TREATMENT OF LANDFILL LEACHATE USING FILTER SUBSTRATES

SUMMARY: Three by-products from the steel and paper manufacturing industries have been tested as filter materials for removal of heavy metals in metal solution and in landfill leachate. Laboratory experiments were used to determine the capacity of the materials to remove heavy metals. A column set-up at a landfill site examined the field application possibilities of pine bark, amorphous and crystalline blast furnace slag. All three materials have shown large potential for removal of heavy metals in metal solution also when the concentrations are low. On-site treatment however was distrurbed by factors not present in batch experiments. Physical parameters such as pH and electric conductivity of the water stream were not significantly affected by the treatment

Treatment of heavily contaminated storm water from an industrial site area by filtration through an adsorbent barrier with pine bark (Pinus Silvestris), polonite and active carbon in a comparison study

Abstract: This study aims to evaluate a simple and robust filtration method for separation of heavy metals from storm water. The storm water, collected at a metals manufacturing site, is heavily contaminated with heavy metals. A first analysis showed exceptionally high concentrations of Zn, which was present in concentrations exceeding 200 mgL -1 . The basic idea is to filter the water as it flows out of the industry area through a passive barrier in the storm water well pipeline. Pine bark was in this study compared to two other materials; polonite and the conventional adsorbent active carbon. The forestry by-product pine bark (Pinus silvestris) consists of approximately 85-90 % dried and granulated pine bark and 10-15 % wood fibres. Polonite is a manufactured product originating from the cretaceous rock opoka. A laboratory experiment was set up, where the storm water from the industrial site was filtered through all three filter materials in a pilotscale model of the proposed installation. The filter cartridge model could be filled with approximately 2.2 L filter material. 3 L of the storm water was poured through the material through natural percolation, approximately 0.35 Lmin -1 . Treated and untreated storm water was analyzed for heavy metals, suspended solids, electric conductivity and pH. Active carbon showed the highest level of adsorption, with nearly 100 % of all metals adsorbing to the filter. However, significant concentrations of As was desorbed from the material into the filtered water. Pine bark retained 90 % of the metals, even the Zn which was present in high concentrations. Polonite could only adsorb 70 % of the heavy metals and released Cr from the material