Maryam Rabiee Abyaneh; Gholamreza Nabi Bidhendi; Ali Daryabeigi Zand
Abstract
Introduction: Landfill leachate is a highly toxic and hazardous form of wastewater due to its complex composition characteristics. Effective removal of heavy metals from landfill leachate is of great concern due to the fact that toxic metals can seriously threaten the food chain, and therefore the human ...
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Introduction: Landfill leachate is a highly toxic and hazardous form of wastewater due to its complex composition characteristics. Effective removal of heavy metals from landfill leachate is of great concern due to the fact that toxic metals can seriously threaten the food chain, and therefore the human health. The main objective of this work was to study the utilizing of low-cost pruning residues in the production of biochar and its application in removal of lead (Pb) from landfill leachate.Material and methods: Leachate produced in Babol municipal solid waste landfill was used as an adsorbent solution. Pruning residues were collected and used for biochar preparation. Biochar produced under the pyrolytic temperature of 700°C with a 1-hour retention time. The adsorption mechanism of pruning waste biochar to Pb was analyzed through BET surface area and scanning electron microscope (SEM) tests. Batch experiments were performed to study the effects of adsorption parameters on Pb removal. The influence of contact time (30-300 min), adsorbent dosage (1-50 g/L), as well as particle size (1-2 mm and 63-75 µm) was investigated. Moreover, the kinetic and isotherm models were applied to the experimental data to predict the adsorption parameters.Results and discussion: The results obtained from the analysis of the untreated Babol landfill leachate was revealed that the Pb concentration was about 4.94 mg L-1. The surface area of the produced biochar was determined to be 292.44 m2 g-1. SEM microstructure of the biochar showed the developed surface area with visible pores. All of these data seem to suggest a great potential for pruning residues biochar to Pb removal. The adsorption of Pb was mainly affected by contact time, adsorbent dose, and biochar particle size. Higher contact time and adsorbent dosage showed higher uptake of Pb. Whereas, the uptake of Pb ions onto pruning residues biochar was substantially reduced with increase the biochar particle size. Maximum Pb percentage removal was observed at a contact time of 90 min and with an optimum biochar dosage of 20 g L-1 (89.06% removal) for biochar with 1-2 mm particle size. While, biochar with particle size of 64-75 µm can removed Pb to almost 100% at a contact time of 120 min and with an optimum biochar dosage of 20 g L-1. The kinetic study showed that adsorption can be well described by the pseudo-second order kinetic model. This supports the chemisorption theory behind the pseudo-second order kinetic model for the adsorption system. The results of isotherm models implied that the behaviors of the isotherms are more appropriate for the Langmuir model, showing a monolayer adsorption capacity for Pb.Conclusion: Findings of this research demonstrated the applicability of pruning residues biochar as an economic adsorbent for the removal of the Pb from landfill leachate. On the other hand, the crop residue burning poses a threat to the environment and human health due to the emission of toxic gasses and particulate matter. So, conversion of pruning residues to biochar and its application to heavy metal removal is a useful and environment-friendly alternative to crop residue and biomass burning.
Gholamreza Nabi Bidhendi; Maryam Rabiee Abyaneh; Omid Hassanzadeh Moghimi
Abstract
Introduction: Sustainable management of increasing amounts of municipal solid waste (MSW) has become a major environmental concern because improper MSW management leads to substantial negative environmental impacts and health and safety problems. The life cycle assessment (LCA) method has been recognized ...
