Measuring Chlorine Disinfection
Water & Wastes Digest
December 2004
By Frank Kaiser and Bill Fehrman
This disinfectant is used by more than 90% of the drinking water plants in the U.S., and more than 200 million Americans and Canadians receive chlorine-disinfected drinking water every day.
The O-Zone: Today's Lesson: How Much is Enough?
Water Quality Products
July 2003
Roger Nathanson
This column will discuss two important topics regarding the use of ozone.
* Ozone dosages. How much ozone is "practical" for certain applications?
* Ozone air treatment. How ozone can be used in air treatment, what your liabilities are and precautions you should be taking.
PDF Version
Bacterial Control with Ozone
Water Quality Products
July 2003
W. Craig Meyer and Partev B. Sarkissian, Pierce College
In the April 2001 issue of Water Quality Products,associates of TCET presented a new method using ozone to treat cooling tower water. Cooling Treatment Systems, Inc. (CTS) of Englewood, Colo., has adapted this method to produce a water treatment system it now is marketing for cooling towers. CTS submitted this new technology to TCET for testing. The results of these tests are presented here.
PDF Version
Brominated Resins
Water Quality Products
July 2003
Ken Korslin, CWS-III, Pentair Water Treatment, Plymouth Products Division
In 1957 The Dow Chemical Corp. addressed the negatives of using bromine by creating a brominated ion exchange resin, which opened up the use of bromine in offshore water treatment applications.2 Today, polybromide resin is used in many offshore water treatment systems. The fact that bromine can be added to water that previously has been chlorinated makes polybromide resin a practical solution to accommodate the multiple sources of water in offshore applications.
PDF Version
The O-Zone: Today's Lesson: Ozonation of Cooling Towers
Water Quality Products
June 2003
Roger Nathanson
The objective of ozone use with cooling towers is to maintain the highest purity of water with the least amount of water waste and chemical use. Chemical use in cooling towers leads to ever-increasing total dissolved solids (TDS), which must be reduced by eliminating water (blow down/bleed off) and then refilling with raw/lower TDS water. This is a vicious circle that will never end unless one of the TDS-increasing culprits (a.k.a. chemicals) is eliminated or reduced.
PDF Version
Ozone Treatment for Residential Well Water
Water Quality Products
June 2003
Myrle Melligan, Triple O Systems, Inc.
Your customers not only are expecting to have enough water supplied from their water source, but they also demand that it is of superior quality. Ozone's technology coupled with such treatment as filters or softeners can fulfill this expectation. Ozone does not need to be complicated in order to treat small water systems.
PDF Version
Pool & Spa Disinfection
Water Quality Products
May 2003
Jeff Roseman, CWS-I, Aqua Ion Plus+ Technologies
This article will address the use of ozone, copper ionization and proper injection of chlorine for a reduced approach to chemicals in providing a clean, clear, healthy pool and spa experience.
PDF Version
E. Coli
Water Quality Products
May 2003
Danielle Duclos
This article provides a general overview of E. coli and drinking water as well as current and emerging monitoring and decontamination technologies.
PDF Version
The O-Zone: Today's Lesson: To Dry or Not to Dry
Water Quality Products
May 2003
Roger Nathanson
Ozone is a gas made from oxygen. One of the processes used to produce ozone is called corona discharge (CD). The CD method is a combination of high voltage electricity and air, dry air or oxygen in a given space.
The efficiency of the ozone generator (ozonator) is based on the quality of the incoming feed gas.
PDF Version
Nonchemical Alternatives to Cooling Tower Disinfection
Water Quality Products
April 2003
Jeff Roseman, CWS-I, Aqua Ion Plus+ Technologies
By explaining some tips and tricks, maybe more water treatment dealers can understand these technologies and use them in their arsenal of treatment methods. Filtration, ozonation, copper ionization and UV light may not be an option on some water supplies or applications, but their usefulness and alternatives to chemical dosing should be considered as an option.
PDF Version
Chlorination: The Love/Hate Relationship
Water Engineering & Management
April 2003
Bill Swichtenberg
Disinfection with chlorine is very popular in water and wastewater treatment because of its low cost, ability to form a residual and its effectiveness at small doses. However, some organisms that cause disease are resistant to chlorine treatment. Many utilities now are using multi-barrier approaches to disinfection.
