In the petrochemical industry, caustic (i.e. NaOH) is a tried-and-true method for removing high levels of H2S from liquid streams. By adding the strong base, you keep the pH of the stream above a set point where 100% of the H2S exists as S2-. This way, you can ensure that none of the sulfur escapes the fluid by evaporation, and that 100% of the dissociated H2S can be effectively precipitated into a removable salt.
In this type of operation, you can either dump expensive caustic blindly or you can use analytics to optimize and save money. At such high H2S saturation, pH sensors can become unstable within a single day. The pH-independent OMA H2S Analyzer uses a multi-component analysis to directly detect the failure condition which a pH meter merely predicts: the formation of HS- in the stream. Using Applied Analytics technology, you can optimize caustic use in real time by monitoring the HS- absorbance curve and ignoring pH altogether.