2041779 TNK Radium Bulletin

Tonka Technical Bulletin
TONKA
WATER
TREATMENT
SYSTEMS
Effective Radium Removal
with HMO
TONKA EQUIPMENT COMPANY
Radium contamination of groundwater is a
serious public health issue addressed by the
USEPA in its Final Radionuclides Rule, effective
December 8, 2003. This rule sets maximum
contaminant levels (MCL’s) for radioactivity from
gross alpha, beta-photons, Ra-226, Ra-228 and
uranium. The MCL for combined radium-226 and
228 was set at 5 pico curies per liter (5 pCi/L).
Utilities affected include all community water
systems (CWS), regardless of size. USEPA
anticipates that approximately 800 systems will
have to install radium treatment, with annual
compliance costs estimated at $81 million.
Design and manufacture of equipment for
removal of this health hazard is a priority for
water treatment equipment manufacturers.
Radium contamination of groundwater is
generally attributed to natural sources. Dissolved
radium is found in many rock formations that
affect drinking water. The areas where radium is
present in public water supplies include the
Midwestern US and the East Coast.
Radium Removal Technologies
Radium is a divalent cation alkaline earth metal
(as are calcium and magnesium). As such, radium
behaves very much as calcium and magnesium do
Background
The purpose of the Final Radionuclides Rule is to
reduce the risk of cancer by reducing exposure to
radionuclides in drinking water. The two radium
isotopes identified to be of primary concern are
radium-226 and radium-228, because of potential
carcinogenic impact. The intent is also to increase
health protection for the public by reducing
overall environmental exposure to radionuclides.
Radium by nature is unstable and is continually
emitting energy in the form of daughter products.
Many of these daughter products of radium are
also public health concerns.
Vertical Pressure Filter
in water. Removal of calcium and magnesium in
public water supplies entails softening, so it
follows that the BAT’s (Best Available
Technologies) identified by USEPA for removal
of radium are also softening treatments. Lime
softening, ion exchange and reverse osmosis have
all been identified as approved processes for
radium removal. Unless softening is also a
treatment goal for the water utility, these
processes can be costly and unnecessary. Tonka
Equipment Company has significant experience
in the use of many of these radium removal
processes, having several installations in
operation that are successfully removing radium
from drinking water.
Community water systems are not restricted to
BAT’s to meet the radium MCL, so it is not
necessary to soften to remove radium. Any
technology that meets state primary agency
approval, and also meets the MCL, is acceptable
to USEPA. Other technologies that have been
marketed for radium removal include various
adsorptive and accumulative medias. These
technologies are particularly troublesome because
they ignore accumulated radiation which can
cause unsafe environmental and workplace
conditions. They also ignore daughter product
decay. Both of these issues, if left unaddressed,
can result in unintended long-term consequences
for the water plant owner.
HMO addition involves the preparation and
controlled dosage of a pre-formed manganese
oxide solution to raw water prior to filtration.
Radium is adsorbed on the surface of the added
HMO particles, which are subsequently filtered.
Because the HMO is backwashed out of the filter
media, radium accumulation (a downfall of other
processes) does not occur.
This treatment approach for radium removal has
been extensively studied and documented in an
American Water Works Association Research
Foundation (AWWARF) study conducted by
Dr. Richard Valentine, professor at the University
of Iowa. HMO technology can be integrated into
an existing water treatment facility removing iron
and/or manganese, or can be used in a treatment
facility specifically targeting radium removal.
Hydrous Manganese Oxide
Hydrous manganese oxide (HMO) addition has
been identified by the USEPA as an acceptable
technology for radium removal in groundwater
supplies. HMO addition is a radium removal
technology that is particularly suited for small
and medium-sized systems. This process relies on
the natural affinity of radium to adsorb onto
manganese oxides.
Horizontal Pressure Filter
HMO Design
Proper engineering considerations in the HMO
delivery system and overall treatment plant design
are critical to optimal operation and radium
removal performance. Careful consideration must
be given to the preparation techniques and
facilities required to produce a consistent,
stable mixture.
