Impact of Nutrients, Aeration and Agitation on the Bioremediation of Crude Oil Polluted Water Using Mixed Microbial Culture

Abstract. Crude oil polluted water was treated using a bioremediation strategy encompassing natural attenuation and biostimulation using a mixed microbial culture of Aspergillus niger and Pseudomonas aeruginosa. Four (4) samples of petroleum hydrocarbon polluted water; Control (no nutrient), A (nutrient from NPK 15:15:15), B (nutrient plus aeration), and C (nutrient, aeration and agitation) were monitored for 8 weeks for bioremediation indicating parameters such as Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Total Hydrocarbon Content (THC) and pH. The results obtained showed an increase in DO levels of 86.4, 87.0 and 87.5 % for samples A, B, and C respectively. The BOD of the samples was observed to decrease in the course of bioremediation with reduction levels of 98.6, 98.7 and 98.8% recorded for samples A, B, and C respectively. Reductions in THC corresponded to 92.3, 93.6, and 94.4% respectively for samples A, B and C. The pH of all samples fell within the acceptable limit of 6-9 as stipulated by regulatory agencies such as the Federal Environmental Protection Agency (FEPA) and the department of petroleum resources (DPR). The final values of BOD and THC fell within the values of 30 and 10 mg/l respectively stipulated by FEPA and DPR with the exception of sample A which had a final THC value of 14 mg/l

Roofing Sheets Produced from Cassava Stalks and Corn Cobs: Evaluation of Physical and Mechanical Properties

Abstract. In this study, roofing sheets were produced from agricultural wastes such as corn cobs and cassava stalks using animal and PVC glue as binders. The sheets were produced using different combinations of the agro-wastes and adhesives. Physical properties of the sheets produced such as percentage water absorption (WA) and thickness swelling (TS) as well as mechanical properties such as modulus of rupture (MOR) and modulus of elasticity (MOE) were evaluated. The roofing sheets produced from a mixture of agro-wastes using a combination of animal and PVC glue gave the best results in terms of the least mean values of WA (2.44%) and TS (0.10%), as well as the highest values of MOR (4.59×10 6 N/m 2 ) and MOE (793.7×10 6 N/m 2 ). These results indicate that the sheets produced from a mixture of the agro-wastes using a combination of animal and PVC glue were more dimensionally stable as well as possessing higher mechanical strength. The same set of sheets satisfied the ANSI/A208.1-1999 standard. The results of analysis of variance (ANOVA) carried out showed that the type of agro-waste and adhesive used had a significant influence on the physical and mechanical properties of the sheets (p < 0.05)

Volume 2, Issue 2 Pages 43 -73 Impact of Nutrients, Aeration and Agitation on the Bioremediation of Crude Oil Polluted Water Using Mixed Microbial Culture Comparative in-vitro Studies on Native Plant Species at Heavy Metal Polluted Soil Having Phytoremedi

Abstract. Crude oil polluted water was treated using a bioremediation strategy encompassing natural attenuation and biostimulation using a mixed microbial culture of Aspergillus niger and Pseudomonas aeruginosa. Four (4) samples of petroleum hydrocarbon polluted water; Control (no nutrient), A (nutrient from NPK 15:15:15), B (nutrient plus aeration), and C (nutrient, aeration and agitation) were monitored for 8 weeks for bioremediation indicating parameters such as Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Total Hydrocarbon Content (THC) and pH. The results obtained showed an increase in DO levels of 86.4, 87.0 and 87.5 % for samples A, B, and C respectively. The BOD of the samples was observed to decrease in the course of bioremediation with reduction levels of 98.6, 98.7 and 98.8% recorded for samples A, B, and C respectively. Reductions in THC corresponded to 92.3, 93.6, and 94.4% respectively for samples A, B and C. The pH of all samples fell within the acceptable limit of 6-9 as stipulated by regulatory agencies such as the Federal Environmental Protection Agency (FEPA) and the department of petroleum resources (DPR). The final values of BOD and THC fell within the values of 30 and 10 mg/l respectively stipulated by FEPA and DPR with the exception of sample A which had a final THC value of 14 mg/l

