JOURNAL OF ENVIRONMENTAL HEALTH ENGINERING
Year:2018 | Volume:5 | Issue:4 |Papers Count:8

Background and Purpose: PAHs and their derivatives have a complex and stable molecular structure with low biodegradability and have from the compounds in the crude oil. The object of this study was to evaluation of efficiency of persulfate activated with ultrasonic waves in Phenanthrene degradation from Soil environments by central composite design. Methods The soil samples were homogenized and filtered using a 2. 0 mm sieve. Then، Phenanthrene solution (PHE) was added into soil sample. In order to carry out the chemical oxidation process، Probe Ultrasonic Wave Generator place out inside the reaction chamber Contains Persulfate/soil slurry environment. A central composite design (CCD) was used for designing and optimizing the operation parameters such as sodium Persulfate concentration، Ultrasound intensity and contact time. The synergy of processes in the system was also studied in optimal conditions. Results ANOVA results indicated that the effect of persulfate concentration، ultrasound intensity and contact time and binary interactions were significant. The Persulfate concentration، has the most significant effect on the phenanthrene degradation. The highest efficacy of the phenanthrene degradation (%58. 05) was obtained in the conditions: initial concentration of persulfate =0. 2 mol، ultrasonic waves with power = %70، and contact time = 120 min. By applying S2O8-2 in a separate approach after 120 min the efficiency was 9. 2% while at these conditions، the efficiency of the ultrasonic process was only 3. 4%. By contrast، the combined PS/US process could remove %58. 05 of phenanthrene. Conclusion The results of this study indicated that، the application of the PS/US process is an effective method for purification of Phenanthrene contaminated soils.

Background and Objective Antibiotics are widely used in veterinary and medicine in the last few decades which presence of these compounds has made potential risks for aquatic and terrestrial organisms in the environment. Metronidazole is one of these antibiotics. The purpose of this study was investigation of the efficiency of metronidazole removal from aqueous solutions using a catalytic ozonation process with magnetic nanoparticles of iron oxide doped with silica and titanium dioxide. Materials and Methods The sol gel method was used to synthesize Fe3O4@SiO2@TiO2 nanoparticles and its properties were investigated by SEM، XRD and EDX analyzes. The effect of parameters such as pH، catalyst dose، reaction time، contaminant concentration، determining the mineralization and scavenger effect were investigated on the process performance. Changes in metronidazole concentration were determined by HPLC. Results According to the results of this study، pH =10 and catalyst dose of 3 g /l were obtained as optimum conditions and the removal efficiency increased with increasing of contact time and decreasing in the concentration of metronidazole. Results showed that the removal of metronidazole followed first degree model by this process. Rate of TOC was 86% under optimal operating conditions. Conclusion Catalytic ozonation process with magnetic nanoparticles of iron oxide doped with silica and titanium dioxide can significantly remove metronidazole and it is an appropriate method for removal of metronidazole.

Background and Objectives The presence of dye organic pollutants such as methyl orange is an imperative threat for environment. Therefore، the main aim of this study is synthesize of the ZnO-SnO2-Ag nanocomposite and elimination of methyl orange from water using advanced oxidation process and synthesized photocatalytic nanocomposite. Material and Methods: The nanocomposite containing ZnO، SnO2 and Ag nanoparticles is synthesized for photocatalytic application. The synthesized nanocomposite is characterized using X-ray diffraction (XRD) spectroscopy and transmission electron microscopy (TEM). The effect of irradiation time ranging from 5 min to 15 min and weight fraction of nanocomposite ranging from 0. 125 %wt to 0. 5 %wt is investigated on the photocatalytic decomposition of methyl orange. Results The results of the XRD pattern reveal that the Ag nanoparticles with cubic structure decorate on the surface of ZnO-SnO2. The results of the photocatalytic activity of the synthesized nanocomposite show that the removal efficiency of the pollutant increases with UV irradiation time and weight fraction. The results of the Duncan’ s multiple range test confirm that there is a significant difference among different level of the UV irradiation time and weight fraction of nanocomposite. Conclusion Base on the experimental results، it is clear that the effect of UV irradiation time is more significant rather than weight fraction.

Background The leather industry is one of the most polluting industries in the country (Iran)، which annually produces several hundred tons of industrial sewage. Electrocoagulation is one of the purification methods for this wastewater. This research aimed to remove COD and turbidity from real wastewater originating from one of the leather tanning units in Charmshahr industrial park with use of electrocoagulation process. Method The research was conducted in laboratory scale in a 480-millimeter EC reactor. The wastewater was collected from a leather tanning unit. The main variables considered were current intensity (1. 5، 2. 5، 3. 5 and 5 A)، retention time (5، 10، 15 and 30min)، initial pH (5، 6 and 8. 6) and electrode material (i. e.، iron، aluminum، and steel). Results The optimum conditions in the electrocoagulation process to achieve the maximum removal efficiency for COD equal to 63. 57% were obtained in an experiment with time of 5 minutes، the current density of 23. 5% mA/cm2، pH=8. 62 and 2 steel electrodes. Also، in an experiment with time of 30 minutes، the current density of 23. 5 mA/cm2، pH=8. 62 and 4 electrodes، the removal rate of 62. 88% was obtained. Conclusions The results of the present study showed that the electrocoagulation can be an effective method for tannery wastewater pre-treatment and the optimum conditions can be obtained using aluminum electrodes، time of 5 minutes، the current density of 7 mA/cm2 and pH of 8. 62.