An appropriately designed HMO treatment
system is necessary to ensure plant performance
and radium removal efficiency and is a very cost
effective, safe and trouble-free solution to radium
removal. Tonka’s extensive experience in design,
start-up and operation is an important asset for
owners and engineers in anticipating and dealing
with all aspects of HMO installations.
Tonka has a line of Dualator® products
incorporating aeration, detention and filtration in
a single treatment unit. These gravity style units
are typically used on water supplies with iron
and/or manganese contamination for which
detention is required to allow for chemical
reactions to occur.
On water supplies in which a fully pressurized
system is preferred, Tonka’s line of pressure
filtration products can be used. All Tonka water
treatment equipment is custom designed with the
customer’s needs and treatment goals in mind.
Tonka Products
HMO technology can be integrated into existing
water treatment processes or can be a stand-alone
treatment technique. A typical water supply that is
ideal for HMO treatment is one with iron and/or
manganese contamination as well as radium.
HMO treatment can be incorporated into gravity
or pressure systems, with or without detention.
Vertical Pressure System
Simul-Wash™
Dualator® III, an ideal treatment system for
Hydrous Manganese Oxide radium removal
The value-added Simul-Wash™ backwash system
can be incorporated into either gravity or pressure
treatment systems. This unique backwash system
uses air and water simultaneously, at subfluidized rates, to provide the most effective
means of backwashing granular filter media.
Tonka’s media rejecting Simul-Wash™ trough
enables the air and water backwash cycle to
continue indefinitely without media loss. This
results in optimal filter cleaning efficiency and
prolonged filter runs, while saving approximately
50% of backwash wastewater compared to
conventional methods. The system is typically
controlled by Tonka’s PLC-based automatic
control panel with an interface touch pad.
Tonka HMO Piloting
References:
Tonka has conducted fifteen (15) pre-formed
HMO pilot studies since 1999. The water quality
varied from low pH and low dissolved solids to
high iron, high hardness and highly alkaline
waters. Just as the type of water piloted varied, so
did the type of equipment. All of our pilots
successfully removed radium using HMO
technology. Tonka’s pilot studies can be scaled up
to either gravity or pressure-type full scale water
treatment equipment.
1. Valentine, R.L. et al., 1992. Radium Removal Using
Preformed Hydrous Manganese Oxides. American Water
Works Research Foundation.
Typical radium removals of over 90% are achieved
with proper HMO pretreatment. As an added
benefit, high percentages of gross alpha and gross
beta radioactivity are usually removed as well.
Tonka offers assistance in preparation of pilot
study and laboratory testing protocols and in
report writing for submission to the reviewing
authority.
2. Environmental Protection Agency, December 7, 2000.
National Primary Drinking Water Regulations;
Radionuclides; final Rule, 40 CFR Parts 9, 141 and 142.
3. Environmental Protection Agency, March 2002.
Implementation Guidance for Radionuclides.
Tonka Equipment Company creates customized
water treatment systems for municipalities across
the United States and abroad. We provide costeffective solutions for the most challenging surface
and groundwater problems, including arsenic,
radium, and nitrate removal. Tonka’s SimulWash™ combined air/water backwash system
provides superior media cleaning while reducing
backwash water volume by 50%.
Tonka HMO Systems
Tonka Equipment Company has broad experience
in HMO technology using specialized Tonka
IMAR® media. Tonka currently has five full scale
installations successfully preparing and using
pre-formed HMO technology in conjunction with
IMAR media for radium removal.
Call your Tonka representative for more
information on radium removal or any other
water treatment challenge.
TONKA
WATER
TREATMENT
SYSTEMS
763-55-WATER • 763-559-2837 • FAX: 763-559-1979 • www.tonkaWATER.com
P.O. Box 41126 • Plymouth, MN 55441-0126 • 13305 Watertower Circle • Plymouth, MN 55441