كاربرد مواد زايد جامد در تصفيه پساب هاي حاوي فلزات سنگين

Application of Organic Solid Waste in Wastewater Treatment

Sawdust is an organic solid waste material of high adsorbing potential in removal of heavy metal ions from wastewater, so it can be used in treating industrial waste. In this study, the removal of copper, chromium, and nickel from laboratory prepared wastewater, through sawdust, was investigated. Waste water containing heavy metals was added was to sawdust to evalute the rate of metal ion adsorption in different conditions of acidity, contact times and concentrations. The results indicated that the adsorption of these heavy metal ions increased with an increase in pH and reached a maximum at pH=5. In addition, percent adsorption depended on kind of ion, so that at pH=5 the percent adsorptions for Cu (II), Ni (II) and Cr (III) were 65%, 56% and 50% respectively. Adsorption increased with the initial concentration of metal ions and then decreased, because of sawdust saturation. Saturation capacity per gram of sawdust for copper, nickel and chrome ions was 28.2, 11.8 and 23.2 ppm respectively. Also adsorption increased with contact time. However, this process was rapid, and in the initial 10 minutes, percent adsorption got to between 45% and 65%. And finally the favorable needed time was determined to be 60 minutes.