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The adsorption ability of activated carbons from sugar beet pulp to remove the cadmium from aqueous solutions has been investigated. Optimum temperature and time for carbonization of sugar beet pulp were determined as 700°C and 120 min. The results of adsorption experiments show that pH for effectiveremoval of cadmium was 6.3 or greater. The maximum removal percentage of cadmium were found to be 99.0, 78.2 and 57.0 by. using 2.5 g j"1adsorbent dosage for initial cadmium concentration of 100, 250 and 500 mg 1. 1 , respectively, at optimum pH and 20°C for a contact time of 120 min. Langmuir and Freundlich adsorption models were applied to the isotherm data. The free energy change of process was found to be-18.03 Kj moj"l.

The optimization of nutrient levels for the production of α-amylase by Bacillus amyloliquefaciens was carried out using response surface methodology (RSM) based on the 2 3 factorial central composite design (CCD). This procedure limited the number of actual experiments performed while allowing for possible interactions between three components. RSM was adopted to derive a statistical model for the effect of starch, peptone and yeast extract (YE) on α-amylase production. The P-value of the coefficient for linear effects of starch and YE concentration was <0.0001, suggesting that this was the principal experimental variable, having the greatest effect on the production of α-amylase. The optimal combinations of media constituents for maximum α-amylase production were determined as 12.61 g L −1 starch, 2.83 g L −1 peptone and 1.25 g L −1 YE. The optimization of the medium resulted not only in a 34% higher enzyme activity than unoptimized medium but also in a reduced amount of the required medium constituents.