Natural Organic Matter in Water

Characterization and Treatment Methods

Mika Sillanpaa, Mika Silanpää, Mika Sillanpää

• Publisher: Butterworth-Heinemann
• Year: 2014
• eBook ISBN: 9780128017197
• Topic: Technology & Engineering
• Subtopic: Environmental Management
• Index: Technology & Engineering

Approximately 77 percent of the freshwater used in the United States comes from surface-water sources and is subject to natural organic matter contamination according to the United States Geological Survey. This presents a distinct challenge to water treatment engineers. An essential resource to the latest breakthroughs in the characterization, treatment and removal of natural organic matter (NOM) from drinking water, Natural Organic Matter in Waters: Characterization and Treatment Methods focuses on advance filtration and treatment options, and processes for reducing disinfection byproducts. Based on the author's years of research and field experience, this book begins with the characterization of NOM including: general parameters, isolation and concentration, fractionation, composition and structural analysis and biological testing. This is followed by removal methods such as inorganic coagulants, polyelectrolytes and composite coagulants. Electrochemical and membranes removal methods such as: electrocoagulation, electrochemical oxidation, microfiltration and ultrafiltration, nanofiltration and membrane fouling.- Covers conventional as well as advanced NOM removal methods- Includes characterization methods of NOM- Explains removal methods such as: removal by coagulation, electrochemical, advanced oxidation, and integrated methods

Chapter 1

General Introduction

Mika Sillanpää Lappeenranta University of Technology, LUT Faculty of Technology, LUT Chemtech, Laboratory of Green Chemistry, Sammonkatu 12, 50130 Mikkeli, Finland

Abstract

Natural organic matter (NOM) is a complex matrix of organic materials and a key component in aquatic environments. As a result of the interactions between the hydrologic cycle and the biosphere and geosphere, the water sources of drinking water generally contain NOM. The amount, character, and properties of NOM vary considerably according to the origins of the waters and depend on the biogeochemical cycles of their surrounding environments. Also, the interrelation between NOM and climate change has attracted a great deal of attention in recent research. NOM has a significant impact on many aspects of water treatment, including the performance of unit processes, necessity for and application of water treatment chemicals, and the biological stability of the water. As a result, NOM affects potable water quality as a carrier of metals and hydrophobic organic chemicals and by contributing to undesirable color, taste, and odor problems. Moreover, NOM has been found to be the major contributor to disinfection by-product (DBP) formation. Changes in NOM quantity and quality have a significant influence on the selection, design, and operation of water treatment processes. These changes also cause operational difficulties in water utilities. High seasonal variability and the trend toward elevated levels of NOM concentration pose challenges to water treatment facilities in terms of operational optimization and proper process control. To improve and optimize these processes, it is vital to characterize and quantify NOM at various stages during the purification and treatment process. It is also essential to be able to understand and predict the reactivity of NOM or its fractions during different phases of the treatment. Once the composition and quantity of NOM in the water source has been examined, suitable methods for efficient NOM removal can be applied. No single process alone can be used to treat NOM due to its high variability. The most common and economically feasible process available is coagulation and flocculation followed by sedimentation/flotation and filtration. Other treatment options for NOM removal include magnetic ion exchange resin (MIEX^®) techniques, activated carbon filtration, membrane filtration methods, and advanced oxidation processes.

Keywords

Characterization; Climate change; Coagulation; Drinking water; Natural organic matter (NOM); Water analysis; Water treatment

Abbreviations

AOP

Advanced oxidation process

DBP

Disinfection by-product

FA

Fulvic acids

FTICR-MS

Fourier transform ion cyclotron resonance mass spectrometry

GAC

Granulated activated carbon

HA

Humic acids

HAAs

Haloacetic acids

HMM

High molecular mass

HMW

High molecular weight

LMM

Low molecular mass

LMW

Low molecular weight

MIEX^®

Magnetic ion exchange resin

NF

Nanofiltration

NMR

Nuclear magnetic resonance

NOM

Natural organic matter

Py-GC-MS

Pyrolysis gas chromatography-mass spectrometry

SEC

Size exclusion chromatography

SUVA

Specific UV absorbance

THM

Trihalomethane

TOC

Total organic carbon

UV–Vis

Ultraviolet and visible

Natural organic matter (NOM) is ubiquitous in waters, sediments, and soils. Aquatic NOM is derived both from the breakdown of terrestrial plants and as the by-product of bacteria, algae, and aquatic plants. NOM is defined as a complex matrix of organic materials present in all natural waters.

A wide range of terminology is used to describe NOM in the environment. These terms are listed and comprehensively discussed in recent reviews by Filella (2009) and Uyguner-Demirel and Bekbolet (2011). NOM is a key component in aquatic environments and is present in all fresh waters, particularly surface waters. As a result of the interactions between the hydrologic cycle and the biosphere and geosphere, the water sources of drinking water generally contain NOM. It consists of a range of compounds with a wide variety of chemical charges, from highly charged to uncharged. These also vary widely according to chemical composition and molecular size, molecular weight (the molecular masses of humic substances range from several hundreds to tens of thousands), and structure. NOM compounds are complex mixtures possessing unique combinations of various functional groups, including esteric, phenolic, quinine, carboxylic, hydroxyl, amino, and nitroso, which are usually negatively charged at neutral pH (Gjessing, 1976). Humic substances, which are the major constituents of NOM in waters, are amorphous, dark colored, and acidic in nature. Structurally, they consist of substituted aromatic rings linked by aliphatic chains (Uyguner-Demirel and Bekbolet 2011). NOM also influences the acidity, mobility, and toxicity of metals and organic pollutants and weathering (Winterdahl, 2013).

Water systems often have multiple sources of NOM, thus different organic carbon fractions (Rigobello et al., 2011). The amount, character, and properties of NOM vary considerably according to the origins of the waters, and depend on the biogeochemical cycles of their surrounding environments (Fabris et al., 2008). The factors that determine the composition of NOM are location dependent and include the source of organic matter, the water chemistry, temperature, pH, and biological processes (Leenheer and Croué, 2003). Thus, the character of NOM varies with source and season (Sharp et al., 2006a,b; Fabris et al., 2008; Rigobello et al., 2011; Nkambule et al., 2012). Moreover, the range of organic components in NOM can vary seasonally at the same location (Sharp et al., 2006a,b; Smith and Kamal, 2009), for example, due to rainfall, snowmelt runoff, floods or droughts. Floods and droughts are the main indications of the impact of climate change on water availability and quality. It has been suggested that these changes may explain the increase in the total amount of NOM (Delpla et al., 2009; Evans et al., ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• List of Abbreviations
• Chapter 1. General Introduction
• Chapter 2. Characterization of NOM
• Chapter 3. NOM Removal by Coagulation
• Chapter 4. NOM Removal by Electrochemical Methods
• Chapter 5. Membranes
• Chapter 6. NOM Removal by Advanced Oxidation Processes
• Chapter 7. NOM Removal by Adsorption
• Chapter 8. Ion Exchange
• Chapter 9. Integrated Methods
• Bibliography
• List of Journal Titles with Abbreviations
• Index