Influence of pollution loading and flow rate on catalytic BTEX removal with a combined Cu2O, Fe0/Zeolite bed

ABSTRACT Environmental impacts and health concerns of BTEX compounds have been pointed in many studies. The agencies responsible for health and environment have delivered standard and guideline for BTEX concentrations. Because of the extensive use in industries and the presence of these compounds in fossil fuels, their emission resources are very divers. Today's, Control of air pollution caused by these compounds is one of the air qualities controlling challenges. "Thermal catalyzed" process is one of the technologies to control this kind of air pollution and consistent with using nanoparticles as a catalyst, this process is further considered now. So, we conducted this study to survey elimination of the BTEX, form polluted air flow, by this process. In this study, removal of the BTEX from polluted air by a thermal catalyzed process in the presence of zero-valent iron and copper oxide nanoparticles was investigated and the effect of changes in pollution load and flow rate was surveyed on removal efficiency and the decomposition of the pollutants. Fe0 and Cu2O nanoparticles were coated on a bed of natural zeolite (Clinoptilolite) with a zeolite grains size of 1-2 mm. The thermal catalyst process was conducted at 350°C and different pollution loading and air flow rate. 96.18% and 78.42% of removal efficiency achieved with the retention times of 14.1s and 7.05s. Increasing the pollution load reduced removal efficiency and pollutants' mineralization. By doubling the pollution load, the removal efficiency declined as much as 14.5 %. According to the results, increasing of the flow rate has a greater effect than the pollution load on the complete decomposition. Also this process showed a good efficiency for BTEX removal under high pollution loading and flow rates

بررسي كيفيت و تعيين انديس هاي پايداري منابع آب شرب روستاهاي استان قم

Background and Aims: Corrosion and scaling are among the problems that despite science advancement, water facilities are still faced it. Corrosion lead to financial and health losses on water supply system and consumer, scaling also causes clogging and head loss in water supply network. Therefore, the aim of this study is to determine the corrosion and scaling potential of Qom villages water supply sources.Materials and Methods: In cross-sectional study 100 samples in 12 months from 2011 to 2012 were collected to verify the water quality according to 1053 standard of Institute of Standards and Industrial Research of Iran (ISIRI). Then water corrosion and scaling were studied using Langelier, Ryznar, Aggressive and Puckorius indexes.Results: The results showed that the Langelier index, Reynar index, aggressive or corrosion index and index Puckorius were -1.62 (±0.11), 10.5 (±0.17), 12.03 (±0.14) and 9.92 (±0.13) respectively. Physical and chemical parameters of the water showed that the mean pH, TDS, total hardness, turbidity, calcium, magnesium, fluoride, sodium, ammonia, phosphate, and chloride were 7.27, 1205.29 mg/L, 435.661 mg/L CaCO3, 0.747 NTU, 132.29 mg/L, 25.58 mg/L, 0.68 mg/L, 245.50 mg/L, 0.015 mg/L, 0.17 mg/L and 231.22 mg/L respectively.Conclusion: The amounts of color, TDS, turbidity, pH, calcium, magnesium, fluoride and ammonia in the study areas are in satisfactory and acceptable status compared to the internal standard but the amount of phosphate, hardness and chloride in this area were exceeded from permissible limit. Comparison of four stability index also showed that water conditions in all parts of this study are located in corrosive range.زمينه و هدف: فرآيند رسوب گذاري و خوردگي از جمله مشکلاتي است که عليرغم پيشرفت علم تاسيسات آبي هنوز با آن مواجههستند. فرآيند خوردگي منجر به خساراتهاي مالي و بهداشتي فراواني براي مصرف کنندگان و سيستم آبرساني مي شود، رسوبگذارينيز سبب مشکلاتي همچون گرفتگي و افت فشار در شبکه آبرساني خواهد شد. لذا هدف از اين مطالعه تعيين پتانسيل خورندگي ورسوبگذاري منابع آب تامين کننده روستاهاي قم و بررسي کيفيت فيزيکي و شيميايي اين منابع مي باشد.مواد و روش ها: در مطالعه توصيفي- مقطعي انجام شده تعداد ۱۰۰ نمونه در مدت ۱۲ ماه طي سال هاي ۹۰ تا ۹۱ به منظور بررسيخصوصيات کيفي آب برداشت و بر اساس استاندارد ۱۰۵۳ موسسه استاندارد و تحقيقات آب ايران مورد آناليز قرار گرفت. سپس بااستفاده از شاخصهاي لانژليه، رايزنر، تهاجمي و پوکوريوس خوردگي و رسوبگذاري آب روستاهاي قم مطالعه شد. نتیجه گیری: میزان رنگ، TDS، کدورت، PH، کلسیم، منیزیوم، فلوراید و آمونیاک در مناطق مورد مطالعه از وضعیت مطلوب و قابل قبولي نسبت به استاندارد هاي داخلي برخوردار مي باشد ولي ميزان فسفات ، سختي و کلرور در اين مناطق بيش از حد مجاز مي باشد.مقايسه ۴ انديس پايداري نيز نشان داد وضعيت آب در بخش هاي مورد مطالعه در محدوده خورنده مي باشد. &nbsp

