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Project name:

Advanced technology for pretreatment of municipal wastewater sludge to improve biogas generation and decrease of dry sludge

Status: Idea
Creation date: 24-02-2023

Project objectives:

Short summary A Swiss SME active in environmental technologies offers a solution for sludge pretreatment in municipal wastewater plants. The solution (technology and machinery) can pre-treat sludge before the digester and by this significantly increase biogas generation (up to 50%) and decrease dry sludge disposal at the end of the process (up to 20%). The dry sludge could be used as fertilizer. The company searches for license, joint venture, commercial or technological cooperation agreements.

Full description Sewage is treated in wastewater treatment plants to recover usable water streams. The semisolid or solid by-product formed during sewage processing is known as sludge. Treatment of sludge is chiefly designed for reducing the sludge volume and converting the organic materials in the sludge into stable substances to enable effective disposal, recover a usable product, or generate biogas. The main processes to achieve these goals are sludge digestion, in which organic matter is biologically decomposed under the action of bacteria, and secondary sludge dewatering, in which water is removed from the sludge. The company's solution is solving the problems associated with sludge digestion and the generation of biogas and sludge dewatering. One of the main challenges in treating sludge is that not all the organic material is available to the bacteria. That's why the biogas generation is still limited. Only 50% of the biogas potential is currently generated in wastewater plants. The second significant challenge of the process is a high concentration of water trapped inside the dry sludgy (up to 90%) at the end of the process. That's why sludge (mechanical or thermal) dewatering is a critical stage before dry sludge can leave the wastewater plant. However, efficient dewatering by conventional mechanical methods is challenging to achieve. The Swiss company offers a solution called sludge pretreatment and partial oxidation process (STP). It is a fully automatic, in-situ, partial chemical oxidation unit for the pretreatment of primary and secondary municipal sludge before digestion. The technology increases the soluble chemical oxygen demand (sCOD) levels before anaerobic digestion (AD) by up to 100% through partial oxidation of sludge. Sludge from clarifiers is pumped to the STP unit, where it is sprayed with an active solution consisting of two stable materials. The materials react to generate superoxide radicals, which partially oxidize the sludge, increasing the sCOD concentration. Under normal temperature and pressure, the average reaction time is one hour, during which mechanical agitators continuously mix the sludge. At the end of the process, the oxidized sludge is pumped to the digester, where the increased sCOD concentration increases the availability of the organic material to the bacteria. This process increases biogas yields by up to 50%, reduces sludge disposal volumes by up to 20%, and improves the secondary dewatering process. Moreover, the sludge could be used as fertilizer at the end of the process (sludge class A). This unique approach not only improves existing processes, increases biogas generation, and saves operational expenditures (OPEX) to wastewater plant operators but also decreases the carbon footprint of the wastewater plant. The technology can be applied in any wastewater facility (centralized and non-centralized plants). However, the technology is especially efficient in wastewater plants with biogas generation units. The company searches for partners/representatives active in the wastewater sector, wastewater plants operators and designers (engineering offices), environmental engineering offices, recycling companies, waste management companies, and companies in the field of biogas generation from waste and wastewater for license, joint venture, commercial or technological cooperation agreement.

Advantages and innovations
  • It can be easily installed in any size wastewater facility
  • Plug and play containerized solution
  • Rapid pretreatment
  • Fully automatic machine
  • Increase in soluble organic material (sCOD) up to 100%
  • Increase in biogas generation up to 50%
  • Decrease in dry sludge disposal up to 20%
  • Cost-effective (savings in dry sludge disposal and profit in additional biogas generation)
  • The sludge at the end of the process can be classified as sludge class A (fertilizer)
  • Small footprint of equipment
  • Very low electricity requirement
  • Save for users and the environment
  • Negligible CO2 footprint (decrease CO2 footprint of the facility)
  • Low capital expenditure (CAPEX)
  • Fast return on investment (ROI in less than one year)
  • Improve dewatering
  • Granted patents
  • High availability of active solutions in all the territories

Contact / source: NEXT EEN Widgets (