Feature Article

Reverse osmosis (RO) with polyamide membrane of spiral wound and precipitation with commercial sodium carbonate were studied to remove hazardous substances [chromium(III), sulfate, chloride and sodium] contained in a tanning wastewater. RO removed chromium(III) very efficiently (99.83%) and with lower but appreciable yields the other three constituents of liquid effluent. Major inconvenience of RO was fast decrease of permeate flux due to insufficient transmembrane pressure used. In turn, 99.71% of chromium(III) was separated with precipitation.

This study presents effect of injection timing on performance, combustion and emission characteristics of mahua biodiesel (Madhuca indica) and its blends with pure diesel on a 4 stroke tangentially vertical single cylinder (TV 1) direct injection diesel engine. At injection timing of 22° bTDC, blend B25 (25% mahua biodiesel and 75% pure diesel, by vol) gave optimum performance, which is very close to pure diesel. Thus B25 fuel can be effectively used in a diesel engine as an alternative fuel without any modification in the engine.

This study presents performance behaviors of a commercial diesel engine fueled with diesel and Jatropha based biodiesel (B100) at various loads (up to 100%) and compared using standard (conventional) and three new face profile designs (I, II & III) of piston rings. BTE of engine fueled with diesel increases 2-8% with new face profile design (III) of piston rings in comparison to standard (conventional) piston rings. BTE enhances 8-16% when engine is fueled with biodiesel using face profile design (III) on piston rings.

This study presents bioconversion of water hyacinth (Eichhornia crassipes) to bioethanol using two-sequential steps of acid hydrolysis (10% sulfuric acid) and yeast (Candida intermedia) fermentation. A maximum ethanol yield (coefficient, 0.21 g g-1; productivity, 0.010 g l-1h-1) was comparable to predicted value (0.23 g g-1) obtained by CCD (Central Composite Design). Two colorimetric methods (phloroglucinol and dichromate assays) were used for determination of xylose and ethanol using UV-Vis spectrophotometer.

Blue green algae (BGA) possess immense morphological and metabolic diversity and can be used in economic developmentand environment management like wastewater treatment, land reclamation, production of fine chemicals, atmospheric fixation ofnitrogen, production of methane fuel, conversion of solar energy, therapeutic functions and so on. This review presents applicationsof BGA in agriculture, food and industry.

After CNG, the national capital is all set to run its public transport fleet on biogas. Ambitious as it may sound, but Delhi plans to run its buses on biogas. In collaboration with the Swedish government, the Union Ministry of New and Renewable Energy plans to set up a biogas plant inside Kesopur Sewage Treatment Plant (STP) complex in West Delhi. The plant will receive raw gas emitted by the STP and upgrade it so that it can be used to propel vehicles.