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Poly and perfluoroalkyl compounds (PFASs) are a group of chemicals that are widely used and are difficult to purify. Within this group, perfluorooctanoic acid (PFOA), known for its highly polar and strong carbon-fluorine bonds, is a frequently encountered species in surface water, drinking water, and groundwater. In this study, we investigated the efficiency of electrooxidation (EO) in PFOA removal, optimization of EO parameters, and groundwater simulation in a realistic scenario. The EO optimization experiments were performed with a boron-doped diamond (BDD) anode for different values of pH, ...Более
Because of the toxic impacts on human health, the arsenic (As) limit value in drinking water was decreased from 50 to 10 μg l −1 by the relevant authorities (WHO 1993; US EPA 2001). In this case, the problem of As pollution in natural water resources used for drinking water has grown even more and turned into a global crisis. According to reports in many parts of the world, over about 230 million people appear to be affected by high arsenic concentrations in groundwater. In this case, it turned out that there was a great need for cost-effective and environmentally friendly technologies from dr ...Более
On the evidence of the earlier research findings, as well as the full-scale and lab-scale test data of 2019–2020, this article describes the ecological situation at Kara-Keche lignite field being developed by five mining companies in the Jumgal district of the Naryn Region in the Kyrgyz Republic. It is found that the field development proceeds with insufficient adherence to legal documents and has a considerable adverse influence on the environment and water bodies. Many large-volume refuse dumps have no isolation from natural water bodies, which ends with acute pollution of the latter. Contam ...Более
Heterogeneous electro-Fenton (EF) is a powerful technology for the removal of emerging organic pollutants from wastewater. However, the development of catalysts with high activity towards the production of •OH by decomposing H2O2 remains a challenge. Herein, Co-doped ZnFe LDH as a heterogeneous catalyst with 2D plate-like morphology was produced by a co-precipitation method. Co-doping increased the pore volume of ZnFe LDH from 0.188 cm3/g to 0.2711 cm3/g and pore diameter from 5.305 nm and 9.39 nm. EF process consisted of a hydrothermally activated graphite felt cathode and a platinum plate an ...Более
The advancement of the machine learning (ML) models has demonstrated notable progress in geosciences. They can identify the underlying process or causality of natural hazards. This article introduces the development and verification procedures of a new hybrid ML model, namely Bat-ELM for predictive drought modelling. The multi-temporal standardized precipitation evapotranspiration index (SPEI-3 and SPEI-6) is computed as the meteorological drought index at two study regions (Beypazari and Nallihan), located in Ankara province, Turkey. The proposed hybrid model is obtained by integrating the Ba ...Более
In this study, the influence of road salts on groundwater was investigated. The use of anti-ice reagents in winter requires certain precautions since the main chemical composition of the salts is chlorides. At the same time, the widely used sodium chloride does not form ion pairs in water, which means that it has a high migration ability and a weak sorption potential. In addition, the concentration of chloride salts in the components of the environment is so high (10-140 ppm). Therefore, the rapid assessment of the concentration of technogenic chlorine ion in water by pH is an urgent task. The ...Более
Here, the cationic poly (3-acrylamidepropyl trimethyl ammonium chloride) [p (APTMACl)], anionic poly (2-acrylamido-2methylpropane sulfonic acid) [p (AMPS)], and amphoteric poly (APTMACl-co-AMPS) hydrogels were prepared via free-radical polymerization techniques as pH-sensitive hydrogels. The prepared systems were used in methylene blue (MB), and Eosin Y (EY) removal from aqueous media. HCl-treated p (APTMACl-co-AMPS) hydrogels prepared in 1:3 mol ratio adsorbed higher amount of MB and EY from their corresponding 50 ml 50 ppm aqueous solutions that are 47.5 /- 0.9, and 10.7 /- 0.1 mg/g, respect ...Более
In this study, ZnCr layered double hydroxide (LDH), ZnCr LDH/carbon nanotube (CNT), and ZnCr LDH/Biochar (BC) were synthesized and characterized by various analyses. The successful synthesis and the great crystallinity of the samples were consented by XRD analysis. SEM and TEM were applied to study the morphology of the synthesized samples. The simultaneous presence of C, Zn, and Cr elements was well confirmed by EDX and dot mapping analyses demonstrating the successful preparation of nanocomposites. According to the BET analysis, ZnCr LDH nanocomposites with BC and CNT had more specific surfa ...Более
As the urban population increases and the level of social life advances, the amount of wastewater originating from houses, institutions and industries increases as well. It is necessary for the infrastructure systems in settlements to be sustained under healthy conditions. Since the subsequent repair of infrastructure systems is difficult, appropriate selection of the materials used in these systems is of importance. Concrete pipes are widely used in sewerage systems. In the present study, it was aimed to improve the biological corrosion resistance of concrete pipes via coating with various ma ...Более
Electrocoagulation (EC) is a significantly efficient method for As removal from waters and received considerable attention recently. In this study, the natural groundwater (GW) samples containing As concentrations of GW-1: 538.8 mu g L-1, GW-2: 1132.1 mu g L-1, and GW-3: 52, 000 mu g L-1 were obtained from different provinces and treated by EC process using different iron anodes (plate, ball, and scrap). To achieve drinking water As standard (10 mu g L-1), the operational time, applied current, and As removal optimization for all anode types were studied. At applied current of 0.025 A, the As ...Более
Application of activated carbon (AC) obtained from cotton wastes (bolls, stems, and roots) for phenol adsorp-tion from water, or wastewater dephenolization, is presented. The kinetics of phenol adsorption by carbon adsor-bents were studied using UV/Vis spectrophotometer. The porosity of the formed ACs ranged from 1.952 to 2.339 cm3/g, the volume of macropores was from 1.79 to 2.09 cm3/g, while the commercial sample BAU-A showed 1.920 and 1.320 cm3/g, respectively. The highest phenol adsorption rate, 32.49-52.80 mg/(g center dot min), was observed for contact time up to 5 min on carbon adsorben ...Более
In this study, a ternary layered double hydroxide containing Zn, Co, and Fe transition metals (ZnCoFe LDH) was developed using a co-precipitation procedure. The as-synthesized photocatalyst was evaluated for its perfor-mance in the degradation of methylene blue (MB) under visible light irradiation. The effects of various process conditions including photocatalyst dosage, pollutant concentration, pH, lamp distance, and lamp power were investigated. The ZnCoFe LDH achieved approximately 74 photodegradation efficiency owing to the narrow bandgap of 2.14 eV. The Langmuir-Hinselwood rate constants ...Более