Chemical reduction of nitrate by zerovalent iron nanoparticles adsorbed radiation-grafted copolymer matrix

Abstract

Abstract. This research specifi cally focused on the development of a novel methodology to reduce excess nitrate in drinking water utilizing zerovalent iron nanoparticles (nZVI)-stabilized radiation-grafted copolymer matrix. nZVI was synthesized by borohydrate reduction of FeCl 3 and stabilized on acrylic acid (AAc)-grafted non-woven polyethylene/polypropylene (NWPE/PP-g-AAc) copolymer matrix, which was grafted using gamma radiation. The use of nZVI for environmental applications is challenging because of the formation of an oxide layer rapidly in the presence of oxygen. Therefore, radiation-grafted NWPE/PP synthetic fabric was used as the functional carrier to anchor nZVI and enhance its spreading and stability. The chemical reduction of nitrate by nZVI-adsorbed NWPE/PP-g-AAc (nZVI-Ads-NWP) fabric was examined in batch experiments at different pH values. At low pH values, the protective layers on nZVI particles can be readily dissolved, exposing the pure iron particles for effi cient chemical reduction of nitrate. After about 24 h, at pH 3, almost 96% of nitrate was degraded, suggesting that this reduction process is an acid-driven, surface-mediated process. The nZVI-water interface has been characterized by the 1-pK Basic Stern Model (BSM). An Eley-Rideal like mechanism well described the nitrate reduction kinetics. In accordance with green technology, the newly synthesized nZVI-Ads--NWP has great potential for improving nitrate reduction processes required for the drinking water industry.

Nitrates Removal from Simulated Groundwater Using Nano Zerovalent Iron Supported by Polystyrenic Gel

“…Nitrate–nitrogen contamination of global water resources has become an environmental and public health problem worldwide. Although nitrates and nitrogenous compounds are used as important elements in the life process, nitrate is a potential hazard when it is found in drinking water at high enough concentrations [ 1 ]. Nitrates act as a precursor to several health hazards: methemoglobinemia (e.g., blue baby syndrome), carcinoma, malformation, and mutation defects [ 2 ].…”

Nitrate removal in potable groundwater by nano zerovalent iron under oxic conditions

“…Drawbacks of the electrodialysis process include high system complexity during operation and energy demand ( Jensen et al 2012). Disadvantages of the biological denitrification process include the accumulation of microbial degradation products in treated water, leading to bacteriological contamination of potable water and associated health risks (Ratnayake et al 2017), and high capital and monitoring costs (Jensen et al 2012). Adsorption using various adsorbents may not be effective and applicable for in-situ treatment of potable water because of the possible interferences from the impurities that are simultaneously present with nitrate in aquifers (Rocca et al 2007).…”

“…Among various technologies proposed to remove nitrate in potable water, nano zerovalent iron (nZVI) has been reported as an effective reductant (Ratnayake et al 2017). In comparison to other technologies, the application of nZVI is effective and superior in nitrate reduction from nitrate-contaminated groundwater because of its effective surface to volume ratio, high electron-donating potency, nano-scale, unique atomic properties, magnetic properties, and abundance (Hwang et al 2011;Ryu et al 2011;Ratnayake et al 2017;Elshafai et al 2018). Also, the use of nZVI does not lead to the generation and discharge of concentrated waste during the treatment process.…”