Visible light-driven ZnO/Fe3O4 magnetic nanoparticles for detoxification of diazinon: the photocatalytic optimization process with RSM-BBD model.

Today, diazinon is one of the most widely used organophosphorus pesticides, whose widespread use can cause many ecological and biological risks. In this research, a magnetic ZnO/Fe3O4 nanoparticle was used to investigate the photocatalytic degradation of diazinon. Sol-gel synthesis was used to create the nanoparticle, which was then characterized using XRD, FTIR, FESEM, VSM, and XPS techniques. The design of photocatalytic degradation experiments was done using the response surface method and the Box-Behnken design model. The investigated parameters include pH, nanoparticle concentration, diazinon concentration, and irradiation time. The characterization of the ZnO/Fe3O4 nanoparticle showed well-formed crystalline phases and a cubic spinel structure. Additionally, the shape of the nanoparticle is almost uniform and spherical. The FT-IR spectrum also confirmed the presence of all functional groups related to ZnO and Fe3O4 in the ZnO/Fe3O4 nanoparticles structure. The synthesized nanocomposite has superparamagnetic properties and a very small coercive field, making it easily recyclable, according to a VSM analysis. XPS results also showed the presence of Fe (Fe 2p1/2 and Fe 2p3/2), Zn (Zn 2p1/2 and Zn 2p3/2), oxygen (O1s), and weak carbon (C1s) peaks in the ZnO/Fe3O4 structure. The results of the photocatalytic optimization experiments showed that the highest efficiency of diazinon toxin degradation is 99.3% under the conditions of pH 7, diazinon initial concentration of 10 mg/L, nanoparticle concentration of 1 g/L, and a contact time of 90 min. This result is very close to the BBD model's predicted removal efficiency under optimal conditions (100%). As a result, the ZnO/Fe3O4 nanocomposite can produce active free radicals through UV radiation, and these radicals can successfully remove diazinon under actual conditions.

Integration of LCSA and GIS-based MCDM for sustainable landfill site selection: a case study.

The paper aims at developing a framework for decision-support to select a sustainable landfill site in Bardaskan City (Iran) by combining life cycle sustainability assessment (LCSA) concepts and geographic information system (GIS)-based multi-criteria decision-making (MCDM). Overall, 13 criteria were chosen (three constraints and 10 factors) and classified into three main aspects of sustainability (i.e., environmental, social, and economic) to achieve the research goals. Boolean and fuzzy logic were employed to standardize the classified constraints and factors, respectively. Analytic hierarchy process (AHP) was used to calculate the factors' weights and then suitability maps were produced using the GIS analysis. The layers were combined using simple additive weighting (SAW). Next, the most sustainable sites were obtained. The results indicated that distance from city backline, groundwater depth, and distance from rural areas were the most significant factors with the weight of 0.338, 0.141, and 0.129, respectively. The final map of suitable sites was created by classifying the SAW layer according to 75, 80, and 85% of suitability to show the high, medium, and low priority areas for landfill site selection, respectively. Therefore, integration of LCSA and GIS-based MCDM to select the sustainable landfill site for municipal solid waste (MSW) is highly important, which can be effectively employed in regional and urban planning to select the location of appropriate and sustainable landfills.

Synthesis of modified beta bismuth oxide by titanium oxide and highly efficient solar photocatalytic properties on hydroxychloroquine degradation and pathways.

With the outbreak of coronavirus pandemic the use of Hydroxychloroquine increased. These compounds have harmful effects on the environment, such as generation of antibiotic-resistant bacteria; therefore, their degradation has been considered as one of the environmental challenges. The purpose of this research is to synthesize heterogeneous structure of TiO2/ß-Bi2O3 by hydrothermal method for solar degradation of Hydroxychloroquine. Then, the accurate characteristics of the synthesized samples were investigated by XRD, FESEM, TEM, XPS, UV-vis (DRS), and BET surface analyzer. Photocatalytic degradation of Hydroxychloroquine was studied under sunlight, and it was found that the visible light absorption of TiO2 photocatalyst by mixing ß-Bi2O3 nanoparticles was greatly increased and 91.89% of the degradation was obtained in 120 min of photocatalytic reaction. This improvement can be attributed to the increased specific surface area, efficient charge transfer, and reduced electron-hole recombination with the ß-Bi2O3 compound. Kinetic studies also reacted to follow pseudo-first-order kinetics. Also, demonstrated high stability and recyclability for nanoparticles, so that after 6 cycles of using the catalyst in take, 70.59% degradation was performed. According to the results, the excellent photocatalytic degradation activity demonstrated by the TiO2/ß-Bi2O3, therefore, it is a potential candidate for the process of removing other organic contaminants from aqueous solutions.

Biogenic transport of glyphosate in the presence of LDPE microplastics: A mesocosm experiment.

The accumulation of plastic debris and herbicide residues has become a huge challenge and poses many potential risks to environmental health and soil quality. In the present study, we investigated the transport of glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA) via earthworms in the presence of different concentrations of light density polyethylene microplastics in the litter layer during a 14-day mesocosm experiment. The results showed earthworm gallery weight was negatively affected by the combination of glyphosate and microplastics. Glyphosate and AMPA concentrated in the first centimetre of the top soil layer and the downward transport of glyphosate and AMPA was only detected in the earthworm burrows, ranging from 0.04 to 4.25 µg g-1 for glyphosate and from 0.01 (less than limit of detection) to 0.76 µg g-1 for AMPA. The transport rate of glyphosate (including AMPA) from the litter layer into earthworm burrows ranged from 6.6 ±â€¯4.6% to 18.3 ±â€¯2.4%, depending on synergetic effects of microplastics and glyphosate application. The findings imply that earthworm activities strongly influence pollutant movement into the soil, which potentially affects soil ecosystems. Further studies focused on the fate of pollutants in the microenvironment of earthworm burrows are needed.