Roekmijati Widaningroem Soemantojo

Enhancement of carbon dioxide fixation by alteration of illumination duringChlorella vulgaris-Buitenzorg's growth

Alteration of illumination with optimum carbon dioxide fixation-based curve in this research successfully enhanced the CO2-fixation (qco2) capability ofChlorella vulgaris Buitenzorg cultivated in a bubble column photo bioreactor. The level of CO2 fixation was up to 1.91 times that observed from cultivation with intensification of illumination on an optimum growth-based curve. During 144 h of cultivation, alteration of light intensity on an optimum CO2-fixation-based curve produced a qCO2 of 6.68 h−1. Increases in light intensity based on a curve of optimum CO2-fixation produced a final cell concentration of about 5.78 g/L. Both cultivation methods were carried out under ambient pressure at a temperature of 29°C with a superficial gas velocity of 2.4 m/h (UG). Cells were grown on Beneck medium in a 1.0 L Bubble Column Photo bioreactor illuminated by aPhillips Halogen Lamp (20 W/12 V/50 Hz). The inlet gas had a carbon dioxide content of 10%.

Prospects for the utilization of water hyacinth (Eihhornia crassipes) and other organic waste as cardboard material

Abstract A brief overview is given of the present efforts and future prospects in waste management for organic waste utilization, including the utilization of water hyacinth (Eichhornia crassipes (Mart.) Solms). Special emphasis is reported on the technical aspects, continuous availability of raw material, marketability, other economic aspects, and environmental risks and benefits in the utilization of water hyacinth, with or without other organic wastes, as raw materials for cardboard and pulp production.