The Improvement of Soil Sorption Characteristics by Biochar Ammendments

Bc. Marek Švec

Master's thesis

Abstract:

The biochar is a re-discovered technology based on pyrolysis of biomass from plant and animal production. It is a carbon rich material with properties and nutrient content depending both on pyrolysis conditions and original biomass. Its major attributes are very large specific surface area, high porosity of different pore size and high cation exchange capacity. Due to its properties, biochar is an effective media for adsorbing and immobilizing soil contaminants, for the case of this study circumscribed to heavy metals. As a soil amendment, biochar alters soil conditions by affecting soil pH, cation exchange capacity, organic matter and nutrient content, water holding capacity, soil biota and other, which might overall enhance soil sorption capacity in relation to soil conditions.This study evaluates a sorption performance of biochar originating from contaminated biomass obtained from phytoextraction technologies, as pyrolysis is one way of disposing contaminated biomass, and compares it to performance of clean commercially available biochar by amending these biochars into two Fluvisols: Litávka soil, characterized as clay-loamy Fluvisol with significant heavy metal pollution coming from smelter facility, and Choťánky soil, unpolluted sandy-loam Fluvisol coming from agricultural field. For each soil the mixtures with both biochars as well as pure soil and biochar materials (creating sample matrix) were tested in desorption and batch sorption experiments, with Cd, Pb, and Zn metals being in focus of the study. During desorption experiments the release of the three metals from matrix was monitored, and during sorption experiments the sample matrix was loaded with 7 increasing concentrations of Cd, Pb, and Zn in a single element sorption.The desorption experiment showed no released metals from contaminated biochar. The sorption results show that contaminated biochar is efficient in enhancing soil sorption capacity, especially in sandy-loam Choťánky soil. Moreover, its sorption efficiency is even higher than the one of clean commercial biochar. The examined 1 % (w/w) biochar amendment ratio is however not sufficient for such contaminated soil as Litávka.

Keywords

Biochar, Contaminated Biochar Disposal, Sorption, Soil Contamination, Lead, Cadmium, Zinc

Language used: English

Date on which the thesis was submitted / produced: 13. 4. 2016

Thesis defence

• Supervisor: prof. Ing. Pavel Tlustoš, CSc.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Natural Resources and Environment / Natural Resources and Environment