Samuel Enahoro Agarry, Ganiyu Kayode Latinwo, Ebenezer Olujimi Dada, Chiedu Ngozi Owabor
Abstract: The study evaluated the effectiveness of indigenous bacterial consortia (Pseudomonas aeruginosa, Bacillus subtilis and Micrococcus letus) and fungal consortia (Aspergillus niger, Aspergillus carmari and Penicillium notatum) as well as their combination (bacterial-fungal consortia) as bioaugmentation agents in the soil bioremediation of petroleum hydrocarbons in the absence and presence of nickel, zinc and cadmium heavy metals. Bioremediation was carried out in 10% w/w crude oil-contaminated soil microcosms for 35 days in the absence and presence of nickel, zinc, and cadmium bioaugmented with or without bacterial, fungal and bacterial-fungal consortia, respectively. In the heavy metal-free soil microcosms, 72.5%, 64% and 90.7% total petroleum hydrocarbon (TPH) biodegradation were attained with bacterial, fungal and bacterial-fungal consortia, respectively, while 45% TPH biodegradation was achieved in the non-bioaugmented soil microcosm. In the heavy metal-soil microcosms: nickel, zinc, cadmium and mixed form (nickel + zinc + cadmium), 79.2%, 81.4%, 75.3% and 68.2% TPH biodegradation was correspondingly obtained with bacterial consortia; 69.4%, 66.4%, 68.2%, and 60.6% with fungal consortia; while 99%, 98.5%, 95.7%, and 100% was respectively attained with bacterial-fungal consortia. The kinetics of TPH biodegradation were adequately described by the first-order kinetics and half-life times were estimated. Soil microcosm bioaugmented with bacterial-fungal consortia displayed the highest biodegradation rate constant with the lowest half-life times in the absence and presence of heavy metals. Therefore, the results suggest that microbial consortia (bacterial and fungal) could be very effective for soil bioremediation of crude oil in the presence of heavy metals.
Keywords: Bacteria; Bioaugmentation; Bioremediation; Crude oil; Fungi; Heavy metals
Sylvester Chibueze Izah
Abstract: This study evaluated the activities of crude, acetone and ethanolic extracts of Capsicum frutescens var. minima fruit against Anopheles gambiae larva. The bioassay was carried out for 24 hours using Anopheles gambiae larva obtained from the wild. The Anopheles gambiae was identified following standard protocol. Results showed that the mortality rate increased statistically at p<0.05 as the concentration of the plant extracts increased. The ethanolic, acetone and crude extracts had LC50 value of 115.24 ppm, 173.16 ppm and 265.19 ppm respectively, being apparently different. The efficacy of the Capsicum frutescens var. minima fruit were in the order aqueous < acetone < ethanol. Based on the findings of this study, there is the need for research to focus on the isolation and purification of the exact bioactive ingredients that enables Capsicum frutescens var. minima fruit confers insecticidal potentials.
Keywords: Capsicum frutescens, Malaria, Medicinal plants, Solvents, Vector borne disease
Ameneh Bazrafshan, Tahereh Talaei-Khozani
Abstract: Global demand for meat is on the rise. Increase in livestock production is the first but not the best solution to supply this demand. Livestock production leads to an increase in the greenhouse gasses, causing global warming and climate change, which also has a negative impact on the livestock breeding. Thus, scientists have concentrated on the production of in vitro-engineered meat which could be tasty, healthy and environmental friendly to substitute livestock meat. In this article, the environmental impacts of livestock production system on the climate change, water quality and public health are discussed, and then the artificial meat production technology, its benefits, challenges and consumer’ sreactions are reviewed.
