Bisphenol A (BPA) is an industrial chemical used primarily in the manufacture of polycarbonate plastics and epoxy resins. BPA is considered an endocrine-disrupting chemical (EDC) because it interferes with hormonal systems. Over the decades, several techniques have been proposed for BPA removal in wastewaters. This study discusses recent advancements and progress of effective techniques for BPA removal, including membrane, adsorption, advanced oxidation process (AOPs), and biodegradation. The mechanisms of BPA adsorption on modified adsorbents include pore-filling, hydrophobic interactions, hydrogen bonding, and electrostatic interactions. Among the various agricultural waste adsorbents, Argan nut shell-microporous carbon (ANS@H20–120) exhibited the highest efficiency in removing BPA. Furthermore, the performance of magnetic treatment for activated carbon (AC) regeneration is introduced. According to the present study, researchers should prioritize agricultural waste-based adsorbents such as ACs, highly microporous carbons, nanoparticles, and polymers for the removal of BPA. In particular, the combination of adsorption and AOPs (advanced oxidations) is regarded as an efficient method for BPA removal. A series of relevant studies should be conducted at laboratory, pilot, and industrial scales for optimizing the application of agricultural waste-based AC to reduce BPA or other refractory pollutants from an aqueous environment.
The realm of diazinon reduction from polluted water has witnessed a surge in the significance of advanced oxidation processes (AOPs) in recent times. However, there is a dearth of research focusing on the mitigation of its toxicity through AOPs. Thus, the primary objective of this study was to evaluate the effectiveness of the Electro-Fenton process (EFP) in the eradication and detoxification of diazinon in aqueous solutions. Synthetic wastewater samples with concentrations of 2, 2.5 and 3 mg/L were prepared. A total of 27 samples were determined using Box Behnken Design. Reaction time, pH and iron to hydrogen peroxide ratio (Fe2+/H2O2) were examined as operational parameters under a constant current of 5.4 amps. The quantification of diazinon concentration was performed using High-Performance Liquid Chromatography (HPLC). To evaluate the detoxification of diazinon, the Daphnia magna bioassay was employed as a methodology in this study. According to the results, the EFP could reduce the diazinon to zero and the LC50 values are increased by applying the process. The LC50 values for diazinon were determined using the Daphnia magna bioassay, considering initial concentrations of 2, 2.5, and 3 mg/L at a pH of 5, a reaction time of 15 min, and an iron to hydrogen peroxide molar ratio of 2. The recorded LC50 values were 3.039, 3.076, and 3.106, respectively, indicating the lowest frequency of cumulative death in Daphnia magna. In this case, after 96 h, only 3 cases (30%) of Daphnia magna death were observed. However, for all the mentioned concentrations of diazinon, after 96 h of exposure to samples without applying the Daphnia Magna death process, it was observed between 60 and 100%. Reducing the diazinon concentration and increasing the 96-h LC50 showed that the EFP can reduce the toxicity of diazinon on Daphnia Magna at the same time. Therefore, EFP can be considered a superior method with low ecotoxicity.
Objectives: Iran's Waste Management Law currently faces three key challenges: outdated definitions, ineffective governance structures, and excessive dependence on punitive approaches. The legislation does not adequately regulate emerging waste categories, including electronic and medical waste, nor does it incorporate modern technological solutions. These shortcomings negatively impact environmental protection, public health outcomes, and economic efficiency. Furthermore, the law fails to align with international waste management standards. Methods: To examine the law in detail, a content analysis method was used in three phases: (1) Coding (2) Thematic categorization, and (3) Gap analysis. A two-round Delphi method was utilized, engaging 15 experts (environmental health, lawyers, policy specialists, and waste management). Results: Proposed reforms should focus on four key areas: (1) establishing precise waste classifications, (2) enhancing interagency coordination mechanisms, (3) implementing incentive-based regulatory approaches, and (4) adopting advanced monitoring technologies. Such measures would create a progressive regulatory framework capable of addressing Iran's pressing environmental concerns while fulfilling its international commitments. Modernizing Iran's Waste Management Law represents an essential step in effectively managing current environmental challenges. Conclusion: Proposed reforms include refining waste classifications, improving inter-agency coordination, embedding incentive mechanisms, and adopting advanced technologies.
