10 research outputs found
Effect of leachate loading rate and incubation period on the treatment efficiency by T. versicolor immobilized on foam cubes
This study focuses on treatment of landfill leachate in column
experiments by immobilized Trametes versicolor on polyurethane foam,
collected from Nonthaburi landfill site, Thailand. In this study,
glucose was used as a co-substrate. The effect of biomass growth on
color removal was observed by immobilizing fungi on polyurethane foam.
The same immobilized fungi were used for four cycles of 5 days each to
find the reuse of fungi. Leachate was diluted to see the effect of
organic loading on color removal. At optimum pH of 4 and in 20 days
with 3 g/L of glucose, the fungi could decolorize 78 % and 63 % for
5-times dilution and concentrated leachate, respectively, using
immobilized fungi after 4 days initial growth. Fungi could also reduce
biological oxygen demand and chemical oxygen demand of 52 % and 42 %
(with initial biological oxygen demand and chemical oxygen demand of
48,900 and 96,512 mg/L), respectively, with glucose 3 g/L in
concentrate leachate and with 4 days initial immobilization of fungi on
polyurethane foam. About 1-6% higher color removal was observed on day
20 with 15 days fungi immobilization initially as compared to 4 days
immobilization. Higher removal efficiency was observed for the same
leachate after dilution due to reduction in organic loading. Addition
of co-substrate enhances significantly removal of color, biological
oxygen demand and chemical oxygen demand. Chemical oxygen demand
removal reached to 0.6 mg/mg of biomass with the co-substrate.
Therefore, white rot fungi can be considered as potentially useful
microorganisms in landfill leachate treatment
Asperidine B : total synthesis and structure correction
A synthesis of the proposed structure of asperidine B is reported, involving a tandem hydroformylation-condensation reaction, a diastereoselective dihydroxylation and the addition of an organozinc reagent to an iminium ion. As the spectroscopic data for the synthetic material is not in agreement with that of the natural product, the structure of asperidine B is reassigned as (+)-preussin.Accepted versio