COD and colour removal efficiency was observed beyond this period up to 72 hr. After this period removal efficiency remained fairly constant up to 120 hr. The maximum COD and colour removal efficiency varied from 66 to 81% and 65 to 75%, respectively for both free and immobilized cells of all the three strains. The strain Bacillus cereus showed the maximum efficiency of COD (81%) and colour (75%) removal out of the three strains. An interrelationship between the percent COD and colour removal was carried out by correlation and regression analysis and was justified by high values of coefficient of correlation (r = 0.99) for all the cases. The first order removal rate kinetics was also applied and rate constants were evaluated for COD and colour removal efficiencies.
Subject(s)
Alcoholic Beverages , Bacillus cereus/metabolism , Bacillus megaterium/metabolism , Industrial Waste , Water Pollutants, Chemical/metabolism , Xanthomonas/metabolism , Alginates/chemistry , Alginates/metabolism , Bacillus cereus/isolation & purification , Bacillus megaterium/isolation & purification , Biodegradation, Environmental , Drug Carriers/chemistry , Drug Carriers/metabolism , Glucuronic Acid , Hexuronic Acids , Industrial Microbiology/methods , Potassium Dichromate/metabolism , Time Factors , Waste Disposal, Fluid/methods , Xanthomonas/isolation & purificationABSTRACT
Three bacterial isolates from the activated sludge of a distillery wastewater treatment plant identified as Xanthomonas fragariae, Bacillus megaterium and Bacillus cereus were found to remove COD and colour from anaerobically digested distillery wastewater in the range of 55 to 68% and 38 to 58% respectively.
