Showing papers by "Ruma Pal published in 2021"
TL;DR: The results of co-culture in batch mode revealed about 2-3 times increase in biomass and two-times increase in total lipid, when compared to the pure culture batches.
Abstract: The co-cultivation approach using cyanobacteria—Leptolyngbya tenuis and green alga—Chlorella ellipsoidea demonstrated in the present study showed additive and synergistic effects on biomass yield, biomass productivity, lipid yield, lipid productivity, CO2 fixation, and cadmium bioremediation efficiency. The results of co-culture in batch mode revealed about 2–3 times increase in biomass and two times increase in total lipid, when compared to the pure culture batches. The results revealed that co-cultures exhibited significantly high CO2 fixation rate of 2.63 ± 0.09 g/L/d, which is 1.5–2 times better than monocultures (P Chlorella (58%, 0.29 mg/L) > Leptolyngbya (50%, 0.25 mg/L) (P < 0.05). In addition, fatty acid composition, CHNS analysis, biodiesel characterization, and biochemical compositions were also determined using co-culture method. The maximum biomass yield, productivity, lipid content, and CO2 fixation rate in cadmium induced co-culture were 3.95 ± 0.13 g/L, 258.88 ± 15.75 mg/L/d, 41.43 ± 0.71%, and 3.21 ± 0.20 g/L/d, respectively which is 1.2, 1.3, 2.3, and 1.2 times higher than the control (P < 0.05). Cadmium induced changes in growth and lipid yield using co-culture suggests cost-effective and eco-friendly production of biodiesel and carbon mitigation.
17 citations
TL;DR: In this article, the nanohybrid dendrite synthesis was initially confirmed by the formation of greyish-brown frustules after 72h of exposure to 9mM of silver nitrate solution.
Abstract: Generally, nanodendrite synthesis is chemical mediated and expensive. The biogenesis of such hierarchical structures is still in its nascent stage. The present study aimed at exploiting the nanoporous frustules of Halamphora subturgida, as a source of biosilica for the biosynthesis and stabilization of conjugate nanodendrites of silica and silver. These minute diatom frustules when exposed to 9 mM of silver nitrate solution, a highly crystalline nanohybride dendrites were synthesized. The nanohybrid dendrite synthesis was initially confirmed by the formation of greyish-brown frustules after 72 h of exposure. The composite dendrites were thoroughly characterized by standard techniques. Electron microscopic images illustrated that the process began with the formation of isotropic hybrid nanospheres with an internal diameter of 20 nm and continued to develop anisotropic nanocrystals with time. The nanodendrites externally formed on the siliceous frustules, acting as a template for the former. They were characterized by distinct 100 nm wide and 1–2 µm long trunks and 70–100 nm wide and 220–220 nm long branches on either side of the trunk. The optical measurement revealed the fluorescence property of the nanostructures owing to the photoluminescent efficiency of the frustules. Both the externally derived hybrid nanodendrites and internally synthesized nanospheres possessed superior stability in the suspension with a zeta potential value of − 35.7 mV and − 24.8 mV, respectively. Thus, this method is eco-friendly and provides a new dimension for nanodendrite synthesis with minimal cost and maximal yield compared to its non-biologically synthesized counterparts that involve several other drawbacks like chemical hazards and high energy consumption.
6 citations
TL;DR: In this article, the ability of L. valderiana to fabricate iron nano particles of definite shape and size, as well as the enhanced effectiveness of the synthesized nanoparticle loaded biomass in removal of hexavalent chromium [Cr (VI)] from aqueous solution compared to free IR nano particles were reported.
Abstract: This study reported the ability of L. valderiana to fabricate iron nano particles of definite shape and size, as well as the enhanced effectiveness of the synthesized nanoparticle loaded biomass in removal of hexavalent chromium [Cr (VI)] from aqueous solution compared to free iron nano particles. Spindle-shaped nano scale zerovalent irons were synthesized by live biomass at intracellular and extracellular levels with the dimensions of 47.42 ± 3.86 × 7.7 ± 2.01 nm and 66.37 ± 3.09 × 12.49 ± 4.01 nm, respectively. The nanosorbents were prepared separately from intracellular particles (NI), extracellular particles (NE) and nano‑iron loaded biomass (BN). All the adsorbents were tested for chromium removal from Cr (VI) aqueous solutions with concentrations in the range of 5–20 mg L−1. The adsorption parameters were optimized. The removal rate and adsorption capacity, i.e., Langmuir constant (KL) of nano‑iron loaded biomass (BN) toward Cr (VI) reached the peak at 0.0439 L mg−1 of adsorbent, followed by intracellular particles (NI) (0.0162 L mg−1 of adsorbent) and extracellular particles (NE) (0.009 L mg−1 of adsorbent). The adsorption kinetics data of nano‑iron loaded biomass (BN) fitted well with the pseudo-second-order kinetic model and Freundlich isotherm model whereas, the other two nanosorbent-assisted removal processes followed the pseudo-first-order kinetic model and Langmuir isotherm model. Moreover, nano‑iron loaded biomass (BN) was the easiest to handle and showed maximum adsorption capacity; therefore, portraying it as a low-cost, environmentally benign potential nanosorbent for the removal of Cr (VI) from industrial waste.
