Tonka Technical Bulletin TONKA WATER TREATMENT SYSTEMS Effective Radium Removal by banger18


									   Tonka Technical Bulletin
                     Effective Radium Removal
 TONKA                        with HMO

Radium contamination of groundwater is a              Radium contamination of groundwater is
serious public health issue addressed by the          generally attributed to natural sources. Dissolved
USEPA in its Final Radionuclides Rule, effective      radium is found in many rock formations that
December 8, 2003. This rule sets maximum              affect drinking water. The areas where radium is
contaminant levels (MCL’s) for radioactivity from     present in public water supplies include the
gross alpha, beta-photons, Ra-226, Ra-228 and         Midwestern US and the East Coast.
uranium. The MCL for combined radium-226 and
228 was set at 5 pico curies per liter (5 pCi/L).
                                                      Radium Removal Technologies
                                                      Radium is a divalent cation alkaline earth metal
Utilities affected include all community water        (as are calcium and magnesium). As such, radium
systems (CWS), regardless of size. USEPA              behaves very much as calcium and magnesium do
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.

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       HMO addition involves the preparation and
public water supplies entails softening, so it      controlled dosage of a pre-formed manganese
follows that the BAT’s (Best Available              oxide solution to raw water prior to filtration.
Technologies) identified by USEPA for removal       Radium is adsorbed on the surface of the added
of radium are also softening treatments. Lime       HMO particles, which are subsequently filtered.
softening, ion exchange and reverse osmosis have    Because the HMO is backwashed out of the filter
all been identified as approved processes for       media, radium accumulation (a downfall of other
radium removal. Unless softening is also a          processes) does not occur.
treatment goal for the water utility, these
                                                    This treatment approach for radium removal has
processes can be costly and unnecessary. Tonka
                                                    been extensively studied and documented in an
Equipment Company has significant experience
                                                    American Water Works Association Research
in the use of many of these radium removal
                                                    Foundation (AWWARF) study conducted by
processes, having several installations in
                                                    Dr. Richard Valentine, professor at the University
operation that are successfully removing radium
                                                    of Iowa. HMO technology can be integrated into
from drinking water.
                                                    an existing water treatment facility removing iron
Community water systems are not restricted to       and/or manganese, or can be used in a treatment
BAT’s to meet the radium MCL, so it is not          facility specifically targeting radium removal.
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.

Hydrous Manganese Oxide
Hydrous manganese oxide (HMO) addition has          Horizontal Pressure Filter
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.
HMO Design                                            Tonka has a line of Dualator® products
Proper engineering considerations in the HMO          incorporating aeration, detention and filtration in
delivery system and overall treatment plant design    a single treatment unit. These gravity style units
are critical to optimal operation and radium          are typically used on water supplies with iron
removal performance. Careful consideration must       and/or manganese contamination for which
be given to the preparation techniques and            detention is required to allow for chemical
facilities required to produce a consistent,          reactions to occur.
stable mixture.
                                                      On water supplies in which a fully pressurized
An appropriately designed HMO treatment               system is preferred, Tonka’s line of pressure
system is necessary to ensure plant performance       filtration products can be used. All Tonka water
and radium removal efficiency and is a very cost      treatment equipment is custom designed with the
effective, safe and trouble-free solution to radium   customer’s needs and treatment goals in mind.
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 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

                                                      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 sub-
                                                      fluidized 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
Dualator® III, an ideal treatment system for          50% of backwash wastewater compared to
Hydrous Manganese Oxide radium removal                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            1. Valentine, R.L. et al., 1992. Radium Removal Using
HMO pilot studies since 1999. The water quality           Preformed Hydrous Manganese Oxides. American Water
                                                          Works Research Foundation.
varied from low pH and low dissolved solids to
high iron, high hardness and highly alkaline           2. Environmental Protection Agency, December 7, 2000.
                                                          National Primary Drinking Water Regulations;
waters. Just as the type of water piloted varied, so      Radionuclides; final Rule, 40 CFR Parts 9, 141 and 142.
did the type of equipment. All of our pilots
                                                       3. Environmental Protection Agency, March 2002.
successfully removed radium using HMO                     Implementation Guidance for Radionuclides.
technology. Tonka’s pilot studies can be scaled up
to either gravity or pressure-type full scale water
treatment equipment.                                   Tonka Equipment Company creates customized
                                                       water treatment systems for municipalities across
Typical radium removals of over 90% are achieved       the United States and abroad. We provide cost-
with proper HMO pretreatment. As an added              effective solutions for the most challenging surface
benefit, high percentages of gross alpha and gross     and groundwater problems, including arsenic,
                                                       radium, and nitrate removal. Tonka’s Simul-
beta radioactivity are usually removed as well.
                                                       Wash™ combined air/water backwash system
Tonka offers assistance in preparation of pilot        provides superior media cleaning while reducing
study and laboratory testing protocols and in          backwash water volume by 50%.
report writing for submission to the reviewing

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.

      WATER      763-55-WATER • 763-559-2837 • FAX: 763-559-1979 •
     SYSTEMS     P.O. Box 41126 • Plymouth, MN 55441-0126 • 13305 Watertower Circle • Plymouth, MN 55441

To top