Sulfur dioxide emissions in Iran and environmental impacts of sulfur recovery plant in Tabriz Oil Refinery

Background: Combustion of fossil fuels contributes to sulfur dioxide [SO2] emissions. To deal with this issue, the government of Iran has appointed the oil refineries to upgrade their installations and produce high quality fuels. Thus, this study investigated the status of SO2 emissions in Iran and the capability of advanced technologies to control SO2 emissions

Methods: The status of SO2 emissions was reviewed and discussed through national online reports. Meanwhile, the environmental impacts of sulfur recovery and tail gas treatment [TGT] plant [STP] were assessed by applying rapid impact assessment matrix [RIAM] for implementation and nonimplementation alternatives in Tabriz Oil Refinery Company [TORC]

Results: SO2 emissions have been increased by 2.1 times during 2004-2014 in Iran. Power plants and transportation play a significant role in this regard and overall contribute 82% of emissions. Among the other fossil fuels, fuel oil and gasoil account for 95% of SO2 emissions. Based on the environmental impact assessments [EIAs], sulfur recovery management and enhancing sulfur removal efficiency from flue gas up to 99.9% are two main positive environmental aspects of STP project that would enable TORC to prevent 87 600 tons of SO2 emissions, annually. Nevertheless, flue gas and sour gas streams which have been determined as probable pollution sources of process, should be managed through proper monitoring framework

Conclusion: The increasing trend of SO2 emissions and significant role of fuel oil and gasoil has required Iranian oil refineries to enhance the quality of fuels by employing clean and cost-effective technologies

Geogenic arsenic contamination in northwest of Iran; role of water basin hydrochemistry

Introduction: Arsenic contamination of surface and groundwater has been categorizd among high profile environmental problems around the world. The matter is of most concern where unsafe water is used for drinking. Sahand region reservoir in northwest of Iran supplies water for drinking, industrial and agricultural purposes through irrigation of 11000 hectares of lands

Materials and Methods: The hydrochemistry status of Sahand dam basin and arsenic plume distribution in water recourse was evaluated by analyzing 308 water samples from surface and ground water according to the standard methods. In addition, geological features information of basin were obtained based on recent site studies and field investigations

Results: Elevated concentrations of arsenic [range = 0-1440 ppb, mean = 171.68 ppb] were detected in water basin and dam. According to the delineating evidences, regional geological background and volcanic activities can be considered as the main sources of the natural genesis of arsenic in the study area

Conclusion: Notable amounts of arsenic sulfide were recorded in seams, gaps, fractures of limestone, marl, sandstone and an overlying ferruginous conglomerate. Concentrations of arsenic varied seasonally highlighting the maximum concentration observed in autumn and early winter [December]. Seasonal fluctuations can be probably attributed to changes in geochemical conditions in sediments at the bottom of reservoir

Performance evaluation of a full-scale ABS resin manufacturing wastewater treatment plant: a case study in Tabriz petrochemical complex

Background: The measurement data regarding the influent and effluent of wastewater treatment plant [WWTP] provides a general overview, demonstrating an overall performance of WWTP. Nevertheless, these data do not provide the suitable operational information for the optimization of individual units involved in a WWTP. A full-scale evolution of WWTP was carried out in this study via a reconciled data

Methods: A full-scale evolution of acrylonitrile, butadiene and styrene [ABS] resin manufacturing WWTP was carried out. Data reconciliation technique was employed to fulfil the mass conservation law and also enhance the accuracy of the flow measurements. Daily average values from long-term measurements by the WWTP library along with the results of four sampling runs, were utilized for data reconciliation with further performance evaluation and characterization of WWTP

Results: The full-scale evaluation, based on balanced data showed that removal efficiency based on chemical oxygen demand [COD] and biochemical oxygen demand [BOD5] through the WWTP were 80% and 90%, respectively, from which only 28% of COD and 20% of BOD5 removal had occurred in biological reactor. In addition, the removal efficiency of styrene and acrylonitrile, throughout the plant, was approximately 90%. Estimation results employing Toxchem model showed that 43% of acrylonitrile and 85% of styrene were emitted into the atmosphere above water surfaces