Determining and Analyzing Corrosion Potential of Groundwater in Ghorveh through Simulating Corrosion Indices

Background and Objective: Scaling and corrosion are factors that cause loss of drinking water quality. They create problems for public health, reduce water quality, and decrease useful life of plumbing equipment. Therefore, their control substantially influences public health and water quality. Consequently, the present research intended to study corrosion or scaling indices of groundwater resources in Ghorveh County in Kurdistan Province using the Monte Carlo statistical method in order to reduce uncertainty and increase accuracy in estimating the values of the indices. Materials and Methods: Sixty four samples from 16 wells supplying water for Ghorveh County were taken during a 12- month period in 2012-2013 in order to study the qualitative characteristics of water and identify the corrosion and scaling potential of the water in the region using the Langelier, Ryznar, Larson-Skold, and Puckorius indices. Results: The mean values for the Langelier, Ryznar, Puckorius, and Larson-Skold indices were 0.5449±0.015, 6.8878±0.017, 7.3754±0.0078, and 0.0919±0.0390, respectively. Moreover, the estimated probabilities for the occurrence of corrosion and scaling phenomena were 6.59% and 47.57% for the Langelier index, less than 11.77% and 54.33% for the Ryznar index, less than 17.47% and 36.33% for the Puckorius index, and 0.15% and 99.74% for the Larson-Skold index. Conclusions All of the studied indices yielded identical results for the water status: they indicated a relatively high scaling potential of the water in the region. Based on Pearson’s test, the most important factors influencing the values of the studied indices were pH and concentration of calcium ions. &nbsp

Degradation of Amoxicillin Using Modified Graphite Felt and Fe3 O4 Nanocatalyst As Electro-Fenton Process

Background: Amoxicillin is the most commonly used antibiotics that draws more attractions due to induce bacterial resistance. This compound can enter the aquatic environment through different routes including sewage and waste disposal of medical health centers, veterinary and industries. The aim of this study was removal of amoxicillin from aqueous environments by Electro-Fenton process using modified graphite felt and synthesized Fe3O4 nanoparticles. Methods: Fe3O4 nanoparticles were synthesized by co- precipitation method. Graphite felt also modified due to avoid aeration. The structural and physical characteristics of nanocatalyst and also modified graphite felt were analyzed by SEM, EDS and BET techniques. After optimization of pH and time variables, the parameters of applied current, amoxicillin concentration, catalyst load and the distance between electrodes were designed using Design Expert 7.0 software and optimized by the response surface method. Results: The graphite felt modification resulted in increase in surface area from 0.89 to 1.92 m2/g. The maximum removal of amoxicillin (97.11%) was obtained in optimal operational conditions (pH=3, time=60 min, applied current =180 mA, amoxicillin concentration=20 mg/L, catalyst load 1 g/L, the distance between electrodes =2 cm) Conclusion: The result of this study indicated that electro-Fenton process using Fe3O4 nanoparticles and modified Graphite felt without external aeration is an effective method for amoxicillin remova

A Study of Efficiency of Zero-valent Iron Nanoparticles in Degradation of Trichlorethylene from Aqueous Solutions

