@The Sustainability Director of the University of California-Davis ran across my ACS 'Story of Bottled Water' presentation and wanted to create a display in the Student Union using my water bottles and slides. Thanks to him, I was able to clear out some space in my basement.
Water Chemistry was developed as a primer for water and wastewater treatment plant operators. It introduced pC-pH diagrams for alkalinity and various acid-base systems encountered in natural waters. It illustrated the calculation of solubility of water treatment coagulants plus a number of USEPA-regulated metals. It provided sample data on removal of metals during wastewater treatment. It demonstrated oxidations and reductions of importance in water and waste treatment. It introduced the chemistry of carbon as viewed in water treatment regulations. It illustrated the chemistry of those well water sources influenced by microbial activity and reducing conditions in the ground - with an emphasis on the gases produced by microorganisms. It utilized bar diagrams to illustrate electroneutrality conditions. It provided previously unpublished data on the organic carbon content and occurrence of disinfection by-products (trihalomethanes) in Missouri drinking water sources and chlorinated supplies. It provided data on residual metals, hardness and sodium ions in finished drinking water supplies. It provided a unique set of data on the total bacterial cell counts enumerated in treated Missouri drinking waters.
Water softening by precipitation with lime is widely practiced throughout the Midwestern United States. This slide show illustrates some of the treatment practices and classical equipment used by several municipal utilities.
Algal blooms, followed by low lake water temperatures in the early winter of 2004, led to taste-and-odor producing compounds in the influent to the drinking water treatment plant at Bloomington, Illinois. The operational procedures adopted to mitigate the taste-and-odor along with extensive data on the presence and removal of geosmin and 2-methyl isoborneol (MIB) are presented in this slide show.
A major finding was that water recovered from the lime sludge storage lagoons contributed significantly to the plant influent geosmin/MIB concentrations.
Since most geosmin/MIB removal occurred primarily during filtration through Bloomington's GAC-capped filters, laboratory studies were undertaken to determine how rapidly geosmin adsorption capacity might change with GAC service age. These results indicated that adsorption on virgin carbon was most effective in geosmin removal. Despite increased colonization with microorganisms, GAC became progressively less effective after one and two years in service.
It was decided that virgin carbon should best be installed in the autumn in preparation for winter taste-and-odor challenges.
On a rotating basis, over a three-year period, the granular activated carbon (GAC) caps on Bloomington, Illinois' 18 sand filters are replaced with virgin GAC. Microscopic examination of both the carbon and sand shows that extensive microbial colonization has occurred on the media.
Moreover, the GAC has changed markedly in size distribution. As 'fines' are lost and larger particles are reduced in size, GAC progressively occupies a narrower size range.
Everyone knows that we shouldn’t dry kittens in the microwave, but how many are aware of the many prohibitions communities have enacted to protect our sanitary sewerage systems and sewage treatment plant processes?
What can’t (or shouldn’t) we put in our toilets, sinks and household drains? Do most communities really prohibit us from emptying pool water or pumping out water from our flooded basements? Are there even ordinances against discharging ‘stinky stuff’?
After consulting the local regulations, we may be left wondering what we are permitted to put into our sanitary sewers.
Worse. In regions where treated wastewater is now destined to be an increasingly large part of our public water supply, prohibitions may get even more restrictive.
Before joining in the national political sport of name calling, backbiting, and sloganeering, the first question that one should clinically address is: ‘are human activities responsible for the observed increases in world temperatures over the past century?’ There is no real question that the earth is warming. Some really competent members of the human race, now with the help of earth-orbiting satellites, have gotten very good at measuring temperature.
A manifesto, it turns out, is a statement of principles. Accordingly, it should address what principles should guide those who are responsible for the safety, security and long-term sustainability of our drinking water supplies. At first glance, most of these principles might seem simple, basic, even humble. Many of these principles have already been articulated by others in recent waterworks literature; they are commonly advanced in technical conferences; and they are undergirded by federal and state regulatory incentives.
