Process optimization for the production of biodiesel from Azolla Microphylla oil and its fuel characterization

The most competent and operative use of renewable feedstock is super critical for the production of biodiesel which has increased attention worldwide pertaining to aquatic fern Azolla. Maximizing the biodiesel yield by optimizing the process parameters of the low-frequency ultrasonic energy-assisted transesterification process of Azolla oil is the need of the hour for minimizing the production cost of biodiesel. Response Surface Methodology (RSM) was applied using central composite rotatable design (CCRD) to find the best optimum reaction parameters for this transesterification process. The optimized reaction parameters arrived from the design of experiments were as following: methanol/Azolla oils molar ratio (A) = 6.49 mole/mole, KOH catalyst concentration (B) = 1.69 (weight% of oil), reactiion time (C) = 34.74 min and reaction temperature (D) = 38.87°C. The best higher theoretical predicted Azolla Fatty Acid Methyl Ester (FAME) yield was Y = 99.76% which is in well coincidence with the actual yield. The extracted Azolla biodiesel was tested for various fuel properties with standard test procedures and found to be in agreement with various Biodiesel standards and the results are promising in terms of utilizing Azolla oil as an inexhaustible and potentially economical source of biodiesel.

The impact of raindrops on Salvinia molesta leaves: effects of trichomes and elasticity

The floating leaves of the aquatic fern Salvinia molesta are covered by superhydrophobic hairs (=trichomes) which are shaped like egg-beaters. These trichomes cause high water repellency and stable unwettability if the leaf is immersed. Whereas S. molesta hairs are technically interesting, there remains also the question concerning their biological relevance. S. molesta has its origin in Brazil within a region exposed to intense rainfall which easily penetrates the trichome cover. In this study, drop impact on leaves of S. molesta were analysed using a high-speed camera. The largest portion of the kinetic energy of a rain drop is absorbed by elastic responses of the trichomes and the leaf. Although rain water is mostly repelled, it turned out that the trichomes hamper swift shedding of rain water and some residual water can remain below the ‘egg-beaters’. Drops rolling over the trichomes can, however, ‘suck up’ water trapped beneath the egg-beaters because the energetic state of a drop on top of the trichomes is—on account of the superhydrophobicity of the hairs—much more favourable. The trichomes may therefore be beneficial during intense rainfall, because they absorb some kinetic energy and keep the leaf base mostly free from water.

Influence of experimental storage conditions of spores of Floating fern (Salvinia natans (L.) All., Salviniaceae Martinov) on the reproduction of the species

Salvinia natans is a heterospore annual aquatic fern from the Salviniaceae family. Increasing the spores’ viability by storage simulations is the basis for creating fern spore banks. In this aspect, S. natans appears to be an unconventional subject. Between October and August 2019–2020 we conducted an experiment on the storage of S. natans spore production for 4 months in 12 combinations of abiotic factors (lighting water content – temperature) and subsequent sporesgermination during the spring – summer under the same conditions of natural temperature regime, natural light and thepresence of water. The spore production viability was assessed by the time of megasporangia germination and the numberof new individuals in each storage option. We established that the of the S. natans reproduction occurs successfully witha natural combination of abiotic environmental factors – a gradually changing temperature with winter freezing, naturallight, and the presence of sporangia in water. Storage has a beneficial effect during stratification (+ 5 °C, water) and in thecombination of factors “natural temperature – dark – dry”. Early germination and the appearance of the maximum number of new individuals in these three wintering options indicate that S. natans adapts to the seasonal climate with low winter temperatures and warm summers. Dormancy of S. natans spores belongs to the forced type. Dry storage delayed germination of megasporangia for a period of two weeks to a month. The dormancy of S. natans spores belongs to the forcedtype, since the content of sporangia in water in the light and at room temperature showed the possibility of the appearanceof new individuals in October-November.

Biomass Growth and Composition of Azolla (Azolla Pinnata R. BR.) Supplemented With Inorganic Phosphorus in Outdoor Culture

An experiment was conducted to know the effect of supplemental phosphorus on biomass growth and composition of a floating aquatic fern, Azolla pinnata, cultured in a pit system for 21 days with 4 levels of phosphorus (0, 5, 10, and 15 ppm) supplementation. Water quality parameters of the pits were within a suitable range for A. pinnata culture. It was observed that fresh and dry weights of A. pinnata increased with phosphorus supplementation up to 10 ppm. Doubling time was the fastest when the culture medium was supplemented with 10 ppm of phosphorus. Phosphorus content of A. pinnata was proportional to the phosphorus supplementation in the culture medium. Supplementation of phosphorus also improved the protein and lipid contents of A. pinnata. It was concluded that supplementation of 10 ppm phosphorus to water used for culturing A. pinnata is optimum under outdoor conditions. SAARC J. Agric., 19(1): 177-184 (2021)

AZOLLA: POTENTIAL BIOFERTILIZER FOR INCREASING RICE PRODUCTIVITY, AND GOVERNMENT POLICY FOR IMPLEMENTATION

Rice is the staple food for the significant population of Asia. Due to projected population growth in this region, the demand for this food is also predicted to be increased exponentially soon. Nitrogen (N) plays a dominant role in increasing rice yield as it is the most critical yield-limiting nutrient of rice. Chemical N fertilizers which are a major source in supplying N nutrients to rice, have adverse effects on overall soil and environmental health in the long term. The application of free-floating aquatic fern Azolla as a biofertilizer can be an alternative to improve rice yield without degrading the environment. It provides a natural source of many nutrients, especially N, improves the availability of other nutrients, plays a critical role in weed suppression, enhances soil organic matter, and improves efficiency of the inorganic fertilizers while maintaining the suitable soil pH condition for rice growth, which overall contribute to rice yield increment. Therefore, Azolla application has tremendous potential to improve soil health and boost yield sustainability.

Azolla as Waste Decomposer and Bio-fertilizer: A Review

In modern-day agriculture, we are well aware of the utilization of artificial fertilizers in the soil to supply major soil nutrients for plant growth and development. The most common used nutrients in agroecosystem are nitrogen (N), phosphorus (P), potassium (K), and sulfur (S). These fertilizers cause an increase in crop production, but the excess use of these fertilizers has several health hazards for the plants and animals feeding on them. Presently the consumer's preference has been shifted from synthetic fertilizer-based food to organic food. This paper aims to review the results of the research work done in the past few decays on the environment detoxification and beneficial effects of Azolla (aquatic fern) on plants and soil health. Hopefully, it will help the collaborative research on this “green gold” in the future.Azolla fixes the free-living atmospheric N as they have symbiotic Cyanobacterium Anabaena Azolla. Azolla adds organic matter and provides natural mulch to the soil because of these benefits is known as bio-fertilizer. Azolla remediates industrial and sewage water by accumulating heavy metals in their body and plays an active role in the reclamation of salt-affected soil by accumulating heavy metals and salts and by increasing the soil organic matter