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Introduction: Sustainable management of increasing amounts of municipal solid waste (MSW) has become a major environmental concern because improper MSW management leads to substantial negative environmental impacts and health and safety problems. The life cycle assessment (LCA) method has been recognized as an indispensable tool to support systematic and accurate decisions taken on waste management systems. LCA can make a comparison between different scenarios of waste management systems performance from top to bottom to assess the environmental impacts and consumption of resources. This paper aims to determine the environmental aspects of a less impactful MSW management scenario in Babol, Iran through LCA methodology.Material and methods: In order to achieve this goal, first, the composition study was conducted in Babol. The results were then utilized as a reliable data source to compare the environmental impacts of MSW management scenarios with a life cycle perspective. System boundaries included collection and transportation of MSW and its treatment and disposal by composting, recycling, incineration with energy recovery, and landfilling methods. Data on the process was evaluated with the IWM-2 model by the means of energy consumption and global warming.Results and discussion: Babol was estimated to generate 91000 tonnes of waste per year. On average, the generation of waste per capita in Babol was about 606 gr/person/day. After being collected throughout the city, the MSW was discharged at stations to transfer to the heavy vehicles and get transported to Anjil-Si complex waste process and disposal. The main component of the waste stream in Babol was food waste (65.3%). The comparative analysis of the six scenarios underscores the fact that the lower potential environmental loads were related to the 4th scenario in all the impact categories. In particular, the lowest energy use was obtained in scenario 4. In this scenario, composting (60%) and recycling (20%) were included in the waste management plan and resulted in a reduction in the amount of waste disposal as well as energy consumption in landfilling. As excess energy was produced in scenario 4 from the composting and recycling stages (by replacing the produced material with raw material consumed in the life cycle, and also by composting and producing other by-products), less amount of energy was consumed in this scenario. In the case of the global warming impact category, the least burden was originating from scenario 4 due to the reduction of greenhouse gas emissions by energy generation as a result of composting and recycling.Conclusion: According to the results, the 4th scenario (60% composting, 20% recycling, and 20% landfilling) was confirmed as the best waste final disposal alternative. In particular, CO2 emissions decreased by 54% and the energy consumption decreased by 19%, when the alternative scenario, including the recalled features, was compared to the base-case one. The majority of the MSW of Babol consisted of food waste. With a detailed investigation of organic waste, it is possible to benefit from the composting process as an ideal disposal method.
Akbar Baghvand,; Ali Daryabeigi Zand,; Gholamreza Nabibidhendi; Nasser Mehrdadi
Volume 8, Issue 2 , January 2011
Abstract
Column leaching tests become increasingly important for assessing the risk of release of pollutants from soil into water. In this study a column leaching test was designed to provide insight into the fate of selected PAHs in soils and their leaching behavior. Two columns (columns 1 and 2) were prepared ...
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Column leaching tests become increasingly important for assessing the risk of release of pollutants from soil into water. In this study a column leaching test was designed to provide insight into the fate of selected PAHs in soils and their leaching behavior. Two columns (columns 1 and 2) were prepared based on a standard procedure in which 5 and 20 percent of contaminated soil were used, respectively. The percolates were collected at specified L/S ratios. Results showed relatively high initial concentrations of flourene, fluoranthene and benzo(a)anthracene for column 2. Released amounts of PAH compounds were decreasing with increasing molecular size, or rather the hydrophobicity of the compound. The effect of dissolved organic carbon on PAHs leaching was also investigated in this research. Approximately 2.45% and 0.67% of the total initial amounts of studied PAHs in the soil was leached in columns 1 and 2, respectively. Results showed that high PAHs concentration in the solid phase does not necessarily imply serious groundwater contamination risk during a leaching event (e.g. rain fall) and significant amount of contaminants may stay in the soil layer for a long time and do not leach down into groundwater.
Babak Jafari Salim; Gholamreza Nabi Bidhendi; Amir Salemi; Masoud Taheryioun; Mojtaba Ardestani
Volume 6, Issue 4 , July 2009
Abstract
Comprehensive information and knowledge about the quality of water resources plays a very important role in preservation plans for water resource management. One of the engineering methods used to assess river water quality conditions without mathematical and statistical complexity is water quality indices. ...
