Efficiency of wastewater treatment plants in removal of intestinal parasites: A review approach

of the spread and entry of parasitic pathogens into the environment and water resources. Numerous studies have been conducted on the presence of parasitic agents in the entry and effluent of WWTPs in different countries. This study was conducted to review the parasite prevalence in different WWTPs and assess their removal efficiency. Methods: ScienceDirect, Scopus, Web of Science, and PubMed databases and other sites with the ability to receive a full-text related articles, were reviewed. Various keywords such as parasites, wastewater, effluent, treatment efficiency, protozoan cysts, parasitic eggs, and similar keywords were used to search articles published from 2005 to 2019. After screening the titles and abstracts of articles, 26 articles were reviewed in this study. Results: Giardia spp, Cryptosporidium spp, Entamoeba spp, Blastocystis spp, Toxocara spp, Trichostrongylus spp, A. lumbricoides, and Hymenolepis are the most prevalent parasites. Studies show that parasitic egg hatching rates are up to 5%, in aerated lagoons, up to 99.9%, in activated sludge, and up to 5%, in ponds due to high retention time and downstream artificial reefs. Conclusion: Studies show that due to the current state of treatment plants and adverse operating and maintenance conditions, it is not possible to completely remove parasitic pathogens from these systems, therefore, it should be considered by regulatory authorities and the systems need to be improved for better performance of treatment plants and optimizing them, and training of users should also be improved. This review indicated that the types of natural constructed wetland in Kermanshah (Iran) and activated sludge of wastewater treatment processes in Iran and Brazil are most effective in removal of intestinal parasites. Keywords: Waste water, Treatment, Parasites, Efficienc

Evaluation of exposure to phthalate esters through the use of various brands of drinking water bottled in polyethylene terephthalate (PET) containers under different storage conditions

Background: There are many concerns about the migration of phthalates into bottled water. These compounds are hazardous to consumers. In this study, the risk factors of the use of various brands of drinking water bottled in polyethylene terephthalate (PET) containers under different storage conditions were examined. Methods: Phthalate esters were measured and analyzed using air-assisted liquid-liquid microextraction (AALLME) and gas chromatography-mass spectrometry (GC-MS). Subsequently, the risk of exposure to the desired compounds was evaluated by calculating the risk factor and excess cancer risk. Data were statistically analyzed using SPSS version 24 software. Results: The average concentration of phthalate esters (DEHP, DBP, DIBP, DEP, and DMP) after 5 and 15 days of storage at incubator temperature of 42°C, and after 15, 45, and 75 days at incubator temperature of 25°C by increasing the initial level of the conditions was 7.28, 8.99, 1.78, 5.6, 6.45, and 8.55 ppb, respectively. The risk factor of non-carcinogenic effects of phthalates for consumers was low and can be ignored (HQ<1). Also, the risk of additional cancer due to the presence of diethylhexyl phthalate (DEHP) in bottled water is very low (4.8551×10-6). Conclusion: However, due to the increase in the concentration of phthalate esters in bottled water by increasing the storage time and temperature, as well as increasing the ethylene hexyl phthalate content from its established limit, the use of bottled water kept in unsuitable conditions for the society, and especially the sensitive groups, is not appropriate. Keywords: Phthalate esters, Bottled water, Storage conditions, Risk assessment, Various brand

Application of Taguchi’s experimental design method for optimization of Acid Red 18 removal by electrochemical oxidation process

Background: Electro-oxidation is developed as an electrochemical method to overcome the problems of the conventional decolorization technologies and is an appropriate alternative for the treatment of colored wastewater from various industries. The purpose of this study was to evaluate the efficiency of the electrochemical oxidation process in removal of chemical oxygen demand (COD) and Acid Red 18 (AR18) dye from aqueous solutions. Methods: In this research, a laboratory scale of electro-coagulation reactor for the treatment of synthetic wastewater was made and studied. The effects of different variables including pH, current density, dye concentration, and electrolysis time were investigated. The experiment steps were designed by Design- Expert 10 software using the selected variables. Finally, the dye and COD analysis was performed by spectrophotometer. The optimization was performed using Taguchi fractional factorial design during the removal of dye and COD. Results: Maximum removal of dye (89%) and COD (72.2%) were obtained at pH=3, current density=20 mA/cm2, initial dye concentration=100 mg/L, and reaction time=45 min. ANOVA test showed a significant relationship between statistical model and test data. Also, the results indicate that the distribution of the residues of the model was normal. Conclusion: By designing experiments through Taguchi method, the removal process will be optimized and by decreasing the number of experiments, the optimal conditions for pollutant removal will be prepared. The results suggest that the Electro-oxidation system is a very suitable technique for the enhancement of wastewater treatment. Keywords: Electrolysis, Wastewater, Azo compounds, Models, Statistical, Analysis of varianc

