فهرست مطالب

Advances in Environmental Technology
Volume:5 Issue: 2, Spring 2019

  • تاریخ انتشار: 1399/04/30
  • تعداد عناوین: 6
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  • Elham Narooei, Davod Mohebbi-Kalhori *, Abdolreza Samimi, Mortaza Zivdar Pages 67-75

    The removal of formaldehyde from contaminated air was investigated via three laboratory-scale biofilters packed with different materials: a mixture of compost and woodchips (І), the natural clinoptilolite zeolite particles in the original form (II), and the mixture of zeolite/activated carbon (III). The biofilters were inoculated using aerobic sludge. The average removal efficiencies of 97.5%, 90%, and 93.5% were obtained at a 100 s empty bed residence time (EBRT) and 20 mg/m3 inlet concentration of formaldehyde for the biofilter of configurations І, II, and III, respectively. Also, the performance of the reactors was investigated at different EBRTs of 20, 30, 60, and 100 s, and the maximum elimination capacity of 2840 mg/m3.h was achieved at the lowest EBRT (20 s) for the biofilter of configuration II. Increasing the inlet formaldehyde concentration from 20 mg/m3 to 80 mg/m3 led to the maximum formaldehyde removal efficiency of 82% for the biofilter of configuration III. Therefore, a comparison of the results of the biofilters' performances showed that the biofilter of configuration III had the best performance, which was validated by obtaining a higher mass transfer coefficient. However, the biofilter of configurations II and III achieved steady-state conditions in a shorter time.