Introduction and purpose: The release of chlorinated organic compounds (COCs) is accounted as a danger for public health and environment due to their harmful effects such as carcinogenicity, toxicity, and flammability. Trichlorethylene (TCE) is one of the most famous COCs, which is commonly used as a solvent for dry-cleaning and industrial degreasing and contaminates soil and groundwater. Thus, it is considered as a possible carcinogenic compound (class B2) for humans. Therefore, this study was to evaluate the effect of zerovalent iron nanoparticles (nZVI) in degradation of TCE. Methods: Iron nanoparticles were prepared through the Ferric Chloride revival method by sodium borohydride. The properties of nanoparticles were determined using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. In addition, the effect of pH, concentration of trichloroethylene, iron nano-particle dosage, and contact time were studied on TCE removal efficiency. Box Behnken model was used to investigate the interaction of these variables. Analysis of variance was considered as the statistical method for analysis of responses. Results: Results showed that the degradation efficiency was equal to 91.23% in optimal conditions (pH=3, nanoparticles dose= 0.63 g/l, TCE concentration= 11 mg/l, and contact time= 86 min). The results of kinetic studies revealed that TCE degradation by nZVI follows first-order kinetic model. Conclusion: It is conclude that zero-valent iron nanoparticles have a good efficiency in the degradation of TCE. On the other hand, separation of these nanoparticles is simple due to its magnetism properties, which can improve the use of these nanoparticles.&nbsp

Health impact caused by exposure to particulate matter in the air of Tehran in the past decade

Background: Air pollution, especially the phenomenon of dust and particulate matter can cause mortality of many civilians, and causes various diseases including cardiovascular and respiratory diseases. One of the major pollutants in the air is particulate matter that concentration has increased over recent years. So, present study with aim of Quantification Health Endpoints Attributed to particulate matter in Tehran, Capital of Iran during the past decade (2005-2014) by AirQ software, version 2.2.3 (WHO European Centre for Environment and Health) was performed. Methods: This study is a descriptive-analytic investigation. The process of performance this study lasted 12 months. Subject of this the study and research was in Environmental Health Engineering Department of Iran University of Medical Sciences. Exact data of every hour pollutants were taken from Department of environmental (DOE) Islamic Republic Iran and Air Quality Control Company of Tehran. Then validated according to the World Health Organization (WHO) guidelines and Statistical parameters for quantifying health effects were calculated in excel software. Finally, assessment of cases total mortality, cardiovascular mortality, respiratory mortality and cardiovascular disease and respiratory disease, with AirQ software was performed. Results: The results of this study showed that the number of total mortality, cardiovascular mortality and respiratory mortality caused by exposure to Particulate matter smaller than 10 microns (PM10) in the past decade is 11776, 12121 and 33066 cases respectively. Also the total number of hospital admission due to cardiovascular disease and respiratory disease in the past decade is 20990 and 54352 cases in 2005-2014 years. Conclusion: According to the results of this study, during the last decade the level of air pollution and Concentration of pollutants in Tehran Increased. Effects and health consequences due to exposure to Particulate matter smaller than 10 microns (PM10) in Tehran Metropolis Is very severe and increased mortality and cardiovascular and respiratory diseases among the citizens of Tehran

Evaluation of Cardiovascular Death, Attributed to CO Exposure in Tehran Megacity in During a Five-Year Period (2010-2014) by Using AirQ Model

Background: Air pollution in large cities is one of the main difficulties that have harmful effects on humans and the environment and cause various diseases including cardiovascular disease. So, present study with aim of Estimation of Cardiovascular Death, Attributed to CO Exposure in Tehran Megacity in during a five-year period (2010-2014) by using AirQ Model were performed. Materials and Methods: This Study was a descriptive–analytic at first, hourly data of pollutants were taken from the environmental protection agency Tehran and Air Quality Control Company and validated according to the WHO guidelines. Required statistical parameters calculated for health effect quantifying and finally processed data converted to input and requirements AirQ model data and health effects quantifying were performed using this model. The final results on deaths due to cardiovascular disease were presented in tables and graphs format. Results: Results showed annual average concentration of CO in Tehran in 2010-2014 are 49, 31, 11,12,21,76 mg/ m3 respectively. In addition, the number of cardiovascular deaths in 2011-2015 is 52,37,29,31,42 respectively Conclusion: According to the results, CO as well as other pollutants can adversely affect human health. Due to high levels of air pollution and its related health consequences, particularly cardiovascular disease, should take appropriate measures to reduce air pollution

