New Stable Biodegradable Scale InhibitorFormulations for Cooling Water:Development and Field Tests

摘要

The increased demand for more sustainability of inhibitor systems in open coolingrnwater circuit applications has dominated much of the development activity in thisrnarea in recent years. Biodegradability has been a top priority in this context due tornever more restrictive legislation in Europe regarding the discharge of chemicals intornflowing waters.rnVarious biodegradable scale inhibitor formulations based on biodegradablerncarboxylic acids have been developed recently and exhibit good scale inhibitionrnperformance in pilot plant tests along with low toxicity and reasonable raw materialrncost. The widespread use of such systems throughout the industry has thus far beenrnprevented by a fundamental concern: depending on circuit conditions, biodegradationrnof inhibitors may commence within the cooling systems as opposed to the desiredrndegradation after discharge. Consequently, inhibition performance will be diminishedrnand additional problems with increasing biological activity in the circuit are posed.rnThe necessary countermeasures would be increased dosages of oxidizing biocidesrnwhich in turn would diminish the effectiveness of the inhibitors, thereby substantiallyrnreducing the environmental and financial customer benefit.rnA novel water treatment composition by Henkel Surface Technologies counteractsrnthis effect, combining good biodegradability of the discharged inhibitors with highrninhibition performance at low concentrations in conjunction with effective biologicalrncontrol. We present field tests from an industrial plant in Germany which clearly showrnthe enhancement of overall performance derived from the full integration of scalerninhibition and biological control treatment programs.