Evaluation of the presence of coliform in bottled drinking water, released in Sari in 2016

Background: Today, bottled water is used in many countries of the world due to its relatively low cost, better taste, ease of access and low levels of impurities. In unfavorable conditions, the maintenance of microorganisms due to hydrophobicity and adherence to bottles and as a result of increased lipolytic activity can lead to undesirable changes in color, taste and odor, and in cases of more severe load, microbial contamination may cause unhealthy water and flooding. In this study, the presence or absence of coliform in a number of bottled water brands was examined. Methods: The microbial quality of 10 markers of bottled water present in the market of Sari that was randomly selected from each mark and three samples was examined. The samples were analyzed using the coliform - presence/absence (P-A) test. The results were compared with national standards and the World Health Organization (WHO) guidelines. Data were analyzed using SPSS version 24 and EXCEL. Results: Samples showed no microbial contamination Also, coliform and fecal coliforms were not observed in any of the samples. Finally, it was revealed that all cases were in accordance with national standards and WHO guidelines. Conclusion: Increasing the health indexes of places, food supply and distribution centers, and maintaining health conditions and measures that have been considered especially in the recent years on the health of bottled water, have greatly reduced the problems. Keywords: Taste, Drinking water, Bacteria, World Health Organization, Bottled wate

Bioremediation of methyl tertiary-butyl ether (MTBE) by three pure bacterial cultures

Background: Bioremediation of groundwater and soil contamination is more economical than physicochemical remediation. The present study focused on the bioremediation capability of two bacterial species (Klebsiella planticola and Enterobacter cloacae) from the family Enterobacteriaceae. These bacteria have been identified as new species with capability of degrading methyl tertiary-butyl ether (MTBE). In order to enhance their degradation capability, selected concentrations and retention time were investigated. Methods: The bacteria were cultured on the nutrient agar (NA) medium at room temperature. pH of the medium was adjusted to 7. The medium was autoclaved at 121°C for 15 minutes and incubated for 24 hours at 35°C. After 24 hours, the mixture was inoculated into 50 mL of Luria Bertani (LB) liquid medium containing 50 and 150 ppm MTBE. The cultures were incubated for 2 and 5 days at 35°C and shacked on a shaker at 150 rpm. Cell concentrations of the bacteria in pure culture were determined from the optical density at 600 nm using a UV–VIS spectrophotometer. Then, the culture was centrifuged at 3800 rpm for 20 minutes. In the next step, the MTBE concentration in the supernatant was measured by gas chromatography/mass spectrometry (GC/MS, Agilent Technologies, 5975, US10304411, 5.02.07). Results: The results showed that both strains are able to grow in the presence of 50 and 150 ppm MTBE. In the best conditions, when cell density was 3×108 CFU/mL during 5 days, the highest rate of MTBE degradation for K. planticola and E. cloacae, was 43% and 40%, respectively. It was also revealed that Escherichia coli can degrade 50 and 150 ppm MTBE about 19.8% and 13.65%, respectively. Conclusion: It seems that E. coli can be a good candidate for MTBE degradation at high concentrations for a time longer than that in the present study. It was also found that the species have high performance at 50 ppm than 150 ppm. So, these bacteria can remove MTBE from the environment. Keywords: Biodegradation, Klebsiella planticola, Enterobacter cloacae, Escherichia coli, methyl tertiarybutyl ethe

Slaughterhouse wastewater treatment by combined anaerobic baffled reactor and anaerobic filter: study of OLR and HRT optimization in ABR/AF reactors

Background: Slaughterhouse wastewater (SWW) is hardly treated due to the large amount of organic matter, nutrients and suspended solids. These materials are naturally decomposed through biological processes, and then environmental pollution, transmission of pathogens and problems become smelled. Conventional purification methods require high investment costs, high energy consumption and expert workforce. Therefore, the efficient and sufficient treatment of SWW with low cost, efficient construction and operation is important. Methods: A combined anaerobic system consisting of three pilot-scale anaerobic baffled reactors (ABRs) in the first stage and three anaerobic filters (AFs) were used to treat SWW. The ABR reactors arranged at three hydraulic retention times (HRTs) of 12, 18 and 24 hours and organic loading rates (OLRs) of 4, 7 and 10 kg/m3/d. The OLR applied for ABR reactors, was 0.5 to 1.55 kg COD/m3/d. Results: Evaluation of the ABR reactor indicated that this reactor at OLR of 7 and 10 kg COD/m3/d and HRT of 18 hours, had removal efficiency of 83.29% and 85.79%, respectively. AF reactor, at OLR of 0.981, 0.576 and 0.561 kg COD/m3/d and HRT of 36 hours, had removal efficiency of 79.39%, 74.09% and 63.14%, respectively. Conclusion: The optimum HRT and OLR were 24 hours and 7 kg COD/m3/d and 36 hours and 1 kg COD/m3/d in ABR and AF reactor, respectively. Keywords: Waste water, Slaughterhouse, Anaerobic treatmen

