Muhandisī-i Bihdāsht-i Muḥīṭ (Aug 2022)
A comparative study on the efficiency of brick kiln ash, thermal power plant Ash and commercial activated carbon for COD removal from domestic wastewater
Abstract
Background and Objective: Since use of domestic wastewater contain organic pollutants for irrigation of agricultural farms will lead to be adverse health effects, this study was conducted to compare the efficiency of brick kiln ash, thermal power plant ash and also commercial activated carbon for removal of chemical oxygen demand (COD) from domestic wastewater. Materials and Methods: In order to removal of COD from domestic wastewater by studied adsorbents, under optimal conditions the effects of pH, amount of adsorbent, contact time and agitation speed were evaluated. Also, equilibrium data were fitted to Langmuir (L) and Freundlich (F) isotherm models. Results: The results showed that the removal efficiency was increased by increasing in adsorbent dose, contact time and agitation speed. The optimum pH for COD removal was 7. Also, the results indicated that, the adsorption isotherm was well fitted by the Langmuir model with R2 = 0.997, 0.996 and 0.993 for commercial activated carbon, thermal power plant ash and brick kiln ash, respectively. Moreover, maximum adsorption capacity of COD for commercial activated carbon, thermal power plant ash and brick kiln ash were obtained 83.0, 28.6 and 14.9 mg/g, respectively. Conclusion: Based on the results obtained, the commercial activated carbon found to be as an effective adsorbent for removal of COD from domestic wastewater compared to thermal power plant ash and brick kiln ash, but due to low cost of them, thermal power plant ash and also brick kiln ash could be used for removal of COD from wastewater.