The COVID-19 pandemic has inflicted major economic and health burdens across the world. On the other hand, the potential airborne transmission of SARS-COV-2 via air can deeply undermine the effectiveness of countermeasures against spreading the disease. Therefore, there is an intense focus to look for ways to mitigate the COVID-19 spread within various indoor settings. This work systematically reviewed articles regarding airborne transmission of SARS-COV2 in various indoor settings since the onset of the pandemic. The systematic search was performed in Scopus, Web of Science, and PubMed databases and has returned 19 original articles carefully screened with regard to inclusion and exclusion criteria. The results showed that the facilities, such as dormitories and classrooms, received the most attention followed by office buildings, healthcare facilities, residential buildings, and other potential enclosed spaces such as a metro wagon. Besides, the majority of the studies were conducted experimentally while other studies were done using computer simulations. United States (n = 5), Spain (n = 4) and China (n = 3) were the top three countries based on the number of performed research. Ventilation rate was the most influential parameter in controlling the infection spread. CO2 was the primary reference for viral spread in the buildings. The use of natural ventilation or a combination of mechanical and natural ventilations was found to be highly effective in the studies. The current work helps in furthering research on effective interventions to improve indoor air quality and control the spread of COVID-19 and other respiratory diseases.
The present study aimed to investigate the rate of accumulation, human health risk assessment, and nitrate-related transfer factor in vegetables irrigated with different sources, including treated wastewater effluent (TWE) of Kermanshah wastewater treatment plant, Gharasoo river water (RW) of Kermanshah, and well water with chemical fertilizer (WWF). For this purpose, three different types of vegetables, including basil, coriander, and radish, was cultivated, and each of them was irrigated by the three irrigation sources mentioned above. Finally, the amount of nitrate in different sources of irrigation, soil (before growing vegetables and after harvesting vegetables), and the mentioned vegetables was measured. Based on the study results, it can be concluded that the water of the Gharasoo River (RW), compared to the other two irrigation sources, causes more nitrate accumulation in the soil and vegetables grown in it. The highest transmission factor was related to basil vegetables irrigated with WWF. The results showed that the average daily intake of nitrate through the consumption of vegetables grown in Kermanshah with any irrigation water is less than the allowable amount, so the consumption of such vegetables is not dangerous to consumers' health. Therefore, it is suggested that the best irrigation source for vegetable cultivation in Kermanshah is TWE, provided that all of its physical, chemical and microbial parameters meet the standards for reuse in agriculture irrigation. Thus, the use of treated wastewater reduces the need for farmers to use chemical and organic fertilizers and cost-effectiveness, high frequency, and high availability.
Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic chemicals formed during incomplete combustion of organic materials. In this study, the 16 PAHs were investigated in meat and meat products. Literature search was performed in Scopus, PubMed and Web of Science databases from 2000 to 2021. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used. Fifteen (15) studies containing 155 observations were selected based on the criteria. The sum of 16 PAHs ranged from 0.4 to 2290.32 mu g/kg (wet weight). Low-weight PAH were dominant species. The pooled weight of the studies indicated that the effect size of PAH concentration was 4.02 mu g/kg (95% CI = 0.495 to 7.545, p = 0.03) with the I-2, Q statistics and Tau(2) corresponding to 47.61, 638.36 values and 100%, respectively. The upper confidence limit (UCL) for excess lifetime cancer risk (ELCR) estimates ranged from 2.76 x 10(-5) to 1.15 and in 97% of estimates, the ELCR value showed high potential risk. The UCL for the hazard index (HI) estimates ranged from 2.53 x 10(-3) to 33.9 from which 39.35% of the estimates displayed high non-carcinogenic health risks. Environmental contamination in raw samples and cooking procedures in processed samples were responsible for further PAH formation.
