Environmental arsenic exposure and reproductive system toxicity in male and female and mitigatory strategies: a review.

Environmental Arsenic (As) exposure is one of the main health challenges in different area of the world. As is a significant factor responsible to the reproductive system toxicity in both male and female. In this study, the most important effects mechanisms and biomarkers related to environmental exposure to As and the reproductive system toxicity, and infertility risk are reviewed in male and female. The results showed that the most important As-induced reproductive system toxicity in the male were alteration in the quantity and quality of semen, testicular toxicity, oxidative stress, testosterone reduction, and sperm apoptosis. For female were oxidative stress, spontaneous miscarriage, reproductive cycle disruption, decrease in the estradiol, progesterone, and testosterone levels and impair fecundity. The main mechanisms of reproductive system toxicity caused by As exposure in male were, genotoxic effects, reduction of glutathione, disruption of sex hormones, sperm flagellum formation impairment, inhibition of spermatogenesis, disruption of cell signaling pathways, and metabolites disruption. For female were abnormal signaling in gene expression, hormonal homeostasis, As-accumulation in placental tissue and creation of reactive oxygen, disruption in the neurotransmitters balance, and sex hormones disruption. The suitable biomarkers for As-induced reproductive toxicity in male were changes in testosterone, one-carbon and lipid metabolism, noncoding RNAs, and steroid hormone homeostasis, and for female was human chorionic gonadotropin (hCG) changes. Finaly, taking selenium, zinc, silymarin, vitamins (C and E) and phytonutrients can be effective in reducing the As-induced reproductive system toxicity and infertility risk.

Association of opium use and tobacco smoking with α-, ß-, and γ-human papillomavirus oral infection.

Head and neck squamous cell carcinomas (HNSCCs) are linked to tobacco smoking, opium use, and human papillomavirus (HPV) infection. However, little is known about the association of HPV infection with risk factors of HNSCCs, including opium and tobacco use. This cross-sectional analysis of a national multi-center case-control study in Iran included 498 HNSCC cases and 242 controls. We investigated the association of opium and tobacco use with α- (n = 21), ß- (n = 46), and γ-HPV (n = 52) types in saliva samples using type-specific bead-based multiplex genotyping assays (TS-MPG). We found that α-HPV positivity was significantly associated with tobacco smoking (OR = 10.35; 95% CI = 1.15, 93; p = .03), but not with opium use (OR = 1.06; 95% CI = 0.41, 2.76; p = .89). Additionally, tobacco smoking correlated with an elevated risk of ß-species 2 HPV infection (OR = 1.28; 95% CI = 1.04, 1.58; p = .020). Conversely, opium use showed a positive association with γ-species 12 HPV infection (OR = 5.67; 95% CI = 1.43, 22.44; p = .013). These findings indicate that tobacco and opium use may influence the risk of HPV infection in different ways depending on the HPV genus and species. Further studies are needed to replicate these findings in other populations.

Reinke's Edema and Risk Factors, A Case-Control Study.

Reinke's edema (RE) is a benign pathological non-inflammatory disorder of the vocal folds with a wide range of clinical manifestations. We aim to investigate the relationship between Reinke's edema and some common inhalant abuse. In this case-control study, subjective consisted of 23 patients with RE (the cases), and 50 patients with sinusitis (control) who underwent surgery in the Department of Otolaryngology, between 2015 and 2020. Demographic characteristics, history of some related disease, methods, and the duration of cigarette, and opium consumption were collected through the patients' files. The chi-square (χ²) test was run to analyze the differences in the categorical and, and the Independent Sample T-test was used to compare two sample means from unrelated groups. A significant level (p-value) was considered less than 0.05. The mean age was 54 ± 12 years, and 42 ± 11 years, respectively for Reinke's edema and sinusitis. More women had been recorded in the RE group, compared to men. Allergy, unprincipled use of voice and talkativeness, history of laryngeal surgery, and type of disease were correlated to RE (p < 0.05). Also, cigarette smoking was significantly correlated with Reinke's edema. The average number of cigarettes per day, the duration of smoking, and opium consumption were more frequent in RE (P < 0.05). 90% of the RE and 4% of sinusitis patients were opium consumers. There was a statistically significant difference in the methods of substance use in the two groups of cases and control (p < 0.0001). Among the different methods, the poker and stone method was the most common (69.6%), and the opium smoking pipe was the second most common method. This study also confirmed the hazardous effects of smoking and inhaling opiates in the formation of lesions of the pharynx and larynx. In particular, longer use of these substances will be associated with more serious side effects. Therefore, it seems that people who are addicted to opiates should undergo periodic visits and counseling to reduce and stop their use.

