Presented at EUEC 2015: February 16, San Diego, CA. (in Session I1 & I2)
I1.1 Pilot Testing of Treatment to Meet Low Mercury Limits in FGD Purge Water at a Coal-
Fired Power Plant
Paul Pigeon, Senior Engineer, Golder Associates Inc.; Troy Patton, Seminole Electric Cooperative Inc.;
Rachel Hanson & Kristen Sealey, Golder Associates Inc;
Seminole Electric Power Cooperative, Inc. (Seminole) operates the coal-fired 1,500 MW Seminole Generating Station near Palatka, Florida. An average purge water flow of 550 gpm from wet, forced oxidation FGD units is currently treated for gypsum desaturization and selenium removal in a unique physical-chemical purge water treatment system (PWTS) prior to discharge to the St. Johns River. The combined effluent from the SGS must meet a challenging, TMDL-based mercury effluent limit. The EPA draft ELG for mercury in FGD wastewater effluent of 119 ng/L will require additional treatment. Seminole commissioned a feasibility study (FS) with the objectives of reducing the risk of non-compliance with the current discharge limit and meeting the future ELG. This paper will present results and findings of a pilot study conducted during the FS of mercury polishing treatment using a physical-chemical process train on current PWTS process effluent. These results should be of keen interest to US power producers who have wet FGD systems and will be faced with meeting the stringent EPA ELG for mercury.
I1.2 Mixed Ash Landfill Emerging Issues
Ivan Cooper, Practice Leader, Civil & Environmental Consultants, Inc.
The new Effluent Limitation Guidelines pose stricter limits on landfill leachate. Leachate produced
by mixed ash & MSW landfills exhibits significant concentrations of constituents that are difficult &
expensive to treat, causing high CAPEX & OPEX expenditures. The reasons for these high constituent
concentrations range from the types of wastes accepted, landfill age, accelerated condensate
extraction, reactions within a landfill, or other reasons. Although arsenic, mercury, & selenium &
other metals are major culprits, constituents include TDS, sulfates, BOD/COD, ammonia corrosion
causing chlorides, & other organics. Increasingly, stakeholders are concerned with microconstituents,
including, endocrine disrupters (estrogen compounds), & pharmaceutical & personal care products
(PPCP). Of increasing importance for discharge is Interference with ultraviolet (UV) disinfection that
results in disinfection problems in receiving waters. This occurs as more of the plants switch to UV
from chlorination. The following alternatives are available for improving UV transmittance of treated
leachate include ozone, ozone with hydrogen peroxide, Fenton’s reagent, & nanofiltration, as well
as less recognized approaches including reverse osmosis, sulfate radical oxidation, activated carbon
adsorption, & electrocoagulation. Power companies & others should be aware of some of the causes,
ranges of contaminants, & treatment & disposal options.”
I1.3 Treatment of Selenium, Arsenic, Mercury, & Nitrate from Flue Gas Desulfurization
Wastewater Using A Vortex Generating Anti-Fouling Membrane System & Concentrate
Treatment
Joon Min, President, BKT; Behrang (Ben) Pakzadeh, Jay Wos & Jay Renew, SRI; Richard Breckenridge,
EPI; Jason (Xinjun) Teng, Southern Company; Allen Chan, JK Kim & GT Park, BKT
The flue gas desulfurization (FGD) process is designed to remove sulfur dioxide from fossil-fuel power
plant exhaust. With over 600 coal burning power plants in the United State alone, FGD wastewater
is becoming of greater & greater concern. As regulations tighten on contaminant discharge
concentrations, the treatment of FGD wastewater is becoming a must. The goal of this collaborative
demonstration project among Southern Company, EPRI, Southern Research Institute, & BKT was to
examine the feasibility of using the FMX-NF membrane system, followed by spiral reverse osmosis (RO)
to reduce selenium, arsenic, mercury, nitrite, & nitrate concentrations in FGD wastewater to meet the
upcoming discharge regulations. Various membranes were tested on a bench top FMX unit to compare
flux & rejection parameters to determine the ideal membrane for full scale treatment. Based on the
effluent sulfate concentrations, two membranes (SR-99 & D50) were selected for larger scale testing
using the FMX pilot unit. The average flux achieved during FMX-P testing for the D50 & SR99 membranes
were 95 & 35 LMH, respectively. Based on flux & rejection data, the D50 membrane was selected
& the spiral RO system was used as a polishing step. The pilot test results confirmed the Anti-Fouling
Membrane System, FMX, in combination with conventional RO technology could meet the upcoming
discharge regulations. Full-scale demo test & concentrate treatment results will be presented.”
