Agricutural by-product as metal adsorbent: Sorption of lead(II) from aqueous solution onto coirpith carbon

Activated carbon prepared from coirpith waste was used for the adsorptive r emoval of Pb(II) from aqueous solution. Parameters such as agitation time, metal ion concentration, adsorbent dose and pH were studied. Adsorption equ ilibrium was reached in 30 min for solution containing 25 and 50 mg l(-1) a nd 40 min for solution containing 75 and 100 mg l(-1) Pb(II), respectively. Adsorption parameters were determined using both Langmuir and Freundlich m odels. The adsorption capacity was 263 mg g(-1). Pb(II) removal increased w ith increased pH from 2 to 4 and remained constant up to pH 10. Desorption studies were also carried out with dilute hydrochloric add to recover both carbon and Po(II). As the raw material for the preparation of activated car bon is discarded as waste during coir processing, the production of this ca rbon is expected to be economically feasible.