Keywords: CO2 reduction, Global warming, Tissue engineering, Laboratory meat production
Farzaneh Sabbagh, Nadia Mahmoudi Khatir, Azam Khodaeyan Karim, Amineh Omidvar, Zahra Nazari, Reza Jaberi
Volume 7 | Issue 2 | Pages: 211-219 | PDF | HTML
Abstract: In this study in order to increase the release ability of acrylamide hydrogels, modified acrylamide-based hydrogel nanocomposites were synthesized. The aim of this research was to evaluate the swelling ratio of hydrogel with the best clay, to reach the highest rate of swelling. To enhance the swelling ratio of hydrogels, the clays were applied in their structure. Amongst the applied clays in the structure of the hydrogels, montmorillonite was found to be more effective than kaolinite. Further using conventional techniques such as X-ray diffraction (XRD) and Energy Dispersive X-Ray (EDX) performed the characterization of the clays, while the hydrogels were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM), and EDX. The XRD analysis of clays showed that there is a different amount of carbon, oxygen, sodium, calcium, magnesium, aluminum, silicon, potassium and iron. The amount of oxygen in montmorillonite was 42.12 however, the amount of oxygen in kaolinite was 2.01. The XRD pattern of montmorillonite including a peak relevant to the basal dividing of (2θ = 7.83°) 11.28 Ĺ was verified. In the acrylamide/montmorillonite hydrogels, this peak was shifted to a lower point of the angle, comparing to the basal spacing of (2θ = 6.40°) 13.78 Ĺ and (2θ = 6.24°) 14.11 Ĺ. Such an increase in the basal spacing oblique that the monomer was inserted into the interlayer of the clay.
Keywords: Nanoparticle, NaCMC, Microstructure, Polymerization, Nanocomposite, Crosslinker
Ayobami Omozemoje Aigberua
Volume 7 | Issue 2 | Pages: 220-228 | PDF | HTML
Abstract: The elucidation of soil residual hydrocarbon (SRH) in oil-impacted dumpsite soils is aimed at distinguishing the principal source (municipal waste dumpsite or oil well-head clusters) of petroleum and polycyclic aromatic hydrocarbons in the mangrove environment receiving mineral oil loading form mixed anthropogenic influences. Chemical fingerprints of soil specimen were obtained on determination by gas chromatographic – flame ionization detection (GC-FID) technique using an HP 5890 series II instrument. Flt/Pyr ratios revealed the presence of petrogenic hydrocarbons while carbon preference index (CPI) showed soils composed mainly of degraded material and fossil fuels, apart from location E-2 which was loaded with non-biodegraded biological materials using Ph/nC18 data. Elucidation of Pr/nC17 ratios showed that the retention of non-biodegraded hydrocarbon was decimated at locations E-4 and E-6 due to reduced microbial degradation in comparison to the other field areas. Overall, the soil was insignificantly impacted by terrestrial sources, as greater magnitude came from surrounding oil well clusters. Therefore, soil toxicants are likely to be bio-accumulated in crops growing along proximate farmlands, especially nypa palm fruits which are commonly consumed. It is imperative to avoid ingesting herbage or other nutriments from this area until residual oil seepages are effectively controlled and hydrocarbons have been monitored for substantial degradation.
Keywords: Soil residual hydrocarbon, Carbon preference index, Total petroleum hydrocarbon, Polycyclic aromatic hydrocarbon, Eagle Island
Asha Embrandiri, Parveen Fatemeh Rupani, Loh Kar Woon, Mohd Hafiz Jamaludin, Mohd Azrul Naim, Jianzhong Sun, Weilan Shao and Suzy Ismail
Volume 7 | Issue 2 | Pages: 229-233 | PDF | HTML
Abstract: Bentonite has been effectively used in many studies for the removal of methylene blue (MB) laden waste waters. This is due to its high swelling ratio, good adsorptive properties and environmentally friendly characteristics. In spite of this, prolonged use renders the BMB non-functional and cause for discard. Sodium persulfate (SPS), has been reported to be an excellent flocculating agent for the functionalization of spent adsorbent due to some of its unique properties. In this study, the functionalization of spent bentonite-methylene blue (BMB) adsorbent in dye wastewater treatment was carried out using SPS at varying temperature conditions. Results revealed that the addition of SPS to MB-loaded adsorbent demonstrated efficient adsorption, high flocculation efficiency as well as faster equilibrium (60 min). The BMB loaded adsorbent showed 95% removal efficiency up to three cycles. A plausible mechanism was proposed and discussed on the basis of the results. Thus, exhausted BMB was found to be effectively used for treatment of coloured wastewater on an industrial scale.
Keywords: Bentonite; Methylene blue; Sodium persulfate; Dye wastewater; Functionalization.
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