Measuring H2S and sulfides in their liquid and gas phases
Your question refers to three aspects of sulfur in the water and the air presumably with regards to an urban wastewater context:
- sampling and measurement in liquid phase,
- measuring H2S gas,
- remote monitoring and control of data (SCADA).
As a preamble, I would say that sampling and measuring sulfides in water is a delicate operation that requires significant equipment and man-hours and only provides one-off data that cannot be analyzed in a centralized system. Moreover I am not aware of any online sulfide analyzers that are sufficiently reliable to replace personnel in the field or laboratory.
If you want to perform the occasional sampling, in light of specific concentrations and using all the required safety equipment, then yes, you can us a portable gas detector or even a Dräger Accuro pump in combination with the tubes: http://www.draeger.com/sites/assets/PublishingImages/Products/cin_x-zone_5000/US/gas-detection-br-9041145-us.pdf
To the extent that you want data that is reliable and recorded continuously and you want to avoid releasing H2S, which in addition to being dangerous for humans affects daily operations, you would have to look into a dosing system like Thiobox to prevent or eliminate sulfides.
It’s a good idea to carefully examine the placement of any sensors, which may have to be adapted to the specific environment and to the fluctuations in concentrations of H2S over time. And they will require periodic maintenance and even replacement.
At the end of the day, you can do a lot even without necessarily having a SCADA system in place.