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Struvite precipitation is an efficient approach to recover phosphorus and ammonium from wastewater to alleviate many operational as well as environmental issues. The sparingly soluble nature of struvite in water makes it a potential slow‐release fertilizer whose adequacy has been investigated in various soil‐based cultivation. However, struvite has diverse applications other than field usage which are yet to be explored. The review highlights the usage of struvite as a fertilizer in soil along with its other applications as a nutrient supplier in hydroponic systems, fire retardants, and sorbent for the adsorption of heavy metals, dye, and gases. The research gaps between the lab and the application of the struvite products in the market for its proper utilization have also been reported. Thus, struvite produced from wastewater can be a promising green chemistry that could replace many costly, synthetic, and harmful products, while conserving phosphorous resource at the same time. This article is categorized under:Climate and Environment > Circular EconomyEmerging Technologies > MaterialsSustainable Development > Goals [ABSTRACT FROM AUTHOR]

The surface of the g-C 3 N 4 was altered by impregnating W 6+ ions that transformed to homogeneously coated oxide layer by a calcination process. An enhanced absorption and the suppressed de-excitation in the emission spectra, with the increasing W 6+ loading, exposed the supporting role of the coated layer in extending the spectral response as well as the prolonged life span of excitons. The same was further supported by electrochemical impedance spectroscopy (EIS). The XRD and XPS analysis revealed the coated layer as highly crystalline pure phase monoclinic WO 3 with the majority of impregnated tungsten ions in 6+ oxidation state respectively, whereas the FESEM and HRTEM analysis substantiated the uniformity of the coated layer with the interlayer spacing of the 0.369 nm. Additionally, the probable formation of individual WO 3 nanoparticles or clusters was ruled out. The as-synthesized impregnated photocatalysts, in comparison to pure g-C 3 N 4, were subjected to natural sunlight exposure for the photocatalytic removal of chlorophenol derivatives (2-CP, 3-CP, 4-CP, 2,3-DCP, 2,4-DCP, 2,4,6-TCP and PCP) that revealed the 5 wt% coating as the optimum level for significant removal. The progress of the photocatalytic process was monitored by periodic HPLC analysis whereas ion chromatography (IC) was used for the estimation of released ions. The mineralization capability of the as-synthesized W 6+ coated catalysts was measured by the time scale TOC measurements. As the formation of intermediates was indicated in HPLC analysis, selected samples were subjected to GC-MS analysis for the identification of the nature of intermediates. The variable degree of removal of chlorophenol derivatives signified the role of the position and orientation of Cl group. The kinetics of the removal process was evaluated with the calculation of rate constants. The results extracted from the analytical tools and the associated band edge potentials were correlated to speculate the probable mechanism as well as the identification of major reactive oxygen species (ROS) involved in the removal process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Industrial dye effluents, which are a major wastage component that enter the natural environment, pose a significant health risk to human and aquatic life. Therefore, the effective removal of dye effluents is a major concern. Against this backdrop, in this study, a low-cost, earth-abundant, and ecofriendly ɤ-Fe 2 O 3 -PPy nanocomposite was prepared employing the conventional hydrothermal method. The morphology, functional groups, and elemental composition of ɤ-Fe 2 O 3 -PPy were characterized by XRD, SEM, XPS, and FTIR studies. Under optimized conditions, the prepared novel ɤ-Fe 2 O 3 -PPy nanocomposite showed a high methylene blue (MB) adsorption capacity of 464 mg/g, which is significantly higher than that of existing adsorbents such as CNTs and polymer-modified CNTs. The adsorption parameters such as pH, adsorbent dosage, and ionic strength were optimized to enhance the MB adsorption capacity. The adsorption results revealed that MB is adsorbed onto the adsorbent surface via electrostatic interactions, hydrogen bonding, and chemical binding interactions. In terms of practical application, the adsorbent's adsorption-desorption ability in conjunction with magnetic separation was investigated; the prepared ɤ-Fe 2 O 3 -PPy nanocomposite exhibited excellent adsorption and desorption efficiencies over more than seven adsorption-desorption cycles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)