PDF Version
Chlorine Residual Boosting in Distribution Water: Problems with Chlorine Application and Disinfection Byproducts - Part 1
Water Engineering & Management
April 2003
Shin-ichi Tokuno
Previous research on the boosting of chlorine residual1 included how to increase low levels of chlorine disinfectants (free and combined chlorine) in the distribution system. Simple bench tests using a pocket photometer showed that there are no problems in boosting the low level of chlorine residual when boosting the same disinfectant to the water (e.g., free chlorine to free chlorine, or chloramine to chloramine). In the boosted chlorine residual, there is no significant instability in decay or dissipation during the time needed (72 hours) after boosting for the small utility distributors.
The O-Zone: Today's Lesson: Ozone Installation
Water Quality Products
February 2003
Roger Nathanson
The installation of ozone equipment on well applications utilizes the same principles and techniques as chlorinators, air injection and softener systems. There are only minor variations in sequence, parts and details.
PDF Version
Disinfection, Part 1: Developments in Ultraviolet Disinfection
Water Quality Products
January 2003
Bruce Laing, Trojan Technologies, Inc.
One of the fastest growing technologies in the water treatment industry is ultraviolet (UV) disinfection. UV disinfection adds no chemicals, and it does not produce byproducts. Additional benefits include easy installation, low maintenance, minimal space requirements and whole-house (point-of-entry) treatment.
PDF Version
Disinfection Part 2: Is Chlorine Still the Answer?
Water Quality Products
January 2003
Joanne Funyak, PPG Industries
Alternatives to the use of chlorine have received increased interest since concerns over the formation of disinfection byproducts (DBPs) have emerged. However, most of these alternatives (i.e., chloramine, chlorine dioxide and ozone) also produce DBPs. Chlorine still is the most common drinking water disinfectant used today and the one we have the most information about. On balance, the health risks of not chlorinating water appear to be greater than risks associated with DBPs.
PDF Version
Air Purification with Ultraviolet Light
Water Quality Products
December 2002
John Garrett, Biozone Scientific
While consumer demand has escalated for water purifying devices, it pales in comparison to what has happened in air purifying. The indoor air purification industry still is in its infancy, yet is recognized by the Environmental Protection Agency (EPA) to be a market valued well into the billions.
PDF Version
Ultraviolet Disinfection of Drinking Water: A Growing Trend
Water Engineering & Management
November 2002
Richard G. Protasowicki, P.E.
The use of ultraviolet (UV) light for the treatment of drinking water is becoming more acceptable by both the public and regulatory agencies as an alternative disinfectant. Water suppliers that are developing new water treatment facilities or modifying existing ones now commonly investigate this technology to determine its applicability to their treatment processes.
PDF Version
Situation Normal During a UV Disinfection Retrofit
Water Engineering & Management
November 2002
Brian M. Balchunas, P.E., and Lawrence H. Hentz, P.E., D.E.E.
At the Patuxent Water Reclamation Facility in Anne Arundel County, Md., a carefully considered construction sequence will keep the facility in operation during its retrofit from chlorine to UV disinfection. Construction started in June 2002 and is expected to be complete by summer 2003.
PDF Version
Evaluation of a Chlorine Dioxide Secondary Disinfection System
Water Engineering & Management
November 2002
Frank P. Sidari III and Jeanne VanBriesen, Ph.D.
Chlorine dioxide is not a new technology for public drinking water facilities or pulp and paper producers, but its use as a secondary treatment system for small-scale applications is new. Beyond the chemistry and microbiology, potential small-scale operators want answers to a few simple questions: Should I use it? How does it work? What extra work is it going to make for me?
PDF Version
Mississippi Town Installs Nation's First RO/Ozone System
Water & Wastes Digest
November 2002
The City of Pascagoula, Mississippi turned to Osmonics of Minnetonka, Minn., to provide a viable solution for the removal of undesired characteristics from their water supply, ensuring compliance with existing and 2001 EPA regulations. Osmonics' process of combining low energy RO in tandem with ozone generation and contacting equipment proved to be the optimal solution to Pascagoula's water deficiencies.
The O-Zone: Today's Lesson: Ozone and Bottled Water
Water Quality Products
October 2002
Roger Nathanson
The following is the first of 11 articles addressing ozone's
applications, installation, sales, service, basics and more. The 12th and final
installment will be a quiz to test your ozone knowledge—so make sure you
come back each month to brush up. Details and instructions will be given in the
final month.