I1.4 A Holistic Approach to Watershed-level Risk Analysis & Management of Bromide
Robert Strange, Associate Project Manager, Southern Research Institute; Brian Mastin, PhD
Bromine containing salts are water soluble, naturally present in the Earth’s crust & salt water brines,
& occur from anthropogenic sources such as power generation & other industrial effluents (e.g.,
mining, hydraulic fracturing). Bromine compounds have significant application in industrial products
including but not limited to flame retardants, pesticides, & water treatment chemicals. Although
bromide is not considered ecologically harmful, release of bromide species into the environment may
result in unintended consequences. Approximately 68% of US Public Water Systems use surface water
sources of raw water. In the presence of bromide & bromine-containing compounds, disinfection via
chlorination poses a significant risk to human health due to increased potential to form disinfection
by-products (DBP) (e.g., bromate, brominated trihalomethanes & haloacetic acids) in these water
distribution systems. Presentation will be focused on the methodology of watershed-level ecological
risk assessment & subsequent risk management decision analysis of increasing bromide discharge;
including watershed-level measurements of DBP surrogates & precursors, evaluation of watershed
buffering capacity, empirical modeling of DBP formation, & feasibility of technologies to minimize risk
associated with bromide released to surface waters. A risk assessment matrix will be illustrated through
a case study focused on DBP formation as a function of receiving water bromide levels.
I1.5 HClearTM Technology: A Solution-Based Approach to HCl Abatement
Ian Saratovsky, Technology Development Manager, Fuel Tech, Inc.; Kent W Schulz, Chris R Smyrniotis,
Emil P Rivera & Heng Wang
HClearTM Technology is a novel, solution-based approach to HCl abatement. HClear is injected
ahead of the air preheater, and gaseous chlorides are removed by the particulate control device
(ESP or fabric filter). HClear is composed of a molecular species that rapidly decomposes in the flue
gas to form small particles that are highly reactive towards HCl. Recent pilot- and full-scale tests show
selectivity towards HCl (no reaction with SO2), mild mercury oxidation, no impact on the ability of
brominated activated carbons to capture mercury, and minimal impact on electrostatic precipitators
owing to low mass application rates. Additionally, the product formed by the reaction between HClear
and gaseous HCl is insoluble and does not impact fly ash leachability. HClear can be injected ahead
of wet flue gas desulfurization (wFGD) units to potentially reduce chloride buildup, lower blowdown
rates, and decrease the quantity of effluent and wastewater treatment required to comply with local
and federal effluent guidelines. The mechanism and performance of HClear will be discussed, and
data from several pilot scale coal-fired boiler and full-scale boilers will be discussed.
I2.1 The Use of Portable Flowmeters for Water Balance Verification
Karen Burchardt, Senior Environmental Engineer, Burns & McDonnell; Maggie Skelton, Minnesota
Power; Samantha Tewell, Burns & McDonnell
In today’s regulatory climate, understanding water use & discharge from power plants is critical. A
plant water system may already have permanent flowmeters installed to measure water flow at various
points in the system. However, the flowmeters may have been removed, may be out of calibration,
or may not be operating properly, leaving gaps in the flow measurements. In addition, there may
be other streams that do not have flow monitoring making it difficult to assess the current state of the
overall plant water balance. This paper discusses the use of portable flow monitors to collect water
flow measurement data at power plants. Portable flow meters can be used to update an existing
plant water balance, verify data collected by permanent flow meters, & provide flow data where
no permanent meters exist. Theoretical water balances, such as those developed for new plants
or processes like flue gas desulfurization (FGD) systems can be verified with a portable flow meter.
Portable flow meters can be used to troubleshoot FGD systems & improve their performance. This
paper will describe the portable flow meter equipment. A comparison of data from portable flow
meters to data from installed flow meters will be provided. This paper will also present lessons learned
from the use of portable flow meters in the field.
I2.2 Water Balance & Recovery at ConEdison’s Generating Stations
Angele Kwimi, Engineer, ConEdison; Gary Thorn & Keith Guberman
Con Edison is the main city water customer and purchased about 3.5 billion gallons of water in 2012.
Not all of the water purchased was used for steam send out. The purpose of this project is to reduce/
eliminate waste water discharge at our stations, produce clean water (through water treatment) of
reusable quality, conserve water as much as possible at the stations and implement the use of watersaving
technologies and practices. In an effort towards a zero liquid discharge goal, recovering and
reusing currently discharged backwash and blowdown water will ensure a sustainable approach to
water use. Therefore, a treatment system will be installed to treat backwash and blow down water
prior to being recycled to the Raw Water Tank. This project also covers the modification of the current
condensate recovery system to recover thermal energy and condensate. Finally, in order to reduce
water used for cooling the air compressors, a water-conservative cooling system will be installed for
the air compressors. This effort will result in water conservation and recovery for ConEdison’s generating
stations and will serve as a frame work for water conservation by other power plants.
