Oxidative degradation of sulfamethoxazole from secondary treated effluent by ferrate(VI): kinetics, by-products, degradation pathway and toxicity assessment.

Sulfamethoxazole (SMX) is a typical antibiotic in the world, which is frequently detected in the aquatic environment. The current study was aimed to investigate the SMX degradation in secondary treated wastewater using potassium Ferrate [Fe(VI)]. The effects of various experimental conditions, EDTA and phosphate as chelating agents, and toxicity assessment were also considered. Secondary treated effluent was spiked with predefined SMX concentrations, and after desired reaction time with Fe(VI), residual SMX was measured using HPLC. Results indicated that SMX degradation by Fe(VI) was favored under acidic condition, where 90% of SMX degradation was achieved after 120 min. Fe(VI) and SMX reaction obeyed first-order kinetic; meantime, the SMX degradation rate under pH 3 was 7.6 times higher than pH 7. The presence of phosphate (Na2HPO4) and EDTA declined SMX degradation, while Fe (III) effect was contradictory. In addition to promising demolition, 10% TOC removal was achieved. Eighteen major intermediates were identified using LC-MS/MS and the degradation pathways were suggested. Transformation products (TPs) were formed due to hydroxylation, bond cleavage, transformation after bond cleavage, and oxidation reactions. The ECOSAR analysis showed that some of the SMX oxidation products were toxic to aquatic organisms (fish, daphnia and green algae). Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-021-00769-9.

Advanced oxidation processes for chlorpyrifos removal from aqueous solution: a systematic review.

Chlorpyrifos (CPF), an organophosphate insecticide, due to its high efficiency and low cost is widely used in the agricultural industry. CPF may lead to lung deficiency, central nervous system damage, developmental and autoimmune disorders. In recent decades, the advanced oxidation processes (AOPs) have been considered in water and wastewater treatment due to their high efficiency in decomposition of organic and inorganic compounds, specially hardly biodegradable or non-biodegradable compounds. In the present review study, the most common AOPs (such as Fenton and Photo-Fenton processes, UV/H2O2 photolysis, UV/TiO2 heterogeneous photo catalysis, electrochemical processes, sonolysis technology, gamma irradiation technology and sulfate-based AOPs) applied for CPF removal from aqueous matrices has been investigated. It can be concluded that the use of AOPs are effective for CPF removal from aqueous media. In addition, Fenton and photocatalytic processes appear to be the most common techniques for CPF degradation.

Arsenic health risk assessment and the evaluation of groundwater quality using GWQI and multivariate statistical analysis in rural areas, Hashtroud, Iran.

Arsenic (As) is a toxic metalloid that can cause significant health issues through drinking water. The present study was aimed to evaluate As distribution and the related health risks from drinking groundwater in rural areas of Hashtroud, Iran. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were also applied to better explain relationship pattern between different resources. The samples were taken from 51 locations in 37 villages. Arsenic concentration was determined by a polarograph device, and the corresponding carcinogenic and non-carcinogenic health risks were calculated based on US Environmental Protection Agency (EPA) guideline. PCA analysis extracted four main components that explained nearly 62% of data variance. Results pointed severe As contamination in the studied area, where As was detected in 78% of the samples ranging from less than 0.001 to 0.250 mg/L. Forty percent of the contaminated places violated guideline value of 10 µg/L suggested by EPA and institute of standards and industrial research of Iran (ISIRI). Based on our findings, 1329 people including 239 children were living in the areas with higher As contamination. Hazard quotient (HQ) in 72%, 59%, and 33% of the samples was higher than one for children, adolescent, and adult age groups, respectively. Excess life time cancer risk (ELCR) in almost 80% of all age groups was significantly higher than EPA recommended guideline (10-4 or 10-6). In summary, from the view point of arsenic HQ and ELCR, water resources in the studied areas were not appropriate for drinking and hygienic purposes; necessary and urgent management strategies to guarantee water supply and health safety for local residents should be considered.

Dermopathy and retinopathy in diabetes: is there an association?

BACKGROUND/AIMS: Diabetic dermopathy is the most common cutaneous marker of diabetes mellitus presenting as single or multiple well-demarcated brown atrophic macules, predominantly on the shins. Although diabetic dermopathy and diabetic retinopathy are both considered by some authors as manifestations of diabetic microangiopathy, only a few studies are published about their possible association. Our purpose was to investigate the association of diabetic dermopathy and diabetic retinopathy. METHODS: We conducted a cross-sectional study in an outpatient diabetes clinic during a 6-month period. One-hundred and eighty-one consecutive patients (8 cases of insulin-dependent diabetes mellitus and 173 cases of non-insulin-dependent diabetes mellitus) were examined for the presence of diabetic dermopathy and diabetic retinopathy. RESULTS: Forty-seven (26%) showed diabetic dermopathy and 68 patients (37.6%) suffered from diabetic retinopathy. The frequency of retinopathy in patients with diabetic dermopathy (44%; 30 cases) was significantly greater than in patients without dermopathy (15%; 17 cases; p < 0.0001). Retinopathy showed a statistically significant association with dermopathy [odds ratio (OR): 3.60; 95% confidence interval (CI): 1.53-8.44; p = 0.003] and diabetes duration (OR: 3.36; 95% CI: 1.67-6.77; p = 0.001). CONCLUSION: Our study further supports that diabetic dermopathy might be used as a telltale sign of diabetic retinopathy, necessitating more intensive ophthalmologic care, especially in long-lasting diabetes.