Previous researches have reported significant levels of heavy metals in indoor air of smoking cafés. The current research aimed to evaluate the potential exposure of smoking cafés workers to heavy metals through quantifying amounts of these pollutants in urine samples. To this end, 35 waterpipe/cigarette cafés workers were selected as the exposed population, 35 employees from non-smoking cafe’ as the control group 1 (CG1) and 25 cases of the normal citizens as the control group 2 (CG2); and their urine samples were taken. Samples were then prepared by acid digestion approach and measured by the ICP in order to determine amount of heavy metals in them. The findings of the current work show the significant difference among urinary levels of metals in the exposed and both CG1 and CG2 (P value < 0.05). Furthermore, urinary metal levels in samples collected from smoking café workers after the exposure were considerably higher than those were collected before the exposure (P-value <0.05). According to the findings, “tobacco type” could be considered as a leading factor for heavy metal exposure in studied smokers. Additionally, a positive and significant association was found between urinary metals and urinary levels of 8-OHdG (a markers of DNA degradation through oxidative stress). Therefore, workers in waterpipe/cigarette café can be classified as high risk people in terms of DNA oxidative damage.
Samples of PM2.5 particulates were collected from indoor air of 36 cafés, 14 cafés in which only water pipe (WS) was used, eight in which only cigarette was smoked (CC), six in which both waterpipe and cigarette were smoked (WCC), and eight cafés in which no smoking occurred (SFC) in Tehran. After that, the concentration of lead (Pb), cadmium (Cd), nickel(Ni), and chromium (Cr) was examined by atomic absorption spectrophotometer (AAS) (GF 5000, Australia). The results indicated that the ƩMetal concentration (Mean ±SD) in WCC, WC, CC, and SFC cafés were 1118.5±50.42, 663.64±40.79, 425.57±17.55, and 79.02±5.13 ng/m3, respectively. The mean bioaccessibility of Pb, Cr, Ni, and Cd was obtained as 39.7, 31.4, 7.35, and 74.6%, respectively. The results of risk assessment indicated that exposure to heavy metals in the indoor air of smoking cafés of Tehran is considered high.
This study aims to evaluate the synergistic effect of alpha-Fe2O3-TiO2 nanocomposite and Na2S2O8 as the process enhancers for a non-thermal dielectric barrier discharge plasma reactor (NTP-DBD). Dimethyl phthalate (DMP), a priority and hazardous pollutant, was selected as the target pollutant to evaluate the efficacy of the studied catalytic process. A central composite design was used to determine the effects of model parameters including reaction time (x(1)), pH (x(2)), Na2S2O8 (denoted as persulfate) concentration (x(3)), alpha-Fe2O3-TiO2 nanocomposite concentration (x(4)), and applied voltage (x(5)). Among linear, quadratic, and interaction terms, the most effective factors were reaction time (x(1)), pH (x(2)(2)), and the interaction between pH and persulfate concentration (x(2):x(3)), respectively. According to optimization results, the complete degradation of DMP can be achieved at: reaction time of 5.2 min, an applied voltage of 14 kV, pH equal to 3, persulfate concentration of 2 mM.L-1, and nano-composite concentration of 1 g.L-1, while the single plasma process required about 19.4 min of reaction time. This study can demonstrate that the heterogeneous addition of alpha-Fe2O3-TiO2 nanocomposite coupled with persulfate into the NTP-DBD reactor could enhance the oxidation rate and potential of the studied process with their catalytic and synergistic effects.
