Developing a New Class of Ion Exchangers for Selective Removal of Arsenic and Exploring an

82 Pages·2006·0.59 MB·English

Arsenic Water Technology Partnership

Developing a New Class of Ion
Exchangers for Selective Removal of
Arsenic and Exploring an Engineered
Approach for Treatment and Reuse of
Spent Regenerant Brine and for
Enhanced Stability of Process Waste
Residuals
Developing a New Class of Ion Exchangers for Selective Removal of
Arsenic and Exploring an Engineered Approach for Treatment and
Reuse of Spent Regenerant Brine and for Enhanced Stability of
Process Waste Residuals

Prepared by:
Dongye Zhao (Principal Investigator), Thomas Steinwinder, Byungryul An,
and Mark O. Barnett
Department of Civil Engineering, Auburn University, Auburn, AL 36849

And
Timothy A. Kramer
Texas A&M University, College Station, TX 77843

Jointly Sponsored by:
Awwa Research Foundation
6666 West Quincy Avenue, Denver CO 80235-3098

and

U.S. Department of Energy
Washington, D.C. 20585-1290

Published by:

WERC, a Consortium for Awwa Research Foundation
Environmental Education and
Technology Development at
New Mexico State University

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About the Awwa Research Foundation

The Awwa Research Foundation (AwwaRF) is a member-supported, international,
nonprofit organization that sponsors research to enable water utilities, public health
agencies, and other professionals to provide safe and affordable drinking water to
consumers.

The Foundation’s mission is to advance the science of water to improve the quality of
life. To achieve this mission, the Foundation sponsors studies on all aspects of drinking
water, including supply and resources, treatment, monitoring and analysis, distribution,
management, and health effects. Funding for research is provided primarily by
subscription payments from approximately 1,000 utilities, consulting firms, and
manufacturers in North America and abroad. Additional funding comes from
collaborative partnerships with other national and international organizations, allowing
for resources to be leveraged, expertise to be shared, and broad-based knowledge to be
developed and disseminated. Government funding serves as a third source of research
dollars.

From its headquarters in Denver, Colorado, the Foundation’s staff directs and supports
the efforts of more than 800 volunteers who serve on the board of trustees and various
committees. These volunteers represent many facets of the water industry, and contribute
their expertise to select and monitor research studies that benefit the entire drinking water
community.

The results of research are disseminated through a number of channels, including reports,
the Web site, conferences, and periodicals.

For subscribers, the Foundation serves as a cooperative program in which water suppliers
unite to pool their resources. By applying Foundation research findings, these water
suppliers can save substantial costs and stay on the leading edge of drinking water
science and technology. Since its inception, AwwaRF has supplied the water community
with more than $300 million in applied research.

More information about the Foundation and how to become a subscriber is available on
the Web at www.awwarf.org.

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DISCLAIMER

This study was jointly funded by the Awwa Research Foundation (AwwaRF) and the
U.S. Department of Energy (DOE) under Grant No. DE-FG02-03ER63619 through the
Arsenic Water Technology Partnership. The comments and views detailed herein may
not necessarily reflect the views of the Awwa Research Foundation, its officers, directors,
affiliates or agents, or the views of the U.S. Federal Government and the Arsenic Water
Technology Partnership. The mention of trade names for commercial products does not
represent or imply the approval or endorsement of AwwaRF or DOE. This report is
presented solely for informational purposes.

Copyright 2006
By Awwa Research Foundation
and Arsenic Water Technology Partnership

All Rights Reserved

Printed in the U.S.A.

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ACKNOWLEDGEMENTS

This report is the product of a collaborative effort between the members of the Arsenic
Water Technology Partnership and was made possible by funds from congress and the
drinking water community. A special thanks to U.S. Senator Pete Domenici for his
support and assistance in helping to develop low-cost, energy efficient solutions for the
removal of arsenic from drinking water.

The research team is grateful to AWWARF project manager, Albert Ilges, and to the
Project Advisory Committee (PAC) for their advice and assistance throughout the
project. We are particularly indebted to Mr. John Balliew from El Paso Water Utilities
(the participating water utility), El Paso, TX, for his assistance with the semi-pilot scale
testing of the proposed technology for treating arsenic contaminated water from El Paso.

Partial in-kind support was provided by the participating El Paso Water Utilities, and the
Department of Civil Engineering of Auburn University.

The team is also grateful to our lab technician, Mr. Jinling Zhuang, for his technical
assistance during this study.

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CONTENTS

LIST OF TABLES………………………………………………………………………ix

LIST OF FIGURES……………………………………………………………….…….xi

FOREWARD...................................................................................................................xiv

ACKNOWLEDGMENTS……………………………………………………………..xiv

EXECUTIVER SUMMARY………………………………………………………….xvi

CHAPTER 1: INTRODUCTION…………………………………………………...1

1.1 Overview………………………………………………………………………….1

1.2 Objectives………………………………………………………………………...1

1.3 Arsenic Chemistry……………………………………………………………….2

1.4 Arsenic Origins…………………………………………………………………..3

1.5 Health Risks and Occurrence…………………………………………………...3

1.6 Legislation and Standards………………………………………………………3

1.7 Arsenic Removal Technology………………………………………...…………4

1.8 The Concept of Polymeric Ligand Exchange…………………………………..4

CHAPTER 2: SYNTHESIS OF POLYMERIC LIGAND EXCHANGERS……..8

2.1 Preparation of DOW 3N-Cu…………………………………………………..…….8

2.2 Synthesis of PLEs Based on Non-Functionalized Polymeric Sorbents (XAD)…...8

2.2.1 Materials……………………………………………………………………………8

2.2.2 Functionalization of XAD Copolymers………………………………..……...9
2.2.3 Copper Loading and Copper Capacity Measurement…………………..…12