Particle boards produced from cassava stalks: Evaluation of physical and mechanical properties

We investigated the potential use of cassava stalks for the production of bonded particle boards. Particle boards were produced from cassava stalks using urea-formaldehyde as a binder. Water absorption and thickness swelling tests were carried out to determine dimensional stability of the boards while modulus of rupture and modulus of elasticity tests were carried out to assess the mechanical strength of the boards. Particle boards produced using an adhesive–cassava stalk ratio of 3:1 gave the best results in terms of the lowest mean values of water absorption (20%) and thickness swelling (6.26%), as well as the highest values of modulus of rupture (4×106 N/m2) and modulus of elasticity (2366.74×106 N/m2). The particle boards produced met the ANSI/A208.1-1999 standard for general-purpose boards. The results of analyses of variance carried out revealed that the adhesive–cassava stalk ratio had a marked influence (p<0.05) on the physical properties (water absorption and thickness swelling) but not on the mechanical properties (modulus of rupture and modulus of elasticity)

Formulation and Optimization of Metronidazole and <i>Lactobacillus</i> spp. Layered Suppositories via a Three-Variable, Five-Level Central Composite Design for the Management of Bacterial Vaginosis

Bacterial vaginosis, a polymicrobial clinical syndrome characterized by a shift in healthy vaginal microbiota due to bacterial colonization, is characterized by high recurrence rates after conventional treatment with an antimicrobial agent. This has necessitated the need to develop a formulation that has the potential to ensure Lactobacilli viability and bacterial clearance. This study seeks to develop and optimize a layered suppository using a five-level central composite design to ensure optimized metronidazole release and lactic acid viability. Layered suppositories were formulated using the fusion method using polyethylene glycol blend 1500/4000 and Ovucire® as suppository bases. Lactobacillus fermentum was incorporated in the molten mass before molding the solid body suppositories into the cavity of hollow-type suppositories and sealing the molten excipients. Artificial neural network model predictions for product optimization showed high predictive capacity, closely resembling experimental observations. The highest disintegration time recorded was 12.76 ± 0.37 min, with the optimized formulations showing lower times of 5.93 ± 0.98 min and an average weight of 1.17 ± 0.07 g. Histopathological observations determined high compatibility of suppositories with vaginal cells with no distortion or wearing of the vagina epithelium. This optimized formulation provides a safe and promising alternative to conventional suppositories in the treatment and prevention of the recurrence of bacterial vaginosis

Development of mucoadhesive electrospun scaffolds for intravaginal delivery of \u3ci\u3eLactobacilli\u3c/i\u3e spp., a tenside, and metronidazole for the management of bacterial vaginosis

Bacterial vaginosis (BV) is an infection of the vagina associated with thriving anaerobes, such as Gardnerella vaginitis and other associated pathogens. These pathogens form a biofilm responsible for the recurrence of infection after antibiotic therapy. The aim of this study was to develop a novel mucoadhesive polyvinyl alcohol and polycaprolactone electrospun nanofibrous scaffolds for vaginal delivery, incorporating metronidazole, a tenside, and Lactobacilli. This approach to drug delivery sought to combine an antibiotic for bacterial clearance, a tenside biofilm disruptor, and a lactic acid producer to restore healthy vaginal flora and prevent the recurrence of bacterial vaginosis. F7 and F8 had the least ductility at 29.25% and 28.39%, respectively, and this could be attributed to the clustering of particles that prevented the mobility of the crazes. F2 had the highest at 93.83% due to the addition of a surfactant that increased the affinity of the components. The scaffolds exhibited mucoadhesion between 31.54 ± 0.83% and 57.86 ± 0.95%, where an increased sodium cocoamphoacetate concentration led to increased mucoadhesion. F6 showed the highest mucoadhesion at 57.86 ± 0.95%, as compared to 42.67 ± 1.22% and 50.89 ± 1.01% for the F8 and F7 scaffolds, respectively. The release of metronidazole via a non-Fickian diffusion-release mechanism indicated both swelling and diffusion. The anomalous transport within the drug-release profile pointed to a drug-discharge mechanism that combined both diffusion and erosion. The viability studies showed a growth of Lactobacilli fermentum in both the polymer blend and the nanofiber formulation that was retained post-storage at 25 °C for 30 days. The developed electrospun scaffolds for the intravaginal delivery of Lactobacilli spp., along with a tenside and metronidazole for the management of bacterial vaginosis, provide a novel tool for the treatment and management of recurrent vaginal infection

