Estimation of landfill gas generation in a municipal solid waste disposal site by LandGEM mathematical model

Anaerobic decomposition of organic compounds in landfills is responsible for generation of greenhouse gases. The present study aimed to determine the total gas and methane emission from a landfill located in Hamedan (west of Iran) from 2011 to 2030. LandGEM 3.02 model was used to estimate the gas emission with the volumetric methane percent of 60%, production potential of 107, and methane generation rate of 0.2. Spatial distribution of annual methane and total landfill gas emission rate in the study area at three decades were provided through ArcGIS software. The results showed that organic and food wastes had the maximum amounts in the solid waste stream (over 75%). The results showed that 4.371×108 m3 methane would be produced after 20 years, mostly (4.053×106m3) in the first year. In addition, methane production capacity in Hamedan landfill site was 107 m3/Mg. According to the results, the maximum and minimum gas generation rates are in summer (the hottest season) and winter (the coldest season) respectively. The results of the LandGEM model represented that the total gas and methane generation rates will be significant in the first 10 years. The potential of rapidly degradable organic compounds for gas emission will be higher than that of slowly degradable organic compounds. The results obtained in the present study can be beneficially used in planning for energy production and other applications in landfill sites

Risk assessment of sari fatemeh zahra hospital using failure mode effect analysis, individualized rapid assessment tool, and preliminary hazard analysis

Abstract Background and purpose: Identification of risk in hospital waste management have a major role in reducing the cost of surplus and preventing the spread of diseases. In this quantitative analysis, we aimed at determining waste components, evaluating hospital waste management, and prioritizing the risks in Sari Fatemeh Zahra Hospital. Materials and methods: We performed a descriptive-cross-sectional study in 2015. Tchobanoglous method was used for quantitative-physical analysis of the waste. The individualized rapid assessment tool was applied to evaluate waste management. Preliminary Hazard Analysis and failure mode and effect analysis models were used to identify and prioritize the risks. Results: Total waste production, general waste, infectious wastes, and sharp objects were 1011.54, 600.45, 384.94, and 26.15 kg/day, respectively. Plastics, organic materials, and textiles constituted the highest amount of waste products. According to the individualized rapid assessment tool, the score obtained by the hospital was 82.15% indicating an excellent waste management. In preliminary hazard analysis, failure mode, and effect analysis models, 23 errors were observed, of which 9 had a priority number greater than 100. Conclusion: The models studied showed that mixing the sharp waste material with other garbage, disposal of non-infectious and semi-household waste in infectious bins and vice versa are of high risk and need corrective measures. Keywords: hospital waste management,quantitative analysis, risk assessment,preliminary hazard analysis, Hazard Analysis and Failure mode

Landfill site selection using a hybrid system of AHP-Fuzzy in GIS environment: A case study in Shiraz city, Iran

Landfilling with simplicity and economic advantages is the most common element for waste management in both developed and developing countries. Landfill site selection in a proper way is an important municipal planning process which prevent environmental issues including water pollution imposed for insanitary landfills. The present research was developed to exhibit a simplified method of multi criteria decision making (MCDM) and Fuzzy memberships in GIS environment to ascertain best landfill sites for Shiraz county, located south of Iran. 15 most common sub-criteria, documented in literature and implicated by Iranian environmental protection organization (IEPO) including surface water, ground water, land use, distance to well, soil type, slope, protected area, fault in environmental group, residential area, road, airport, village, infrastructure, historical area, wind direction in socio-economical group were selected and the weight of each criterion was determined based on expert's knowledge with use of analytical hierarchy process (AHP). The results of the present research are as follows: � Distance to residential area and groundwaters with weight of 0.36 and 0.28 were recognized as the most important criteria for landfill site selection. � The six suitable areas for landfill in Shiraz county is 1.003 of total area equal to 8710 ha. � AHP and Fuzzy memberships has a great potential and ability for landfill site selection. © 2019 The Author(s

Catalytic decomposition of 2-chlorophenol using an ultrasonic-assisted Fe3O4-TiO2@MWCNT system: Influence factors, pathway and mechanism study.

