A modified alkaline peroxide pre-bond process for the surface treatment of titanium is useful as a practical production process. In this modified process, an exceptionally wide range of allowable peroxide concentration, namely, from 0.001 molar to 0.2 molar (and preferably 0.001 molar to 0.01 molar) may be tolerated and a novel real-time peroxide monitoring and control technique is employed. The process is further improved by means of the use of stabilizers such as precipitated magnesium silicate which greatly increases bath life-time and reduces the overall operating cost of the process. Solution operating conditions have been defined which permit titanium adherends to be processed satisfactorily over a wide range of hydrogen peroxide concentration. In particular, the acceptable temperature range is 125.degree. F.-165.degree. F. (51.7.degree. C.-73.8.degree. C.); the treatment period is 15 to 25 minutes and the hydroxide concentration is 0.3 to 0.9 molar. The preferred values are approximately 145.degree. F. (62.7.degree. C.); 20 minutes, and 0.5 molar, respectively. An electrochemical method has been established utilizing a magnesium electrode (114) which provides a stable potential characteristic that is dependent only on the concentration of the peroxide. The resultant capability to reliably monitor the peroxide concentration in real time in turn permits an automated feed system to be effectively utilized for sustaining the peroxide concentration within the desired limits.
(a) Apparatus for regulating the concentration of an oxidizing solution, particularly a solution containing disinfecting molecules. (b) Apparatus characterized in that it comprises a secondary pipe (6) branched to a main pipe (1) upstream of a readjustment pipe (5) to which is fitted a measuring cell (2), as well as an addition pipe (12) connected to a reservoir (8) containing an adapting solution (7).
A computerized chemical application system for a water treatment system. The water treatment system includes a main header conduit through which water flows. Connected in shunt with the main header is a chemical introduction header of smaller diameter and a lower flow rate than the main header. A computer control is provided to sense the conductivity of a reference water flowing through the chemical introduction header. Injection means are provided to introduce a water treatment liquid into the chemical introduction header and to mix it thoroughly with the water flowing therein. The conductivity of the mixture is sensed, and based upon the differential conductivity and values relating conductivity to concentration for the water treatment liquid (which values are stored within the computer control) the amount of the water treatment liquid introduced is precisely controlled.
