BS EN 13656:2020 pdf free.Soil, treated biowaste, sludge and waste一Digestion with a hydrochloric (HCI), nitric (HNO3) and tetrafluoroboric (HBF4) or hydrofluoric (HF) acid mixture for subsequent determination of elements.BS EN 13656 This document specifies three methods for the digestion of soil, treated biowaste, sludge and waste by the use of an acid mixture composed of hydrochloric (HCI), nitric (HNO3) and...