    Keywords: Biofilter, Biodegradation, Formaldehyde, Packing materials, Contaminated air
  • Farhad Afshar, Madjid Abbaspour, Akramolmolok Lahijanian * Pages 77-96
    The purpose of this study is to present a practical model of strategic waste management using two SWOT models and hierarchical analysis. In this regard, using the strengths and weaknesses, the present situation and factors affecting the waste management in Tehran have been investigated. In this study, the importance of public participation in waste management using Delphi and FAHP methods was investigated. Based on the results of this analysis, the team of experts identified internal and external factors and rated the information obtained by SWOT analysis, each factor was weighted, then according to the weighted scores obtained, the competitive waste management effect range. Finally, the strategies were quantitatively prioritized by the planning matrix. Then using the analysis method the hierarchy used in this study as a SWOT supplement; the results of two questionnaires designed in this study, socio-economic, educational, cultural, and political factors were identified as first to fourth, respectively. Using the potential of social networks to encourage society to reduce waste and promote segregation of origin and compliance with the schedule and providing economic incentives to maximize public' participation in waste generation and separating them from dry waste origin were the top strategies selected based on the analysis.
    Keywords: Waste Management Master Plan, SWOT, QSPM, FAHP
  • Amin Hedayati Moghaddam *, Jalal Shayegan Pages 99-105
    The selection of optimum high strength wastewater treatment process is complicated. Be familiar with wastewater treatment methods is not enough to design a plant. In this research, five alternative wastewater treatment methods (upflow anaerobic sludge blanket (UASB) + membrane bioreactor (MBR), UASB + Extended aeration (EA), Anaerobic baffled reactor (ABR), anaerobic lagoon (ANL) + aerated lagoon (AL), and sequencing batch reactor (SBR) + ABR) for high strength wastewater were investigated and ranked based on the analytic hierarchy process (AHP) fuzzy method. These treatment methods were investigated and ranked based on five criteria (energy consumption, effluent total suspended solid (TSS), effluent chemical oxygen demand (COD), cost, and level of technology). Rating the different options of wastewater treatment plant was done by expert decision makers in this field. The results show that for typical high strength wastewater using an UASB reactor followed by a MBR is the most appropriate alternative to treating the wastewater.
    Keywords: Wastewater treatment, AHP, Fuzzy, COD
  • Javad Rahbar Shahrouzi *, Sakineh Molaee, Amanollah Ebadi, Farshid Towfighi, Farshad Bakhti Pages 107-114
    In this study, the adsorption of amoxicillin onto activated carbon was investigated. The effect of particle size and the effluent flow rate was discussed as well as the kinetics and isotherm of adsorption equilibrium. The isotherm equilibrium studies showed that the Langmuir model was appropriate for describing the adsorption equilibrium of amoxicillin onto the activated carbon. Furthermore, the kinetics of adsorption fit the pseudo-second-order model while the highest adsorption amount occurred at pH = 5. Moreover, the change of particle size from 600 microns to 125 microns resulted in increasing the adsorption amount of 102 mg.g-1 to 225 mg.g-1. Furthermore, the breakthrough curves indicated that the controlling mechanism of mass transfer was intra-particle diffusion. Also, by reducing the length of the bed from 6.8 to 3.4 cm, the breakpoint time decreased from 3.2 hours to 54 minutes at 300 ppm initial concentration. Eventually, the breakpoint time increased from 2 minutes to 55 minutes by decreasing the average particle diameter from 840 to 250 microns.
    Keywords: Adsorption, Amoxicillin, activated carbon, Breakthrough curve, Isotherm
  • Ali Drayabeigi Zand *, Azar Vaezi Heir Pages 115-125
    Kish Island is a popular tourist destination in Iran, and tourism plays an important role in its economy. The volume of waste produced in the island has increased given the construction of numerous industrial projects over the past decade, as well as an increase in the tourist population. This expansion signals a need to create new methods of waste disposal. Environmental Impact Assessment (EIA) is a process that can be used to evaluate the impact of waste disposal options on Kish Island. Rapid impact assessment matrix (RIAM) is a powerful tool to carry out the environmental impact assessment. The RIAM conducted in this research incorporated the mathematical sustainability model to evaluate the impacts of four municipal solid waste disposal options on the environment on Kish Island. The options included: (Option 1) Continuing the current disposal activities in Kish Island, i.e., 50% waste recycling and 50% waste landfilling; (Option 2) 30% composting, 50% waste recycling, and 20% waste landfilling; (Option 3) 30% composting, 50% waste recycling, and 20% waste incineration; and (Option 4) 50% waste recycling and 50% waste incineration. Among these options, option 4 was the priority for the establishment of final waste disposal with the highest score (0.043) in terms of sustainability, as well as having fewer adverse environmental impacts. However, the current environmental status of the Kish Island disposal site (Option 1) had the lowest score (-0.263) in terms of sustainability and was found to be the last priority with the most destructive environmental effects.
    Keywords: Disposal, Environmental impact assessment, Sustainability, Solid waste, Touristic island
  • Fatemeh Ziaadini, Ali Mostafavi, Tayebeh Shamspur, Fariba Fathirad * Pages 127-132
    In the present study, the core-shell magnetic nanostructure of Fe3O4@SiO2@CeO2 was synthesized to investigate its use as an effective photocatalyst for methylene blue removal. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and a vibrating sample magnetometer (VSM). The photocatalytic activity for the Fe3O4@SiO2@CeO2 core-shell magnetic nanostructure was investigated under visible light by determining the degradation rate of methylene blue for 50 min. At the end of the photocatalytic degradation process, the magnetic catalyst was recovered by an external magnetic field. The performance of the proposed catalyst for the degradation of methylene blue was improved with the optimization of the effective parameters such as the amount of catalyst, pH, and reaction time. Under optimum conditions, the efficiency of methylene blue removal with the proposed photocatalyst remains higher than 92 % after five times of use. The second pseudo-model was selected as the kinetic model to calculate catalytic degradation. The present results show that the Fe3O4@SiO2@CeO2 can be an efficient nanocatalyst for the photodegradation of dye pollutants.
    Keywords: Core-shell magnetic nanostructure, Photodegradation, Visible light driven, Methylene Blue