Investigating the properties of persistent organic carbon in municipal wastewater treatment biosolids
type: CreativeWork
description: Wastewater treatment plants (WWTP) are the primary pathway for many organic contaminants such as pharmaceuticals and persistent organic pollutants (POPs) found in domestic, industrial and hospital effluents to reach the environment. These substances can accumulate in WWPT sludges or treated biosolids, which are currently subject to limited environmental monitoring or regulation for organic contaminants. The lack of practical tools for assessing the relative quantities of organic contaminants and the potential for these to transfer into the environment presents a barrier to environmental regulators. The aim of this study was to improve understanding of the persistent organic composition of sludges and biosolids to better inform sludge treatment and disposal guidelines. The study combined conventional test methods in a novel approach to assess the leachable and non-biodegradable fraction of organic carbon in sludges and biosolids to characterise how persistent organic pollutants accumulate in these matrices, and subsequently leach when applied to land. Sludges and biosolids from four municipal WWTP were investigated for desorbable dissolved organic carbon (DDOC) using leaching tests. Leachates were then assessed for their relative quantity of persistent DDOC (PDDOC) using biodegradation experiments and optical properties of both DDOC and PDDOC were examined using UV-Vis and FTIR analysis. Sludges from primary and secondary treatment stages, from both nitrifying and non-nitrifying WWTP, and processed biosolids were compared to identify the effect of treatment on relative quantities of DDOC and PDDOC. This is one of the first studies to quantify leachable and non-biodegradable DOC in municipal WWTP sludges and biosolids, comparing results between treatment plant stages and types. The study found that there was little variability in DDOC for primary sludges but DDOC for secondary sludges varied by degree of nitrification in the WWTP, ranging from 11,760 mg.kg-1 in a nitr…
abstract: Wastewater treatment plants (WWTP) are the primary pathway for many organic contaminants such as pharmaceuticals and persistent organic pollutants (POPs) found in domestic, industrial and hospital effluents to reach the environment. These substances can accumulate in WWPT sludges or treated biosolids, which are currently subject to limited environmental monitoring or regulation for organic contaminants. The lack of practical tools for assessing the relative quantities of organic contaminants and the potential for these to transfer into the environment presents a barrier to environmental regulators. The aim of this study was to improve understanding of the persistent organic composition of sludges and biosolids to better inform sludge treatment and disposal guidelines. The study combined conventional test methods in a novel approach to assess the leachable and non-biodegradable fraction of organic carbon in sludges and biosolids to characterise how persistent organic pollutants accumulate in these matrices, and subsequently leach when applied to land. Sludges and biosolids from four municipal WWTP were investigated for desorbable dissolved organic carbon (DDOC) using leaching tests. Leachates were then assessed for their relative quantity of persistent DDOC (PDDOC) using biodegradation experiments and optical properties of both DDOC and PDDOC were examined using UV-Vis and FTIR analysis. Sludges from primary and secondary treatment stages, from both nitrifying and non-nitrifying WWTP, and processed biosolids were compared to identify the effect of treatment on relative quantities of DDOC and PDDOC. This is one of the first studies to quantify leachable and non-biodegradable DOC in municipal WWTP sludges and biosolids, comparing results between treatment plant stages and types. The study found that there was little variability in DDOC for primary sludges but DDOC for secondary sludges varied by degree of nitrification in the WWTP, ranging from 11,760 mg.kg-1 in a nitr…
author: O'Keeffe, Juliette
language: eng
keywords: Biosolids, Sewage, Sludge, Wastewater treatment, Dissolved organic carbon, Persistent organic pollutants, Leaching, FTIR, PDDOC, Environmental risk, Land application, Primary treatment, Secondary treatment, Anaerobic digestion, Thermal treatment
date published: 2019-10
date modified: 2026-07-24T00:50:23Z
provider: Abertay University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Abertay University