Calcium and Magnesium in Ilam Drinking Water Sources during 2009-2013 using Geographic Information System (GIS)

Physicochemical quality of water from the acceptability point of view is essential for consumers; protecting the health of consumers and maintenance of water supply systems. The aim of this study is to determine temporal and spatial variations of Calcium and Magnesium in Ilam drinking water sources using the GIS system. This cross-sectional study was conducted on 20 drinking water sources in Ilam city and the 5 years results by water and wastewater company archive GIS software version 3.9 were analyzed via SPSS version 16 as well as one-way variance analysis. Water and wastewater sampling and measurement were conducted in order to verify the data by researchers according to standard methods. Based on interpolation map, the maximum calcium and magnesium contents are related to western and central regions. ANOVA test showed that there no a significant difference between the mean calcium variable verification test in summer during 2009-2013 and at 95% level. (P=0.760>0.05). The one-way analysis of variance showed that there is a significant difference between the average magnesium variable in summer during 2013-2009 years and the verification test at 95% level. (P=0.01

Measurement of BTEX (benzene, toluene, ethylbenzene and xylene) concentration at gas stations

Background: Fuel stations are one of the major sources of air pollution with volatile organic compounds, especially the four main petrol compounds benzene, toluene, ethylbenzene, and xylene (BTEX). BTEX in gasoline enters the air of gas stations due to high evaporation of gasoline. Therefore, determining the concentration of these compounds in gas stations in crowded and busy cities is one of the important priorities of environmental health, which is doubly important in terms of its negative effects on health. Methods: In this descriptive cross-sectional study, a total of 39 samples were collected from 13 gas stations. Sampling was performed in autumn 2018 in three working shifts (morning, noon, and night). The method NIOSH-1501 (i.e., using charcoal sorbent tubes and SKC pump with a flow rate of 0.2 L/min) was used for sampling the BTEX compounds. The mean difference and correlation of BTEX compounds based on meteorological parameters and the number of nozzles in gas stations were assessed using one-way ANOVA and correlation tests. Results: The mean and standard deviation of benzene, toluene, ethylbenzene, and xylene concentrations in the air of fuel stations were 2.784 ± 1.461, 3.495 ± 1.390, 2.091 ± 0.811, and 1.140 ± 0.419 mg/m3, respectively. The relationship between BTEX compounds and meteorological parameters such as humidity and exposure time is very important. There is a strong correlation between the concentrations of BTEX compounds. The highest correlation was observed between benzene and toluene and the lowest one was observed between benzene and xylene. In this study, no significant relationship was observed between air temperature and concentration of BTEX compounds, but there was a relationship between relative humidity and the concentration of BTEX compounds. Conclusion: The average benzene concentration in the air at the fuel stations was about 5.5 times the standard limit. Authorities should improve fuel quality and reduce its evaporation through engineering measures to overcome the issue. Keywords: BTEX, Gas stations, Ira

Spatial, temporal, and demographic patterns in prevalence of chewing tobacco use in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Findings In 2019, 273 center dot 9 million (95% uncertainty interval 258 center dot 5 to 290 center dot 9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 center dot 72% (4 center dot 46 to 5 center dot 01). 228 center dot 2 million (213 center dot 6 to 244 center dot 7; 83 center dot 29% [82 center dot 15 to 84 center dot 42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global agestandardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 center dot 21% [-1 center dot 26 to -1 center dot 16]), similar progress was not observed for chewing tobacco (0 center dot 46% [0 center dot 13 to 0 center dot 79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 center dot 94% [-1 center dot 72 to -0 center dot 14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Summary Background Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. Methods We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. Findings In 2019, 273 & middot;9 million (95% uncertainty interval 258 & middot;5 to 290 & middot;9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 & middot;72% (4 & middot;46 to 5 & middot;01). 228 & middot;2 million (213 & middot;6 to 244 & middot;7; 83 & middot;29% [82 & middot;15 to 84 & middot;42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 & middot;21% [-1 & middot;26 to -1 & middot;16]), similar progress was not observed for chewing tobacco (0 & middot;46% [0 & middot;13 to 0 & middot;79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 & middot;94% [-1 & middot;72 to -0 & middot;14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Copyright (c) 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe