Optimization of the photocatalytic degradation of phenol using superparamagnetic iron oxide (Fe3O4) nanoparticles in aqueous solutions.

The present work was carried out to remove phenol from aqueous medium using a photocatalytic process with superparamagnetic iron oxide nanoparticles (Fe3O4) called SPIONs. The photocatalytic process was optimized using a central composite design based on the response surface methodology. The effects of pH (3-7), UV/SPION nanoparticles ratio (1-3), contact time (30-90 minutes), and initial phenol concentration (20-80 mg L-1) on the photocatalytic process were investigated. The interaction of the process parameters and their optimal conditions were determined using CCD. The statistical data were analyzed using a one-way analysis of variance. We developed a quadratic model using a central composite design to indicate the photocatalyst impact on the decomposition of phenol. There was a close similarity between the empirical values gained for the phenol content and the predicted response values. Considering the design, optimum values of pH, phenol concentration, UV/SPION ratio, and contact time were determined to be 3, 80 mg L-1, 3, and 60 min, respectively; 94.9% of phenol was eliminated under the mentioned conditions. Since high values were obtained for the adjusted R2 (0.9786) and determination coefficient (R2 = 0.9875), the response surface methodology can describe the phenol removal by the use of the photocatalytic process. According to the one-way analysis of variance results, the quadratic model obtained by RSM is statistically significant for removing phenol. The recyclability of 92% after four consecutive cycles indicates the excellent stability of the photocatalyst for practical applications. Our research findings indicate that it is possible to employ response surface methodology as a helpful tool to optimize and modify process parameters for maximizing phenol removal from aqueous solutions and photocatalytic processes using SPIONs.

ß-cyclodextrin grafted multi-walled carbon nanotubes/chitosan (MWCNT/Cs/CD) nanocomposite for treatment of methylene blue-containing aqueous solutions.

ß-cyclodextrin (CD) was grafted with multi-walled carbon nanotubes/chitosan (MWCNTs/Cs) to obtain MWCNTs/Cs/CD nanocomposite (NC) for methylene blue (MB) adsorption from aqueous media. TEM, XRD, TGA, Raman spectra, and BET & BJH analyses were utilized to characterize and confirm the successful synthesis of as-prepared NC. MB capture was investigated by considering the parameters of pH (1.9-9.0), temperature (∼16-63 °C), sonication time (∼5-15 min), MB concentration (∼1.2-48 mg/L), and NC dose (0.03-0.26 mg). The obtained responses were then modelled using CCD, generalized regression neural network (GRNN), and least squares support vector machine (LS-SVM), of which the latter found to provide most reliable and accurate results (RMSE = 0.0235, MAE = 0.020, AAD = 0.0047, and R2 = 0.999). Moreover, the genetic algorithm-based optimization results showed that under the respective values of 7.05, 45.5 °C, 10 min, 23 mg/L, 0.12 g, MWCNTs/Cs/CD NC would be able to remove 96.75% of MB with an adsorption capacity of 603 mg/g, through different mechanisms mainly electrostatic interactions. Following from Dubinin-Radushkevich (D-R) isotherm (qs = 460.66 ± 8.9 and R2 > 0.99) and intraparticle diffusion kinetic (R2 = 0.75-0.90) models indicated a chemical adsorption mechanism. Besides, thermodynamic parameters (ΔH◦ = -66.9 kJ/mol, ΔG◦ = between -3.77 kJ/mol and -8.52 kJ/mol, and ΔS◦ = 237.1818 J/mol K) confirmed an endothermic and spontaneous nature for the adsorption. These findings along with appropriate recyclability (five times), turn the as prepared NC to a promising material in removing MB from aqueous solutions.

Temporal trends of incidence and prevalence of multiple sclerosis in Razavi Khorasan Province, Northeast Iran.

