Effects of adsorption on mass transfer in immobilization matrices

Selection of support materials for immobilization of Burkholderia cepacia PCL3 in treatment of carbofuran-contaminated water

This study investigated the utilization of agricultural matrices as the support materials for cell immobilization to improve the technique of bioremediation. Coir, bulrush, banana stem and water hyacinth stem in both delignified and undelignified forms were used to immobilize Burkholderia cepacia PCL3 in bioremediation of carbofuran at 5 mg l(-1) in synthetic wastewater. Undelignified coir was found to be the most suitable support material for cell immobilization, giving the short half-life of carbofuran of 3.40 d (2.8 times shorter than the treatments with free cells). In addition, it could be reused three times without a loss in ability to degrade carbofuran. The growth and degradation ability of free cells were completely inhibited at the initial carbofuran concentrations of 250 mg l(-1), while there was no inhibitory effect of carbofuran on the immobilized cells. The results indicated a great potential for using the agricultural matrices as support material for cell immobilization to improve the overall efficiency of carbofuran bioremediation in contaminated water by B. cepacia PCL3.

Optimisation of entrapped activated carbon conditions to remove coloured compounds from winery wastewaters

The objective of this work was to study the entrapped conditions of activated carbon in calcium-alginate beads for the clarification of winery wastewaters. An incomplete 3(3) factorial design was carried out to study the efficiency of activated carbon (0.5-2%); sodium alginate (1-5%); and calcium chloride (0.050-0.900 M), on the following dependent variables: colour reduction at 280, 465, 530 and 665 nm. The activated carbon and calcium chloride were the most influential variables in the colour reduction. Nearly 100% colour reductions were found for the wavelengths assayed when employing 2% of activated carbon, 5% of sodium alginate and intermediate concentrations of calcium chloride (0.475 M). Instead, other conditions like, 2% of activated carbon, 4% of sodium alginate and 0.580 M of calcium chloride can also give absorbance reductions close to 100%.