In the present study, we assessed the concentration of airborne HMs (Zn, Cu, Pb, and Cd) and their probable sources using the bark of Pinus eldarica as a bio-indicator. Hence, 47 tree bark samples were harvested according to the land uses and biomonitoring techniques in the city of Yazd, Iran. The potential health risks in 13 age groups, ecological risk, as well as the possible relationship between HM concentrations and traffic indicators, were evaluated. The order of average HM concentrations in the P. eldarica bark samples was as Zn > Pb > Cu > Cd. The mean values of non-carcinogenic risks of all HMs in entire age groups were within secure range (HQ < 1); however, the carcinogenic risk of Cd was higher than the allowed level (TCR > 1 × 10-6). About Pb, it was in the safe level. The main element causing potential ecological risks was Cd, indicating moderate to very high ecological risk in most of the study areas. There was an inverse significant association between distance from major roads and Pb concentration (β = -0.011 95% confidence interval (CI): 0.022, -0.0001). All HMs in bark samples render the negative Moran's index, representing a random spatial distribution pattern. Besides, according to principal component analysis (PCA), the first component accounted for 36.55% of the total variance, dominated by Cd, Pb, Cu, and Zn, respectively, and characterized by vehicle and industrial emissions. Our results infer that industrial activities and traffic are the main sources of HMs pollution in urban environments that should be considered by decision-makers.
The present study evaluated the performance of an integrated two-phase fixed-film baffled bioreactor for wastewater treatment with regard to its energy consumption and production. The total potential of the bioenergy recovery of the bioreactor was evaluated not only from the anaerobic wastewater treatment but also from the produced bio-wasted sludge of both phases. Statistical correlations between bio-methane production and kinetic coefficients were uncovered. Methane yields between 0.15 and 0.30 L CH4.g sCOD(removed)(-1) were obtained during anaerobic wastewater treatment. The maximum energy recoveries from the digestion of bio-wasted sludge (sloughed biofilm) equaled 0.28 and 0.3 L CH4.g TS-1 for aerobic and anaerobic units, respectively. The Grau model was appropriate for predicting the performance of the bioreactor and the potential of bio-methane production. It was demonstrated that substrate utilization rate (R-su) and Grau coefficient (K-G) can be applied to predict the rate of methane production. Regarding the volume of treated wastewater, the energy production was in the range of 2.8-12 kWh.m(-3). Moreover, the overall energy consumption of wastewater treatment was in the range of 0.32-0.79 kWh/kg sCOD(removed), while the total energy production was 3.7-5.1 kWh/kg SCODremoved. Therefore, the designed bioreactor was energy positive with net energy production of 3.39-4.5 kWh/kg sCOD(removed)(-1). The total energy requirement for both wastewater treatment and bio-wasted sludge digestion was 7-15.5% of the total energy production, and, therefore, the bioreactor is a sustainable energy process. The contribution of anaerobic wastewater treatment and anaerobic digestion of bio-wasted sludge of aerobic and anaerobic units for energy recovery as bio-methane was 53, 26, and 21%, respectively. As the bioreactor achieved more than 95% of sCOD removal and have a high bioenergy production, and since kinetic coefficients demonstrated the considerably high performance of the bioreactor, it can be of interest as an appropriate treatment process.
