Fred A. Blanchard, S. Gonsior, Daniel L. Hopkins
Jul 1, 1987
Citations
2
Influential Citations
20
Citations
Journal
Water Research
Abstract
Abstract An important environmental feature of 2,2-dibromo-3-nitrilopropionamide (DBNPA), the active ingredient in Dow's Antimicrobials 7287 and 8536 is that the compound rapidly degrades in dilute aqueous solutions. High performance liquid chromatography analyses of ppm-concentrations of DBNPA and its degradation products in laboratory tests of several natural water samples were used to follow the reactions involved. A hydrolysis pathway leads to dibromoacetonitrile (DBAN) and other products. The presence of organic material in the water leads to degradation by a second pathway in which monobromonitrilopropionamide (MBNPA) and several other degradation products are formed. From the data, a computer simulation model of the reactions has been developed using DACSL (Dow Advanced Continuous Simulation Language). The model describes quantitative relationships of DBNPA dosage and the natural water's organic material content, as measured by total organic carbon (TOC), in the degradation pathways of DBNPA. The model helps interpret the aquatic toxicity of the rapidly changing complex mixture produced during these degradations. Simulations of the DBNPA treatment of cooling towers were compared to limited experimental data which indicated that most of the degradation occurred by the pathway which produced the less toxic products (MBNPA et seq. rather than DBAN et seq. )