OBJECTIVES: The prevalence of multiple sclerosis (MS) in the Persian Gulf countries has been significantly increasing during the past decades. This study was conducted for investigating the prevalence and incidence of MS in Northeast Iran (Khorasan Razavi province). METHODS: This cross-sectional study was conducted during 1 January 1988 and 23 September 2018. All patients with a clinically definite diagnosis of MS according to the McDonald criteria (2005) and MRI along with the medical diagnosis, recorded in the Khorasan MS society, were considered for calculation of crude and age-standardized prevalence, and incidence rates of MS. The periodic incidence rates were calculated based on the year of onset of MS. Also, we calculated gender ratios for prevalence and incidence rates. RESULTS: The mean age-standardized prevalence and incidence rates of MS in the Khorasan Razavi were 8.69 (95% CI 8.05-9.41) per 100,000 (3.99 (95% CI 3.39-4.74) for males, 13.49 (95% CI 12.37-14.76) for females). Age-standardized prevalence was 48.87 (95% CI 48.37-49.35) per 100,000 (22.47 (95% CI 22.01-22.93) for males, 75.65 (95% CI 74.80-76.51) for females). Also, the mean incidence and prevalence for Mashhad County as capital of province were 11.38 and 59.09 per 100,000 populations, respectively. The female/male ratio was 3.33 for all age groups. CONCLUSION: Our results showed that this region is a high-risk area for MS like central region of Iran. Our results revealed that the prevalence and incidence of MS in the study area have increased during the recent decades with a sharp slope.

Relationship of fluoride in drinking water with blood pressure and essential hypertension prevalence: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Previous studies showed controversial results of the relationship between fluoride exposure through drinking water and elevated blood pressure. We conducted a systematic review and meta-analysis to assess the direct relationship of drinking water fluoride exposure with blood pressure and essential hypertension prevalence in general populations. METHODS: We conducted a systematic search in databases including Web of Knowledge, PubMed, Scopus, and Embase by MeSH and non-MeSH terms for relevant studies with any design published until August 2019, with no limitation in time and language. The pooled effect measure was calculated within a 95% confidence interval (CI). RESULTS: Our search retrieved 630 journal articles, six of which were eligible for data extraction. The random-effects model found significantly higher systolic blood pressure (mean difference = 6.49 mmHg; 95% CI 3.73-9.25; p value < 0.01) and diastolic blood pressure (mean difference = 4.33 mmHg; 95% CI 1.39-7.26; p value < 0.01) in groups exposed to high-fluoride drinking water than in groups exposed to normal/low-fluoride drinking water. A significant relationship was also found between high-fluoride drinking water and essential hypertension (odds ratio = 2.14; 95% CI 1.02-4.49; p value = 0.045). CONCLUSION: The risk of elevated blood pressure increases in the general population of fluoride endemic areas. However, more research is needed to make a firm conclusion about the adverse effects of excess fluoride intake on the cardiovascular system at the individual level.

Socioeconomic determinants of global distribution of multiple sclerosis: an ecological investigation based on Global Burden of Disease data.

BACKGROUND: Socioeconomic factors may be involved in risk of multiple sclerosis (MS), either indirectly or as confounding factors. In this study two comprehensive indicators reflecting socioeconomic differences, including the Human Development Index (HDI) and Prosperity Index (PI), were used to assess the impact of these factors on the worldwide distribution of MS. METHODS: The data for this global ecological study were obtained from three comprehensive databases including the Global Burden of Disease (as the source of MS indices), United Nations Development Programme (source for HDI) and the Legatum Institute Database for PI. MS indices (including prevalence, incidence, mortality, and disability-adjusted life years) were all analyzed in the form of age- and sex-standardized. Correlation and regression analyses were used to investigate the relationship between HDI and PI and their subsets with MS indices. RESULTS: All MS indices were correlated with HDI and PI. It was also found that developed countries had significantly higher prevalence and incidence rates of MS than developing countries. Education and governance from the PI, and gross national income and expected years of schooling from the HDI were more associated with MS. Education was significantly related to MS indices (p < 0.01) in both developed and developing countries. CONCLUSION: In general, the difference in income and the socioeconomic development globally have created a landscape for MS that should be studied in more detail in future studies.

Association of the global distribution of multiple sclerosis with ultraviolet radiation and air pollution: an ecological study based on GBD data.