PDF Version
Legionella Solutions
Water Quality Products
September 2002
Bernard Banga, Freelance Writer, French Technology Press Office
Legionnaires' disease is considered so catastrophic that, in France, it must be reported to the medical authorities immediately. This practice has been in place since 1987. During the last decade, public health monitoring systems for this disease have been strengthened. Today, this hazard that arises from buildings has become an emerging public health problem in industrialized countries. The resulting respiratory infections are behind the recurrent epidemics emanating from hot water systems in buildings and air-conditioning cooling towers.
PDF Version
Impact of Mixing Chlorine and Chlorine Dioxide on Total Trihalomethane Formation - Part 1
Water Engineering & Management
August 2002
Douglas Rittmann, Ph.D., P.E., and Anthony Tarquin, Ph.D., P.E.
Two rules in 1986 amendments to the Safe Drinking Water Act are challenging many water utilities to meet stricter water quality requirements. The Surface Water Treatment Rule (SWTR)2 and the Disinfection?Disinfection By-Products (D-DBP) Rule3, are requiring utilities to implement more advanced technologies in water treatment. The Surface Water Treatment Rule emphasizes the need for utilities to meet minimum levels of disinfection for surface waters, whereas the Disinfection/Disinfection By-Products Rule limits the disinfectant byproducts. Therefore, utilities will have to implement a treatment approach that balances the benefits of disinfection against disinfection byproducts.
PDF Version
Making the Most of Modular Pumps
Water & Wastes Digest
August 2002
In order to ensure municipal water demands were met, the city of El Dorado, Arkansas contracted with Tanner Engineering & Carter-Burgess to design five new deep wells, water transmission mains, ground storage tanks, pump station, and chlorination facilities. In order to complete the project before the sultry days of summer, the municipality and engineering firm decided to save time and energy by installing a modular pumping system.
Back to the Basics, Part 3
Water Quality Products
July 2002
Jeff Roseman, CWS-1, Aqua Ion Plus+ Technologies
In this last section of a three-part series, the use of
ozone, ionization, distillation and aeration is discussed in a simple fashion
to help the beginner rationalize the importance for a full understanding of
these technologies and the need, again, for a professional water treatment
specialist.
PDF Version
Developments in Ozone Technology
Water Quality Products
July 2002
Rip G. Rice, Ph.D., RICE International Consulting Enterprises
Ozone technology developments have opened new applications for these established water treatment technologies. Driving these changes has been the identification of new, more disinfection-resistant microorganisms such as Giardia and Cryptosporidium cysts and governmental regulations designed to protect the public health from the hazards of ingestion of these microorganisms. Additionally, the desire to prevent or minimize the formation of halogenated disinfection byproducts formed during chlorination has stimulated new interest in the use of ozone. Combinations of ozone with hydrogen peroxide and/or ultraviolet (UV) radiation can destroy many contaminants present in ground water.
PDF Version
Ultraviolet Dechlorination Technology
Water Quality Products
July 2002
Aquionics
At the Procter & Gamble manufacturing plant in Greensboro, N.C., an Aquionics ultraviolet (UV) dechlorination unit was installed before two banks of reverse osmosis (RO) membranes. Trials that ran soon after the UV system’s installation showed a dramatic reduction in the RO membrane wash frequency—down from an average of eight cleanings per month to only two per month.
PDF Version
The Practical Use of Ozone for the Well Water Application
Water Quality Products
July 2002
Roger Nathanson, Ozone Pure Water, Inc.
We?ll discuss the well ozone water treatment application. Each application is a potential business in itself, which means greater revenue and profit. All that is necessary from you is the motivation to boldly go where you have not gone before.
PDF Version
River Contaminates Town’s Water Supply When State Leaves It to Beavers
Water Engineering & Management
July 2002
Louis Manring
For nearly 70 years, the public water system in the Town of Sterling, Massachusetts operated without incident, delivering clean water to more than 2,000 homes. Because the water from the town’s well field was clean and free of contamination, there was no need for a permanent disinfection system. That all changed in September 1999 when a storm caused by Hurricane Floyd and the state’s increasing beaver population combined to cause bacterial contamination in the town’s water supply.
