The treatment of Sulfuric Acid (Sunfua) in wastewater is crucial for environmental protection and human health. Sulfuric acid is a strong mineral acid that can be harmful if released into the environment untreated. When present in wastewater, sulfuric aci

Handling Sulfur in Wastewater

Methods for treating sulfur compounds in wastewater are divided into 3 groups: inhibiting the formation and removal of sulfur, minimizing the spread of hydrogen sulfide from wastewater, and controlling concrete corrosion by sulfuric acid.

Inhibiting the Formation and Removal of Sulfur

During wastewater treatment, inhibiting the formation, removal of sulfur, and sulfur-reducing bacteria are carried out using chemicals with strong oxidizing properties such as ClO₂, NaNO₃...

ClO₂ is introduced into wastewater in large quantities to remove biofilm - the habitat of Nitrate-reducing bacteria to limit the formation of sticky sulfur.

NaNO₃ is usually added to large holding tanks with a retention time of over 4 hours to enhance the oxidation process to help remove odors in the water. Nitrate-reducing organisms can oxidize organic matter faster than sulfate-reducing bacteria. The reduction process is shown by the following chemical reaction:

Organic matter + NO₃- → N₂ + CO₂ + biomass

In addition, chemicals such as NaOCl, H2O2, and iron salts can be used to inhibit the formation and removal of sulfur. The reactions in this process are as follows:

• 2H₂S + NaClO₂ → 2SO + 2H₂O + NaCl (9)
• H₂S + H₂O₂ → SO + 2H₂O (pH < 8.5) (10)
• H₂S + 4H₂O₂ → SO₄2- + 2H₂O (pH > 8.5)(11)
• 8NO_3- + 5H₂S → 5SO₄2- + 4N₂(12)
• Fe²⁺ + HS- → FeS + H⁺ (13)
• 2Fe³⁺ + 3HS- → Fe₂S₃ + 3H⁺

Some wastewater treatment systems use forced aeration to control Eh. With this method, the dissolved oxygen concentration in the water increases significantly, helping to reduce the BOD content in the water. This helps reduce organic matter and limit the formation of sulfur.

Minimizing the Spread of Hydrogen Sulfide from Wastewater

The second control method is applied from the design of the wastewater treatment system. Engineers and experts must calculate the hydraulics, air venting paths, drainage pipes, and pump stations of the wastewater treatment system to control the spread of sulfur.

In addition, businesses can minimize the spread of hydrogen sulfide from wastewater by building systems to extract toxic gas and odors from the wastewater.

Controlling Concrete Corrosion by Sulfuric Acid

To control concrete corrosion by sulfuric acid, the optimal solution is to isolate concrete with condensed H₂S gas. The exterior of concrete structures must be treated with membrane-forming materials, sealants that resist H2S from penetrating inside.

The waterproofing membrane group used includes: Urethane, Neoprene, or Epoxy. The sealants covering the waterproofing membrane are usually Silicone-based.

In addition, businesses can use durable sulfate-resistant cement containing C3S and C3A to build wastewater treatment systems. This method helps ensure the durability of the structure and saves chemical costs during operation.

The presence of sulfur in wastewater causes many negative impacts on treatment facilities and the water environment, air. Therefore, treating sulfur is extremely essential, requiring the application of various technologies to achieve the best efficiency.

Businesses without experience in building wastewater treatment systems according to regulations and standards should seek environmental companies with years of experience in the field such as Toan A JSC.

Toan A JSC is a leading address in designing and constructing wastewater treatment systems in Hanoi. With the requirement to treat sulfur in wastewater, Toan A's experts support businesses in optimizing processes in a common system. This approach achieves high efficiency, contributes to environmental protection, and saves costs.