Given the growing global trend of multiple sclerosis (MS), this study was designed to evaluate environmental determinates of the worldwide distribution of MS in the presence of socioeconomic and geographic indices. MS data was obtained from the Institute for Health Metrics and Evaluation website. The air pollution parameters, including particles with aerodynamic diameter less than 2.5 µm (PM2.5), tropospheric ozone, and solid fuel use, were acquired from global burden of disease resources and the World Health Organization. Ultraviolet index (UVI) values were obtained from the Tropospheric Emission Monitoring Internet Service website. Correlation and linear regression analyses were used to investigate the relationship between air pollution and environmental parameters with MS variables. The average prevalence and incidence rates in countries with high UVI were 5.17 and 0.25 per 100,000, respectively, and in countries with low UVI were 101.37 and 0.78, respectively. The results showed negative associations between prevalence, incidence and mortality of MS with ozone concentrations (ß = - 1.04, - 0.04, and - 0.01 respectively; P < 0.01). Also, the fully adjusted model showed significant negative correlation of UVI with the MS variables in the presence of other variables (P < 0.01). Our findings demonstrated that UVI had the strongest significant inverse association with MS distribution. Consequently, vitamin D intake may be a major contributor to MS development. However, this study showed a slight influence of air pollution on the prevalence of MS in the presence of other parameters. Given the inconsistent results of previous studies, further studies may be required.

Review of environmental challenges and pandemic crisis of Covid-19.

INTRODUCTION: Spread of novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) has become a global and pandemic crisis. Some measures such as excessive use of disinfectants, increased production of nonbiodegradable waste, and water pollution will be the consequences of fighting against coronavirus disease 2019 (COVID-19), which harms the environment. Due to the fact that these effects will be identified in the long term, they may be neglected in the current situation. Therefore, the aim of this study was to investigate the environmental challenges caused by the SARS-CoV-2 pandemic crisis. MATERIALS AND METHODS: This was a review study conducted by search in databases, including Scopus, PubMed, and science direct until early May 2020. Keywords included "SARS-CoV-2," "COVID-19," and "Environment." Studies published in English and conducted in different countries were also selected for the analysis. The guidelines published by reputable organizations such as the World Health Organization, the Centers for Disease Control prevention (CDC), and the Ministry of Health have also been used in this study. CONCLUSION: The results of this study have shown that the COVID-19 virus, in addition to human damage and mortality, also affects the environment, and the damages and losses resulting from this pandemic may be identified later. Water pollution, increasing chemical pollution in the air, and increasing the production of nonbiodegradable waste are of these issues. For this purpose, it is recommended that, in addition to trying to improve the control of this pandemic, other environmental aspects in disinfection methods and disposal of dry and wet contaminated waste should be done more accurately and based on standard protocols. Infectious waste, in addition to the problem of standard sanitation, will become a major challenge that pollutes the environment. Based on this, it can be said that if home quarantine is observed voluntarily, in addition to reducing the risk of the SARS-CoV-2 and reducing the volume of visits to medical centers, it can be associated with another positive achievement, which is the reduction in waste production and protection of the environment.

Efficient technologies for carwash wastewater treatment: a systematic review.

Carwash wastewater (CWW) is considered as an important source of either water pollution or water consumption. Therefore, its treatment is critical not only from the prevention of environmental contamination but also from the recycling of such high-volume water source. Unfortunately, the effective treatment of CWW is almost unknown, complex, and expensive. To overcome the former challenge, this study aimed to systematically review different technologies for CWW treatment. For this, a comprehensive literature survey was conducted and 48 research articles were found suitable to be included in the investigation. The included studies were of coagulation and adsorption (n = 5), membrane-based technologies (n = 15), and electrochemical (n = 11) and combined (n = 17) systems. This comprehensive review showed that the treatment methods of advanced filtration membrane techniques, electrical and chemical coagulation, and advanced oxidation processes can be effective in the removal of pollutants from carwash wastewater (CWW). The mining of different studies, however, showed that the combined methods are the most promising option in the remediation of such wastewater.

Human health risk assessment of trace elements in drinking tap water in Zahedan city, Iran.

Daily intake of elements through the consumption of drinking water, due to its detrimental effects, is accounted for an important concern. Although the health risk assessment of heavy metals in different water sources has extensively carried out in various studies, the effect of age and the concentration of all trace elements in drinking tap water have neglected. Therefore, this study was conducted to evaluate the concentrations of heavy metals, e.g., As, Cd, Cr, Ni, Pb, B, Al, Hg, Mn, Zn, Cu, Fe, Se and Ba in the drinking tap water of Zahedan city and to estimate their non-carcinogenic and carcinogenic effects. Moreover, this is the first research in Iran that has also been dedicated to complete investigation on daily intakes of trace elements in tap water. A total of 155 samples of drinking water were randomly taken from the tap water and were analyzed using ICP-OES device. The estimation of the carcinogenic and non-carcinogenic risks of analyzed elements was carried out based on the guidelines of the U.S EPA. The hazard index (HI) values for children and adult age groups were 9.84E-01 and 4.22E-01, respectively. The cumulative Excess Lifetime Cancer Risk (ELCR) for carcinogenic trace elements was in range of tolerable carcinogenic risk 10-6 to10-4 and for all carcinogenic elements were in the order of Pb > Cd > Cr. It also detected that the total carcinogenic risks of the Cd, As and Cr in water samples through the ingestion route are at the levels of "low risk" and "low-medium risk".

