Waste Pretreatment

Waste in many countries must pass Waste Acceptance Criteria (WACs) prior to landfill. The leachability of heavy metals such as lead is often a key component of such WACs. The methods used to assess leachable metals within waste to be landfilled differ from country to country, although the main two tests are the US Toxicity Characteristic Leach Protocol (TCLP) and the European Union EN12457 Leach Protocol for Granular Solid Waste.

Leachate threshold values are set for wastes to be landfilled. For example within the European Union the leachate threshold for lead disposal is 50mg.kg-1 in a hazardous landfill and 10mg.kg-1 in a stable, non-reactive hazardous waste cell within a non-hazardous landfill. Wastes which fail these leachate threshold values require some form of pretreatment prior to disposal.

TRAPPS™ is very effective for the pretreatment of waste. It offers long term, effective stabilisation of a range of wastes at economical cost. TRAPPS™ treatment allows for waste to conform and pass WACs. It can be used to treat hazardous waste so as to conform to two possible objectives;

Case Data

A contaminated topsoil contained a total lead concentration of 32,000mg.kg-1. Landfill was chosen as the remedial method. The soil was classified as hazardous due to its high total Pb content. WAC investigation showed that TRAPPS™ treatment could stabilise the material, enabling disposal as stable, non-reactive hazardous waste. This allowed for a significant cost saving to the customer.

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