H₂S determination in waste water for the petrochemical industry

Do you know what a difficult job it is collecting and treating the wastewater in a refinery?

It is not so easy……..

Together with collecting and treating the wastewater, the aim is to ensure that there are no odor emissions or any damages occurring to the system……

In the sewage works, Hydrogen sulphide and volatile organosulfur compounds are considered to have the greatest health risk potential along with the obvious odor nuisance.

Crude oil contains a lot of Sulphur compounds. So, in the production process of fuels and other petrochemical products, the separation of the sulphur is an important step.

In these processes, some of the sulphur compounds can be released into the waste water.

To combat the problem of toxic Hydrogen sulphide, strict treatment strategies are used as the impact to the sewer system and wastewater treatment plant is substantial:

1. Extensive odor nuisance from the sewers is observed, specifically at connection pits from pressurised systems into open channels. 

2. When different wastewater streams are flowing together, it is dangerous, particularly for the staff working in sewage plants. Due to lethal high gas concentrations, the workforce can suddenly be in danger as H₂S can spontaneously strip out from the anaerobic wastewater.

3. Due to the deteriorated biological degradation of the organic matrix, bulking sludge is formed which substantially hinders the treatment in the wastewater treatment plant. In extreme cases, the entire biology of the plant is affected.

A direct analysis of the H₂S-loading of wastewater is mandatory in order to achieve goal-oriented regulation for wastewater treatment as well as to create redevelopment concepts.

ECH Elektrochemie Halle have developed a revolutionary procedure to precisely determine Sulphides and H₂S…. This ECH technique can be used in your laboratory, as a portable tool or as a totally hands free online system fully integrated in to your process, not only accurately measuring H₂S in real time, but automatically controlling and dosing the treatment chemicals.

The ECH Sulfimax GX procedure is as follows.  

Quite simply, Sulphide/H₂S in aqueous solutions are determined by a highly effective gas extraction and a detection method.

After dosing into the ECH H₂S-analyser, the sample is automatically acidified.

The released H₂S gas is stripped out from the solution by using a continuous gas flow and, subsequently, is selectively detected by an electrochemical sensor.

This ECH principle is extremely robust, incredibly sensitive and with no cross contamination….

Further more, there is the advantage that the ECH procedure is working without any sample preparation.

Components of the sample (such as oil residues or particles) are separated effectively due to the indirect determination procedure and therefore cross-sensitivities are avoided.

This is yet another example of the ECH advantage……

The ECH procedure as used on the new Sulfimax GX has been fully recognised with a new standard….

Method DIN 38405-27 for easy releasable sulfide in water.

This new method developed in Germany was released in October 2017.

Many tests were conducted in comparison to the manual procedure of gas extraction with photometric detection. This old method requires a lot of preparation by the analyst and needs 90 minutes or more to perform just 1 test!

The ECH procedure used by the Sulfimax confirming to DIN 38405-27 is fully automated, requires no sample preparation and needs less than 5 minutes to perform the measurement…..

A broadly based round robin test had proven the robustness of the analytical process. 20 labs measured industrial wastewater samples with a reproducibility better than 3.9 %.

The round robin and data received shows how the ECH advantage can help speed up H₂S analysis and vastly reduce the time required by the analyst to perform the test…..

ECH H₂S analysers according to the method DIN 38405-27, can be used to analyse H₂S in all kinds of water and wastewater.

ECH H₂S analysers are offered with autosamplers for large sample throughput, can be taken to the sample points directly when using the small and portable Sulfimax GX and in the case of S-Online, it can be fully integrated in to the process as an online system.    

Our specialists are here to answer all your questions. ECH Elektrochemie Halle have a lot of data, applications knowledge and documentation for you to see.   

In addition to this, please contact Mr Tom Gallant to book your ECH Studio session presented to you by ECH Scientific, the global sales division of ECH Elektrochemie Halle.

The ECH “live lab” allows you to see the instruments, watch the analysis take place and see the procedure and results for yourself….

You are welcome to request an on-line session where you can fully interact with our application specialist team.     

We look forward to seeing you soon.