Amongst the various pollutants in the air, particulate matters (PM) have significant adverse effects on human health. The current research is based on existing epidemiological literature for quantitative estimation of the current health impacts related to particulate matters in some selected principal Iranian megacities. In order to find the influence of air pollution on human health, we used the AirQ software tool presented by the World Health Organization (WHO) European Centre for Environment and Health (ECEH), Bilthoven Division. The adverse health outcomes used in the study consist of mortality (all causes excluding accidental causes), due to cardiovascular (CVD) and respiratory (RES) diseases, and morbidity (hospital admissions for CVD and RES causes). For this purpose, hourly PM10 data were taken from the monitoring stations in eight study cities during 2011 and 2012. Results showed annual average concentrations of PM10 and PM2.5 in all megacities exceeded national and international air quality standards and even reached levels nearly ten times higher than WHO guidelines in some cities. Considering the short-term effects, PM2.5 had the maximum effects on the health of the 19,048,000 residents of the eight Iranian cities, causing total mortality of 5,670 out of 87,907 during a one-year time-period. Hence, reducing concentrations and controlling air pollution, particularly the presence of particles, is urgent in these metropolises.
Background: Nitrate is an acute and well-known hazardous contaminant, and its contamination of water sources has been a growing concern worldwide in recent years. This study evaluated the feasibility of nitrate removal from water using the traditional coagulants alum and ferric chloride with lower concentrations than those used in the conventional coagulation process. Methods: In this research, two coagulants, alum and ferric chloride, were compared for their efficiency in removing nitrate in a conventional water treatment system. The removal process was done in a batch system (jar test) to examine the effects of coagulant dosages and determine the conditions required to achieve optimum results. Results: The results revealed that ferric chloride at an initial dose rate of 4 mg/L reduced nitrate concentration from 70 mg/L to less than the World Health Organization (WHO) guideline value (50 mg/L N-NO 3). However, the removal efficiency of alum was not salient to significant nitrate reduction. Conclusion: In conclusion, ferric chloride was more effective than alumin removing NO-3 , even in common dosage range, and can be considered a cost-effective and worthy treatment option to remediate nitratepolluted water. Furthermore, the removal of nitrate by coagulation can be simple and more economical than other treatment alternatives.
Background: Air pollution is an important issue and public concern throughout the world. Sulfur dioxide is one of the pollutants that can lead to many adverse effects on human health, animal and plant life.
A B S T R A C TWater quality entering the drinking water distribution network often provides requirements for corrosion and scaling in rural areas due to the lack of suitable treatment methods. It leads to pipe clogging, reducing longevity of the equipment, and health problems caused by dissolved compounds in the water. The present study aims to evaluate the corrosion and scaling potential in water distribution networks of four villages located in different geographical locations of Urmia, Iran. In this descriptive cross-sectional study, 36 samples of water entering the villages of Dizaj-e Siavosh, Dolama, Gogtapeh, and Band distribution networks were analyzed according to standard methods for water and wastewater examinations. The corrosion and scaling potential were evaluated based on Ryznar stability (RSI), Langelier saturation (LSI), Puckorius scaling (PSI), and Larson-Skold (LRI) indices after determination of pH, total dissolved solids, sulfate, alkalinity, calcium hardness, and chloride. The results indicated that the values of LSI, RSI, PSI, and LRI indices were −1.94, 12.05, 12.20, and 0.68 for Gogtapeh water supply; −2.22, 12.72, 13.6, and 0.4 for Dizaj-e Siavosh water supply; −2.03, 12.1, 12.06, and 0.3 for Band water supply; and finally −2.09, 12.30, 12.59, and 0.29 for Dolama water supply, respectivly. Therefore, the water entering Gogtapeh distribution system has a tendency to scaling based on the LRI as an only appropriate index for the corrosion and scaling potential in this village. However, the water entering Dizaj-e Siavosh, Dolama, and Band distribution networks are highly corrosive based on the LSI, RSI, and PSI indices. The concordance between the analysis of chemical water quality and national standards could not be sufficient to confirm the water quality balance in terms of corrosion and scaling potential.
Linear alkyl benzene sulfonate (LAS), which is the most common used anionic surfactant in detergents manufacturing, can discharge onto water resources through wastewater and causes change in taste and odor, disruption in water treatment processes, aquatics death, and oxygen transfer limitation. Accordingly, this article investigates to optimize LAS removal using Fenton oxidation process in Taguchi Method for the first time. LAS removal using Fenton oxidation was perused experimentally in a lab-scale reactor. In order to save relevant costs, 25 runs were qualified to specify the optimum conditions of Fenton oxidation using Taguchi method by Minitab 16 software. Sampling and testing procedures were executed based on the standard methods for the examination of water and wastewater. The optimum conditions included 900 mg/L hydrogen peroxide, 170 mg/L ferrous ion, pH of 4 and the reaction time of 20 min. Fenton oxidation, as a second order reaction with the rate coefficient of 0.0152 L/mg ⋅ min, provided 86.5% efficiency for LAS removal in the optimum conditions. Despite Fenton oxidation appeared as a high efficiency process in LAS removal, low removal efficiency of chemical oxygen demand corresponding with LAS affirmed its partial degradation.
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