However, there are impediments to both the adoption of and adherence to the seemingly most self-evident of principles. For example, in regions where water sources are deemed adequate to meet current and projected demands, calls for restraint and conservation may seem punitive both to water users and utility management. Since water utilities derive about three-quarters of their income from selling water, reductions in water use can only result in lost revenue. To water utility management, promoting restraints on water use is often regarded as akin to asking General Motors to sell fewer vehicles. For balance, revenue lost from any proposed water use reduction must be offset by a compensating rate structure adjustment for the utility. As for those profligate users in the community, equity requires that they be billed to pay the true costs associated with meeting their excessive demands.
In Columbia, Missouri, our local independent movie theater group, the Ragtag, hosts (free to all attendees) a series of talks from a wide range of local people -- constraining them to show 20 slides, each for 20 seconds. Hence, "20/20". Obviously, the fast pace is a challenge for the speakers, but a guarantee for the audience that no presentation will last more than 7 minutes.
The youtube link, below, is to my son Tom's sub-7 minute presentation. Tom came to local attention as he reduced his electrical consumption, over a number of years, by 90%, solely by conservation. How? Tom keeps no secrets.
Why the bass solo? Tom elected to eliminate one of his slides.
Having determined that chloramine disinfectant residuals were corroding copper in household plumbing, an effort was made to reduce the chloramine concentrations applied in the Willmar, Minnesota water distribution system. This involved controlling microbial-mediated nitrification, which led to the formation of nitrite during distribution. Nitrite ion, in turn, depleted the applied residual. Controlling the formation of nitrite then allowed less chloramine to be applied to the system.
This paper was presented at the Minnesota Chapter, American Water Works Association, in 1998.
A year later, after further trials of alternative methods, chlorite ion was adopted to control nitrification.
Benefits of Air-Assisted Backwash of Granular Filter Media - A Slide Show
This presentation summarizes comparative operational performance data stemming from a water treatment plant filter upgrade completed in 2009. It illustrates the installation of air-assisted backwash (air scour) and details the resulting changes in backwash protocols. The paper also quantifies the economic benefits of the upgrade in terms of reduced backwash water use and reduced frequency of filter backwashing. A series of slides illustrate the revised backwash process.
This work was presented by Tim Price, Senior Chemist, Associated Electric Cooperative, Inc., Thomas Hill Energy Center, Cliffton Hill, MO at the Joint Meeting of the Missouri Water Environment Association and the Missouri Section, American Water Works Association, March 25-28, 2012, Tan-Tar-A, Osage Beach, Missouri.
How effective are water treatment processes in controlling human enterovirus in a major water supply? In 1976, USEPA undertook to have this question addressed at a location downstream from the waste discharges of Kansas City, Missouri.
One highlight of the study's results was the seasonality of the virus challenge. During the summer, the steady input of virus to the Missouri River appeared to decline en route to the study site at Lexington, Missouri. Unlike bacterial indicators, it was during the winter months, when water temperatures were near freezing that most human enterovirus were recovered.
Cold water periods are also those times when water treatment processes are least efficient. Chemicals dissolve slowly or incompletely. Due to increased viscosity, flocculation is less effective (unless paddle speeds are increased which they rarely are). With increased water density, sedimentation rates are greatly retarded. Filtration through granular media becomes relatively ineffective in removing planktonic cells. Even the rates of chemical disinfection are retarded.
Finally, our conventional microbiological indicators (total coliform, fecal coliform, and heterotrophic plate counts) become irrelevant because they are inversely correlated with virus.
Thirty years ago, USEPA was starting to assess the capabilities of various alternative drinking water treatment processes for reducing the consumer's exposure to trihalomethanes and organic carbon compounds. This pilot plant study, using Missouri River water, was one of the first to directly compare the use of chlorine versus chloramine for reducing the formation of trihalomethanes while maintaining disinfection capability. Over the ensuing generation, chloramine has become the dominant means for disinfection of surface waters throughout the United States.