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The development of controlled release fertilizers (CRF) is a green technology that not only reduces nitrogen loss, caused by volatilization and leaching, but also alters the kinetics of nitrogen release, which, in turn, provides nutrients to plants at a pace that is more compatible with their metabolic needs. With an increasing awareness towards human health and environmental protection, there is a rapid shift towards the development of eco-friendly fertilizers based on natural resources. Majority of the literature on CRF pertains to organic and inorganic material based coatings on fertilizers and among them in the case of neem oil coated urea (NCU) most of the literature is confined to the elucidation of coating effect on increasing the crop yield and plant growth. However, literature lacks any comprehensive study on NCU as a CRF, covering major aspects such as its characterization, determination of nutrient release rate, and comparison with other CRF. The present work is an attempt to fill this gap in scientific knowledge about NCU. In the present study, neem oil coated urea (NCU) was prepared to achieve the controlled release mechanism necessary to meet crop requirements. The characterizations of the uncoated urea (UCU) and NCU were done using scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), Fourier transform infra-red (FTIR), refractive index (RI) and crushing strength test. To establish the superior behaviour of NCU as a CRF, the results were also compared to the literature data of other CRF, namely phosphate slimes (PCU) and bentonite coated (BCU) with chitosan as a binder. The nutrient release experiments showed that NCU gave a release of 1.03 and 45.03 % at the first day and day 30, respectively. The crushing strength test was carried out for the same size particles, and the results showed that NCU has better mechanical strength as compared to UCU, PCU and BCU.

Biopotent hybrid diorganotin(IV) complexes, derived from salicylaldehyde Schiff bases having general formula R2SnL, where LH = (OH)C6H4HC: NCR′(R″)CHR‴OH] [where R = Me or Bu], were logically designed, generated, and characterized using spectroscopic techniques, single‐crystal X‐ray investigations, and DFT studies. Different diorganotin(IV) complexes were synthesized because of interaction between diorganotin(IV) dichloride and sodium salts of Schiff bases of salicylaldehyde ligand in anhydrous refluxing THF at 1:1 and 1:2 molar ratio (Product A and B). The chelating property of Schiff bases replaces organo group from diorganotin(IV) dichloride. It creates an O2SnL type of complex when diorganotin(IV) dichloride and ligand interact in 1:2 ratio, which is this study's most fascinating aspect. The characterization of these complexes is aided by physicochemical and spectroscopic investigations, including IR and NMR (1H, 13C, and 119Sn). Single‐crystal X‐ray investigations, mass spectrum studies, and DFT investigations suggest the dimeric structure of these compounds. These diorganotin(IV) complexes have a dimeric structure containing hexacoordinated central tin atom. Two µ2─O atoms bridge the gap between two Sn(IV) atoms in the dimeric dimethyltin(IV) complexes. The DPPH assay results for radical scavenging activity and IC50 values demonstrate the antioxidative potential of diorganotin(IV). [ABSTRACT FROM AUTHOR]

Present work is focused on the preparation of mustard stalk activated carbon (MSAC) using chemical activation with H3PO4 and exploring its properties for its use in dye removal from wastewater. Adsorption variable (dosage, contact time, and solution pH), pore structure, morphology, surface functional groups, equilibrium kinetics and isotherm study for the removal of methylene blue (MB) using MSAC were investigated. The present study showed that an adsorption dosage of 0.2 g L-1 and pH 8 can be considered as optimum for the MB removal. SEM result showed that pore of MSAC was larger than the pore of the mustard stalk (MS). BET surface area and total pore volume of MSAC were found as 510 m2 g-1 and 0.33 cm3 g-1, respectively. Equilibrium adsorption data were examined by Langmuir and Freundlich isotherm models. Better correspondence to the Langmuir model with a maximum adsorption capacity of 212.76 mg g-1 (MB onto MSAC) was obtained. Dimensionless factor, RL revealed favourable nature of the sorption in the MSAC–MB system. Adsorption rates were found to follow the pseudo-second-order kinetics with good correlation. These results show that the MSAC could be used as a renewable and economical alternative to commercial activated carbon in the removal of MB dye from wastewater.