Rhinocerebral Mucormycosis Following COVID-19 Infection in Iran.

Background & Objective: Mucormycosis (also called black fungus) is an opportunistic serious fungal infection caused by mucormycetes. It can occur in diabetes mellitus patients and other immunosuppressive conditions with recent predisposing factors such as maxillofacial surgery and corticosteroid usage. Methods: In this study, 14 patients were referred to the otorhinolaryngology or ophthalmology ward of Shafa Hospital (Kerman, Iran) with primary symptoms of nasal fullness and facial nerve dysfunction; they were admitted to the hospital to rule out the fungal infection. An endoscopic biopsy was taken from facial sinuses or orbit, and a microscopic evaluation was performed using hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining methods to rule out mucormycosis. Results: In the histopathological examination, broad-based nonseptate branching fungal hyphae were found in nasal sinuses through the endoscopic biopsy. Most of the patients had diabetes mellitus with a primary symptom of facial nerve palsy; also, most of them received corticosteroids (intravenous [IV] or intramuscular [IM] injection). All patients have recently been infected with COVID-19 (less than 1 month ago). Conclusion: COVID-19 infection might be a predisposing factor for many opportunistic infections, such as fungal elements); thus, the physician should be aware of the dosage and duration of corticosteroid therapy to prevent the development of these infections.

Risk of urinary tract cancers following arsenic exposure and tobacco smoking: a review.

Bladder cancer, prostate cancer, and kidney cancer, due to their high morbidity and mortality rates, result in significant economic and health care costs. Arsenic exposure affects the drinking water of millions of people worldwide. Long-term exposure to arsenic, even in low concentrations, increases the risk of developing various cancers. Smoking is also one of the leading causes of bladder, prostate and kidney cancers. Accordingly, this research reviews the relationship between arsenic exposure and smoking with three kinds of urinary tract cancers (bladder cancer, prostate cancer, and kidney cancer) due to their widespread concern for their negative impact on public health globally. In this review, we have gathered the most current information from scientific databases [PubMed, Scopus, Google Scholar, ISI web of science] regarding the relationship between arsenic exposure and tobacco smoking with the risk of bladder, prostate, and kidney cancer. In several studies, a significant relationship was determined between the incidence and mortality rate of the above-mentioned cancers in humans with arsenic exposure and tobacco smoking. The decrease or cessation of smoking and consumption of arsenic-free water significantly declined the incidence of bladder, prostate, and kidney cancers.

Ecological risk assessment of trace elements (TEs) pollution and human health risk exposure in agricultural soils used for saffron cultivation.