Removing 2,4-dichlorophenol from aqueous environments by heterogeneous catalytic ozonation using synthesized MgO nanoparticles.

2,4-Dichlorophenol (2,4-DCP) is one of the seriously toxic chlorophenol compounds found in agricultural environments, in water disinfected by chlorine, and in outgoing effluents from the pulp and paper industries and paper manufacturing factories. This research studied the feasibility of using MgO nanoparticles (MgO-NPs) as a catalyst in the ozonation process for removing 2,4-DCP from aqueous environments under laboratory conditions. This study was conducted using a laboratory-scale semi-continuous reactor. It studied the effects of critical variables such as solution pH, ozonation time, dose of MgO-NPs and initial 2,4-DCP concentration. A statistical model of response surface model (RSM) was designed and utilized to obtain the optimum experimental conditions. Analysis of the data showed that initial concentration of 2,4-DCP and dose of MgO-NPs had the maximum effect on the response variable (percentage degradation of 2,4-DCP). Moreover, based on analysis of variance on the model, the optimum removal conditions were reaction time of 50 min, pH > 7, initial 2,4-DCP concentration of less than 50 mg/L, and an MgO-NPs dose of 0.3 mg/L. Under these optimum conditions, a removal efficiency of 99.99% was achieved. In addition, results indicated that catalytic ozonation in the presence of MgO-NPs was very efficient at removing 2,4-DCP from aqueous environments.

UV Activation of Persulfate for Removal of Penicillin G Antibiotics in Aqueous Solution.

Penicillin G (PG) is one of the most widely consumed antibiotics around the world. Release of PG in environment may lead to contamination of water resources. The aim of the present work is to assess feasibility of applying UV-activated persulfate process in removal of PG from aquatic environments. The study examined the effect of pH (3-11), persulfate initial concentration (0.5-3 mM), reaction time (15-90 minutes), and initial concentration of PG (0.02-0.14 mM) on PG decomposition. Also, the pseudo-first-order kinetic model was used for kinetic analysis of PG removal. The results indicated that UV-activated persulfate process can effectively eliminate PG from water. The highest PG removal efficiency was obtained as 94.28% at pH 5, and the decomposition percentage was raised by increasing persulfate dose from 0.5 to 3 mM and the reaction time from 15 to 90 minutes. Besides, the removal efficiency decreased through increasing the initial concentration of PG. UV-activated persulfate process effectively decomposes PG and eliminates it from water.

Optimisation of chemical oxygen demand removal from landfill leachate by sonocatalytic degradation in the presence of cupric oxide nanoparticles.

Leachate is the liquid formed when waste breaks down in the landfill and water filters through that waste. This liquid is very toxic and can pollute the land, ground water, and water resources. In most countries, it is mandatory for landfills to be protected against leachate. In addition to all other harms to the environment, disposal of raw landfill leachate can be a major source of hazard to closed water bodies. Hence, treatment of landfill leachate is considered an essential step prior to its discharge from source. This article describes the sonocatalytic degradation of chemical oxygen demand in landfill leachate using cupric oxide nanoparticles as sonocatalyst (cupric oxide/ultrasonic) and aims to establish this method as an effective alternative to currently used approaches. An ideal experimental design was carried out based on a central composite design with response surface methodology. The response surface methodology was used to evaluate the effect of process variables including pH values (3, 7, 11), cupric oxide nanoparticles dose (0.02, 0.035, 0.05 g), reaction time (10, 35, 60 minutes), ultrasonic frequency (35, 37, 130 KHz), and their interaction towards the attainment of their optimum conditions. The derived second-order model, including both significant linear and quadratic terms, seemed to be adequate in predicting responses (R2 = 0.9684 and prediction R2 = 0.9581). The optimum conditions for the maximum chemical oxygen demand sonocatalytic degradation of 85.82% were found to be pH 6.9, cupric oxide nanoparticles dosage of 0.05 gr L-1, and the ultrasonic frequency of 130 kHz at a contact time of 10 min.