As a reusable sonocatalyst, magnetically separable Fe3O4-TiO2@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N2-physisorption. The efficiency and kinetics of 2CP removal by FMT-assisted sonocatalysis (FMT-US) was systematically investigated under various operational parameters i.e. pH, FMT and 2CP concentration, temperature and ultrasonic power. The results indicated that 0.4gL-1 FMT dosage, pH 5, temperature of 35°C as well as 50 w ultrasound power are the most favorable conditions for the degradation of the 2CP. Furthermore, both of the superoxide and hydroxyl radicals were produced in the reaction, however, superoxide radicals were assumed to be the dominating reactive species for the 2CP degradation, according to the scavenging tests and electron paramagnetic resonance tests. Moreover, the FMT catalyst exhibited a high reusability and stability in the US/FMT system during the five repetitive experiments. The intermediate products were identified by GC-MS, thereby a possible degradation pathway is proposed. The chemical oxygen demand (COD) and corresponding total organic carbon (TOC) removal efficiencies were 64.9% and 56.7%, respectively. Finally, toxicity tests showed that the toxicity of the solution increased during the first 5min and then decreased significantly with the progress of the oxidation. The mechanisms of ultrasound irritation enhanced FMT activation were also proposed. Copyright © 2017 Elsevier Inc. All rights reserved

Influence of bioaugmentation on biodegradation of phenanthrene-contaminated soil by earthworm in lab scale

Background: Use of earthworm to eliminate the phenanthrene from the soil (bioaccumulation) is developed as an economical method. Bioaugmentation of microorganism was used for promotion of bioaccumulation by earthworm. The aim of this study was to determine the bioaccumulation or biodegradation of phenanthrene by Eisenia fetida and bacterial consortium in polluted soil. Methods: The amount of 0.4 kg of the polluted soil in the ratio of 10 and 30 mg phenanthrene per kg of dry soil was transferred into each pot. Afterwards, bacteria and earthworms were added to each pot in separate and combination. The samples were kept under field conditions, and the retention concentrations of phenanthrene were analyzed after 8 weeks. Results: Results showed that the Eisenia fetida was able to significantly remove phenanthrene from the polluted soil samples. Bioaccumulation and bioaugmentation alone have the removal efficiency of 60.24 and 50.3, respectively. In the combined mode, phenanthrene removal efficiency was 63.81. Conclusions: The current study indicated that the use of earthworms, could improve both phenanthrene bioavailability and microbial activity, which led to enhancing removal of carbon-based pollutants. ©2014 Asgharnia et al

Comparison between Windrow and Pit Composting of Poultry Wastes, Leaves and Garbage of Municipal Solid Waste in Damghan, Iran

Basic principles of Integrated Solid Waste Management (ISWM) are: Reduction, Reuse, Recycling and Recovery (4Rs). Composting as an element of ISWM strategy that can be applied to separately collected or mixed wastes, is a controlled aerobic process carried out by successive microbial populations combining both mesophilic and thermophilic activities and leading to the production of carbon dioxide, water, minerals and stabilized organic matter. In this research, comparing between windrow and pit co-composting methods was studied in the city of Damghan, Iran. Waste proportioning was done based on C/N ratio (about 25:1) and moisture content (about 55%). Mixed wastes were located in windrow and pit with natural aeration tunnel. Sufficient oxygen supply was provided in the piles of compostable materials in two systems through frequent turning of the piles in 7 d intervals during the first month. Temperature reached to maximum level in 10-15 d and then depleted (days: 20-25). It reached to the safety level (about 60°C) based on U.S.EPA and WHO recommendations. Finally, compost was produced with pH=7.7, dark brown color and 30- 35% moisture content. N, P, K, organic matter and organic carbon were measured by standard methods. Results were compared with WHO and U.S.EPA recommendations showing suitable conditions Also it was indicated that pit method was better for maintaining temperature, nitrogen, organic C and organic matter

