SLG-F Sewage Sludge Treatment Efficiency Trial

SLG-F Trial Revolutionizes Sewage Sludge Treatment Efficiency

Wastewater treatment sludge dewatering efficiency trial offers pioneering solutions for sustainable sludge management.

Wastewater treatment plant operators are contending with soaring costs for sludge haulage and disposal. Rising polymer prices and stricter regulations exacerbate these challenges. Enter SLG-F, a sludge treatment method by Orège UK Ltd that significantly reduces sludge volumes for disposal. SLG-F also cuts polymer use. For Yorkshire Water, which transports sludge to drying facilities from around 700 wastewater treatment works, successfully implementing this technology would be a game changer.

Orège UK Ltd and Yorkshire Water entered the Climate Change Trial Reservoir in 2022 to conduct a SLG-F wastewater efficiency trial. The objective was to assess the performance and impact of SLG-F technology at one Yorkshire Water site using a skid-mounted thickening unit. The trial goals included evaluating the technology’s efficiency and operational feasibility under specific performance criteria. An additional aim was to explore how SLG-F could be used more broadly within Yorkshire Water.

The SLG-F plug and play package plant proved itself in handling rags and grit, while consuming – at design throughput 20 m³/hr – 7.5 kWh, which included all ancillaries. Its liquid poly dose of 2.5 to 4.5 kg/TDS depending on solids load showcased efficiency. Operating automatically for >95% of the trial period, it demonstrated reliability and efficacy. Thickened sludge up to 9% was possible, however for operational reasons 6% was deemed practical (from a variable input of 0.8 – 1.2%).

Benefits of Approach/Innovation
  • Enhanced Sludge Management: By transforming sludge into a more manageable form with a higher dry solids content, the technology minimizes the volume of waste. Yorkshire Water imports sludge from ~700 water treatment sites: implementing SLG-F will lead to a 50% reduction in sludge tanker trips.
  • Reduced Carbon Footprint: Fewer sludge tanker trips means a smaller transportation carbon footprint. The initial wave of units will reduce annual CO₂ emissions from transportation by 120,000kg CO₂.
  • Lower Operating Expenses: The carbon savings is equivalent to a six-figure operational saving for the company over the lifespan of the asset.
  • Operational Efficiency: The ability of the SLG-F unit to operate automatically for more than 95% of the trial period with minimal human intervention translates to reduced energy use, further enhancing overall energy savings.
  • Reduced Disposal Costs: The frequency and associated costs of disposal are significantly reduced. This makes the disposal process more efficient, more sustainable and more cost effective.
  • Operational Flexibility: The plug and play nature of the SLG-F package plant allows for easy integration into existing wastewater treatment frameworks, providing a solution that can be tailored to varying operational demands and disposal requirements.
Specialist Services Involved:
  • Trial Design Support: We evaluate technology trial plans based on users’ innovation frames. The Trial Reservoir specifically addresses key questions that the trial must answer.
  • Trial Validation: We receive and assess the trial end report from the technology vendor. We offer a neutral professional opinion on whether the conclusions that have been drawn are well supported by the data generated.
  • Due Diligence: Isle has a robust process for helping stakeholders adopt innovative technologies and ensuring they are fit for purpose.
  • Loan Funding: Isle facilitates negotiation with technology developers and end users to agree upon the trials’ critical success factors and key performance indicators (KPIs). Loans are then released to the technology developers.
  • Zero Risk Trial: Should a trial not meet its KPIs, there is no obligation for the tech company to pay back the loan. Similarly, there is no obligation for the end user to make a purchase order; the Trial Reservoir assumes the risk.
  • Investor Introductions: Isle uses its extensive worldwide network to provide introductions to potential investors.
  • Reduced Sludge for Disposal: Trial halved the number of tanker journeys from the Yorkshire Water site. This significantly cut transport costs and environmental impact, contributing to the overall water environmental transition of the utility’s wastewater management practices.
  • Met Sludge Thickening Targets: Achieved 6% dry solids in thickened sludge, surpassing the target. This demonstrates the technology’s capability to enhance sludge consistency and manageability.
  • Excellent Energy Efficiency: Operated on just 7.5kWh, including ancillaries (at design throughput of 20 m³/hr). This was far below the maximum allowance of 183 kWh per day, demonstrating excellent energy efficiency and cost effectiveness.
  • Slashed Polymer Use: Liquid polymer dosing ranged between 2.5-4.5kg/TDS depending on solid loads, significantly cutting polymer use while achieving desired outcomes.
Key Contacts:

For enquiries and further information, please contact Jo Burgess, Head of Trial Reservoir at Isle Utilities.


Service Spotlight
SLG-F wastewater efficiency trial offers pioneering solutions for sustainable sludge management by reducing sludge for disposal, offering significant energy savings and slashing polymer use.
Enhanced sludge management by minimizing volume of waste
Contributed to Yorkshire Water’s overall water environmental transition
Demonstrated excellent energy efficiency, operating well below the maximum daily allowance
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