Contamination of farmland soils by trace elements (TEs) has become an international issue concerning food safety and human health risks. In the present research, the concentrations of TEs including cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) and iron (Fe) in soils of 16 farmlands were determined in Gonabad, Iran. In addition, the human health risks due to exposure to the TEs from the soils were assessed. Moreover, the soil contamination likelihood was evaluated based on various contamination indices including contamination factor [Formula: see text]), enrichment factor (EF), geo-accumulation index (Igeo), and pollution load index (PLI) calculations. The soil mean concentrations for Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and Fe ranges as 0.102, 6.968, 22.550, 29.263, 475.281, 34.234, 13.617, 54.482 and 19,683.6 mg/kg in farmland soils. The mean concentrations of the TEs decreased in the order of Fe > Mn > Zn > Ni > Cu > Cr > Pb > Co > As > Cd. Levels of all metals in this study were within the FAO/WHO and Iranian soil standards. The HQ values from investigated elements for adults and children in the studied farms were less than the limit of 1, indicating no health risks for the studied subpopulations. The results of the present research indicated no significant carcinogenic health hazards for both adults and children through ingestion, skin contact and inhalation exposure routes. [Formula: see text] values of Ni and Zn in 100% and 6.25% of farmlands were above 1, showing moderate contamination conditions. EF values of metals in farmlands were recorded as "no enrichment", "minimal enrichment" and "moderate enrichment" classes. Furthermore, it can be concluded that the all farms were uncontaminated except Ni (moderately contaminated) based on Igeo. This is an indication that the selected TEs in the agricultural soils have no appreciable threat to human health.

The Patients' Characteristics And Non-Surgical Treatment Results For Hypopharyngeal Cancer In Southeast Of Iran: A 13-Year Study.

BACKGROUND: Various modalities have been used to treat hypopharyngeal cancer. Non- surgical modalities include radiotherapy alone, sequential chemoradiation and concomitant chemoradiation or bio radiation. This study was conducted to evaluate the primary non-surgical treatment. METHODS: A total number of 67 patients treated from March 2009 to January 2022 were enrolled in this study. The 2-year and 5-year survival rates were estimated using the Kaplan-Meier method. Log-rank test was used to compare the survival outcomes according to various factors. To define independent prognostic factors, we used Cox regression analysis. RESULTS: The mean age of the patients was 56.2 years, and 55.2% of them were male. These patients were treated by radiation alone (9 patients) or induction chemotherapy followed by either radiation (4 patients), chemoradiation (33 patients), or bio-radiation (21 patients). The mean follow-up time was 18.12 months. The 2-year and 5-year overall survival rates were estimated to be 43% and 18%, respectively. Multivariate analysis showed that T stage, N stage, and treatment modality had a statically significant relationship with overall survival. CONCLUSIONS: The results of non-surgical treatment for hypopharyngeal cancer are not satisfactory. More studies are needed to investigate the role of salvage surgery.

Non-Surgical Treatment Prognosis For Laryngeal Cancer Based On American Joint Committee On Cancer Staging And T And N Integer Score.

Background: The American Joint Committee on Cancer (AJCC) system is the most acceptable staging method. In this study, an attempt has been made to evaluate the survival rate of laryngeal cancer based on the AJCC and T and N integer scores (TANIS). Methods: In this prospective cohort study, from March 2004 to March 2021, laryngeal cancer patients who were considered for non-surgical treatment were included. Radiation alone was considered for T1-T2 lesions without nodal involvement. Sequential or concomitant chemoradiation (based on physician choice) was considered for locoregionally advanced patients (T3/T4 or node positive). The 2-year, 5-year and 10-year overall survival (OS) and progression-free survival (PFS) rates were estimated using Kaplan-Meier method. Cox -Regression method was used for covariates analysis. Results: The 2-year, 5-year and 10-year overall survival (OS) rates in all patients were estimated to be 82%, 70% and 41%, respectively. The 2-year, 5-year and 10-year progression-free survival (PFS) rates in all patients were estimated to be 78%, 59% and 41%, respectively. The 5-year OS rates for stages I, II, III, IVa, and IVb were 83, 84, 51, 12, and 19 percent, respectively. The 5-year OS rates for TANIS 1, 2, and 3 were 85, 62 and 53 percent, respectively. Based on multivariate analysis, the group stage (p=0.001), TANIS group (p=0.003) and tumour subsite. (p=0.006) were independently effective in survival rates. Conclusion: TANIS-3 can simply predict the prognosis of non-surgically treated laryngeal cancers. The separation of different prognostic groups by TANIS is better than the AJCC system. More extensive studies are necessary to confirm this.

