H2O Transformers - Water Environmental Consultant - polymer evaluations, training, testing and other complex water issues. Water Clarification.

"Catest"

The effects of synthetic polyelectrolyte, cationic polymers, on selected aquatic organisms. -
A Summary from U.S. Environmental Protection Agency,
Kenneth E. Biesinger and Gertude N. Stokes.

1. Cationic polymers when overdosed can increase toxicity of wastewater effluents. Synthetic polyelectrolyte, polymers, are used extensively to promote flocculation in potable water and municipal/industrial wastewaters. They are used by the pulp and paper, textile, fiberglass, ceramic, paint, metal, metal finishing, mining and petroleum industries for the recovery of products as well as liquid/solids separation, clarification, thickening, dewatering and color removal. Notwithstanding their extensive use and discharge into most water in the developed countries, there have been very few technical papers published in the open literature on the toxicity or other adverse effects to aquatic organisms. Biesinger et al. (1), exposed selected aquatic animals to 6 different types of polymers and reported acute toxicites ranging from 0.29 mg/L to 345 mg/L. Personnel from Dow Chemical Company (2) reported safe concentrations of polymers to fathead minnows (Pimephales promelas) ranging 2-1000 mg/L. Brocksen (3) stated that 1 mg/L or less of Purifloc C-31 was acutely toxic to rainbow trout ranging from 0.42 mg/L to 7,180 mg/L for cationic Magnifloc polymers. The toxicity of many more compounds, polymers, is supplied in various reports and in brochures from various chemical companies which manufacture their polymers.

The aquatic toxicity of several polymers was tested to daphnids (Daphnia magna) and midges (5) (6) (7) (Paratanytarsus parthenogeneticus). A microcosm test using 5 aquatic animals and 10 algal species was also conducted. In addition, tests were made to determine the detoxificaiton of cationic polymers by adding proprietary products supplied by H2O Transformers (H2OT) . In the product line from H2OT the Catest series represent 3 dry products and 4 liquid forms of detoxicants. The Catest procedure is available from H2OT and could reveal if residual cationic polymer is present. The Catest procedure would quantify how much of the detoxicant would be required by adding one or a combination of the products developed.

References:

Biesinger, K.E. et al. "Comparative Toxicity of Polyelectrolytes to selected aquatic animals." Journal of Water Pollution Control Federation. 48(1): 183(1976)
Dow Chemical Co., "Chemical Treatment of Combined Overflows." EPA, Water Pollution control Research Services. 11023fdb09/70. Washington, D.C. (1970)
Brocksen, R.W. "An evaluation of potential sources of toxicity to fish in Martis Creek." U.S. Army Corps of Engineers, Sacremento District, CA (1971)
Kobunski, Gyoshuzzi Konwakai, "Safety of polyacrylamide flocculants and safety of catioinic polyacrylamide flocculants".
Yamamoto, S. "Safety of cationic polymeric coagulants." Seikatsu to Kankyo 24 (1979)
Furuno, A. et al. "Method to rendering cationic polymers harmless to fish". Japan Patent Agency, Gazette. Koakai No. 1976-454-51.
German Patent application 29-42-111. "Process for the detoxification of water treated with cationic polymer flocculation agents."