Comparing biosorbent ability of modified citrus and durian rind pectin

Biosorbent ability of modified durian rind, durian rind, citrus and modified citrus pectin for removals of toxic heavy metals was investigated, and data were analyzed using multivariate analysis of variance (MANOVA) and cluster analysis (CA). Degree of esterification (% DE) of the biosorbents ranged between 22.33% and 60.81%, and was in the order; modified citrus pectin < modified durian rind pectin < durian rind pectin < citrus pectin. In most cases the order of biosorbent ability was; modified citrus pectin > modified durian rind pectin, citrus pectin > durian rind pectin. MANOVA showed a significant difference between samples and concentration of biosorbents, while CA classified the four biosorbent samples (based on biosorbent ability) into three different clusters; (1) citrus pectin and modified durian rind pectin, (2) durian rind pectin and (3) modified citrus pectin. The uptake of heavy metal by biosorbents was dependent on chemical structure of pectin and increased with biosorbent concentration and in most cases in accordance with the reduction in % DE.