Comparison of poly ferric chloride and poly titanium tetrachloride in coagulation and flocculation process for paper and cardboard wastewater treatment.

The current study investigated the efficiency of poly ferric chloride (PFC) and poly titanium tetrachloride (PTC) in coagulation-flocculation process for treatment of paper and cardboard wastewater. The effect of pH (5-11), coagulant concentrations (100-1000 mg/L), mixing rate (10-60 rpm), mixing time (5-25 min), and settling time (5-30 min) were examined. The results showed that the removal efficiency for turbidity, total suspended solids (TSS), and chemical oxygen demand (COD) by PFC and PTC coagulants increased with pH rising up to 9 for the former and 7 for the latter coagulant. Furthermore, the removal efficiency for the afore-mentioned parameters increased along with a 30 rpm increase in the mixing rate, while the mixing time reached 20 min. It was also found that the best removal efficiencies for turbidity, TSS, and COD by PFC under optimal conditions (pH 9, coagulant dose 800 mg/L, and settling time of 25 min) were 97.11%, 99.1%, and 84.91%, respectively. In addition, the removal efficiencies for PTC (optimal conditions of pH 7, coagulant dose 600 mg/L, and settling time of 15 min) were found to be 98.29%, 99.29%, and 86.42%, respectively. Water recovery and the produced sludge volume by PFC were 80% and 200 cm3, respectively, in the settling time of 25 min and for PTC were 81.5% and 185 cm3, respectively, in the settling time of 15 min. Costs of the coagulation-flocculation process for treatment 1 m3 of paper and cardboard wastewater using PTC and PFC were 0.42 $ and 0.32 $, respectively. Finally, it can be concluded that compared to PFC, PTC with higher settling rate has a greater efficiency for treatment of paper and cardboard wastewater.

The role of environmental factors to transmission of SARS-CoV-2 (COVID-19).

The current outbreak of the novel coronavirus disease 2019 (COVID-19) in more than 250 countries has become a serious threat to the health of people around the world. Human-to-human transmission of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs most often when people are in the incubation stage of the disease or are carriers and have no symptoms. Therefore, in this study, was discussed the role of environmental factors and conditions such as temperature, humidity, wind speed as well as food, water and sewage, air, insects, inanimate surfaces, and hands in COVID-19 transmission. The results of studies on the stability of the SARS-CoV-2 on different levels showed that the resistance of this virus on smooth surfaces was higher than others. Temperature increase and sunlight can facilitate the destruction of SARS-COV-2 and the stability of it on surfaces. When the minimum ambient air temperature increases by 1 °C, the cumulative number of cases decreases by 0.86%. According to the latest evidence, the presence of coronavirus in the sewer has been confirmed, but there is no evidence that it is transmitted through sewage or contaminated drinking water. Also, SARS-COV-2 transmission through food, food packages, and food handlers has not been identified as a risk factor for the disease. According to the latest studies, the possibility of transmitting SARS-COV-2 bioaerosol through the air has been reported in the internal environment of ophthalmology. The results additionally show that infectious bio-aerosols can move up to 6 feet. There have been no reports of SARS-COV-2 transmission by blood-feeding arthropods such as mosquitoes.

The relationship of indoor radon gas concentration with multiple sclerosis: a case-control study.

This case-control study aimed to investigate the relationship of indoor radon gas concentration and residential building characteristics with mental health with multiple sclerosis (MS) in Yazd City, Iran. The participants included 45 patients with MS and 100 healthy individuals. The participants' socio-economic status and residential building characteristics were investigated using a questionnaire. The radon gas concentration was also measured by CR-39 detectors over a 6-month period. Furthermore, the participants' mental health data were collected using General Health Questionnaire (GHQ-28). The mean concentrations of radon gas were 66.77 and 65.33 Bq/m3 in the homes of patients with MS and healthy individuals, respectively, but the difference was not significant (p = 0.882). However, the radon gas concentration had a significant relationship with the building's age (p = 0.038), ventilation (p = 0.053), and cooling system (p = 0.021). A significant difference was observed between the two study groups in terms of the mental health (p = 0.018), depression (p = 0.037), somatic symptoms (p ≤ 0.001), and physical activity (p = 0.030). Since the indoor radon gas concentration did not have any significant relationship with MS prevalence, more studies are required in this regard, especially in long-term exposure.