The present study aimed to model and optimize the dimethyl phthalate (DMP) degradation from aqueous solution using UVC/ Na2S2O8/Fe2+ system based on the response surface methodology (RSM). A high removal efficiency (97%) and TOC reduction (64.2%) were obtained under optimum conditions i.e. contact time = 90 min, SPS concentration = 0.601 mM/L, Fe2+ = 0.075 mM/L, pH = 11 and DMP concentration = 5 mg/L. Quenching experiments confirmed that sulfate radicals were predominant radical species for DMP degradation. The effect of CO3- on DMP degradation was more complicated than other aquatic background anions. The possible pathway for DMP decomposition was proposed according to HPLC and GC-MS analysis. The average oxidation state (AOS) and carbon oxidation state (COS) values as biodegradability indicators demonstrated that the UVC/SPS/Fe2+ system can improve the bioavailability of DMP over the time. Finally, the performance of UVC/SPS/Fe2+ system for DMP treatment in different aquatic solutions: tap water, surface runoff, treated and raw wastewater were found to be 95.7, 88.5, 80.5, and 56.4%, respectively. Graphical abstract
Background and Objective: The activities of various industries produce a wide range of pollutants and toxic compounds. One of these compounds is the catechol, a cyclic organic compound with high toxicity and resistant to degradation. Therefore, the purpose of this study was to investigate efficiency of powder activated carbon magnetized with Fe3O4 nanoparticles in the removal of catechol from aqueous solutions by response surface methodology. Materials and Methods: The co-precipitation method was used to synthesize magnetic powder activated carbon and its properties were analyzed by SEM and XRD analysis. Then, the effect of the parameters such as pH, contact time, absorbent dose, initial concentration of catechol and temperature on the efficiency of adsorption process were investigated using a response surface methodology (Box–Behnken). The residual concentration of catechol was measured by HPLC at 275 nm. Results: The results showed that the maximum efficiency of the adsorption process was obtained at concentration of 20 mg/L, pH=3, contact time 90 minutes, at 25 °C and absorbent dose of 1.5 g/L. The study of isotherm and kinetics showed that the experimental data of the catechol adsorption process correlated with the Langmuir and pseudo-second order models, respectively. Thermodynamic study of the reaction also expresses the Exothermic and Spontaneous process. Conclusion: The results showed that the adsorption process using powder activated carbon magnetized with Fe3O4 nanoparticles at acidic pH had better efficiency. As a result, the studied process as an effective, rapid and inexpensive method for removal of catechol from aqueous solutions is proposed. Due to its short reaction time, it is economically affordable process.
Many studies have been conducted on hospital solid waste management (HSWM) throughout the world, especially developing countries. This interdisciplinary study aims to summarize the available knowledge on the health and environmental risks of hospital solid waste (HSW) and also, develop a dynamic associational assessment among hospital solid waste generation rate (HSWGR), hospital solid waste composition (HSWC), gross domestic product (GDP) per capita, and environmental performance index (EPI) in some developing countries for the first time. The results of this study showed that researchers from India, China, Pakistan, Brazil, and Iran had found more evidence about the health, economic, and environmental issues in HSW than the other developing countries. The literature showed that the highest and lowest reported HSWGR (in national average level) belonged to Ethiopia (6.03) and India (0.24) kg bed -1 day-1, respectively. It has also been shown that all studied countries except Serbia, have higher levels of hazardous waste in their HSWC, based on the WHO's standard. Furthermore, the quantity and quality of HSW in developing countries depend on the service provided by the hospital, type of hospital, HSWM system, and the level of regional economic and culture. The association analysis showed that the EPI and GDP per capita of developing countries were significantly (p-value <0.05) associated with HSWGR, non-hazardous HSW, and hazardous HSW by the Spearman coefficients equal to 0.389, 0.118, -0.118, and 0.122, 0.216, and -0.346, respectively. However, it can be concluded that GDP per capita and EPI have a weak correlation with hazardous HSW and non-hazardous HSW. Moreover, HSW has many hazardous health and environmental risks such as dioxin and furan, that must be controlled and managed through implementing programs and policies based on sustainable development. As a final point, we believed that the present study can be considered to be a guide for future studies on HSWM in developing countries.
