Combined effect of CO2 concentration and low-cost urea repletion/starvation in Chlorella vulgaris for ameliorating growth metrics, total and non-polar lipid accumulation and fatty acid composition.

Different CO2 concentration such as 0.03, 5, 10 and 15% and low-cost urea repletion/starvation in Chlorella vulgaris on growth, total and non-polar lipid content and fatty acid composition was studied. Chlorella vulgaris grown at 0.03% CO2 apparently revealed inferior biomass yield 0.55 g/L on 14th day compared to CO2 supplemented cells. In the case of CO2 supply, 15% CO2 has unveiled higher biomass yield at about 1.83 g/L on day 12 whereas biomass yield for 5 and 10% CO2 supplemented cells was 1.61 and 1.73 g/L, respectively on 12th day of cultivation. The biomass productivity (g) per liter per day was 32 mg in control condition whereas it was 125, 134 and 144 mg/L/d in 5, 10 and 15% CO2 supplied cells, respectively. Lipid content of the strain grown at control, 5, 10 and 15% CO2 was 21.2, 22.1, 23.4 and 24.6%, respectively and however, without CO2 addition in low-cost urea repleted and urea depleted medium grown cells revealed 21.2 and 24.2%, respectively. Interestingly, strain grown at 15% CO2 supply in urea deplete medium yielded 28.7% lipid and contribution of non-polar lipids in total lipids is 69.7%. Further, the fatty acid composition of the strain grown in 15% CO2 supply in urea depleted medium showed C16:0, C16:1, C18:1 and C18:3 in the level of 30.12, 9.98, 23.43, and 11.97%, respectively compared to control and urea amended condition.

Impact of novel deflocculant ZnO/Chitosan nanocomposite film in disperser pretreatment enhancing energy efficient anaerobic digestion: Parameter assessment and cost exploration.

This paper proposed to interpret the novel method of extracellular polymeric substance (EPS) removal in advance to sludge disintegration to enrich bioenergy generation. The sludge has been subjected to deflocculation using Zinc oxide/Chitosan nanocomposite film (ZCNF) and achieved 98.97% of solubilization which enhance the solubilization of organics. The obtained result revealed that higher solubilization efficiency of 23.3% was attained at an optimal specific energy of 2186 kJ/kg TS and disintegration duration of 30 min. The deflocculated sludge showed 8.2% higher solubilization than the flocculated sludge emancipates organics in the form of 1.64 g/L of SCOD thereby enhancing the methane generation. The deflocculated sludge produces methane of 230 mL/g COD attained overall solid reduction of 55.5% however, flocculated and control sludge produces only 182.25 mL/g COD and 142.8 mL/g COD of methane. Based on the energy, mass and cost analysis, the deflocculated sludge saved 94.1% of energy than the control and obtained the net cost of 5.59 $/t which is comparatively higher than the flocculated and control sludge.

PM emissions - assessment of combustion energy transfer with Schizochytrium sp. algal biodiesel and blends in IC engine.

The continuous growing demand for fossil fuel puts an enormous pressure on finding a better replacement. This research paper explores the detailed information on the improved production, emission and performance characteristics of the distinct bio-oil derived from the micro algae of Schizochytrium. The algae were grown in the artificial seawater with enough nitrogen supply at the required standard conditions. The lipid growth and production of the bio-oil were monitored closely and measured. Different fuel blends were used at different concentrations as B0 (100% Diesel), B10 (10% schizochytrium biofuel +90% diesel), B20 (20% schizochytrium biofuel +80% diesel) and B30 (30% schizochytrium biofuel +70% diesel). A small single cylinder, four stroke diesel engine was used to conduct the tests. All tests were conducted at different speed conditions of 1200 rpm to 2100 rpm in six intervals. The performance qualities of bio-oil such as CO, NOX, and smoke and CO2 emission along with the performance qualities of brake thermal efficiency and brake specific fuel consumption. Form the results, the Schizochytrium microalgae bio-oil as the bio fuel for diesel engines in the moderate level showed the improved performance by increasing the BTE and reducing the harmful gas emissions except NOX. However, the emission level of NOX was slightly higher than the diesel emitted value. The difference between them was negligible.