Conclusion: It can be concluded that the volatilization of styrene and acrylonitrile is the main mechanism for their removal along with corresponded COD elimination from the WWTP

[Estimation of health effects attributed to PM10 exposure in Tabriz, Iran]

Background and Objectives: Air pollution from particulate matters and dust storms is considered one of the most challenging of health problems in our country, nowadays. Most of the epidemiological studies have shown a relationship between health outcomes and airborne particles. The main aim of this study was the assessment of health impacts of PM10 in Tabriz

Materials and Methods: In this cross sectional study, PM10 levels were monitored in fixed stations of air monitoring and its adverse health effects were estimated for one year. We applied the approach proposed by the World Health Organization [WHO] using the AirQ2.2.3 software developed by the WHO European Center for Environment and Health on air pollutants in Tabriz

Results: The results showed that 5.94% [CI 95% 5.02%; 6.83%] of natural death, 6.39%[CI 95% 4.09%; 13.31%] of cardiovascular death, 9.28% [CI 95% 6.39%; 23.98%] of respiratory death, 7.13% [CI 95% 4.87%; 9.98%] of hospital admissions for cardiovascular disease and 6.39%[CI 95% 3.93%; 8.72%] of hospital admissions for respiratory disease can be attributed to PM10 concentrations over 10 microg/m3

Conclusion: Based on the output of this model, air pollution due to airborne particles is a serious problem that necessitates attention and preventive measures by authorities and decision-makers

[Epidemiological study of skin effects of exposure to low concentration of arsenic from drinking water in two villages of sarab]

Background and Objectives: arsenic in drinking water is a well-known hazardous material that its pathogenesis has been reported by different researches. Present study was conducted as an epidemiological study for skin effects of exposure to low concentration of arsenic from drinking water

Materials and Methods: present study was conducted as a cross sectional study in two exposed and unexposed villages to arsenic through drinking water [Sarab county: Razliq and Farkoosh villages, in 2012] and skin effects were studied among 279 persons over 10 years. Drinking water sources of both villages were analyzed chemically with an emphasis on arsenic. For statistical analysis of data, independent sample T-test was used and p value less than 0.05 was considered significant

Results: arsenic concentration in drinking water of the exposed and unexposed villages was 96micro g/l and zero, respectively. 9.7% of studied population had pigmentation [13.8% of exposed population, 6% of unexposed population]. Odds ratio of pigmentation in the exposed village was calculated 2.5 fold higher than unexposed village [CI 95% = 1.082- 5.778]. In the exposed village, keratosis just was observed in three persons [equal to 2.3% of village population] however, in unexposed village there was no keratosis

Conclusion: although there were more pigmentation cases in exposed village compared to unexposed one, however, in comparison with other studies, rate of skin lesions [keratosis and pigmentation] were lower indicating that incidence of skin lesions will be minimal if exposure dose of arsenic through drinking water be less than 100 micro g/l

Assessment of water supply system and water quality of Lighvan village using water safety plan

Background: Continuous expansion of potable water pollution sources is one of the main concerns of water suppliers, therefore measures such as water safety plan [WSP], have been taken into account to control these sources of pollution. The aim of this study was to identify probable risks and threatening hazards to drinking water quality in Lighvan village along with assessment of bank filtration of the village

Methods: In the present study all risks and probable hazards were identified and ranked. For each of these cases, practical suggestions for removing or controlling them were given. To assess potable water quality in Lighvan village, sampling was done from different parts of the village and physicochemical parameters were measured. To assess the efficiency of bank filtration system of the village, independent t test was used to compare average values of parameters in river and treated water

Results: One of the probable sources of pollution in this study was domestic wastewater which threatens water quality. The results of this study show that bank filtration efficiency in water supply of the village is acceptable

Conclusion: Although Bank filtration imposes fewer expenses on governments, it provides suitable water for drinking and other uses. However, it should be noted that application of these systems should be done after a thorough study of water pollution level, types of water pollutants, soil properties of the area, soil percolation and system distance from pollutant sources