Uklanjanje teških metala iz vode piljevinom drveta, celulozom i lignitom

Abstract

Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR). Istraživana je mogućnost primene piljevine različitih vrsta drveta, tehničke celuloze i Kraft lignina kao adsorbenata različitih teških metala iz vode. Za adsorpciju teških metala koji su u vodi prisutni u vidu katjona, kao najbolji adsorbenti su se pokazale piljevine drveta hrasta i bagrema i Kraft lignin. Za adsorpciju hromatnih anjona najbolje su se pokazali Kraft lignin i piljevina drveta jele. Kapacitet adsorpcije piljevine drveta se može poboljšati prethodnim tretiranjem piljevine rastvorom natrijum hidroksida. Efikasnost adsorpcije teških metala iz vode je bolja: kada se primenjuju sitnije čestice piljevine, kada se radi sa većom količinom piljevine i/ili dvostepeno, na povišenoj temperaturi. Utvrđen je optimalni pH za adsorpciju pojedinih teških metala, optimalno vreme kontakta adsorbenta i vode, uticaj prisustva različitih teških i lakih metala i anjona na efikasnost adsorpcije teških metala. Adsorbovani teški metali se mogu desorbovati sa piljevine drveta rastvorima različitih mineralnih kiselina. Piljevina drveta se može primeniti u više ciklusa adsorpcije-desorpcije, uz nešto smanjeni kapacitet adsorpcije. Ispitivani adsorbenti se mogu primeniti i u dinamičkim uslovima adsorpcije u koloni.

Abstract was processed by technology for Optical character recognition (OCR). The possibility of adsorption of different heavy metals from water by sawdust of different species of wood, pulp, and Kraft lignin has been investigated. Oak and black locust sawdust, and Kraft lignin were shown to be the most efficient adsorbents for heavy metals in cationic form. Kraft lignin and fir sawdust were shown to be the most efficient adsorbents for chromium anions. Previous treatment of wood sawdust by sodium hydroxide solution can increase its adsorption capacity. Better adsorption efficiency was accomplished: when smaller parts of sawdust were used, when a large amount of sawdust was used and/or two stage process was applicated, and adsorption process was done on higher temperature. There were established: optimum initial pH value for different heavy metals, optimum adsorbent - water contact time, and degree of influence of other different heavy and lite metals, and anions on adsorption efficiency. Adsorbed heavy metals can be desorbed from vvood sawdust with solutions of different mineral acids. Sawdust can be applied in several cycles of adsorption - desorption, with some decrease of adsorption capacity. Investigated adsorbents can be also used in dynamic conditions of adsorption in column.