Here is what appears in Volume 4 Number 2 of the Journal of the Swimming Pool and Spa Industry:

General:

An Introduction to the Journal

The Submission Criterion

Articles:

John A. Wojtowicz

Chemcon

Cyanuric Acid Technology

Cyanuric acid was identified as a chemical substance over two centuries ago. However, it was not until the late 1950’s that it attained industrial significance with the introduction of chlorinated isocyanurates by Monsanto and FMC. Although the majority of cyanuric acid production is used in the manufacture of chlorinated isocyanurates, some of it is also used as a swimming pool available chlorine stabilizer. Cyanuric acid is also used in the manufacture of specialty intermediates used in the production of plastics and coatings. The properties, chemistry, uses, etc. of cyanuric acid and chloroisocyanurates have been comprehensively reviewed (Wojtowicz 1993a and 1993b). In addition to its function as a stabilizer for available chlorine, cyanuric acid also contributes to buffering of swimming pool water. This paper discusses the structure, properties, analysis, chemistry, manufacture, and uses of cyanuric acid as well as the mechanism of stabilization, the effect on disinfection, and the effect of chloramine formation.

John A. Wojtowicz

Chemcon

Factors Affecting the Cyanuric Acid Concentrations in Swimming Pools

Use of chloroisocyanurates for swimming pool sanitation results in a build-up of cyanuric acid (CA) with time. This is a concern because the kill time of bacteria increases with the ratio of cyanuric acid to free available chlorine at a given pH (Wojtowicz 1996). This is due to the fact that cyanuric acid reduces the concentration of hypochlorous acid. The NSPI (ANSI/NSPI–5 1995) recognizes that cyanuric acid affects the rate of disinfection by chlorine and recommends higher av. Cl levels for stabilized pools compared to unstabilized pools, i.e., 1–3 ppm vs. 0.4 ppm. In fact the NSPI has a draft proposal to raise the ideal recommended av. Cl range to 2-4 ppm (ANSI/NSPI–4 199X). Excessive concentrations of cyanuric acid should be avoided, not only to avoid compromising disinfection but also algae control. Equations for calculating the rate of build-up and the steady state concentration of cyanuric acid are developed. The NSPI recommends a maximum of 150 ppm CA and many Health Departments limit CA in public or commercial pools to 100 ppm because they recognize that CA affects disinfection. Various options are discussed for limiting or reducing the cyanuric acid concentration in swimming pools sanitized with chlorisocyanurates, including water purge, precipitation with melamine, adsorption on activated carbon, and oxidation with hypochlorite. The most practical method of controlling or limiting CA build–up is water purging. The loss rate of cyanuric acid from hypochlorite or chlorine sanitized pools is also discussed.

John A. Wojtowicz

Chemcon

Oxidation of Cyanuric Acid with Hypochlorite

The oxidation of cyanuric acid with available chlorine was studied in order to determine if excessive levels of cyanuric acid could be reduced by treatment with hypochlorite. This study showed that prohibitively high concentrations of available chlorine would be required to achieve significant reductions in cyanuric acid levels in a practical time. The study also indicates that the cyanuric acid loss rate under typical swimming pool conditions is probably not significant.

J. Que Hales, Doug Latta and Kim Skinner

onBalance

A Critique of the Dow Whitney Report

A study was conducted at the University of Florida which concluded that “deterioration of marcite (including both etching, pitting and staining) is chemically related and is primarily due to leaching of calcium hydroxide (portlandite) from the portland cement paste.” However, a close reading of the draft report itself reveals that no such conclusion can be reached based on the data published. Indeed, critical data, which would be expected to support any conclusions made, are missing from the report.
The study was composed of three major components: research and summarization of pertinent, previously published material; failure analysis of samples acquired from the industry (referred to as “field diagnostic studies”); and a lab study designed to replicate field conditions and cause coupons to exhibit the failure characteristics (referred to as an “etching and staining mechanistic” study).
The study contains numerous incorrect assumptions, which led to a careful analysis of the report. It was discovered that many of the incorrect ideas were plagiarized from material found in an earlier study performed by a Monsanto employee.
Also, the laboratory study utilizing coupons was duplicated by this paper’s authors, and the results are given, which indicate that the conclusions made in the Dow Whitney report about the lab study are unwarranted.