I2.3 The Thirst of Power: Water scarcity changing the economics of power generation
Alex Klaessig, Senior Analyst, IHS CERA
The story of US economic and population growth driven by the extensive use of water will eventually
come to an end as demand reaches or even exceeds the rate at which supplies recharge. With
increased demand and fixed supply, the value of water will increase. Therefore comprehending the
short and long term impacts of water scarcity is of crucial importance for the water-intensive power
industry. Strategies are heavily influenced by variations in the regional abundance of water and states
water right laws. This presentation discusses water consumption across generation types, then analyzes
how power generation and prices react to severe drought in the context of various state water laws.
I2.4 Use of Treated Municipal Wastewater in Power Plants for Cooling and Demineralization System
Behrang Pakzadeh, Senior Process Engineer, Kiewit Power Engineers Co.; Brad Buecker, Brian Clarke,
P.E., & Michael McMenus, Kiewit Power Engineers Co.
Drought, population growth, and new regulations limit available water resources for power plant use.
To address this challenge, treated municipal wastewater can and is being reused as cooling water
and demineralizer makeup, and even for (indirect) potable/sanitary uses. In 2009, the National Energy
Technology Laboratory (NETL) reported that 81 percent of proposed new power plants had access
to sufficient cooling water supply from one or more publicly owned treatment works (POTW) within a
10-mile radius. Furthermore, 97 percent of the proposed power plants would be able to pipe/pump
cooling water needs from one or more POTWs within 25 miles. Therefore, NETL determined municipal
wastewater to be viable and locally obtainable in required quantities as the makeup water source.
Treated wastewater must undergo further processing at the power plant, where the type of treatment
depends on the reuse purpose and specified water quality. Processes may include biological
treatment primarily to remove ammonia, oxidation to remove iron and manganese, disk, media, or
membrane filtration to remove suspended solids, reverse osmosis/electrodeionization or ion-exchange
for demineralization, and finally disinfection for sanitary uses. This report summarizes the available
technologies to process treated municipal wastewater for reuse in power plants. Also outlined are
engineered solutions for an existing plant and a new power plant.
I2.5 Identification of Aroclors in Environmental Samples by Pattern Matching
Randall Bramston-Cook, Principal, Lotus Consulting; Edward Bramston-Cook, Lotus Consulting; Mark
Scesny, M Solutions
Commercial PCB products were comprised of a mixture of these congeners. The analysis for PCBs
becomes more difficult than the routine quantitation process since a single peak does not represent
the total concentration. Fortunately, the manufacturing process for generating PCBs yielded very
consistent congener mixtures for each commercial product. In the United States, nearly all PCBs were
sold under the brand name Aroclor. By comparing the pattern of an unknown with various Aroclor
standards, the Aroclor can be identified. Concentration is computed by comparing the relative peak
sizes of the unknown to the standard To overcome limitation in standard methods, a novel approach
to identify and quantitate Aroclor mixtures in transformer oils was developed. When unknown samples
are examined, their peak areas were ratioed with standard areas matched by retention times. If these
ratios are consistent with a given Aroclor, then a perfect match is confirmed. Typically 40 to 50 peaks
for each Aroclor are used in this process. To illustrate this process, samples of transformer oils and NIST
carp fish tissue were analyzed by gas chromatography with electron capture detection and resulting
chromatograms were processed through the program to match up with common Aroclors. Even
though the fish tissue showed some PCB congener loss due to expected environmental degradation,
specific Aroclor patterns were still identified.
I2.6 Weathering the Storm – Update on Electric Utility Industry Wastewater Issues
Tisha Scroggin, Section Manager, Burns & McDonnell Engineering Company, Inc.
The ever changing regulatory environment that the electric utility industry plays in is now faced with
significant water and solid waste regulations in addition to the air quality control emphasis seen
over the last several decades. The delayed Effluent Limitation Guidelines (ELG’s), the imminent Coal
Combustion Residual (CCR) rule and the state specific Water Quality Criteria (WQC) Standards could
very well lead us into a “Perfect Storm” for the electric utility industry. This presentation will not only
discuss the specifics of some of these rules, but emphasize the compounded effects these rules will
have on the electric utility industry.