PDF Version
Measuring Ammonia with Online Analyzers
Water Engineering & Management
July 2002
Tony Palmer, Maureen Ross, P.E. and Stephen G. Nutt, P.E.
Treatment facilities use online ammonia analyzers to monitor and control treatment processes. Controlling ammonia levels can make treatment processes more reliable and cost effective. Currently, there are three major types of online ammonia analyzer technologies available to measure ammonia concentration in a treatment process stream.
PDF Version
Advanced Technology Brings the Power to Chlorine Dioxide
Water Quality Products
May 2002
Michael Cochran, Engelhard Corp
Chlorine dioxide is an extremely effective and powerful biocide that has been used for many years as a bleaching agent and slimicide in the pulp and paper industry, as a disinfectant in municipal water treatment and in many other industrial water treatment operations. However, significant capital and operating costs have limited the use of chlorine dioxide to large-scale applications. New technology now makes it practical to use the biocide in a wider range of water treatment applications.
PDF Version
Automated Chlorine Control Brings Precision to Water Reclamation Operation
Water Engineering & Management
May 2002
By Steve Kobler
Using reclaimed water for non-potable purposes as a means of conserving potable water supplies is the most prevalent method of water reuse in the United States today. One of the significant challenges for water reclamation facilities is to keep up with the demands for safe, compliant chlorine (Cl2) treatment. One utility that is effectively meeting this challenge is Southern California’s Otay Water District.
Ultraviolet for Disinfection
Water Quality Products
April 2002
Tom Schaefer, Aquionics
Historically, industry has relied on hazardous chemicals such as chlorine and expensive processes such as pasteurization to rid its water supplies of pathogens. Currently, though, the use of ultraviolet (UV) light, the same as the portion of the electromagnetic spectrum of sunlight responsible for killing microorganisms, is providing a safe, reliable and highly effective method of getting the job done.
PDF Version
Effects of Recharge of Chlorinated State Water Project Waters to Groundwaters in Lancaster Area of California
Water Engineering & Management
April 2002
Hisam A. Baqai, P.E., G.E.
As the population in Southern California increases, more and more demands are being put on the state’s groundwater resources, further exacerbating the overdraft problem. Many communities in Southern California are recharging their aquifers with imported surface waters to combat this problem. The major recharge normally is carried out during wet weather periods when surface water is plentiful. However, recharging these groundwater aquifers with imported surface water can create the potential for water quality degradation. The problem can start when surface water is disinfected with chlorine to prevent biofouling and remove pathogens.
PDF Version
Chlorination and Its Alternatives
Water Quality Products
March 2002
By Anne Penkal and Nadia Abboud, Severn Trent Services, Inc.
Purification of drinking water containing microbiological contamination requires some form of disinfection treatment to kill or render microbiological organisms harmless.
Of the available disinfection treatment methods for private water systems, chlorination in the most commonly used.
Metering Pump Technology
Water Quality Products
March 2002
By Steven Ebersohl, Pulsafeeder, Inc.
Since the introduction of the metering pump, chemical feed for disinfection has been a primary application. As we move into the 21st Century, it again is time to review how we introduce chemicals such as sodium hypochlorite into our water systems. While the goal remains the same, changes in pump technology have been created to provide more accurate and consistent results. This article will discuss current metering pump technologies, proper pump sizing, installation and future enhancements.
Chlorine Taste in the Customer’s Drinking Water?
Water Quality Products
March 2002
By Ron Grage, Chlorinators Incorporated
Chlorine produces bacteria-free water and eliminates algae and slime. It also removes hydrogen sulfide from ground water (wells and springs) and eliminates iron bacteria (cenothrix), which are associated with objectionable odor and taste.
Despite these important facts, some people still object to chlorine in their drinking water. Comments such as “I don’t like the way chlorine makes my water taste” are common.
Consider the Source
Water Engineering & Management
February 2002
Bill Swichtenberg
A report released by the Environmental Working Group (EWG)
and U.S. Public Interest Research Group (U.S. PIRG) has taken aim at
chlorination byproducts (CBPs) in tap water. The group‘s assessment
states that more than 100,000 women are at elevated risk of miscarriage or
birth defects because of CBPs in tap water.
PDF Version
Legionella Management and Monitoring: Part 2
Water Quality Products
February 2002
Paul S. Warden, Kristen S. Fallon, Ph.D., M.S.E.L., & Colin R. Fricker, Ph.D.
