M2 PM Non-Point Source Pollution and TMDLs
Monday, 14 November 2005: 1:50 PM - 5:30 PM in Ballroom 2

(TWA-1117-870630) Prevention and control of non-point source pollution of soil and ground waters using abundant natural and waste organogenic materials.

Twardowska, I.¹, Kyziol, J.¹, Janta-Koszuta, K.¹, Stefaniak, S.¹, ¹ Polish Academy of Sciences, Institute of Environmental Engineering, Zabrze, Silesia, Poland

ABSTRACT- Growing human-induced impact on soil and water quality, among others due to worldwide increase of sewage sludge (biosolids) generation and use in agriculture, as well as disposal of metal-rich sufidic waste from mining results in the need of simple, efficient and cost-effective methods of non-point pollution prevention and control through reduction of metals content in sewage sludge (SS) and prevention of metals leaching and transport from dumping sites to the aquatic environment. Source control of metals from artisan activities in municipal wastewater and application of permeable barrier layers during waste dump construction might greatly reduce a risk to the environment. Application of abundant, low-cost organogenic natural (e.g. peat) or waste materials, e.g. stabilized SS as sorbents seems to be an attractive contribution to the solution of these problems. Studies on the use of peat for metals removal from strongly acidic polymetallic electroplating wastewater (EPW) in batch and flow-through systems confirmed high efficiency of these processes. In the batch process at input concentrations of Me-SO₄ in EPW: 14985 mgFe/L>2807 mgZn/L>335 mg Cr/L>171 mgCd/L>122 mgMn/L, pH 1.47, sorption capacity of peat for metals from undiluted EPW accounted for 107330 mgFe/kg, 3520 mgZn/kg, 2002 mgCr/kg, 1053 mgCd/kg and 371 mgMn/kg. The removal efficiency with respect to the total input load was 75% Fe, 85% Cr, 61% Cd, 30% Mn and 13% Zn. Flow-through process showed considerably higher sorption capacity for all the metals, in particular for Zn (22985 mg/kg) and Cr (17431 mg/kg) that accounted for 80% and 84% of total input load of these metals. In both systems the predominant role in metal binding played strongly bound organometallic and labile exchangeable sorption "pools". Peat appeared to be an efficient sorbent to be used both in simple batch reactors and in protection layers, as well as in constructed wetland systems, also for strongly acidic wastewaters. Wetland protection requirements limit extensive use of peat. For this reason, stabilized SS is better applicable in batch reactors, where Me remowal from the EPW in the range 83->95% for Me concentrations in the input >50 mg/L, and 47-65% at lower Me input concentrations was achiewed, showing high feasibility of these materials application as efficient sorbents.

Key words: non-point metal pollution, source control, high-metal wastewater, mining waste dumps