Development and application of an auto-normalization program for optimal treatment of numerous metal-containing hazardous sludges

Precise control of all pollutant concentrations during co-treating numerous hazardous materials is difficult because of the variety of pollutants and concentrations. An Auto-Nor program for normalizing various concentrations of numerous hazardous materials had been developed, and the normalization theory, processes, and a practical case of 20 metal-containing sludges was presented. Metal concentrations (Cij) of each sludge, including Cd, Cr, Cu, Pb and Zn, were divided by toxicity characteristic leaching procedure (TCLP) regulatory limit to be relative concentrations (Rij). Computations at a systematic threshold of normalization (U) by the Auto-Nor program would automatically sort out optimal co-treatment groups. In the 20-sludge case, three optimal co-treatment groups, comprising 14, 3 and 3 sludges, were sorted out and the application results show that all random samples passed the TCLP test. The Auto-Nor program can be further applied to the treatment or remediation of hazardous fly ashes and contaminated soils, improving and benefiting their concentration control, dosage management and cost reduction.