3 research outputs found
Evaluation Low Cost Adsorbent of Walnut Bark Granule for Methylene Blue Dye Removal from Aqueous Environments
Background & Aims of the Study: Methylene blue (MB) is a risk for human and environment. Adsorption process is one of the removal mechanisms of MB. The purpose of this research was the evaluation of low cost adsorbent of walnut bark granule for MB dye removal from aqueous environments.
Materials & Methods: In this experimental research, the effect of various operating parameters such as dose of dye (100-500 mg/L), contact time (10-50 min), adsorbent dosage (1-5 g/L) and pH (3-8) was investigated. Color concentration was measured by spectrophotometer (Shimadzu Model UV-120-02) at 663 nm wavelength and pH was analyzed through pH meter (Digimed model DM-20, Digicron AnaliticaLtda, Sao Paulo, Brazil).
Results: The findings of this research were showed that the walnut bark granule was able to remove up to 41% of MB dye (100 mg/L) from solutions at initial pH 7. Removal efficiency was increased by adsorbent dosage and contact time. MB concentration has a reverse effect on removal. Also, the equilibrium data were also fitted to the Freundlich equilibrium isotherm model (R2=0.95).
Conclusions: Present study showed that use of walnut bark granule, as an absorbent, could be utilized in methylene blue removal. Therefore, considering the production wastes of this compound, utilization the essence of this substance as inexpensive absorbent with inexpensive and available raw material is clear
Application of Response Surface Methodology for Optimization of Ammonia Nitrogen Removal from Aqueous Solutions Using Powdered Activated Carbon
Abstract: Background and Objective: High nitrogen compounds in natural water results from industrial and agricultural activities made the water ecological problems. Therefore, elimination or decrease of nitrogen compounds in the receiving environment must be considered. The objective of the present study was to compare the performance of commercial powdered activated carbon (CPAC) and modified commercial powdered activated carbon (MCPAC) with H2SO4, NaNO3 and KMnO4 for the ammonia removal from aqueous solution. Methodology: This experimental study was carried out at pilot scale. The effects of various operational variables such as adsorbent dosage (0.5-1.5 g L–1), ammonia initial concentration (100-200 mg L–1), pH (3-9) and contact time (2-120 min) on ammonia removal were examined for both MCPAC and CPAC. In this study, experiments were performed base on central composite design (CCD) and response surface methodology (RSM) to analyze and optimize the variables. The adsorption isotherm was evaluated using Freundlich and Langmuir models. Kinetics study was analyzed using pseudo-first order, pseudo-second order and penetration particle kinetics models. Data were analyzed by one way ANOVA. All the statistical tests were carried out using Design expert software. Results: The results showed that the removal rate increased by the increase of adsorbent dosage, pH and contact time. The maximum removal rate was seen at the pH 9, contact time 120 min, ammonia initial concentration 50 mg L–1 and adsorbent dosage 1.5 g L–1 (above 95%). The removal rate decreased as the ammonia initial concentration increased. According to CCD result, CPAC and MCPAC were fitted to linear and quadratic equation, respectively. Ammonia adsorption for CPAC and MCPAC followed the Langmuir (R2 = 0.9831) and Freundlich (R2 = 0.9745) isotherm model. The maximum adsorption capacity for MCPAC achieved 40.323 mg g–1.The analysis of adsorption kinetic for both CPAC and MCPAC indicated that the ammonia adsorption was well-fitted by pseudo-second order kinetic model (R2 = 0.997). Conclusion: Results confirmed that modified activated carbon can be uesd as an appropriate and cost effective adsorbent for water and wastewater treatment due to high adsorption capacity
Effectiveness of Quercus Branti Activated Carbon in Removal of Methylene Blue from Aqueous Solutions
Background & Aims of the Study: Dyes are one of the most contaminants in textile industrial wastewater that they are often carcinogenic, mutagenic and non-degradable. Therefore, with regard to environmental aspects, their removal from effluents is very essential. The purpose of this study was the perception of adsorption process and promotion of an economic technology for colored wastewater treatment. Therefore, activated carbon from Oak fruit bark was used as an effective and economic adsorbent.
Materials & Methods: This study was performed at laboratory scale and batch system. At present study, the adsorbent surface properties was evaluated by use of the (FT-IR) test and scanning electronic microscope (SEM). Also, effect of various operating parameters such as pH, contact time, adsorbent dose, initial dye concentration and temperature on dye removal from synthetic wastewater were studied.
Results: In this study, maximum removal efficiency of methylene blue were achieved at optimal pH=6, reaction time 180 minutes, and adsorbent dose 2 gl-1. Methylene blue removal efficiency with initial concentration of 100 mg.l-1 was 91.08%.
Conclusions: According to results, it was cleared that : Quercus branti activated carbon can be used as an effective and economic adsorbent in waste water treatment processes