Metal removal from wastewater using peat

Peat has been investigated by several researchers as a sorbent for the capt ure of dissolved metals from wastestreams. Besides being plentiful and inex pensive, pear possesses several characteristics that make it an effective m edia for the removal of dissolved metal pollutants. The mechanism of metal ion binding to peat remains a controversial area with ion-exchange, complex ation, and surface adsorption being the prevalent theories. Factors affecti ng adsorption include pH, loading rates, and the presence of competing meta ls. The optimum pH range for metals capture is generally 3.5-6.5. Although the presence of more than one metal in a solution creates competition For s orption sites and less of a particular ion may be bound, the total sorption capacity has been found to increase. Studies have also shown that metals r emoval is most efficient when the loading rates are low. In addition, recov ery of metals and regeneration of the peat is possible using acid elution w ith little effect on peat's sorption capacity. The utilization of peat and other biomass materials for the treatment of wa stewater containing heavy metals is gaining more attention as a simple. eff ective and economical means of pollution remediation. Pelleting processes c an now produce a robust media for a variety of applications where tradition al methods of pollutant removal would he economically or technologically di fficult. (C) 2000 Elsevier Science Ltd. All rights reserved.