Introduction: High concentration of inhalable airborne particles can increase the risk of lung disease in exposed people. This study aimed to determine the respirable particulate matter (PM₅) concentration in traditional bakeries of Saveh in 2020.
Materials and Methods: This cross-sectional descriptive study was conducted among 25 bakeries where the samples were collected by cyclone and teflon filter equipped by air sampling pump. Later, the respirable particulate matter concentration was measured using gravimetric method. The collected PM₅ was scanned using a FTIR (Fourier-transform infrared spectroscopy) with regard to flour dust. In addition, size and shape of the collected PM₅ were analyzed using a scanning electron microscope (SEM).
Results: Findings showed that the Lavash bakery had the highest PM₅ concentration (9.15 mg/m³) in comparison with two other bakeries (Sangak and Barbari). However, an inverse relationship was observed between RH and particle concentration. In addition, the results demonstrated that increasing RH decreased the particle concentration, but the relationship was not significant
(P = 0.052, Spearman's rho = -0.393). Furthermore, Lavash bakery had the lowest average size of PM₅ (0.63 ± 0.32 μm). However, the FTIR scans confirmed that the flour dust had the predominant amount of PM_5.
Conclusion: Based on the findings, the density of respirable PM₅ has a high level in Saveh bakeries and workers  are exposed to high levels of PM.

Introduction: Endocrine disruptive compounds as a class of organic contaminants in the aquatic environment received severe attention in the last decades. The release of bisphenol A (BPA) as a hazardous organic chemical into the environment has caused high health and environmental concerns. Therefore, its removal from aquatic environments is strongly recommended. The present study deals with BPA removal efficiency from an aqueous environment using the electrocoagulation process (ECP).
Materials and Methods: The effects of parameters including BPA concentration (1-10 mg L^-1), current density (3-15 mA cm^-2), pH (4-10), and reaction time (5-30 min) on the treatment process were investigated. Response surface methodology (RSM) was employed for optimization of the ECP. The significance of the developed model was investigated by the obtained F-value and P-value.
Results: The maximum BPA removal of 98.2% was attained at pH of 8.5, BPA concentration of 3.25 mg L^-1, the current density of 12.0 mA cm^-2, and reaction time of 23 min. The significance of the developed model was confirmed by the high F-value of 46.69 and the very low P-value of < 0.0001. Furthermore, the electrical energy consumption of the process was found to be 0.308 kWh m^-3 in the optimum condition.
Conclusion: The obtained experimental results revealed that the co-precipitation and the adsorption process through the electrostatic interactions as the main removal mechanisms controlled the treatment process.

Introduction: Since phthalate esters and their derivatives have the potential to disrupt proper endocrine function, these compounds are considered as one of the most important groups of endocrine-disrupting chemicals. The presence of these compounds in various aquatic environments has caused main concerns about human and animal health and causes problems in the environment.
Materials and Methods: The treatment process was carried out in a glass reactor containing 200 mL polluted water at room temperature. The Mg-Al layered double hydroxides (Mg-Al-LDH) were successfully synthesized and were applied as adsorbents for the removal of Diethyl Phthalate (DEP) from polluted water. The kinetics and isotherm of the process were investigated to determine the exact mechanism of DEP removal from the water medium.
Results: The Mg-Al-LDH was a surface area of 673 (m² g^-1), a total pore of 0.716 (cm³ g^-1), and microspore volumes of 0.627 (cm³ g^-1), and a pore diameter of 8.64 nm. The maximum DEP removal efficiency of 96.7% was obtained at the DEP concentration of 10 mg L^-1, Mg-Al-LDH dosage of 0.50 g L^-1, and the reaction time of 30 min. The second-order kinetic model well depicted the kinetics of DEP adsorption (R² = 0. 99). The Langmuir isotherm model best described the data by predicting the maximum adsorption capacity (q_m) of 95.6 mg g^-1 and R² of 0.99.
Conclusion: All the results demonstrate that the Mg-Al-LDH is an efficient, safe, and efficient adsorbent in water and wastewater treatment.

Introduction: The increasing trend of petroleum production in Iran and lack of proper and systematic management of waste products in the deposition of petroleum storage tanks have made the existing hydrocarbons as a major hazards to the environment. In this study, the ozonation process was used to remove the petroleum deposits.
Materials and Methods: In this experimental study, effects of pH, ozone dose, and petroleum hydrocarbons (PHCs) concentration were evaluated. In order to measure the PHCs, using the n-pentanes, the hydrocarbons were first extracted from the environment followed by detection using the GC-FID. The response surface methodology (RSM) was used to evaluate the effect of independent variables on response function.
Results: In this study, the efficiency was calculated 45.47% in the optimal conditions of removing PHCs with respect to the optimal energy consumption for the process. Analysis of variance and regression showed that the fitted model had good agreement with the laboratory results.
Conclusion: The results demonstrated that the advanced oxidation process (AOP) of ozone at high pH levels could be a useful method for the degradation and reduction of heavy hydrocarbons in petroleum waste. However, regarding the energy consumption, it is suggested to use less costly reactions as pretreatment or final treatment steps.

Introduction: Perchloroethylene (PCE) is one of the most well-known chlorinated organic compounds recently detected in aqueous environments. The presence of PCE in aquatic ecosystems has caused many health problems and environmental challenges. Therefore, its removal and treatment from aqueous environments are essential.
Materials and Methods: The electro-Fenton (EF) process was carried out in a cylindrical reactor containing 250 mL contaminated water with PCE. The effects of parameters, including solution pH (3-12), current density (2-10 mA cm^-2), H₂O₂ concentration (20-70 µL H₂O₂ per 250 mL sample.), PCE concentration (5-50 mg L^-1), and electrolysis time (1-15 min) on PCE degradation were investigated. The kinetics and radical’s scavenger of the EF process were examined to detect the exact mechanism of PCE degradation.
Results: The degradation of the PCE of 98.1% was obtained in the optimum condition, including solution pH of 5, the current density of 8 mA cm^-2, H₂O₂ concentration of 50 µL per 250 mL sample, PCE concentration of 15 mg L^-1, and electrolysis time of 10 min. The kinetics studies of the EF process indicated that the obtained results were in satisfactory agreement with the first-order model (R² = 0.9858, K_app = 0.2822). Also, the addition of ethanol and tertiary butanol caused an inhibiting effect.
Conclusion: The EF process was effectively applied to degrade PCE from polluted water as an efficient technique.  The obtained results indicated that the generation of ^•OH throughout the EF process was the key mechanism that controlled the EF process.