Comparison the efficiency of Fenton and Photo–fenton processes for the removal of Reactive red 198 Dye from the aqueous solution

The textile industry produces a large amount of polluted effluents discharged into the environment. Therefore, this research was carried out to compare the efficiency of removal of Reactive red 198 (RR–198) dye by fenton and photo–fenton processes and determine the optimal conditions for maximum removal. This study was conducted on a laboratory scale. The effect of influential parameters, including pH (3–9), Fe(II) concentration (10–200mg/L), H2O2 concentration (25–150mg/L), dye concentration (50–200mg/L) and reaction time (15–90min.) on dye removal was investigated and the optimal conditions were determined according to the maximum dye removal efficiency. The results indicated that the dye removal rate increased as the pH and Fe(II) concentration decreased. The optimal conditions for RR–198 removals from the aqueous solution are pH of 3, Fe (II) concentration of 10mg/L, H2O2 concentration of 50mg/L, the initial dye concentration of 50mg/L, and the reaction time of 15min.. The maximum dye removal efficiency under optimal conditions was 98.82%. The results of this study revealed that the photo–fenton process was superior to the removal of dye compared to fenton process

Investigating the relationship between the long-term exposure to air pollution and the frequency of depression in Shiraz during 2010-2017

Background: Exposure to environmental pollutants which have entered the atmosphere due to human and industrial activities results in harmful and unwanted effects on human health. The undesired effects of air pollution on mental disorders, mortality, and psychological disorders have been proven. Depression is a common mental health problem in today’s societies which impacts the quality of life. The objective of this study was to determine the relation between exposure to air pollution and frequency of depression in Shiraz (Southern Iran). Methods: Archived documents of 2658 patients diagnosed with major depressive disorder (MDD) from a psychiatric university hospital were reviewed. The concentrations of five air pollutants including CO, NOX, O3, PM10, and NO2 were determined daily in two air quality monitory stations in downtown Shiraz (Imam Hossein Square) and Kazeroon Gate. The data relevant to these five pollutants were gathered every day for 83 months, from 2010 to 2017, and for more precision, the mean values were used. The relationship between the concentration of each pollutant in the air and the number of patients referring to hospital was determined using the Spearman’s correlation coefficient. Results: There was a direct and significant relationship between all pollutants and the number of hospital admissions in each month (P < 0.05) except for CO which did not show a significant relationship with hospital admission due to depression (P > 0.05). Conclusion: The results of this study indicated a positive relationship between air pollution and depression. Of course, to prove this relationship, it is essential to conduct a number of studies with appropriate methodology and design. Keywords: Air pollutant, Environmental exposure, Inhalation exposure, Mental disorders, Depressio

Optimization of the Parameters Affecting the Fenton Process for Decolorization of Reactive Red 198 (RR-198) from the Aqueous Phase

Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Reactive dyes are widely used in textile industry. Advanced oxidation processes are one of the cost-effective methods for the removal of these dyes. The main aims of this study were determining the feasibility of using Fenton process in removing Reactive Red 198 (RR-198) dye from aqueous solution and determining the optimal conditions. Methods: This is a cross-sectional study conducted at a laboratory scale. A total of 69 samples were considered and the effect of pH, Fe (II) concentration, H2O2 concentration, initial dye concentration and reaction time were investigated. Results: According to the results, a maximum removal efficiency of 92% was obtained at pH of 3 and the reaction time of 90 min; also, the concentration of Fe (II), H2O2, initial dye concentration were 100 mg/L, 50 mg/L, and 100 mg/L, respectively. The results revealed that by increasing the concentration of Fe (II), H2O2 and initial dye, the removal efficiency was increased. Conclusions: The results showed that Fenton process could be used as a cost-effective method for removing RR-198 dye from textile wastewater efficiently

Comprehensive health risk analysis of heavy metal pollution using water quality indices and Monte Carlo simulation in R software

Abstract Rapid urbanization, population growth, agricultural practices, and industrial activities have led to widespread groundwater contamination. This study evaluated heavy metal contamination in residential drinking water in Shiraz, Iran (2021). The analysis involved 80 groundwater samples collected across wet and dry seasons. Water quality was comprehensively assessed using several indices, including the heavy metals evaluation index (HEI), heavy metal pollution index (HPI), contamination degree (CD), and metal index (MI). Carcinogenic and non-carcinogenic risk assessments were conducted using deterministic and probabilistic approaches for exposed populations. In the non-carcinogenic risk assessment, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index (HI) are employed. The precision of risk assessment was bolstered through the utilization of Monte Carlo simulation, executed using the R software platform. Based on the results, in both wet and dry seasons, Zinc (Zn) consistently demonstrates the highest mean concentration, followed by Manganese (Mn) and Chromium (Cr). During the wet and dry seasons, 25% and 40% of the regions exhibited high CD, respectively. According to non-carcinogenic risk assessment, Cr presents the highest CDI and HQ in children and adults, followed by Mn, As and HI values, indicating elevated risk for children. The highest carcinogenic risk was for Cr in adults, while the lowest was for Cd in children. The sensitivity analysis found that heavy metal concentration and ingestion rate significantly impact both carcinogenic and non-carcinogenic risks. These findings provide critical insights for shaping policy and allocating resources towards effectively managing heavy metal contamination in residential drinking water