Studies on the adsorption of amoxicillin on multi-wall carbon nanotubes.

This study examined the feasibility of removing amoxicillin (AMO) from aqueous solutions using multi-wall carbon nanotubes. The equilibrium adsorption data were analyzed using four widely applied isotherms: Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich. The results showed that the Langmuir isotherm model fits well the obtained experimental data. The adsorption process followed the pseudo-second-order model. The activation energy was found to be 19 kJ/mol. The Standard free energy changes, ΔG0, values were negative; the standard enthalpy change (ΔH0), and standard entropy change (ΔS0) values of the process were 4 kJ/mol and 36 J/mol.K. Results suggested that the AMO adsorption on carbon nanotubes was a spontaneous process.

Evaluation of UV/S2O8 process efficiency for removal of metronidazole (MNZ) from aqueous solutions.

Antibiotics are known today as emerging contaminants due to potentially adverse effects on aquatic ecosystems and the health of humans and animals, even at very low concentrations. The present study was conducted to evaluate the efficiency of the UV/S2O8 process and affecting factors (pH, initial metronidazole (MNZ) concentration, initial persulfate concentration and reaction time) in removing antibiotic MNZ. The results obtained from the experiments showed that the UV/S2O8 process efficiency is higher in acidic pH values due to production of further radical SO4- and increases with extended contact time, but the efficiency of the process is reduced by increasing the concentration of MNZ. In assessing the effect of initial persulfate concentration on the process efficiency, MNZ removal efficiency was also increased by 99.5% after contact time of 35 min with increasing the initial persulfate concentration up to 1 g/L. However, the process efficiency was decreased at higher concentrations (2 mg/L) due to reaction of sulfate radicals with each other or with persulfate and its saturation. The kinetic data fitted the pseudo-first-order kinetic model (R2 > 99%). The findings of this study clearly demonstrated the high potential of the UV/S2O8 process in the degradation of MNZ.

Investigation of Parasitic Contaminations of Vegetables Sold in Markets in the City of Tabriz in 2014.

Parasitic diseases are among the most common problems in developing countries. Various parasitic forms such as cysts, larvae and eggs of the parasite are transmitted orally through the consumption of vegetables. So, the aim of this study was to evaluate parasitic contamination of fresh vegetables consumed in the city of Tabriz. This cross-sectional study was conducted for 3 months in 2014 in Tabriz. In this study, 1620 samples from 10 kinds of vegetables (leeks, basil, mint, chives, radishes, parsley, lettuce, watercress, tarragon and coriander) were collected from 54 vegetable shops. After the washing process, centrifugation, sediment preparation and staining, each sample was examined for parasitic contamination. The parasitic infection was observed in 316 (19.5%) which 141 samples (8.7%) was related to metazoan and 175 samples (10.8%) was related to protozoan. the highest contamination was observed in leeks and the lowest in radish. Most parasitic contaminations were related to Ascaris eggs and E. coli cyst and the lowest parasitic contaminations were related to Heterophyes eggs. It can be concluded that vegetables sold in Tabriz are potential sources of human contamination with parasites. It is suggested that the use of fertilizers of human source in agriculture should be avoided.

Prevalence of Intestinal Parasitic Infection among Food Handlers in Northwest Iran.

Parasitic diseases are among the most important infectious diseases and pose health problems in many countries, most especially in developing countries. Workers at food centers could transmit parasitic infections in the absence of sanitation. This is a descriptive study conducted to determine the prevalence of intestinal parasitic infections in food clerks in the city of Tabriz in 2014. Data was recorded in the offices of the health center for all food handlers who were referred to the laboratory for demographic and stool tests to receive the health card. Parasitic infection was observed in 172 cases (3.73%) of 4612 samples. A total of 156 positive samples (90.69%) were related to protozoa and 16 (9.3%) were related to helminthes. Most of the parasitic infections were related to Giardia and Entamoeba coli and the lowest infection was related to H. nana. Also, there was a significant relationship between level of education and parasitic infection rate (P = 0.0044). But there was no significant difference between the type of infection and amount of intestinal parasites. The results show that the prevalence of intestinal parasites, especially pathogenic protozoa, is common in some food handlers. Therefore, more sanitary controls are required and increasing of education will play a crucial role in improving the health of these people.

Heavy metals removal from aqueous environments by electrocoagulation process- a systematic review.