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Comprehensive information and knowledge about the quality of water resources plays a very important role in preservation plans for water resource management. One of the engineering methods used to assess river water quality conditions without mathematical and statistical complexity is water quality indices. In this method, different water quality parameters are analyzed and interpreted in a river water quality assessment study. It is one of the most important parts of river quality monitoring plans in which the qualitative indices are converted to a single and dimensionless number. Water quality classification is undertaken on the basis of the value of the indices comparing with a predefined rated scale. In this study, a monitoring plan is achieved for the 18 stations located along with Gheshalgh River in Kurdistan province in Iran. Water quality assessment has been conducted using two NSF quality indices of general water use and the British Columbia index for drinking and agricultural consumption. Based on the results obtained from these indices, water of this river has the worst quality due to agricultural use downstream of the wastewater treatment plant of Sanandaj city. Its condition is degraded up to the discharge point of Morghe Par slaughterhouse due to the assimilation capacity of the river. In this location water quality is acceptable for drinking purposes and most of the stations have appropriate conditions except for Dare Kuleh and the downstream station which are on the border. Results indicate that the degree of influence of urban pollutant sources such as entry of urban wastewater and also of a landfill leachate brook is high, especially in the Gheshlagh bridge area up to the tributaries.
Naser Mehrdadi; Gholamreza Nabi Bidhendi; Shahin Mohammadnejad
Volume 6, Issue 4 , July 2009
Abstract
In this paper, six methods of water pinch analysis are introduced to illustrate the advantages and disadvantages of each method. Although, these methods can be used in some industries which generate single contaminant during their processes, otherwise all contaminants can be considered as a single contaminant, ...
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In this paper, six methods of water pinch analysis are introduced to illustrate the advantages and disadvantages of each method. Although, these methods can be used in some industries which generate single contaminant during their processes, otherwise all contaminants can be considered as a single contaminant, but actually it is impossible. On the case of multiple contaminants, we can apply pinch analysis by using mathematical programming methods. While graphical methods are unusable in the most situations, some researchers such as Wang and Smith, Gomez and James G. Mann, have developed their methods to cover the multiple contaminant problems. However, more applicable results may be achieved by using mathematical methods as discussed in relation to the Tan and Yee methods. Among the methods considered, Gomes’ mass transferring network is the most satisfactory for use in most industries. This method can be used for both single and multiple contaminant problems.
Hassan Hoveidi; Gholamreza Nabi Bidhendi,; Hamid Reza Jafari,; Touraj Nasrabadi; Toktam Shahriari
Volume 5, Issue 2 , January 2008
Abstract
During recent years, surface water resources supplying Tehran's potable water – Karaj, Lar and Jajrood Rivers – are contaminated with different microorganisms due to population growth. Additionally, the amount of organic materials generating odor, taste and color in the surface water has ...
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During recent years, surface water resources supplying Tehran's potable water – Karaj, Lar and Jajrood Rivers – are contaminated with different microorganisms due to population growth. Additionally, the amount of organic materials generating odor, taste and color in the surface water has increased sharply. By considering the trihalomethane (THM) production potential of dissolved chlorine in reaction with innocuous humic substances, future use of chlorine as a disinfectant in Tehran's drinking water is clouded in uncertainty. Accordingly, the use of ozone as another alternative was taken in to consideration for disinfection of drinking water in this mega city. In order to evaluate advantages and disadvantages of water ozonation a pilot with a generating capacity of 4 gr ozone per hour was designed. This study was performed between April and September 2005 and Tehran Pars water treatment plant in the Northeast of Tehran was chosen for the case study. Bacteria removal was considered to be at highest level in all monthly samples. Different ozone contact times and dosages were tested in the deactivation of nematodes and the results showed the perfect removal in specified periods. Although the initial investment for construction and implementation of the required apparatuses is relatively high, since the raw material for ozone generation is air, the use of ozone is financially justifiable during the predicted time of operation. Moreover, the transfer and storage of ozone is much easier in comparison with chlorine which is currently in use. Unlike chlorine, the use of ozone as a disinfectant does not have the potential of THMs generation. On the other hand, ozone must be generated on site and is instable in water. Therefore, a continuous and precise monitoring and maintenance process must be taken in to consideration. Furthermore, due to high corrosive potential of ozone, special resistant materials must be used in the applied instruments.