Opium Use and Head and Neck Cancers: A Matched Case-Control Study in Iran.

BACKGROUND: Head and Neck (H and N) cancers include malignant tumors of the nasal cavity, pharynx, paranasal sinuses, oral cavity, larynx and salivary glands. Opium use might be related to these cancers. The aim of this study was to investigate the relation between Opium and its Derivatives (O and D) use and the incidence of H and N cancers. METHODS: In this case-control study conducted in Kerman, 140 patients with HandN cancers and 280 healthy controls (matched for age, gender, and place of residence) were included. Information about their use of O and D, cigarette smoking, alcohol and diet were collected using a structured questionnaire. Conditional logistic regression was used to investigate the relation between variables. RESULTS: The use of opioids was associated with an increased risk of H and N cancers (Adjusted OR: 8.13; CI: 4.08-16.2). A significant dose-response relation between O and D use was observed, with high use Adjusted OR=8.91; 95% CI: 4.03-19.65 and low use Adjusted OR=6.52; 95% CI: 3.18- 13.36. This dose-response association was stronger in patients with laryngeal cancer and opioids use, with high use Adjusted OR = 11.17; 95% CI=4.48-28.09 and low use Adjusted OR = 9.46; 95% CI= 3.97- 22.52. CONCLUSION: The results show that opium use can be considered as an important risk factor for H and N cancers. Also in Iran, opium seems to play a more important role than cigarette smoking.

Adsorption of Pb (II) and Zn (II) ions from aqueous solutions by Red Earth.

This study was carried out to investigate Pb (II) and Zn (II) removal from aqueous solutions by Red Earth (RE) as a new local natural adsorbent in using the batch method. The chemical structure of RE adsorbent was characterized by XRF. Giles, Langmuir, and Freundlich isotherms were used to describe the adsorption data. The effect of metals concentration, initial pH, adsorbent dosage, and agitation time were studied. The results showed that RE contains of SiO2 (58 %) and Al2O3 (15.2 %) as major compounds. The equilibrium time was reached following 30 min and the maximum adsorption capacities (mg/g), based on Langmuir equation were 10.31 and 8.74 for Pb (II) and Zn (II), respectively. By increasing the initial metal ions concentration, the adsorption efficiencies were decreased and adsorption capacity of RE increased with an increase in the initial pH.

Efficient removal of Pb(II) and Zn(II) ions from aqueous solutions by adsorption onto a native natural bentonite.

The new Native Natural Bentonite (NNB) for adsorption of Pb(II) and Zn(II) ions from aqueous environments was investigated at 27 ±â€¯10C by in batch laboratory experiments. Chemical and mineralogical structure of the NNB adsorbent was characterized by XRF and cation exchange capacity (CEC). The effect of pH, metals concentration, adsorbent dose, and agitation time were also studied. Langmuir and Freundlich isotherm and the Giles classification isotherm were used for describing the equilibrium data. The results show that the NNB contains silica (SiO2) and alumina (Al2O3) as a major chemical compound. The maximum adsorption capacity (mg/g), based on Langmuir isotherm were 8.55 and 7.90 for Pb(II) and Zn(II), respectively. Pb(II) and Zn(II) removal efficiency was increasing by increasing the initial pH of solutions, adsorbent dose, and contact time. Therefore, the results of this study show that the equilibrium is reached slowly (180 min), indicating the adsorption sites are not well exposed. By increasing the initial metals ion concentration, the capacity of adsorption decreased and the uptake of Pb(II) and Zn(II) per unit weight of the adsorbent (mg/g) increased. The adsorption efficiency of Pb(II) was higher than Zn(II).