A Study on the Comparative Investigation of Air Quality in Tehran Metropolis Over a Five-year Period Using Air Quality Index (AQI)

Introduction and Purpose: Air pollution is one of the major problems of megacities that seriously threatens the health of their residents. Considering this, taking some actions such as studying pollutant variations, comparing pollutants with standards, and informing the health authorities and public paly a fundamental role in developing preventive schemes. This study was targeted toward a comparative investigation of the air quality of Tehran metropolis based on Air Quality Index (AQI) over a period of five years (2011-2015). Methods: This study was a descriptive–analytic one. Firs, hourly data of four criteria pollutants were taken from the Environmental Protection Agency and Air Quality Control Company. These data were validated according to the World Health Organization (WHO) guidelines. Then, the daily AQI for the given pollutants were determined based on the available standard tables and equation. Finally, the highest value among the calculated indexes obtained from all the stations was recognized as the final index and the pollutant which was responsible for this index was introduced as the responsible pollutant of day. Results: Tehran’s air quality was shown to exceed the standards of Environmental Protection Agency of Iran (AQI>100) _ 327, 330, 343, 350, and 352 days of the year during 2011-2015 respectively. Besides, PM2.5 was found to be the main pollutant which was responsible for this condition. Conclusion: Comparing air quality of Tehran over five years demonstrated that the air quality is not in a proper condition in terms of health status; and the level of air pollution in Tehran is constantly increasing

Photocatalytic degradation data of benzene and toluene by ZnO coated on glass plates under simulated sunlight

For this data article the photocatalytic oxidation of benzene and toluene by ZnO nanoparticles coated on glass plates were studied under simulated sunlight. ZnO nanoparticles were coated on three glass plates by heat attachment methods. To evaluate the photocatalytic removal of benzene and toluene, coated plates irradiated by metal halide lamp in a rectangular reactor in batch mode. The effect of initial pollutants concentration, temperature, relative humidity, irradiation time, concentration of zinc oxide suspension, were assessed. The surface morphology and structure of ZnO nanoparticles and ZnO coated on glass plates were characterized by scanning electron microscopy, X-ray diffraction and Field Emission Scanning Electron Microscopy. Sampling and analysis of pollutants were performed according to the National Institute for Occupational Safety and Health (NIOSH) method. To analyze the concentration of benzene and toluene, gas chromatography with flame ionization detector (GC-FID) was used. The data results indicated that photocatalytic process by ZnO under irradiation of metal halide lamp could remove benzene and toluene at optimum experimental conditions. Coating of glass surfaces by ZnO suspension, resulted in 46% and 57% removal of benzene and toluene as concentration of 50 ppm at 45 °C, and relative humidity of 40% after 240 min irradiation of metal halide lamp. Keywords: Toluene, Benzene, Air pollution, Nanophotocatalytic oxidation, ZnO, Simulated sunligh

The effect of biological treatment methods on the concentration of carbonaceous pollutants in the slaughterhouse wastewater: A systematic review

The systematic review conducted in this study aimed to investigate the effect of biological methods of slaughterhouse wastewater treatment (SWWT) on reducing carbonaceous pollution concentration in the effluent. The researchers performed a comprehensive search for relevant articles in databases such as Scopus, PubMed, Web of Science, and Embase, focusing on studies published up to January 2022. After screening the retrieved records, the researchers identified 71 relevant articles that contained data on the removal efficiency of carbonaceous pollutants in slaughterhouse wastewater. These pollutants included total chemical oxygen demand, chemical oxygen demand, soluble chemical oxygen demand, biochemical oxygen demand, five-day biochemical oxygen demand, organic material, soluble organic compounds, and total organic carbon. The results of the qualitative synthesis indicated that certain SWWT methods exhibited higher removal efficiencies for carbonaceous pollutants. These methods were characterized by long hydraulic retention times, the use of polymeric filter media, attached growth processes, and operation at maximum organic loading rates. It's important to note that specific details regarding the individual studies and their findings are not provided in the given information. However, the systematic review suggests that certain biological treatment methods can effectively reduce carbonaceous pollution concentrations in slaughterhouse wastewater