CHAPTER 3: SORPTION AND DESORPTION OF ARSENATE USING
VARIOUS POLYMERIC LIGAND EXCHANGERS: BENCH-
SCALE TESTS ……………………………………………………..14

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3.1 Materials…………………………………………………………………………….14

3.2 Experimental Methods…………………………………………………………..…15

3.2.1 Equilibrium Sorption Tests…………………………………………………..15
3.2.2 Fixed–Bed Column Tests……………………………………………………..15
3.2.3 pH Effect………………………………………………………………………16
3.2.4 Kinetic Tests…………………………………………………………………..16
3.2.5 Resin Regeneration and Reuse………………………………………………16

3.3 Chemical Analysis…………………………………………………………………..16

3.4 Results and Discussion……………………………………………………………...17

3.4.1 Equilibrium Isotherms and Arsenate Adsorption…………………….........17
3.4.2 Breakthrough Behaviors……………………………………………………..20
3.4.3 Effect of pH……………………………………………………………………23
3.4.4 Kinetic Test……………………………………………………………………24
3.4.5 Regeneration and Reuse of PLEs………………….………………………...28

CHAPTER 4: ENGINEERED TREATMENT OF SPENT REGENERATION
BRINE………………………………………………………..……...33

4.1 Introduction……………………………………………………………….........33

4.2 Experimental Methods and Materials………………………………………...33

4.2.1 Preparation of Simulated Spent Brine…………………………………..33
4.2.2 Treatment of Spent Brine………………………………………………...33
4.2.3 pH and Aging Effect on Arsenic Removal………………………………34
4.2.4 Calcium Addition…………………………………………………………34
4.2.5 Regeneration with Treated Brine………………………………………..34

4.3 Results and Discussion………………………………………………………….34

4.3.1 As Removal from Spent Brine…………………………………………...35
4.3.2 Treated Brine Reuse……………………………………………………...38

CHAPTER 5: STABILIZATION OF SOLID WASTE RESIDUAL……………42

5.1 Introduction…………………………………………………………………….42

5.2 Materials and Methods…………………………………………………………42

5.2.1 Preparation of Arsenic-Laden Solid waste/Sludge……………………..42
5.2.2 Arsenic-Leaching Tests…………………………………………………..43
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5.2.3 Effect of Fe and Ca on Arsenic Stability………………………………..43
5.2.4 Effects of Aging and Temperature on Stability………………………...44

5.3 Results…………………………………………………………………………...44

5.3.1 Effect of Fe and Ca on Stability………………………………………….44
5.3.2 Effect of Aging and Temperature on Stability………………………….47

5.4 Discussion and Conclusions……………………………………………………55

CHAPTER 6: PRELIMINARY SEMI-PILOT SCALE TESTING OF THE PLE
TECHNOLOGY …………………………………………………...57

6.1 Experimental Procedures………………………………………………………57
6.2 Preliminary Column Run results……………………………………………...57

REFERENCES………………………………………………………………………….59

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LIST OF TABLES

Table 2-1 Properties of parent polymer matrices………………………………….... 9

Table 2-2 Maximum copper loading of the chelating resins………………………... 13

Table 2-3 Effect of chloromethylation time on maximum copper loading capacity
of di(2-picolyl)amine-functionalized XAD1180………………………… 13

Table 3-1 Salient properties of various ion exchange resins used in this study…….. 14

Table 3-2 The model-fitted Langmuir parameters (Q, b), and experimentally
determined arsenate/sulfate binary separation factor (αAs/S)…………… 19

Table 4-1 As remaining in solution after treatment and % initial As removed at
different Fe/As molar ratio and pH 6, 7, and 9. Initial As in brine was
310-350mg/L……………………………………………………………... 35

Table 4-2 Characteristics of three treated brine batches used for
regeneration…………................................................................................. 39

Table 5-1 Fe addition for stability tests……………………………........................... 43

Table 5-2 Calcium addition for stability tests……………………………………..... 44

Table 5-3 TCLP and WET results for effect of Fe addition on stability…………..... 45

Table 5-4 Amount of Ca added to each sample and the resulting effect on
extraction by TCLP (µg/L) and WET (mg/L)............................................ 46

Table 5-5 As remaining in brine and %As removed is shown after treatment where
contact time was 2, 20, and 60 days…………………………………….... 47

Table 5-6 Results of TCLP and WET tests for treatment at 2, 20, and 60 days.
Fe/As was held at 10 and pH adjusted to 5.5-6.5. Results of 3050B (acid
digestion) are also shown………………………………………………… 49

Table 5-7 Results of TCLP and WET reported in mg-As extracted per kg-sample
are shown for different aging periods (2, 20, or 60 days) and temperature
(5, 35, and 50ºC). Results of Method 3050B showing total As in sample
in mg-As per g-sample are also give…………………………………....... 50

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