BACKGROUND AND OBJECTIVE: Phthalic acid has high toxicity and low degradability which has put treatment of wastewater containing this compound prior to prevent its health and environmental hazards. Present study was conducted to Optimization of (UV/Na2S2O8/Fe2+) process for phthalic acid removal from aqueous solutions with response surface methodology. METHODS: This is an experimental study which was conducted at laboratory scale and synthetically in the cylindrical reactor containing UV-C lamp with 16 Watt power. Effects of variables including pH of solution (3-11), reaction time (0-60 min), concentration of persulfate (0.1-0.5 mmol/L), concentration of Fe2+ (0.1-0.2 mmol/L) and initial phthalaic acid (5-50 mg/L) on efficacy of process were investigated by response surface method (box Behnken method). The residual concentration of phthalic acid was measured by HPLC at a wavelength of 254 nm FINDINGS: The removal efficiency of phthalic acid increased by increasing pH level and reaction time. The maximum removal efficiency of phthalic acid attained as 98 percent at pH of 11, reaction time of 60 min, 0.15 mmol/L of Fe2+ concentration, persulfate concentration of 0.3 mmol/L and 5 mg of phthalic acid. The process of removing phthalic acid followed from first-order kinetic (R2=0.9766). The effects of all studied independent variables with p<0.05 on removal efficiency of phthalic acid were found significant. CONCLUSION: Obtained results indicated that the UV/Na2S2O8/Fe2+ process for removing phthalic acid from the aquatic environments has high efficiency. This issue confirms the acceptable efficiency of mentioned method for the removal of phthalic acid. © 2018, Babol University of Medical Sciences. All rights reserved.
Although chlorination can inactivate most of the microorganisms in water but protozoan parasites like C. parvum oocysts and Giardia cysts can resist against it. Therefore, many researches have been conducted to find a novel method for water disinfection. Present study evaluated the synergistic effect of H2O2 and ferrate followed by UV radiation to inactivate Bacillus subtilis spores as surrogate microorganisms. Response surface metho-dology(RSM) was employed for the optimization for UV/ H2O2/ferrate and H2O2/ferrate processes. By using central composite design(CCD), the effect of three main parameters including time, hydrogen peroxide, and ferrate concentrations was examined on process performance. The results showed that the combination of UV, H2O2 and ferrate was the most effective disinfection process in compare with when H2O2 and ferrate were used. This study indicated that by UV/ H2O2/ferrate, about 5.2 log reductions of B. subtilis spores was inactivated at 9299 mg/l of H2O2 and 0.4 mg/l of ferrate concentrations after 57 min of contact time which was the optimum condition, but H2O2/ferrate can inactivate B. subtilis spores about 4.7 logs compare to the other process. Therefore, the results of this research demonstrated that UV/ H2O2 /ferrate process is a promising process for spore inactivation and water disinfection.
1.Department of Environmental Health Engineering, Faculty of Public Health, Iran University of Medical Sciences, Tehran, I.R.Iran. 2.Department of Environmental Health Engineering, Aradan Faculty of Public Health and Paramedical, Semnan University of Medical Sciences, Semnan, I.R.Iran. 3.Department of Environmental Health Engineering, Faculty of Public Health, Kashan University of Medical Sciences, Kashan, I.R.Iran. 4.Department of Environmental Health Engineering, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, I.R.Iran. 5.Department of Environmental Health Engineering, Faculty of Environmental Health, Ardabil University of Medical Sciences, Ardabil, I.R.Iran.
Phthalic acid esters including Diallyl phthalate (DAP), which commonly named as phthalates, are considered as top priority and hazardous pollutants, and have received significant concernsover the last decades(1,2).
One of the most important aspects of environmental issues is the demand for clean and safe water. Meanwhile, disinfection process is one of the most important steps in safe water production. The present study aims at estimating the performance of UV, nano Zero-Valent Iron particles (nZVI, nano-Fe-0), and UV treatment with the addition of nZVI (combined process) for Bacillus subtilis spores inactivation. Effects of different factors on inactivation including contact time, initial nZVI concentration, UV irradiance and various aerations conditions were investigated. Response surface methodology, based on a five-level, two variable central composite design, was used to optimize target microorganism reduction and the experimental parameters. The results indicated that the disinfection time had the greatest positive impact on disinfection ability among the different selected independent variables. According to the results, it can be concluded that microbial reduction by UV alone was more effective than nZVI while the combined UV/nZVI process demonstrated the maximum log reduction. The optimum reduction of about 4 logs was observed at 491 mg/L of nZVI and 60 min of contact time when spores were exposed to UV radiation under deaerated condition. Therefore, UV/nZVI process can be suggested as a reliable method for Bacillus subtilis spores inactivation.