Rhizoremediation is one of the most accepted, cost-effective bioremediation techniques focusing on the application of rhizospheric microorganisms in combination with plants for the remediation of ...organic and inorganic pollutants from the contaminated sites. This work focuses on isolation and identification of metal resistant bacteria to grow on medium with the copper ion concentration of 1500 mg/L. The resistant isolate was identified as Pantoea dispersa by a 16S rRNA sequencing. The bioaccumulation of Cu(II) ions in plant is high at the concentration of Cu(II) ion is 125 mg/L in soil. In Sphaeranthus indicus the Cu(II) ion translocation factor has expanded with an expansion of grouping of Cu(II) ion in the soil and the most extreme TF factor was acquired at the centralization of Cu(II) ion is 150 mg/L in soil. Surface morphology of biochar was characterized by Scanning Electron Microscopy (SEM) analysis. The adsorption performance of biochar (Sphaeranthus indicus biomass) and mechanism for the removal of Cu(II) ion were investigated. This study resolves that pyrolysis is promising technology for the conversion of metal ion contaminated plant residues from phytoremediation into valuable products.
The current world energy crisis and increasing greenhouse gas emissions demand a shift from fossil-based fuels to alternative and sustainable biofuels. The innate potential of microalgae over ...traditional terrestrial feedstocks to provide a high-quality and sustainable fuel portfolio has been recognized. Microalgae are known to mitigate atmospheric CO
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and convert it to valuable metabolites and bioactive compounds. The high growth rate of microalgal biomass with no additional requirements of feed and arable land makes microalgae as realistic alternative to existing biofuels sources. Micro-algae can store more primary metabolites under abiotic stress, which can be used as a possible source of energy. These metabolite storing abilities of microalgae have become a point of interest for the scientific community as the accumulated lipids serve as potential feedstock for biodiesel production by transesterification, whereas the carbohydrates can be used as the feedstock for bioethanol production by fermentation. Although microalgae-based biofuels are viable sources of energy, their commercialization and deployment in the fuel market remain a challenge. As a result, efforts are being undertaken to make it more cost-effective. This review describes the microalgae biorefinery method for producing biofuel along with its commercial potential, latest research updates in biofuel research, strategies to improve the algal metabolite content along with the limitations of using algal biomass for biofuels with possible solutions to overcome those limitations.
Tannery wastewater contains high pollutants concentrations such as nitrogen, organic matter, salinity, toxic metals, etc. Membrane bioreactor has been widely recognized as potential technology for ...wastewater treatment and reuse. Finding proper operating conditions and a strategy for fouling mitigation in MBR process is essential to application to tannery wastewater treatment. Herein, this study investigated the effect of organic loading rate (OLR) on the performance and fouling behavior of membrane bioreactor (MBR) treating tannery wastewater during 280 days of operation. The MBR was operated under the low fluxes of 4.2 and 8.3 L m−2 h−1, corresponding to organic loading rates of 1.3 (OLR1) and 2.6 kg COD m−3d−1 (OLR2). The results show that the COD removal was obtained at 78 ± 19% and 89 ± 2% for OLR1 and OLR2, respectively. For the former condition the average removal of total Kjeldahl nitrogen (TKN) and NH4+-N reached 53%–68% and 58%–70%. TKN removal was mainly contributed by cell assimilation. Incomplete nitrification was due to high TDS (11,000–16,790 mg L−1) and the presence of free ammonia ( 6.77–31.11 mg L−1) concentrations under pH 8.7–8.8. Membrane fouling rate was strongly governed by operated flux. At flux of 4.2 LMH the fouling rate was as low as 0.19–0.4 kPa d−1 while the fouling rate accelerated (1.87–1.93 kPa d−1) as increased two times flux . These findings proposed a low flux of 4.2 LMH for MBR operation in treating real tannery wastewater. It was found that influent total suspended solids (TSS) played a crucial factor in spiking mixed liquor suspended solids (MLSS) into MBR. Thus, a pretreatment process is suggested to remove major suspended solids from raw tannery wastewater prior to biological treatment.
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•Nitrification achieved 88% at loading rate of 1.3 kg COD m-3 d-1 and TDS 13 g L-1.•MLVSS/MLSS ratio was ranging from 0.15 to 0.20 hinders pollutant removal in MBR.•Salt concentration and free ammonia inhibited nitrification.•Fouling rate increased 6.4 times when flux shifted from 4.2 to 8.3 L m-2 h-1.•SS reduction from raw tannery wastewater should be done prior to MBR treatment.