QUALITY AND QUANTITY SURVEY OF HOSPITAL WASTEWATERS IN HORMOZGAN PROVINCE

Hospital wastewaters are one of the most contaminating wastewaters and need to be paid more attention due to containing infectious agents. In this study, which had been conducted in a period of one year, 7 public hospitals were selected out of 12 public hospitals in Hormozgan Province of Iran. For studying quality of wastewater in hospitals, both influent and effluent wastewaters of treatment plant, if any, were sampled once in each season and totally 30 mixed samples were obtained. In order to determine the quality of hospital wastewaters in all samples, parameters such as pH, BOD5, COD, TSS and temperature were measured. Results of investigation on annual water consumption indicated that average water consumption in hospitals of the province was 194m3/d., considering water-to-wastewater conversion ratio of 0.8 and green yard ratio of 0.3. Wastewater production rate had been estimated to be 47m3/d and 0.362 m3/d.bed. Results indicated that in 7 hospitals of Hormozgan province, mean values of BOD5, COD ,TSS in raw wastewater were 242.25 mg/L, 628.1 mg/L and 231.25 mg/L, respectively, pH=7.42 and temperature=30.17 °C. In Khalij-e-Fars hospital which had wastewater treatment plant, values of these parameters in effluent were 12.53 mg/L and 51.7 mg/L, 19.68 mg/L, respectively, with pH=7.39 and temperature=26.1 °C. Comparison between values of influent and effluent wastewaters indicated that in understudy cases, contamination rate was higher than determined limits, as compared to environmental standards of the country and it was necessary to establish appropriate treatment plants in these units

The survey of Malathion removal using magnetic graphene oxide nanocomposite as a novel adsorbent: thermodynamics, isotherms, and kinetic study

Malathion is a persistent organophosphorous insecticide, which is widely used in industry, agriculture, and public health. The characterization of Magnetic Graphene Oxide (MGO) was determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, energy dispersive X-ray, vibrating sample magnetometer, and zeta potential. The performance of the adsorbent in removing of malathion was evaluated in different operational conditions including pH, contact time, adsorbent dosage, initial adsorbate concentration, and temperature. The Langmuir and Freundlich isotherms and pseudo-first-order and pseudo-second-order models were applied to describe the adsorption process. The results showed that the maximum adsorption capacity was obtained 43.29 mg g�1 and equilibrium data fitted well with the Langmuir isotherm and kinetics of reactions obeyed the pseudo-second-order model. It was also found that the adsorption process was dependent on pH and it was spontaneous and exothermic in terms of thermodynamic studies. Desorption experiments implied that MGO has high stability (very low component leaching) and is probable that can be applied as a novel material for malathion removal from aqueous environments. © 2016 Balaban Desalination Publications. All rights reserved

Qualitative and Quantitative Assessment of Wastewater of Pistachio Processing Terminals (Case Study: Kerman city)

Introduction: Wastewaters resulting from seasonal processing such as pistachio processing industry are one of the most important factors of environmental pollution. High concentration of pollutants are the qualitative characteristics of wastewaters that due high consumption of water and energy resources as well as high levels production of waste have a good potential to realization of projects to reduce the environmental impacts and optimizing the consumption of energy resources.The aim of this study was to determine the wastewater̛ s quality and quantity of pistachio processing terminals. Methods: this study is cross-sectional study that has been implemented from mid –September until late October (pistachio harvest season) in each of the years 2012-2013-2014 in Kerman.Firstely according to field study, the characteristics and location of 20 pistachio processing terminals were determined by a GPS device. Then 8 pistachio processing terminals were selected in around of wastewater collection system. Composite sampling method with total of 72 samples was done in each year during pistachio operation. Samples were conducted from pistachio processing wastewater screen filter outlet. In each of samples BOD5, COD, TSS, pH and Total phenolic were determined. Sampling and tests were done according to water and wastewater standard methods book (20th edition). Concentration of Phenolic compounds was measured by folin ciocaltive method. The Data was analyzed by SPSS software. Results: the average of total produced wastewater in pistachio processing terminals in this study was 85.9m3/d. The average BOD5, COD, TSS, Total phenolic and PH were 6106, 21570, 682, 4154 (mg/L) and 5.5 respectively. Conclusion: The obtained results from raw wastewater of pistachio processing terminals showed they have high BOD and COD. This is caused by presentation of priority pollutants (phenolic compounds) which have high potential in pollution and toxicity for discharging any receiving resources