Anaerobic Digester Capacity and Sediment Assessment Using Lithium Trace Testing

The Bioresource and Energy Services team seeks a qualified supplier to conduct non-intrusive tank capacity and sediment assessments of Anaerobic Digesters using Lithium chloride as a trace element. This testing is required every 5 years to comply with Environmental Permitting (England & Wales) Regulations 2016 and the Industrial Emissions Directive (IED), which control pollution to air, water, and land from industrial activities. The supplier must develop and implement a methodology to determine the effective volume of anaerobic digesters over a short testing period by measuring lithium concentration at steady state. The effective volume will be calculated using the dose of lithium chloride added, measured lithium concentration, and background concentration established before testing. The final report must present: mixing efficiency, hydraulic retention time (HRT), identification of short-circuiting or dead zones, and sediment/grit accumulation levels. Lithium chloride will be dosed into each digester's feed line or other suitable location. Prior to dosing, initial samples must be collected from designated sampling points (identified during a pre-test site visit) to establish baseline lithium concentrations. The supplier should have expertise in trace element testing, anaerobic digester operations, and environmental compliance.