The importance of the current research is to isolate the pigment-producing fungal species from the pomegranate fruit using Sabouraud Dextrose Agar (SDA) and characterized as Aspergillus tamarii by ...18S rRNA sequencing. Aspergillus tamarii was allowed for mass cultivation in the pigment production using Sabouraud Dextrose broth and incubated at 25 ± 2 °C for 28 days. Pigment production by Aspergillus tamarii was confirmed by OD510. Harvesting of pigment was done after 28 days of incubation by filtration with cellulose filter paper having porous size of 20μm and it was purified by extraction using 95% v/v of ethanol as well column chromatography techniques with 95% v/v of ethanol. The fractions obtained from the column chromatography techniques were allowed for the phytochemical analysis and antimicrobial activity of the pigment was tested. The results observed that the high distinctive antibacterial activity was obtained against Streptococcus pyogenes and Escherichia coli and the high antifungal activity was obtained against Chrysosporium keratinophilum and Candida albicans. The thermal stability of the pigment was investigated by determining the thermal degradation constant (Dc), half-life (t1∕2), and activation energy (Ea). Due to an increase in the degradation rate of the pigment, the half-life of the pigment was decreased. The maximum value has been obtained as 35.4 kcal mol−1 for activation energy (Ea), 288.8 min for half time (t1∕2), and 0.004 min−1 for degradation constant (Dc).
•Aspergillus tamarii MK211202.1 was identified by 18S rRNA sequencing.•Significant results on pigments and biomass yields were resolved.•Pigment from Aspergillus tamarii showed distinctive antibacterial activity.•Fungal pigments can be used as food colourants hence this study has food industry application.
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The pinnacle of all the efforts of nutrient removal is practically put-down the moment biological cells are lysed, hydrolyzed or digested causing subsequent reappearance of assimilated nitrogen and ...phosphorus in any biological process. While sludge reduction requires high SRT, the enhanced phosphorus assimilative uptake demands low SRT. A novel reactor configuration for enhanced sludge and phosphorus removal was put to test by incorporating a side stream anaerobic reactor to an Anaerobic-Anoxic-Aerobic (A
O) SBR with a pre-anoxic chamber and an influent receiving inlet anaerobic reactor. The reactor was operated at the average and lowest range of prevailing carbon/phosphorus (C/P) ratio of 50 and 15 in the sewage. The phosphorus enrichment was 0.0469-0.135 mgTP/mgVSS resulting in 1.76-5.05-fold increase from cellular content by virtue of maintaining sludge recycle from SBR aeration tank to side stream anaerobic reactor from 3.78 to 9.78 (average 4.4-8.2) gVSS/gVSS present in the reactor. However, the sludge was also reduced from 3% to 51% on an average basis during the same recirculation regime. This novel configuration consists of an inlet anaerobic reactor, one pre-anoxic chamber and one intermittent oxic anoxic reaction SBR and a side stream anaerobic reactor. The first anaerobic reactor at inlet followed by pre-anoxic chamber was provided for increased ortho-p released and nitrification respectively and a side stream anaerobic reactor for sludge reduction through sludge fasting mechanism. The EBPR and lesser sludge growth were two conflicting parameters reconciled to the extent that if sludge recycled up to 6.41 gVSS/gVSS the sludge growth would be reduced by 25% and phosphorus enrichment could be attained up to 3.46 times the stoichiometric value. Any further recirculation would reduce the sludge further but at the expense of enhanced phosphorus uptake as released phosphorus from side stream anaerobic reactor also recycled back to main SBR causing looping and at more than 6.41gVSSrecycled/gVSS it nullified the enhanced effect.
This study examined the effects of nitrogen species (NH4+N/NO3−N ratio) and biomass retention time (BRT) on nutrient uptake and biomass productivity in Chlorella sp. In batch photobioreactors (PBR), ...microalgae were cultivated with varied nitrogen species ratios (100% NH4+N, 50% NH4+N:50% NO3−N, and 100% NO3−N). It was observed that a medium containing 100% NO3−N boosted algae growth, with a maximum biomass concentration of 3188 mg/L. However, the lowest nutrient removal rates were obtained under the 100% NO3−N condition, according to the reverse logistics model. In contrast, the highest removal rates occurred for substrate containing 100% of NH4+N species based on first-order decay models, although yield biomass was lower (2940 mg/L). The presence of the ammonia nitrogen resulted in the flocculation of the microalgae into large flocs, suggesting that ammonia nitrogen was rapidly consumed to produce flocculation-related metabolic products rather than for biomass production. Using the 100% NH4+N medium, different BRT values (7, 5, 3, 2 days) were examined under continuous operation using a membrane photobioreactor (MPBR). At 3-day BRT, the maximum biomass productivity, nitrogen, and phosphorous removal rates were 214 ± 4, 63.1 ± 4.1, and 2.1 ± 0.6 mg/L d, respectively. The biomass yield increased as the BRT decreased, leading to an increase in pollutant removal rates. Finally, this study provides some essential information for improving the operating conditions of membrane photobioreactor system under different biomass retention times and various nitrogen sources in the feed.
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•The highest biomass productivity was achieved in the 100% NO3−N medium.•The highest nutrient removal occurred in the 100% NH4+N medium.•The highest biomass productivity and nutrient removal was observed at 3-day BRT.•Lower fouling rates were achieved at higher BRTs.
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