Ecology, Environment and Conservation Paper

BEHAVIOUR OF CYANIDE ADSORPTION ONTO LAWN WASTE FROM AQUEOUS SOLUTION AND REAL WASTEWATER

Bahman Ramavandi

Abstract

In this research, a new and simple-prepared adsorbent was provided from lawn waste (LW) for eliminating of cyanide from aqueous solutions. The LW was a mesoporous material with the BET specific surface area of 2.055 m2/g. By FTIR study, several functional groups including hydroxyl, amide, aromatic C=C, and carboxylic groups were identified on the surface of the LW. Kinetic evaluation indicated that the adsorption of cyanide ions onto the LW clearly followed the pseudo-second order rate reaction. The equilibrium adsorption of cyanide onto LW at different temperatures (20, 35, and 50°C) was well represented by Langmuir model. By increasing the temperature from 20 to 50°C, the maximum adsorption capacity was increased. The maximum adsorption capacity of cyanide by LW was attained 128.67 mg/g at 50°C. The results of cyanide adsorption onto LW revealed that the main adsorption mechanisms could be the ionic exchange and chemisorption. A real wastewater of an electroplating plant was effectively treated by LW. Thus, it can be concluded that the lawn waste is cost–effective promising adsorbent for efficient treatment of cyanide– laden wastewater.