Let us talk a bit about different forms of Sulfur
-Hydrogen sulphide is one of the most difficult substances in wastewater treatment since it is both dangerous in enclosed places and a nuisance at low levels.
-Sulfate is one of the most frequent sulphur compounds found in nature. Plants consume sulphate, which is a vital micronutrient for life.It is available in two forms: yellow powder and rock.This type of sulphide can bind to iron, giving septic effluent a dark grey to black hue.
-Sulphides’ are more soluble in higher pH water. Reduced sulphides in wastewater have a high chemical oxygen demand, making them hazardous to ammonia-oxidizing bacteria (AOB).
-H2S is a caustic, highly hazardous gas that is emitted into the atmosphere when the pH of wastewater lowers.
How is Sulfur used in Wastewater Treatment Plants?
The various forms of bacteria involved in the sulphur cycle in wastewater treatment are:
1: Sulfate Reducing Bacteria - These bacteria use sulphate as an electron acceptor to breakdown organics in anoxic environments. When there is oxygen or nitrate in the system, sulfate-reducing bacteria are outcompeted by bacteria that use oxygen or nitrate as an electron acceptor to obtain more energy.
2: Sulfur Reducing Bacteria - These chemotrophic bacteria get their energy by converting sulphur to sulphide. These bacteria are less frequent in most wastewater than sulfate reducing bacteria, which utilize sulphur as an alternate electron acceptor.
3: Sulfur Oxidizing Bacteria - These are chemotrophic bacteria capable of converting reduced sulphur species to sulphur and sulphate. While certain species can use nitrate as an electron acceptor, most sulphur oxidizers require oxygen. If the process is completed, sulphuric acid is produced (H2SO4). These are the well-known sewage corrosion bacteria that can grow when H2S concentrations in the vapour phase reach critical levels. These are essential for eliminating sulphides from wastewater. Alkalinity is required to protect the system from pH drops. Thiobacillus, Anwoodia, Paracoccus, and Thiosphaera are common wastewater SOB taxa.
How is sulfur useful?
Sulfur generating ?solutions for collection systems, equalisation tanks, and headworks are:
1: Sulfides can be retained in the water phase by raising the pH of the collection system and adding ferric or sulphide scavengers. This is a simple remedy, but it doesn't address sulphide production in anoxic/anaerobic zones.
2: Alternative electron acceptors such as nitrate, liquid oxygen, and hydrogen peroxide are commonly used to hinder the growth of sulfate-reducing bacteria. All of them work by providing microorganisms in the system with a higher energy electron acceptor than sulfate/sulfide.
3: To avoid sulphide development, use a comprehensive control programme. This method employs monitoring and testing to identify zones with favourable redox potential for SRB growth.
Conclusion
In wastewater, sulphides are an issue. Most sulphide is generated in wastewater under anoxic/anaerobic conditions that encourage SRB growth unless you have an influent source of reduced sulphides. Disfavouring SRB growth is the greatest way to prevent sulphides from developing in the system.
Netsol Water provides a complete variety of standard and fully configurable wastewater treatment systems, as well as their comprehensive maintenance. Choosing a trained, accredited, and experienced wastewater system specialist will considerably boost your chances of long-term satisfaction with your overall system.
We have over 10 years of experience custom-designing and manufacturing wastewater treatment plants. You can schedule a conversation with our engineer or obtain an estimate by visiting our website. We can guide you through the process of determining the best solution and a reasonable price for your wastewater treatment system requirements.To begin the conversation, please contact us at +919650608473 or send an email to enquiry@netsolwater.com for further information or product purchase related query.
