Abstract: Leakage of water from a boiler water system wherein steam is generated in a boiler from feedwater fed to the boiler, and the concentration of impurities in the boiler water within the boiler is reduced by withdrawing fractions thereof as blowdown while admitting additional feedwater as boiler-water makeup, is determined. The boiler has a concentration cycle value, the concentration cycle value being the average value of the concentration of an inert component in the blowdown at steady state (C.sub.F) divided by the concentration of the inert component in the feedwater (C.sub.I). The concentration of the inert component in the boiler at steady state varies from a high concentration C.sub.H, having a value that is higher than C.sub.F, to a low concentration C.sub.L, having a value between the (C.sub.I) and the (C.sub.F), within a time period.

Abstract: The discharge of copper from isothiazolone biocides into industrial waste water streams is prevented by contacting the isothiazolone biocide as it is withdrawn from a point of use storage container with an ion exchange resin capable of removing copper from aqueous solutions. When the treated isothiazolone biocide is added to an industrial process water which will produce waste stream, potential copper contamination is virtually eliminated.

Abstract: Black liquor is rendered more pumpable by reducing its viscosity by adding to the black liquor at least a part per million of a wax based on the solids present in the black liquor.