Preparation, characterization of wheat residue based anion exchangers and its utilization for the phosphate removal from aqueous solution

Iranian Natural Red Soil and Its Modified Form with EDTA for Removal of Phosphorous from Aqueous Solution

“…The removal rate of amended soils was higher than raw soil. Similar results have been observed on absorbent that made of coal ash, red mud and wheat waste [9]- [11].…”

Characteristics of amine-crosslinked wheat straw and its adsorption mechanisms for phosphate and chromium (VI) removal from aqueous solution

“…4a). As shown in some literatures, the adsorption process of some adsorbents with positive surface charges often displayed a general trend of decrease as the solution pH value increases (Krishna & Susmita, 2006;Park et al, 2008;Xu et al, 2010); this may be attributed to the less attractive or more repulsive electrostatic interaction resulting from the increased negatively charged surface sites at higher solution pH values. What is more, when the pH increases beyond 10.0, the OH − will increase significantly, and the exchange sites for phosphate adsorption will decrease on the outer surface of AC-WS due to the presence of excess OH − ions competing with phosphate ions for adsorption sites and a result of the adsorption capacity decreases (Ong, Lee, & Zainal, 2007).…”

“…Three milliliters of ethylenediamine was added and the mixture was stirred for 45 min at 85 • C, followed by adding 9 ml of triethylamine for grafting and stirring for 120 min at 85 • C. The product was washed with 250 ml of distilled water to remove the residual chemicals, dried at 60 • C for 12 h and sieved to obtain particles smaller than 250 m in diameter (Orlando, Baes, Nishijima, & Okada, 2002;Xu, Gao, Yue, Zhong, & Zhan, 2010).…”

Preparation of cationized pine sawdust for nitrate removal: Optimization of reaction conditions

“…dimethylamine, epichlorohydrin, N,Ndimethylformamide (EDM method) and a pyridine catalyst (Orlando et al, 2002), N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHMAC) (Wartelle and Marshall, 2006), and choline-based ionic liquids (Abbott et al, 2006). A commonly used method involves cationization and cross-linking using epichlorohydrin, ethylenediamine and triethylamine in the presence of N,Ndimethylformamide (ETM method) (Wang et al, 2010;Xu et al, 2010;Ker€ anen et al, 2013;Leivisk€ a et al, in press). The ETM method is an effective, high-yield method for the production of strong base anion exchange resins from lignocellulosic materials but the epichlorohydrin used in the synthesis is highly toxic.…”