Biodegradability of organic carbon following hydrothermal carbonization treatment
Date
2021-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Hydrothermal carbonization (HTC) is a ‘wet pyrolysis process’ that opens up a
field of potential for feedstocks such as the non-traditional renewable and
abundant wet agricultural residues, and municipal wastes for char production.
It reduces waste and substitutes primary fuels as a source of energy. The
product, known as hydrochar, has received attention because of its potential
as precursors of activated carbon in wastewater remediation, soil remediation
applications, solid fuels, and other carbonaceous materials. However,
persistent priority and emerging micropollutants are consistently detected in
numerous wastewater treatment plants that could potentially serve as
feedstock for the process- this is a cause for concern. The goal of this study
was to assess the impact of HTC on organic micropollutants. The working
hypothesis was that the combination of high temperature and pressure would
sterilize the biomass and transform micropollutants into benign products, while
any residue would be readily biodegradable. Experiments indicated that char
resulting from belt press sludge carbonized at 240 (with a corresponding°C
pressure of 3,3MPa) was sterile, exhibiting a high fuel ratio of 0,72 and HHV
21,40 Mj/kg. Subsequently, 4 test compounds that are; carbamazepine,
chloramphenicol, methylparaben, and bisphenol-A were studied for their
biodegradability following HTC. Biodegradation of the test compounds
extracted from the hydrochar ranged between 84% and 100% while only
methylparaben indicated complete biodegradability from the liquid phase.
Results of the study prove that with optimization, the question presented by
residual micropollutants persisting in the natural environment following HTC
technologies can be mitigated.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
Description
Thesis (MSc)--Stellenbosch University, 2021.
Keywords
Hydrothermal carbonization (HTC), Biodegradation, Micropollutants -- Environmental aspects, Hazardous waste site remediation, Sewage sludge -- Disinfection, UCTD