Maryam Bahiraei
Abstract
Background and purpose: Urban waste leachate due to had organic matter, minerals and heavy metals as one of the environmental problems has require treatment. Surface absorption is one of the methods used in absorbing contaminants by absorbent materials. In this study, the efficiency of removal of zinc ...
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Background and purpose: Urban waste leachate due to had organic matter, minerals and heavy metals as one of the environmental problems has require treatment. Surface absorption is one of the methods used in absorbing contaminants by absorbent materials. In this study, the efficiency of removal of zinc from leachate of landfill waste in Hamadan city by absorbent of banana skin modified by acidic solution has been investigated.Materials and Methods: In study of descriptive-analytical, the effect of contact time, adsorbent amount, pH and concentration variables performed on the efficiency of Zn metal removal from leachate. In order to investigate the interaction between the adsorbent and the absorbed object were used the absorption models of Langmuir and Freundlich isotherm and aspect investigation the velocity of the adsorption process were used from the adsorption kinetics of first and second order pseudo-adsorption.Results: The highest efficiency of zinc removal (92%) was caused by adsorbent of banana fruit skin modified in the optimum pH 7, the contact time 70 minutes, the adsorbent amount 6 g/l concentration 1 mg/l. The maximum absorbent absorption capacity was also determined 34 mg/g. The results showed that the behavior of the desired process followed Langmuir adsorption isotherm model and its kinetics is adapted to the second-order pseudo-reaction.Conclusion: The use of natural adsorbent banana fruit skin modified by nitric acid solution has a high ability to remove zinc metal from leachate and can be used as an appropriate replacement for reducing the problems caused by common chemical adsorption.
HOSEIN ALIDADI; Ali Asghar Najafpoor; somayeh etemadi mashhadi; Batoul Mohebrad; aliakbar dehghan
Abstract
Introduction: Waste leachate contains hazardous organic compounds such as nitrogen compounds and high concentrations of poisonous compounds; the remediation of these pollutants from the environment is considered as a global problem. These pollutants make serious environmental problems through their penetration ...
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Introduction: Waste leachate contains hazardous organic compounds such as nitrogen compounds and high concentrations of poisonous compounds; the remediation of these pollutants from the environment is considered as a global problem. These pollutants make serious environmental problems through their penetration into groundwater and bioaccumulation. Therefore, leachate treatment is essential with suitable and appropriate methods. Anaerobic digestion is considered as one of the most cost-effective methods for this mean. This study aimed to evaluate the efficiency of an anaerobic digester in simultaneous removal of chemical oxygen demand (COD) and TKN from landfill leachate during the process of anaerobic co-digestion for landfill leachate and fresh cow dung. Materials and Methods: In this study, landfill leachate of Mashhad and cow dung was mixed in 3/1, 1/1 and 1/3 ratios. These treatments were exposed under anaerobic digestion with same conditions such as environmental temperature. COD and TKN were measured at the beginning and the end of the process. Results: In the control treatment, COD decreased about 5% and the reduction of TKN was 9.09%. Whilst COD reduction was about 65%, 75%, and 70% in the treatments of 3/1, 1/1 and 1/3 Ratio respectively. Also, TKN decreased 33.26, 82.16 and 84.73% in the 3/1, 1/1 and 1/3 Ratio correspondingly. Conclusion: The results of this study indicated that the applied method is an efficient and economical approach for elimination of COD and TKN from waste leachate. Because it not only is considered as an environmentally friendly method for this regard, but also it will also make economic benefits from methane production.