Heavy metals pollution has become a more serious environmental problem in the last several decades as a result releasing toxic materials into the environment. Various techniques such as physical, chemical, biological, advanced oxidation and electrochemical processes were used for the treatment of domestic, industrial and agricultural effluents. The commonly used conventional biological treatments processes are not only time consuming but also need large operational area. Accordingly, it seems that these methods are not cost-effective for effluent containing toxic elements. Advanced oxidation techniques result in high treatment cost and are generally used to obtain high purity grade water. The chemical coagulation technique is slow and generates large amount of sludge. Electrocoagulation is an electrochemical technique with many applications. This process has recently attracted attention as a potential technique for treating industrial wastewater due to its versatility and environmental compatibility. This process has been applied for the treatment of many kinds of wastewater such as landfill leachate, restaurant, carwash, slaughterhouse, textile, laundry, tannery, petroleum refinery wastewater and for removal of bacteria, arsenic, fluoride, pesticides and heavy metals from aqueous environments. The objective of the present manuscript is to review the potential of electrocoagulation process for the treatment of domestic, industrial and agricultural effluents, especially removal of heavy metals from aqueous environments. About 100 published studies (1977-2016) are reviewed in this paper. It is evident from the literature survey articles that electrocoagulation are the most frequently studied for the treatment of heavy metal wastewater.

Photocatalytic degradation of Metronidazole with illuminated TiO2 nanoparticles.

Metronidazole (MNZ) is a brand of nitroimidazole antibiotic, which is generally used in clinical applications and extensively used for the treatment of infectious diseases caused by anaerobic bacteria and protozoans. The aim of this investigation was to degrade MNZ with illuminated TiO2 nanoparticles at different catalyst dosage, contact time, pH, initial MNZ concentration and lamp intensity. Maximum removal of MNZ was observed at near neutral pH. Removal efficiency was decreased by increasing dosage and initial MNZ concentration. The reaction rate constant (k obs ) was decreased from 0.0513 to 0.0072 min(-1) and the value of electrical energy per order (EEo) was increased from 93.57 to 666.67 (kWh/m(3)) with increasing initial MNZ concentration from 40 to 120 mg/L, respectively. The biodegradability estimated from the BOD5/COD ratio was increased from 0 to 0.098. The photocatalyst demonstrated proper photocatalytic activity even after five successive cycles. Finally, UV/TiO2 is identified as a promising technique for the removal of antibiotic with high efficiency in a relatively short reaction time.

Heavy metal contamination in street dusts with various land uses in Zahedan, Iran.

A total of 78 street dust samples (75 within city and 3 from suburban) were collected from different areas with various land use within the city of Zahedan in November 2013 at the end of a long dry period. After digestion, the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were measured by using ICP-OES. The degree of pollution by heavy metals was assessed with respect to the background concentration by calculation and comparison of the pollution index, integrated pollution index (IPI) and enrichment factor (EF). The mean IPI values (aggregate of six heavy metals) in commercial, high traffic, industrial, urban park, and residential were 3.65, 2.76, 1.68, 1.53 and 1.25, respectively. The results of EF analysis showed almost all sampled urban land use types to be enriched in heavy metals compared with sampled background levels, suggesting heavy metals contamination of street dust in the urban center is from anthropogenic sources.

Phytodegradation potential of bisphenolA from aqueous solution by Azolla Filiculoides.

Many organic hazardous pollutants such as bisphenolA (BPA) which are toxic and not easily biodegradable can concerns for environmental pollution worldwide. The objective of this study was to examine whether Azolla Filiculoides is able to remove BPA from aqueous solutions. In this study, the Azolla with different biomass (0.3, 0.6, 0.9, 1.2 g) has been cultured in solution that was contained 5, 10, 25 and 50 ppm BPA. Samples were collected every 2 days from all of containers. The analytical determination of BPA was performed by using of DR4000 uv-visible at λmax = 276 nm. The results indicated that Azolla has high ability to remove BPA from aqueous solutions. The BPA removal was 60-90%. The removal efficiency is increasing with decreasing of BPA concentration and increasing of biomass amount and vice versa. The removal efficiency was more than 90% when BPA concentration was 5 ppm and amount of biomass was 0.9gr. It is concluded that Azolla able remove BPA by Phytodegradation from the aqueous solutions. Since conventional methods of BPA removal need to high cost and energy, phytoremediation by Azolla as a natural treatment system can decrease those issues and it can be a useful and beneficial method to removal of BPA.