Well-designed water distribution and cooling systems,
coupled with sound management and operational procedures, are essential to
control Legionella in industrial facilities—and a monitoring program
should not be considered as a replacement. However, most experts even those
ill-disposed towards routine Legionella monitoring, would agree that monitoring
should be considered if enough legionellosis risk factors apply to the system
in question. No management program, regardless of its treatment, maintenance or
monitoring components, can guarantee the absence of future legionellosis, but
prudent operational practices combined with ongoing review of risk factors will
allow facility managers to minimize exposure to Legionella and to its legal consequences.
PDF Version
Legionella Management and Monitoring: Part I
Water Quality Products
January 2002
Paul S. Warden, Kristen S. Fallon, Ph.D., M.S.E.L., Analytical Services, Inc., and Colin R. Fricker,
This article will present an overview of Legionella bacteria, its ecology and sample collection strategies. A discussion of the pros and cons of Legionella monitoring also is included.
PDF Version
The Right Time for Bottled Water, POU
Water Quality Products
December 2001
Wendi Hope King
Although in October, the IBWA had seen only a slight increase in sales overall since the attacks, individual companies have reported increased sales since Sept. 11. This partly is due to bottled water being named as one of the must-have items in case of further terrorism.
PDF Version
Water and Air UV Treatment
Water Quality Products
November 2001
By Bak Srikanth, Aquafine Corp., and David Witham, UltraViolet Devices, Inc.
UV is an accepted and rapidly growing technology for treating wastewater in the United States. In Europe, it commonly is used as a primary disinfectant in municipal drinking water systems. Other applications include food and beverage, pharmaceutical, semiconductor and power generation. This article will discuss three other commercially successful and growing applications.
PDF Version
Coping with Resistance to Copper/Silver Disinfection
Water Engineering & Management
November 2001
By W. Craig Meyer
Numerous facilities have invested in copper/silver disinfection systems to address the limits of traditional water treatment methods. It seems likely that, as bacterial populations develop resistance, many of these systems will become less effective through time.
PDF Version
Editorial Emphasis
Water & Wastes Digest
November 2001
Oxygen-fed Ozone Generation Offers Advantages Over Ambient
Air
Products In Action
Water & Wastes Digest
November 2001
Microfiltration, Nanofiltration Help Meet EPA Standards at Lake
Mead
Troubleshooting Bottled Water Complaints
Water Quality Products
October 2001
Barbara L. Marteney and Kristin Safran, National Testing Laboratories, Ltd
Customer complaints are an unfortunate but unavoidable part of business. Bottled water complaints typically arise when a customer perceives an off taste, odor or appearance in the water.
PDF Version
Ozone for Bottled Water
Water Quality Products
October 2001
Andrew Zaske and Aaron Edland, Osmonics, Inc.
The proliferation of bottled beverages worldwide and an increased awareness of consumer health issues have beverage suppliers rethinking how to keep their liquids safe for consumption.
PDF Version
Reclaim Greenhouse Water
Water Quality Products
October 2001
Jeff Roseman, CWS, Aqua Ion Plus+ Technologies
Reclaiming water in the greenhouse industry will soon be something the government will be mandating the growers in the industry to do, as more wells are becoming contaminated from nitrates and phosphorus levels are becoming a concern for public health.
PDF Version
Testing Bottled Water
Water Quality Products
September 2001
Barbara L. Marteney and Kristin Safran, National Testing Laboratories
One of the most important (and sometimes the most complex) area of the bottled water business is compliance with federal, state and industry regulations. As the EPA continues to evaluate contaminants in drinking water for regulation under the Safe Drinking Water Act (SDWA), the FDA must review these regulations for their suitability for bottled water.
PDF Version
Gas Chlorine Education
Water Quality Products
September 2001
The Gas Chlorine Education Committee
The Gas Chlorine Education Committee announced the launch of an industry-wide campaign entitled, "Gas Chlorine: The One and Only Choice for Water Disinfection."
PDF Version
High-tech: Samplers
Water & Wastes Digest
September 2001
Hach Company
New Analyzer Offers Continuous Measurement, Dual Stream Sample
Calcium Hypochlorite
Water Quality Products
July 2001
Joanne Funyak, PPG Industries, Inc.
