Comprehensive dataset on fluoride removal from aqueous solution by enhanced electrocoagulation process by persulfate salts.

Depending on the quantity and concentration, drinking water containing fluoride (F-) ions can have either favorable or unfavorable impacts on individuals and the environment. High levels of F- (over 2 to 4 mg/L) can cause skeletal problems, dental fluorosis, and brain damage in children. Conventional F- removal is often complex and thus causes an adverse effect on the environment and financial burdens. The use of persulfate salts to enhance the electrocoagulation process is one of the most recent advances in the removal of F- from water. To investigate the efficacy of F- removal, a laboratory-scale electrochemical batch reactor with iron and aluminum electrodes was employed with various persulfate doses, pH values, current intensities, and supporting electrolyte concentrations. It was observed that the performance of the enhanced electrocoagulation process by persulfate increased over time, and it worked well in a certain range of pH. Also, for the initial F- concentration of 10 mg/L, increasing the supporting electrolyte concentration to 1.5 g/L improved fluoride removal efficiency from 80 to 91.2%, but higher concentrations (2.5 g/L) reduced efficiency to 71%. The most effective removal of F- was found to occur at a persulfate dose of 0.2 mg/L. At this dose, F- removal efficiency exceeded 92% for all studied F- concentrations. Overall, electrocoagulation using persulfate salts proved more efficient than electrocoagulation alone at removing fluoride from water sources.

Dataset of fluoride concentration and health risk assessment in drinking water in the Saveh City of Markazi Province, Iran.

This study aims at analyzing fluoride levels in water sources and drinking water in Saveh City, with a focus on health risks assessment. Excessive fluoride concentrations (above 2 to 4 mg/L) can lead to skeletal issues, dental fluorosis, and brain damage, while low concentrations (below 0.7-1.5 mg/L depending on temperature) can harm tooth health and strength. For drinking water consumptions, centralized and decentralized desalination units were utilized from, Saveh's brackish water. In this research study a total of 63 samples were collected randomly from underground and surface water sources, distribution networks, and desalination units during both Winter and Summer seasons. Fluoride analysis was conducted using the spectrophotometric method with the DR6000 device and SPADNS reagent. The results indicated that during winter, average fluoride concentrations in underground water, water treatment plant output, distribution network, centralized desalination unit output, and decentralized desalination unit output were 0.67, 0.64, 0.62, 0.064, and 0.07 mg/L, respectively. In summer, the average concentrations were 0.79, 0.75, 0.71, 0.04, and 0.07 mg/L, respectively. For desalinated water produced by centralized desalination units during the summer season, the Estimated Daily Intake (EDI) values for fluoride in different age groups, including infants, children, teenagers, and adults, were found to be 0.0003, 0.0023, 0.0016, and 0.0013 mg/kg, respectively. Health risk assessment data indicated Hazard Quotient (HQ) values for fluoride in these age groups were 0.005, 0.037, 0.026, and 0.02, respectively. Similar values were observed in the winter data. However, it is important to note that the fluoride concentration in Saveh's drinking water is nearly zero, and the absence of fluoride in desalinated drinking water can have a negative impact on dental health. Therefore, it is crucial to address the lack of fluoride in the drinking water of this city.

Short-term effects of exposure to air pollution on biophysical parameters of skin in a panel of healthy adults.

Little research on impact of air pollution on human skin is available. We aimed to clarify the association between acute exposure to criteria air pollutant with biophysical characteristics of the skin. We followed a panel of 20 volunteers free of any skin diseases in skin evaluation study in Tehran, Iran from April 2017 to April 2018. Two distinct body parts including middle forehead and inside the right upper arm were evaluated at six time periods. The associations of the weighted averages of personal exposure to air pollutants at 24 hours up to 6 days, and multiday average before the skin assessment with biophysical characteristics of normal skin including sebum content, hydration, transepidermal water loss (TEWL), erythema index, melanin index, pH, temperature, friction, and elasticity were assessed in a random intercept linear mixed effects modeling approach. We observed significant positive association for the arm sebum content with exposure to PM2.5 , and SO2 ; the arm and forehead TEWL with NO2 , the arm and forehead friction with O3 , and forehead hydration with PM2.5 and PM10 in early lags. We found significant negative association for the arm melanin index, elasticity, and erythema index with exposure to O3 ; and forehead elasticity with PM2.5 and PM10 . Our results provided some evidence that short-term exposure to particulate and gaseous air pollutants have detrimental effects on biophysical and biomechanical properties of skin. The association varied across body area and depended on pollutant type.

National and sub-national exposure to ambient fine particulate matter (PM2.5) and its attributable burden of disease in Iran from 1990 to 2016.

