Effects of nano zero valent iron and entrapped nano zero valent iron in alginate polymer on poly aromatic hydrocarbons removal

Abstract

A BSTRACT Modern countries deal with the different types and variety of industries. Large number of these industries depends on water and mainly causes water contaminations. One of these contaminants is poly aromatic hydrocarbons (PAHs). This study successfully used magnetic nano sorbent especially nano zero-valent iron (nZVI) and encapsulated nZVI in alginate polymer to reduce hydrocarbons contaminations in water by studying the effects of contact time, adsorbent dose, pH, stirring rate, initial PAHs concentration and temperature. Batch study was conducted and removal efficiency between 43% and 56 % was achieved for different PAHs concentrations (222, 74, and 37 µg/L) with 0.2 g of nZVI/L pH 7, stirring rate 100 rpm, 30 o C and 30 min contact time. On the other hand the encapsulated nZVI in alginate biopolymer was also studied under the same conditions. The encapsulation process was mainly depended on the quantity of the nZVI entrapped in alginate biopolymer. The quantity of nZVI used in this research was 4 g/L of alginate gel matrix. Removal efficiency between 50 and 75% was achieved for different PAHs concentrations (222, 74, and 37 µg/L) with 20 g/L Ca-alginate/nZVI, pH 7, stirring rate 100 rpm, 30 o C and 30 min contact time. The results indicated that alginate increase stability of nZVI against oxidation and increase PAHs removal efficiency. KEYWORDS alginate biopolymer; encapsulate nZVI/alginate; magnetic nanosorbents; nano zero valent iron; poly aromatic hydrocarbons remova