It was more than 90 years ago that Booton, N.J., became the first utility in the nation to use chlorine to purify water. Subsequently the use of chlorinated water became the norm across the country and safe drinking water is something we all take for granted. In that respect, how many people realize how water chlorination affects other aspects of everyday life? To many people, a nice dip in the pool provides recreation and relaxation, and they don’t need to think about the effort that went into the treatment and sanitation that made that pool a safe and clean place for fun. That is left to the professionals and drinking water fundamentals that can be applied to pool water care.
PDF Version
Troubleshooting Ozone Water Treatment Equipment
Water Quality Products
July 2001
Roger Nethanson, Ozone Pure Water, Inc.
This article will serve as a troubleshooting principles outline that will quickly and simply guide you through ascertaining, locating and fixing the problem.
PDF Version
Commercial, Industrial Ultraviolet Systems
Water Quality Products
June 2001
Adam Donnellan
In past articles, we discussed the benefits of ultraviolet (UV) disinfection as well as the many available options. In this article, we will focus on the available technologies and provide an overview of how these technologies are being applied in commercial and industrial applications.
PDF Version
Ultraviolet System Design
Water Quality Products
May 2001
Adam Donnellan
In the last issue, we reviewed ultraviolet (UV) disinfection as a suitable technology for treating biologically unsafe water supplies. In this article, we will focus on system design and understanding the many available options for residential and commercial applications.
PDF Version
Using Maintenance Benchmarking Practices to Specify Chlorine Residual Analyzers
Water Engineering & Management
May 2001
Tony Palmer and Maureen Ross,P.E.
We all have been to that meeting where new regulatory standards requiring more stringent guidelines are announced, when it is demanded that the treatment facility be run more efficiently and that it has been decided that automation is inevitable. Of course, there is a limited budget.
PDF Version
Cryptosporidium - A brief overview of a new technology
Water Quality Products
March 2001
Danielle Duclos
The occurrence of Cryptosporidium parvum and other pathogens in water supplies poses a dangerous problem to the water industry and human health. Read about a new technology that is helping rid of this problem.
PDF Version
Water Quality Deterioration in Distribution Systems
Water Engineering & Management
February 2001
Thomas L. O'Connor and John T. O'Connor
While temperature is acknowledged to be an important factor in water treatment, remarkably little study has been made of the adverse influence of low temperatures on physical treatment process effectiveness. An early study concluded that "there is no preventative or retarding effect on alum floc formation with low raw water temperatures."
PDF Version
Basic Essentials
Water Quality Products
January 2001
Adam Donnellan, Sunlight Systems
The benefits of ultraviolet (UV) light in destroying waterborne diseases are well established. This article (part one in a continuing series) will focus on explaining the basic terminology associated with the technology.
PDF Version
Roundtable Discussion: E. coli (Escherichia coli)
Water Quality Products
November 2000
Wendi Hope King
Recent outbreaks of E. coli have brought consumer’s attention to their drinking water. Understanding its source, regulations and prevention will be key to combating this waterborne illness.
An Overview of Ozone in Water, Wastewater Treatment
Water & Wastes Digest
November 2000
There are more than 2,000 installations worldwide that use ozone to treat drinking water. Ozone is an effective disinfectant for treating municipal and industrial wastewater, enabling the end user to meet EPA pre-treatment standards.
Well Water Treatment: Ozone Helps Solve Water Problems at Bassi Ranch
Water Quality Products
September 2000
Ted Rich
An analysis of the raw well water (Table 1) shows a pH of 7.9 and 30 color units with >20 mg/L hydrogen sulfide, 5.6 mg/L iron and 0.6 mg/L manganese. Odor was detected at 10 threshold odor number (TON), indicative of the high hydrogen sulfide levels. To meet these water problems head-on, the homeowners formed the Bassi Ranch Mutual Water Co. in 1992.
Legionella: Minimizing Risks
Water Engineering & Management
August 2000
W. Craig Meyer
Legionellosis, the disease caused by Legionella spc., is common, though most people would guess it is extremely rare. Outbreaks of Legionellosis, defined as a cluster of three or more cases in a single locale, occur regularly in the United States and much of the developed world.
Membrane Filtration As an Alternative: Part 2
Water Engineering & Management
August 2000
Dr. Mohamed Lahlou
Part one of this article appeared in the July issue and discussed microfiltration and utrafiltration. This article discusses nanofiltration and reverse osmosis.