Ambient particulate matter is a public health concern. We aimed (1) to estimate national and provincial long-term exposure of Iranians to ambient particulate matter (PM) < 2.5 µm (PM2.5) from 1990 to 2016, and (2) to estimate the national and provincial burden of disease attributable to PM2.5 in Iran. We used all available ground measurements of PM < 10 µm (PM10) (used to estimate PM2.5) from 91 monitoring stations. We estimated the annual mean exposure to PM2.5 for all Iranian population from 1990 to 2016 through a multi-stage modeling process. By applying comparative risk assessment methodology and using life table for years of life lost (YLL), we estimated the mortality and YLL attributable to PM2.5 for five outcomes. The predicted provincial annual mean PM2.5 concentrations range was between 21.7 µg/m3 (UI: 19.03-24.9) and 35.4 µg/m3 (UI: 31.4-39.4) from 1990 to 2016. We estimated in 2016, about 41,000 deaths (95% uncertainty interval [UI] 35634, 47014) and about 3,000,000 YLL (95% UI: 2632101, 3389342) attributable to the long-term exposure to PM2.5 in Iran. Ischemic heart disease was the leading cause of mortality by 31,363 deaths (95% UI: 27520, 35258), followed by stroke (7012 (5999, 8062) deaths), lower respiratory infection (1210 (912, 1519) deaths), chronic obstructive pulmonary disease (1019 (715, 1328) deaths), and lung cancer (668 (489, 848) deaths). In 2016, about 43% of all PM2.5 related mortality in Iran was, respectively, in the following provinces: Tehran (12.6%), Isfahan (9.3%), Khorasan Razavi (8.0%), Fars (6.5%), and Khozestan (6.4%). In summary, we found that the majority of Iranians were exposed to the levels of ambient particulate matter exceeding the WHO guidelines from 1990 to 2016. Further, we found that there was an increasing trend of total mortality attributed to PM2.5 in Iran from 1990 to 2016 where the slope was higher in western provinces.

Biohydrogen production from alkaline wastewater: The stoichiometric reactions, modeling, and electron equivalent.

Hydrogen gas (H2) is the cleanest energy carrier with 142 kJ/g energy content and without toxic byproducts release during combustion. There is interest to H2 production by biological process from sustainable resources including municipal and industrial wastewater and also solid waste. Here, we describe the biohydrogen production that involves first survey the effect of alkalinity on biohydrogen production based on stoichiometric reaction, followed by the electron equivalent balances determination and examination of prediction capability of Gamperts model for biohydrogen production. •The method uses a dark fermentation biological process for H2 production from wastewater.•As the influent alkalinity increased, the hydrogen production increased and then promptly descended.•The predicted gas volume, based on Gamperts model confirmed good agreement with experimental value.

Formation of disinfection by-products and fungal contamination data in public swimming pools: A case study in Gonabad, Iran.

Existence of fungi and disinfection by-products (DBPs) in public swimming pools water are dangerous since it can seriously affect on health of swimmers. This data study aimed to determine the fungi contamination and DBPs concentration including trihalomethanes (THMs), haloacetic acids (HAAs), halamines and cyanogen halides and haloacetonitriles (HANs) of swimming pools (chlorine based) in Gonabad County, Iran. So, the fungal load and DBPs concentration were investigated in two swimming pools in the middle of spring of 2017 by collecting a number of 9 water samples and 9 samples of lateral facilities of each pool by membrane filtration technique and sterile carpet. The DBPs concentrations were measured by gas chromatograph technique. The results showed that the pools were contaminated with Dermatophyte (trichophyton mentagrophytes and epidermophyton flucosomes), yeasts, and more with opportunistic saprophytic fungi. 24.8%, 22.7%, 16.9%, and 11.4% saprophytic fungi were separated from pool side, locker room, pool water, and shower positions, respectively. 7.4% and 3.2% of yeast fungi as well as 0.23% and 0.2% of dentofacies of causative agents of tinea were separated from the pools water and showers as well as locker room and shower positions, respectively. According to the data, halamines and cyanogen halides had the highest concentrations, followed by HAAs, THMs and HANs respectively. Among the halamines and cyanogen halides, HAAs, THMs and HANs, trichloramine acid was the most dominant species, followed by trichloroacetic acid and dichloramine, respectively.

Fluoride concentration data in groundwater resources of Gonabad, Iran.

The data was obtained from fluoride ion concentrations determined in groundwater sources of Gonabad. A number of 144 samples from 12 drinking groundwater wells located in different regions at the mid of spring, summer, autumn and winter from each regions, were collected from spring 2016 to spring of 2017. The fluoride ions in the samples were determined through the SPADNS colorimetric method at a wavelength of 580 nm. Dispersion of fluoride ions in terms of concentration in groundwater resources of Gonabad was planned using geographic information system (GIS) base on inverse distance weighted (IDW) method. The data showed that lowest and highest concentration of fluoride ions were determined 0.46 in winter and 1.56 mg/l in summer season, respectively. The average, max and min amount of fluoride concentration in groundwater resources of Gonabad were 0.67 ± 0.03, 1.56 and 0.46 mg/L, respectively. The average chemical parameters concentration of Potassium, Sodium, Magnesium, Calcium, Phosphate, Nitrate, Bicarbonate, Sulfate and Chloride were 6.61 ± 1.2, 281.17 ± 3.08, 26.75 ± 2.55, 68.14 ± 3.89, 0.2 ± 0.04, 10 ± 1.83, 275.02 ± 7.20, 282.08 ± 5.04 and 235 ± 5.83 mg/L, respectively.