The rapidly growing electroplating industry has led to the discharge of large amounts of wastewater containing heavy metals and organic acids. Innovative techniques are required for the efficient and effective treatment of such effluents. The present work explored electroplating wastewater treatment through new TiO2-NTs/GO/SnO2 electrodes by electro-oxidation (EO) in batch and once-through continuous system. A new electrode with excellent oxidation ability was successfully fabricated by introducing a SnO2 outer layer through a simple anodization method. Moreover, a response surface methodology (RSM)-Box-Behnken design (BBD) model was used to optimize the responses. The effects of operating conditions, i.e. pH (3–9), current (0.1–0.9 A), and time (30–180 min), on the efficiency of the process were investigated. With optimum conditions, 97.1% Cu, 95.7% Zn, 91.2% COD degradation, and 7.32 kWh/m3 energy consumption were achieved. A once-through continuous setup working at a flow rate of 5–20 mL/min was performed under optimal conditions. The electrodes remained durable even after 50 cycles. The contribution of several reactive species to the EO was examined in the presence of scavengers. Moreover, according to a toxicity study, EO can detoxify electroplating effluents. Hence, this EO process, which is low-cost and highly efficient, can be applied to the treatment of electroplating wastewater. [ABSTRACT FROM AUTHOR]

Electro-Fenton (E-Fenton) is a versatile treatment method; however, it has not yet been used for the treatment of electroplating wastewater using graphene oxide (GO) coated TiO2 nanotubes (GO/TiO2NTs) electrode. A simple anodization technique has been adopted to synthesize GO/TiO2NTs electrode. The present work aimed to study an E-Fenton treatment to investigate the effect of different parameters on % COD removal and energy consumption using GO/TiO2NTs electrode. The performance of the treatment process was examined in terms of % COD removal and energy consumed at three process parameters: current, time, and ferrous sulfate concentration. The optimum operating conditions were determined using multiple responses optimization based on Box-Behnken design (BBD). At optimum operational parameters, the results revealed that the % COD removal and energy consumed were 96.27% and 15.35 kWh/m³, respectively. The pseudo-first-order reaction kinetics was fitted to the experimental data at optimum conditions. Possible intermediates were identified based on the GC-MS analysis, and a corresponding tentative degradation pathway has been proposed. Furthermore, a recyclability and stability study of the synthesized electrode has also been performed. Moreover, total organic carbon (TOC) study revealed that E-Fenton has the potential to detoxify electroplating effluents. Hence, GO/TiO2NTs electrodes can be highly efficient in degrading hazardous pollutants. [ABSTRACT FROM AUTHOR]

The graphene oxide (GO) deposited TiO2 nanotube (GO/TiO2) electrode on a titania plate was prepared using a simple anodization method. The morphological and structural properties of TiO2 and GO/TiO2 electrodes have been studied using field emission scanning electron microscopy energy dispersive spectroscopy (FESEM-EDS), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), Raman spectroscopy, Fourier transform infrared spectra (FT-IR), and X-ray photoelectron spectroscopy (XPS). FESEM-EDS analysis confirmed that the 13.56% wt of GO nanoparticles was formed over the TiO2 substrate, with the thickness of the wall to be ∼300 nm. The crystallite size of GO/TiO2, i.e., 19.53 nm, was confirmed by XRD analysis. Analysis of the UV-DRS spectrum showed the bandgap of the synthesized GO/TIO2 nanotube electrode to be 3.052 eV. Box-Behnken design (BBD) under response surface methodology (RSM) was used to design the experiments. The effect of operating input parameters like pH, current (i), and degradation time (t) on % COD degradation (X1) and energy consumed (X2) were also examined. At optimum process parameters, the value of X1 and X2 were 57.61% and 15.00 kWh/m3, respectively. Possible intermediates were identified based on the GC–MS data analysis. Scavenger tests showed that •OH radical plays a major role in electroplating effluents degradation. Based on the results, the EO process using GO/TiO2 electrodes could be considered a promising technique for electroplating effluent degradation due to high degradation efficiency. [ABSTRACT FROM AUTHOR]