Developing a system dynamics model for prediction of phosphorus in facultative stabilization ponds.

System dynamics is considered as a computer-aided approach to policy analysis and design. It includes the response and reaction of a system to external shocks. In the present research, following the sampling and testing phases, a system dynamics model was developed for modeling of phosphorus in facultative stabilization ponds. First, the scheme of soluble reactive phosphorous stock, its specifications and parameters were determined and created in the VenSim PLE 7.1 software. Then, mathematical relations were determined for each process. Finally, the model was calibrated and verified based on the data from the Yazd facultative ponds, Iran. Sensitivity analysis showed that the most important factors affecting phosphorus concentration in the ponds are the phosphorus settling rate, losses caused by algal respiration and excretion, while the losses caused by herbivorous zooplanktons, hydrolysis rate of inorganic carbon, and ratio of phosphorus to chlorophyll-a had the least importance. Results showed that, algal growth rate and phosphorus settling rate were important factors in phosphorus removal. Hence, with appropriate retention time in the pond, it can be managed more properly. The ratio of phosphorus to algae had less importance in the model. The ratio of carbon to phosphorus and rate of respiration of carnivorous zooplanktons did not affect the phosphorus concentration. It is recommended that this model can be used for pond management and overall assessment of facultative ponds.

Decolorization and biodegradation of reactive Red 198 Azo dye by a new Enterococcus faecalis-Klebsiella variicola bacterial consortium isolated from textile wastewater sludge.

The present study investigated biodegradation and removal of Reactive Red 198 (RR198) dye from aqueous environments using a new bacterial consortium isolated from textile wastewater sludge on laboratory scale via batch study. Two bacterial species, Enterococcus faecalis (EF) and Klebsiella variicola (KV), were identified after isolation, through biochemical assays, Polymerase chain reaction (PCR), and 16S rRNA gene sequencing. To determine their ability to biodegrade RR198 dye, physicochemical parameters, including bacterial concentration, time, pH, and temperature, were tested; the results showed that the best conditions included a bacterial concentration of 3.5 mL × 105 cells/mL and incubation time of 72 h. Under such conditions, the removal efficiency of RR198 dye at an initial concentration of 10-25 mg/L was more than 98%; however, for concentrations of 50, 75, and 100 mg/L, removal efficiency was reduced to 55.62%, 25.82%, and 15.42%, respectively (p = 0.005). The highest removal efficiency occurred at pH 8.0, reaching 99.26% after 72 h of incubation. With increasing the incubation temperature from 25 °C to 37 °C, removal efficiency increased from 71.71 to 99.26% after 72 h of incubation, and increasing the temperature from 37 to 45 °C, the removal efficiency was reduced (p ≤ 0.001). Therefore, the EF-KV bacterial consortium can be used for efficient removal of RR198 dye from textile effluent.

Toxicity evaluation and management of co-composting pistachio wastes combined with cattle manure and municipal sewage sludge.

To manage the pistachio de-hulling waste (PW), investigated the co-composting process using a mixture of PW and cattle manure (CM) (5.5:10 dry weight) as well as PW and municipal dewatering sewage sludge (DSS) (1:10 dry weight) at the laboratory scale for 60 days. Compost toxicity was evaluated using the seed germination index (GI). The maximum temperatures in co-composting processes of PW+CM (51.9 °C) and PW+DSS (49.9 °C) were reported on the seventh day. The increase of temperature was higher in PW+CM and remained in the thermophilic phase for five days. In both reactors, the pH rates decreased, increased, and finally remained neutral. The C/N ratio decreased in both reactors, but the reduction rate was faster in the PW+DSS reactor. Sodium (Na%) and potassium (K%) contents were increased, while the concentrations of Cu, Zn, Fe, and Mn were decreased during the processes. The numbers of parasite eggs in the final composts of the reactors containing PW+CM and PW+DSS were zero and 8 Number/4gDW, respectively. The amounts of Salmonella were zero in the final products of reactors containing PW+CM and PW+DSS. The results of GI showed that the final compost of PW+CM process was not toxic for the plants, whereas the PW+DDS final compost was toxic. In conclusion, the co-compost product of the PW+CM reactor had higher quality than the PW+DSS reactor. So, it is suitable for PW management.

