Removing Pb2+ with a pectin-rich fiber from sisal waste

Abstract

A pectin-rich dietary fiber from sisal waste (P-SF), containing 11.8% pectin, was produced by a sequential enzymatic-ultrasonic process. P-SF was effective in adsorbing Pb²⁺ from aqueous solution with a maximum adsorption amount of 184 mg g⁻¹. Adsorption isotherms were fitted well by the Langmuir equation, and the adsorption kinetics could be described by a pseudo-second-order model. X-ray photoelectron spectroscopy and energy dispersive spectroscopy suggested that Pb²⁺ was adsorbed by P-SF via ion exchange, complexation and mineral precipitation. Dietary supplementation with 10% (w/w) P-SF in basal feed led to a significant decrease in Pb²⁺ in the brain, liver and kidney. P-SF has greater in vivo efficacy of Pb²⁺ removal as compared to commercial soybean dietary fiber. The reduction of brain Pb²⁺ level by P-SF was as effective as by a Pb²⁺ excretion drug. These findings suggested that P-SF has a great potential to be used as a dietary supplement to cope with Pb²⁺ poisoning.