Background Persian Gulf is one of the most important ecosystems in the world that in recent decades has been exposed to various environmental pollutants such as heavy metals from human and natural activities. Therefore، the aim of this study investigates the concentration of heavy metals (cadmium، lead، copper and zinc) and ecological risk assessment of them in coastal sediments in of Bushehr province in Persian Gulf. Methods In order to assess the concentration of metals، 54 stations along the coastal zones were selected and in each station three samples of sediment and plant were taken. After preparation and digestion of the samples، the concentrations of these metals were determined by using polarography. Results The average of total concentration of detected metals Zn، Cu، Pb and Cd in sediment 52. 40 ± 2. 62، 34. 99± 2. 76، 11. 53 ± 2. 01 and 2. 41± 0. 89 μ g/g، respectively. Also، the results of comparison of heavy metals concentration in coastal areas in Bushehr Province (Jam، Deir، Bushehr، Dashti، Genaveh and Deilam) with ANOVA test showed there was a significant difference between the concentrations of sediments in different coastal areas. The results showed that the Pollution Load Index (PLI) and ecological risk represents less to moderately pollution in the region. Also، the environmental risk of metals in the region was evaluated as (Cd>Cu> Pb> Zn). Conclusion According to the results، the pollution and ecological risk of metals in the region for Zn، Cu and Pb is low but for Cd is moderateevaluated

Background Fish farming requires proper water quality to increase productivity and reduce health risk exposures while they are emission sources in rivers themselves. The purpose of this research is to evaluate river water quality regarding physicochemical parameters coupling with water quality index (WQI) to study the viability of fish farming expansion. Methods This study is carried out both as field survey and laboratory analysis. Samples were taken bimonthly in 6 periods (2016-2017) from 21 stations from Kabkian River، Iran، including the water body and discharge points. Afterwards، results were statistically analyzed by T-Test regarding the spatial and temporal specifications with SPSS. Results Experimental results show that dissolved oxygen is over 7 mg/L and WQI is 70 which is classified as good. However، temporal variations of BOD، COD and nitrite concentrations are significant and their average are rather high about 10، 16 and 0. 14 mg/L، respectively. Since، BOD is the only parameter with significant spatial variations، it is introduced as the main parameter for river water quality monitoring. Conclusion Overally، Kabkian water quality is suitable for fish farming. However، due to the possibility of presence of malachite green، it is highly recommended that strict monitoring should be implemented upstream to control fish farm discharges and reduce health risk exposures.

Background and objective The paper aims to estimate the environmental gases of Landfill No. 2 in Shahin Shahr (total landfill gas، methane gas and carbon dioxide gas)، comparison of gas emissions over a period of 30 years، and the availability of landfill for energy extraction. Methods The field of research is Landfill No. 2 at Shahin Shahr Recycling Plant (Isfahan) located in Ja’ farabad Mountains، whose capacity was completed in 1391 and landfill gas assessment was carried out. The total amount of produced gases، methane and carbon dioxide has been calculated using the first-order degradation model over a period of 30 years. Results The amount of these gases in Landfill has been calculated from 1394 to 1424. The results show that the amount of landfill gases has declined over time. The most amounts of methane and carbon dioxide production is about 1050000 and 287000 kilograms in 1394 and the least amount of methane and carbon dioxide production is estimated about 174 and 476 thousand kilograms، respectively، in 1424. The total volume of gases produced in this landfill has been estimated to be about 15 million cubic meters in 30 years، of which 27 percent are methane and 73 percent are carbon dioxide. The amount of methane and carbon dioxide gas is estimated to be about 15 million and 42 million kilograms in 30 years، respectively. Conclusion Generally، landfill gases have declined over time. It is recommended to use energy recovery technologies for controlling greenhouse gas emissions and generation of required energy for the ShahinShahr recycling plant in order to use this volume of gas.

Background In recently years، plant-assistant bioremediation is preferred to the other methods and causes increasing of remediation efficiency. Among this، applying chelating such as Ethylenediamine disuccinic acid (EDDS) can probably affect soil heavy metal availability that increase phytoremediation efficiency. Thus، this research was conducted to evaluate the effectiveness of EDDS chelate on corn (Maxima CV) Cadmium uptake in a soil treated with Arak municipal waste compost. Methods A factorial experiment with a randomized complete block design with 3 factors in three replications was conducted in greenhouse conditions. Treatments were consisted of applying Arak municipal waste compost (0. 15 and 30 t ha-1)، soil polluted cadmium (0، 20، 30 and 40 mg Cd kg soil-1) from Cd(NO3)2 sources and applying EDDS chelate (0 and 1. 5 mmol kg soil-1). After 60days، soil physic-chemical properties and root and shoot cadmium concentration was measured. Results Applying 1. 5 mmol kg soil-1 EDDS chelate in a Cd polluted soil (40 mg Cd kg soil-1) without receiving Arak municipal waste compost caused a significant increasing in Cd availability by 21 percent، while applying 1. 5 mmol kg soil-1 EDDS chelate in a Cd polluted soil (40 mg Cd kg soil-1) with receiving 30 t ha-1 Arak municipal waste compost increased the Cd availability by 10 percent. Conclusion The EDDS chelate effectiveness was affected by soil organic matter، as، with increasing the amount of Arak municipal waste compost، the effectiveness of applying EDDS chelate was decreased. The similar results for root and shoot Cd concentration confirm this matter clearly.