Optimization and economic evaluation of modified coagulation-flocculation process for enhanced treatment of ceramic-tile industry wastewater.

Enhanced treatment of ceramic-tile industry wastewater was investigated by modified coagulation-flocculation process using combination of poly-aluminum chloride (PAC) with anionic (A300), cationic polymer (C270) and nonionic polymers. The effects of pH, PAC coagulant dose alone and with polymers dose in various combinations was studied by jar tests. To compare the removal efficiencies of turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and color at different levels, we run multivariate analysis of variance. Regarding the economic evaluation, we applied the incremental cost-effectiveness ratio. PAC had the best performance in pH 7 and in optimal dose of 400 mg/L; so that removal efficiency of wastewater turbidity, TSS, COD and color were 99.63%, 99.7%, 47.5% and 50.38%, respectively. The best removal efficiency for wastewater turbidity, TSS, COD and color were 99.87%, 99.89%, 87.5% and 93.02%, respectively which were obtained by combination of anionic polymer (1.5 mg/L) with PAC (300 mg/L). Furthermore, with combination of PAC + anionic + non-ionic polymers, the removal efficiency for wastewater turbidity, TSS, COD and color were 99.93%, 99.94%, 88% and 94.57%, respectively. The imposed cost for treating one cubic meter of ceramic-tile wastewater treatment by PAC + anionic and PAC + anionic and non-ionic polymers in comparison with PAC alone was reduced to 22.96% and therefore economically more affordable for the tile industry wastewater treatment.

An overview report on the application of heteropoly acids on supporting materials in the photocatalytic degradation of organic pollutants from aqueous solutions.

Organic pollutants contaminate water resources and the environment when discharged into water streams. Also, the presence of these materials in incompletely treated or untreated wastewater leads to serious environmental hazards. The hydroxyl radicals and holes are regarded as the most oxidant species in the degradation of organic pollutants using the studied composites. The results of this review show that heteropoly acids on supporting materials could be considered as appropriate photocatalysts in the removal of organic pollutant from aqueous solutions.

Efficient photocatalytic oxidation of arsenite from contaminated water by Fe2O3-Mn2O3 nanocomposite under UVA radiation and process optimization with experimental design.

The efficiency of photocatalytic oxidation process in arsenite (As(III)) removal from contaminated water by a new Fe2O3-Mn2O3 nanocomposite under UVA radiation was investigated. The effect of nanocomposite dosage, pH and initial As(III) concentration on the photocatalytic oxidation of As(III) were studied by experimental design. The synthesized nanocomposite had a uniform and spherical morphological structure and contained 49.83% of Fe2O3 and 29.36% of Mn2O3. Based on the experimental design model, in photocatalytic oxidation process, the effect of pH was higher than other parameters. At nanocomposite concentrations of more than 12 mg L-1, pH 4 to 6 and oxidation time of 30 min, photocatalytic oxidation efficiency was more than 95% for initial As(III) concentration of less than 500 µg L-1. By decreasing pH and increasing the nanocomposite concentration, the photocatalytic oxidation efficiency was increased. Furthermore, by increasing the oxidation time from 10 to 240 min, in addition to oxidation of As(III) to arsenate (As(V)), the residual As(V) was adsorbed on the Fe2O3-Mn2O3 nanocomposite and total As concentration was decreased. Therefore, Fe2O3-Mn2O3 nanocomposite as a bimetal oxide, at low doses and short time, can enhance and improve the efficiency of the photocatalytic oxidation and adsorption of As(III) from contaminated water resources. Furthermore, the energy and material costs of the UVA/Fe2O3-Mn2O3 system for photocatalytic oxidation of 1  mg L-1 As(III) in the 1 L laboratory scale reactor was 0.0051 €.