In wastewater, dissolved sulfide is a mixture of molecular hydrogen sulfide (H2S) and hydrosulfide ions (HS-) existing in equilibrium with hydrogen ions. The standard analytical methods for sulfide determination in solution (e.g. Iodine method) permit measurement of total sulfide (H2S + HS-) rather than the direct measurement of H2S. In this work, the direct determination of H2S in sewage samples was determined using a method which was similar to that of Broderius and Smith Jr. The procedure involves bubbling nitrogen through the aqueous sulfide solution to strip all the H2S which could escape to the gas phase and measure it by an H2S-gas detector. The amount of molecular H2S was determined from the calculation of the total area under the curve relating the volume of nitrogen (L) and H2S concentration (mg/L) in the gas phase. The area was calculated using the Trapezoidal Numerical Method. The H2S for the same sewage sample was also determined by using the standard iodine method.
ASJC Scopus subject areas
- Waste Management and Disposal
- Management, Monitoring, Policy and Law