5 citations
TL;DR: In this paper, the authors demonstrate and evaluate the diatom communities in the copper infected areas readily associated with the Hindustan Copper Limited (HCL) at the bank of the Subarnarekha River.
Abstract: The aim of this study was to demonstrate and evaluate the diatom communities in the copper infected areas readily associated with the Hindustan Copper Limited (HCL) at the bank of the Subarnarekha River. This study was based on three sampling sites commonly designated as high copper (>100 μg.L-1), medium copper (≤100 μg.L-1) and low copper (≤50 μg.L-1) contaminated area. Results indicated the detailed taxonomic description of 31 species that are dominant or less dominant over these contaminated area. Among the identified taxa, 10 were recorded as new to the Jharkhand state. Water analysis has suggested the presence of 17 species in the high copper contaminated area adjacent to HCL. Nine species was less dominant in the outlet of HCL that belonged to the medium contaminated and only 5 species were dominant over the low copper contaminated area. Physico-chemical parameters like pH, air and water temperature, salinity, conductivity, light extinction coefficient, turbidity, dissolved inorganic salts, dissolved oxygen and carbon-di-oxide, biological oxygen demand and total hardness were also estimated in the copper contaminated sites. Relatively all the species of Cymbella and Navicula were associated with high copper accumulation. Most interestingly, one harmful species Halamphora coffeiformis, which was recorded as most dominant species in high copper exposed area, has shown to be the best copper tolerant and copper indicator species.
2 citations
TL;DR: In this paper, the authors used Arthrospira platensis as a potential bio-reagent for Fe3+ to Fe0 bioconversion followed by spindle shaped magneto-fluorescent nano-iron production.
Abstract: Bioconversion of Fe3+ to Fe0 followed by spindle shaped magneto-fluorescent nanoiron production has been investigated using Arthrospira platensis as a potential bio-reagent. The characteristic feat...
1 citations
TL;DR: In this paper, a year-long intensive study revealing seasonal algal mat composition patterns in these WTPs will ultimately safeguard the livelihood and security of adjoining localities through proper site-specific pollution control.
Abstract: Wastewater Treatment Pond (WTP) is an effective remediation technology for economically developing nations. Although it's excessive organic and nutrient loads with higher water logging time triggers mixed and unprofitable microalgal mats. This may serve as a seeding source for Cyanobacterial bloom in receiving waterbodies. Since, to maintain the growth of desirable algal species in WTPs, understanding towards environmental regulation and algal mat composition is important, especially for tropical countries, like India. In this study, biological treatment pond (BTP) and outlet pond (OP), of a tannery effluent treatment plant in eastern coast of India, were chosen for surveying the algal community composition concerning ecological parameters. Nearly, both the ponds were polluted, but the diversity was lower in BTP due to its elevated nutrient content (Ammonia 173 mg L−1) and higher persistent organic matters (COD 301.7 mg L−1) than OP. Using canonical correspondence analysis, seasonal variations showed higher species abundance during early summer compared to other seasons. A total of 37 taxa forming thick algal mats were recorded. The matrix of mats was mainly composed of Cyanobacterial members such as Phormidium, Leptolyngbya, Spirulina, and Pseudanabaena, followed by diatoms, especially Amphora and Nitzschia. Diatoms commonly occurred as embedded component in the entangled matrix of blue-green algal filaments. Hierarchical cluster analysis was employed to group all these taxa based on their seasonal appearance and abundance. This year-long intensive study revealing seasonal algal mat composition patterns in these WTPs will ultimately safeguard the livelihood and security of adjoining localities through proper site-specific pollution control.