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Over the past few decades, the issue of heavy metal contamination in agricultural soils has gained significant attention due to its potential threat to soil ecosystems, food security, and human health. This research studied the source and potential risk associated with heavy metals in agricultural soils of Mian-Ab plain, Khuzestan, Iran. Source identification of the heavy metals using different methods indicated a combination of natural and anthropogenic (agricultural activities and vehicle emissions) origin. According to the positive matrix fraction (PMF) model, natural sources were found to be dominant for elements such as As (69%), V (58%), Mn (55%), Co (54%), Cr (50%), and Ni (48%). In contrast, atmospheric deposition, mainly from vehicle emission was a major contributor to Pb (72%), Cu (30%), and Zn (30%), while, agricultural activities, particularly fertilizer use, were associated with Zn (29%), Cd (29%), Cr (28%), and Cu (26%). The quality assessment of the agricultural soil in the study area showed low to moderate contamination of Cd, Cu, Pb, and Zn in some stations. Human health risk assessment indicated that non-carcinogenic and carcinogenic risks for adults through different pathways were negligible. However, the total carcinogenic risk for children (6.8 × 10-6) exceeded the safety level (1×10-6), indicating a potential risk of developing cancer. Notably, heavy metals such as As and Ni were identified as the primary contributors to this carcinogenic risk. [ABSTRACT FROM AUTHOR]

The landfill leachate is a highly contaminated matrix containing large amounts of organic and inorganic substances that require effective treatment methods.This study was aimed to evaluate the efficiency of electrokinetic-assisted phytoremediation (EAPR) to treat the solid waste leachate in a hydroponic system (with Cyperus alternifoliusplant). According to the results, the removal efficiency of biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN),total suspended solids (TDS), total dissolved solids (TSS), total organic carbon (TOC), chlorides, and ∑metal were 34.92 mg/L,35.21 mg/L, 42.53 mg/L, 42.68 mg/L, 46.87 mg/L, 46.92 mg/L, 44.12 mg/L, and 23.41 mg/L, respectively in sole phytoremediation process, 38.83 mg/L, 43.71, 43.72 mg/L, 45.42 mg/L, 53.78 mg/L, 47.71 mg/L, 45.74 mg/L, and 24.32 mg/L, respectively in sole electro-kinetic process, and 60.18 mg/L, 63.53 mg/L, 67.42 mg/L, 68.72 mg/L, 75.46 mg/L, 72.26 mg/L, 69.96 mg/L, and 41.39 mg/L, respectively in EAPR process. Based on the results, we can concludethe EAPR process is an efficient option for the elimination of contaminants and hazards from the landfill leachate. [ABSTRACT FROM AUTHOR]

The problem of the deep elimination of antibiotics in environmental bodies is exceptionally warranted. In this work, a ternary nanocomposite of FeNi3/SiO2/CuS (FSC) was fabricated and then integrated with UV light irradiation and hydrogen peroxide as the heterogeneous Fenton-like photocatalytic system for the decomposition of tetracycline (TC) from aqueous media. During this process, various influencing parameters such as pH, catalyst dosage, initial content of TC, hydrogen peroxide (H2O2) dose, and operating time were explored. At optimized circumstances, i.e., 5 of pH, 10 mg/L of TC concentration, 150 mg/L of H2O2 dosage, and 200 min of degradation time, the elimination proportion of TC was 96%. The results of capture agent tests clarified that hydroxyl radical (HO•) played the predominant role in the photocatalytic decontamination of TC. Moreover, with the elevated contact time and content of H2O2, the efficiency of TC decontamination increased significantly. Additionally, the findings of the stability and reusability experiments of the fabricated nanocomposite showed that the percentage of TC removal decreased by only about 5% after six cycles. Furthermore, the photocatalytic mechanism of the decontamination of TC over the FSC photocatalyst was elucidated. Eventually, the non-carcinogenic risk analysis in the surface water sample was carried out using multiple photocatalytic processes for the first time. These outcomes obtained in this study validate that coupling the photocatalytic system and the H2O2 oxidation agent facilitates the elimination of a great variety of pharmaceutical contaminants from aqueous media. [ABSTRACT FROM AUTHOR]

In this study, Alginate@ Fe3O4/Bentonite nanocomposite was utilized to eliminate formaldehyde from wastewater. Structural features of bentonite, bentonite@Fe3O4, and Alginate@Fe3O4@Bentonite were determined using FT-IR, PXRD, Mapping, EDX, TEM, SEM, VSM, and BET analyses. The central composite design method was employed to find the optimal conditions for formaldehyde removal using Alg@Fe3O4@Bent nanocomposite. The maximum formaldehyde uptake efficiency (94.56%) was obtained at formaldehyde concentration of 10.69 ppm, the nanocomposite dose of 1.28 g/L, and pH of 9.96 after 16.53 min. Also, Alginate@Fe3O4@Bentonite composite was used to eliminate formaldehyde from Razi petrochemical wastewater and was able to eliminate 91.24% of formaldehyde, 70% of COD, and 68.9% of BOD5. The isotherm and kinetic investigations demonstrated that the formaldehyde uptake process by the foresaid adsorbent follows the Langmuir isotherm and quasi-first-order kinetic models, respectively. Also, the maximum uptake capacity was obtained at 50.25 mg/g. Moreover, the formaldehyde uptake process by the aforementioned nanocomposite was exothermic and spontaneous. Furthermore, the formaldehyde adsorption efficiency decreased slightly after six reuse cycles (less than 10%), indicating that Alginate@Fe3O4@Bentonite nanocomposite has remarkable recyclability. Besides, the influence of interfering ions like nitrate, carbonate, chloride, phosphate, and sulfate was studied on the formaldehyde removal efficiency and the results displayed that all ions except nitrate ion have low interaction with formaldehyde (less than 3% reduction in removal efficiency). [ABSTRACT FROM AUTHOR]