ABSTRACT
The ability of microalgae to remove nitrogen and phosphorus from wastewater has been used in recent years as an alternative treatment for discharges from livestock slurry, which generate a negative environmental impact on vulnerable ecosystems. With this background and the feasibility of using microalgae, we have evaluated the effect of Chlorella sp. and Synechocystis sp., in removing contaminants from the pig manure collected from El Prado ESPE. Slurry samples were collected, filtered and autoclaved, and the supernatant was further diluted to three different concentrations of 40%, 60% and 80%. The microalgal growth and pollutants removal property was evaluated up to 15 days in batch culture. The cell density was determined by counting in a Neubauer hemocytometer, and the pollutants removal was analyzed by standard colorimetric methods. The microalgae Chlorella sp. showed a maximum cell growth of 1.70 ± 0.09 x107 cells/mL at 60% effluent concentration on day 6. While Synechocystis sp. showed a maximum growth of 1.04 ± 0.05 x107 cells/mL, at 60% concentration on day 9. On the other hand, there exists a competition when microalgae used as a consortium. The cell growth of Chlorella sp. was higher at all concentrations compared to Synechocystis sp.. Overall, efficiency of pollutant removal were between 40% and 90%, which demonstrate the feasibility of using microalgae in tertiary swine wastewater treatment.
ABSTRACT
It is well established fact that bacterial species promotes plant growth. This growth enhancing activity was believed to be through different mechanisms such as synthesis of phytohormones, nitrogen-fixing, and biological control. For this reason, in this present investigation we have isolated and identified Azotobacter spp. and Azospirillum spp. through macromorphologically and micromorphologically in order to assess its effect on growth and yield of strawberry (Fragaria vesca) an Albion variety in hydroponic system. The inoculation and co-inoculation of bacterial culture was performed in combination with three nitrogen levels (50, 100 and 150 ppm), growth parameters such as plant height, root length, fresh and dry weight of root and aerial parts, leaf area, chlorophyll content, nutrient content, solid soluble, caliber, yield/plant. It is observed that in T8 (co-inoculation in100 ppm N) group showed significantly increase in plant height (18.57cm), chlorophyll content (48.57 Soil Plant Analysis Development-SPAD), fresh root weight (25.82g) and dry root weight (5.93g), while in treatment group T5 (Azotobacter spp. 100ppm of Nitrogen) and T6 (Azotobacter spp. 150ppm of Nitrogen) showed significant increase in root length, leaf area, dry and fresh weights of aerial parts. The N content of leaf for all treatments was in the ranges of 2.42 - 2.83 % that is suitable for cultivation. Similarly, the treatment group T5 and T6 showed increase in yield per plant and soluble solids content. So, Azotobacter and Nitrogen treatment has growth related benefits in strawberries under hydroponic system.