Membrane Filtration as an Alternative: Part 1
Water Engineering & Management
July 2000
Dr. Mohamed Lahlou
Once considered a viable technology only for desalination, membrane processes are increasingly employed for removal of bacteria and other microorganisms, particulate material and natural organic material that can impart color, tastes and odors to the water.
Considerations for POE Residential Ozone Treatment
Water Quality Products
February 2000
Gabe Ergler
Residential ozone systems are becoming more common as the preferred method to treat common water problems such as iron, manganese and hydrogen sulfide.
Ozone Generator Improves Cobb Area County Water Quality
Water Quality Products
November 1999
The Cobb Area County Water District of Middleton, Calif., achieved a major improvement in the district’s water quality by approximately 40 percent, from one of its major water sources—a well near one of its pumping stations.
Georgia Golf Course Greens Up With Ultraviolet Disinfection
Water & Wastes Digest
October 1999
The process of reusing wastewater for sprinkling at the Sugar Hill Golf Course in Gwinnett County, Georgia, was time consuming, costly and problematic. An in-line ultraviolet disinfection unit installed at the treatment plant solved the problem.
UV Disinfection 101
Water Quality Products
May 1999
by Edwin L. Roberts
An overview of UV disinfection and its applications.
UV Disinfection Q&A
Water Quality Products
May 1999
by Robert Voitle
Some common UV-realted questions are answered by UV Expert Bob Voitle.
Membrane Filtration for Water and Wastewater
Water Quality Products
February 1999
Membrane filtration, widely used in chemical and biotechnology processes, is already established as a valuable means of filtering and cleaning wastewater and industrial process water.
Ozone Pilot Plant Design:Why Use Ozone?
Water Quality Products
January 1999
Gabe Ergler, CWS-III
In this article, some of the many reasons ozone would be chosen over other oxidants such as chlorine are discussed. If you have a reason to apply ozone as part of your water treatment project, you may be required to conduct a pilot study prior to installation of the equipment.
Generating Chlorine Dioxide Gas:Chlorate vs. Chlorite
Water Engineering & Management
September 1998
Douglas Rittmann, P.E. and Joel Tenney
Is a new method of generating chlorine dioxide gas using sodium chlorate more effective than the typical sodium chlorite system?
The Effect of Nitrification on Sampling Sites
Water Engineering & Management
November 1997
Shin-Ichi Tokuno and Floyd Baker
This article reports on chloramine dissipation with regard to nitrification and how it affects the CT value in plant operation
Making the Third-Party Certification Choice
Water Quality Products
July 1997
by Nancy Culotta
Manufacturers' claims have become more sophisticated as the industry branches into two diverse segments: water conditioning and health effects claims. Within both segments, opinions have developed that claims made by manufacturers should be truthful and not misleading--resulting in a need to have products independently tested to verify water treatment claims made and promoted in the field.
Ozone, Direct Filtration System Performance Prove Technology's Value
Water Engineering & Management
March 1997
A three-year test of ozone and direct filtration so convinced the Altoona City Authority (ACA) of its merits that the central Pennsylvania water authority is now installing the technology at six new treatment plants and will retrofit another by 1999.
Cryptosporidium and Giardia Inactivation Device
Water Quality Products
October 1996
G. Michael Furst, Jr.
A new water disinfection system has been developed to inactivate Cryptosporidium oocysts and Giardia cysts in drinking water. The technology, known as the CID, inactivates these pathogenic waterborne microorganisms using enhanced ultraviolet (UV) irradiation technology without filtrate disposal, chemical addition or related hazardous by-products.
Ultrafiltration Basics
Water Quality Products
April 1996
Lynn Cotterill
Municipal and industrial sectors are looking to new and innovative technologies to meet the demands of modern day consumers' requirements. One such technology is ultrafiltration.
Cryptosporidium, Ozone & the POE/POU Industry
Water Quality Products
November 1995
Ron Long
The challenge Cryptosporidium brings to all water professionals, whether municipal plant technicians or POE/POU industry members, is more than finding a means for treating a specific microbe.
DAF and Ozone Eliminate Quality Woes, Meet New Regs
Water Engineering & Management
October 1994
Ian Lisk
A New York State town developed a water treatment plant which uses dissolved air flotation and ozone disinfection to ensure meeting anticipated tighter regulations.
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