Experimental data for aluminum removal from aqueous solution by raw and iron-modified granular activated carbon.

This dataset deals with the modification of granular activated carbon (GAC) with FeCl3 under basic conditions (pH ≈ 12) for removal of aluminium (Al) from aqueous solution. The structural properties and operational parameters including Al ion concentration (2.15 and 10.3 mg/L), pH solution (2-10), adsorbent dosage (0.1-5 g/L), and contact time (0-10 h) was investigated for raw and modified GAC. This dataset provides information about Al removal by GAC and modified GAC at conditions including: pH = 8, contact time = 6 h, initial Al concentration = 2.15 mg/L. The characterization data of the adsorbents was analysed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) test. The data showed that Freundlich isotherm with and Pseudo second order kinetic model were the best models for describing the Al adsorption reactions. The acquired data indicated that the maximum adsorption capacity of GAC and modified GAC to uptake Al (C0 = 10.3 mg/L) was 3 and 4.37 mg/g respectively.

Dataset on the cost estimation for spent filter backwash water (SFBW) treatment.

The dataset presented in this article are related to the research article entitled "Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl3 as a pre-treatment" (Ebrahimi et al., 2017) [1]. This article reports the cost estimation for treating produced spent filter backwash water (SFBW) during water treatment in Isfahan- Iran by various methods including primary sedimentation, coagulation & flocculation, second clarification, ultra filtration (UF) and recirculation of settled SFBW to water treatment plant (WTP) entrance. Coagulation conducted by PAFCl and FeCl3 as pre polymerized and traditional coagulants. Cost estimation showed that contrary to expectations, the recirculation of settled SFBW to WTP entrance is more expensive than other method and it costs about $ 37,814,817.6. Versus the cheapest option related to separate primary sedimentation, coagulation & flocculation in WTP. This option cost about $ 4,757,200 and $ 950,213 when FeCl3 and PAFCl used as coagulant, respectively.

Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration.

During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl3) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).

Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl3 as a pre-treatment.

In this study, the reclamation of clean water from spent filter backwash water (SFBW) was investigated through pilot-scale experiments. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF). Two coagulants of PAFCl and FeCl3 were investigated with respect to their performance on treated SFBW quality and UF membrane fouling. At the optimum dose of PAFCl and FeCl3 turbidity removal of 99.6 and 99.4% was attained, respectively. PAFCl resulted in an optimum UV254, TOC, and DOC removal of 80, 83.6, and 72.7%, respectively, and FeCl3 caused the removal of those parameters by 76.7, 80.9, and 65.9%, respectively. PAFCl removed hydrophilic and transphilic constituent better than FeCl3, but FeCl3 had, to some extent, higher affinities to a hydrophobic fraction. It was concluded that PAFCl showed a better coagulation performance in most cases and caused a lower membrane fouling rate compared to FeCl3. Finally, the treated SFBW with both coagulant-UF systems met the drinking water standards.

Trends in health burden of untreated water and insanitary environments in Iran, 1990-2010: Findings from the global burden of disease study 2010.

Background: Water, sanitation and hygiene have a very important role in public health. Poor sanitation is the cause of water contamination, which causes many types of diseases. The aim of this paper was to present the attributable death and disability adjusted life year (DALYs) of untreated water and insanitary environments from 1990 to 2010 in Iran. Methods: In the Global Burden of Disease 2010 study, using the comparative risk assessment, the proportion of death and DALYs attributable to untreated water source and insanitary environment has been calculated in 1990 to 2010. The certain outcomes were intestinal infectious diseases for both untreated water source and insanitary environments. Estimated attributable deaths and DALYs were reported with 95% uncertainty interval (UI). Results: DALY number for untreated water source and insanitary environments was 5838 (95% UI: 198- 14837) in 1990, which decreased to 326 (95% UI: 9-863) in 2010 and the percent of decrease was 94.42%. In addition, DALY rate was 5667 (95% UI: 192-14402) DALY per 100,000 in 1990, which decreased to 453 (95% UI: 13-1199) DALY per 100,000 in 2010 and the percent of the reduction was 92.01%. The greatest percentage of decrease in the attributed number of deaths was also found in the late neonatal age group (95.45%). Conclusion: A significant decrease has occurred in a number of DALYs and deaths between 1990 and 2010, which was attributed to the development of new water systems and environmental sanitations in Iran.