Evaluation of Far‐Field Electrospun Polyvinyl Alcohol/Hyaluronic Acid Nanofibrous Membranes for Skin Tissue Engineering Applications

Abstract Electrospinning has emerged as one of the major technologies for designing and fabricating tissue engineering membranes. The resemblance of the electrospun fiber structure to blood capillaries endowed them with unique capabilities to mimic the native tissue biological characteristics, while the high surface‐to‐volume ratio enables them to exert a controlled release of drug directly to the exposed interstitial tissue. This research attempts to compare the characteristics of different electrospun polyvinyl alcohol/hyaluronic acid (PVA/HA) composite material nanofibrous membranes in order to identify the optimal material‐fabrication combination for wound dressing and skin tissue engineering applications. Far‐field electrospinning equipped with both rotatory and wire collectors is considered for membrane fabrication. PVA with different concentrations and molecular weights of HA are electrospun as nanofibrous membranes considering a voltage of 30 kV on both types of collectors. Comprehensive characterization is conducted including morphological, chemical, thermal, mechanical, and in vitro mucoadhesion analysis. In vitro cell viability/proliferation studies are also carried out and pointed out that the designed membranes are cytocompatible, and able to support keratinocytes proliferation. All these results proved that the fabricated PVA/HA nanofibrous membranes are suitable for wound dressing and skin tissue engineering applications, the optimal material‐fabrication combination is also determined

Biochar-facilitated batch co-digestion of food waste and cattle rumen content: An assessment of process stability, kinetic studies, and pathogen fate

Anaerobic digestion is an established sustainable route for managing the organic fraction of municipal solid waste. The commonly adopted mono digestion of organic waste is often beset by many challenges chief of which is process instability. This study assessed the role of biochar in process stability and pathogen fate for batch co-digestion of food waste (FW) and cattle rumen content (CRC). Biochar had different functional groups, a large surface area (627.50 m2/g), and a pore volume (0.32 cm3/g). Biochar amendments helped stabilize the pH and reduce the accumulation of volatile fatty acids (VFAs) and total ammonia nitrogen (TAN). Biochar amendment using 5 g biochar also facilitated biogas production at low pH conditions (3.72 – 4.45), yielding a cumulative biogas yield of 706.11 ml/gVS with a biomethane composition of 64.3%. Pathogen counts revealed significant log reductions in the range 3.0–3.2 for E. coli, Bacillus, and Salmonella within the first 7 days of digestion, corresponding to 99.9% removal, indicating the safety of the resulting digestate for agricultural use. The modified Gompertz model adequately represented the kinetics of the anaerobic digestion process. The study has provided insights into biochar-facilitated digestion of CRC and FW for enhanced process stability

Assessment of Anaerobic Digestate Amended with Wood Ash and Green Vegetable Matter and Impacts on Microbial Growth

Anaerobic digestion (AD) is a waste management method worldwide, that results in biogas and digestate production. The digestate remains is a potential biofertilizer but may fall short of vital nutrients required for optimal plant growth, hence, requires amendment with other biomass residues. This study was aimed at investigating the microbial quality of digestate amended with wood ash and vegetable matter during treatment. Digestate from cattle rumen content (CR), food waste (FW), fruit waste (FRW) and their combinations were amended with wood ash, vegetable (green) matter and a blend of both. Amendment was carried out for 5 weeks, and samples were analyzed weekly. Enumeration and identification of bacteria and fungi were carried out on culture media. The rhizobacterial potential of the identified bacterial isolates was also investigated using standard microbiological procedures. The results showed high bacterial and fungal load in vegetable amended digestate from the first to the fourth week. Comparatively, cattle rumen content and food waste digestate amended with vegetables were highly significant, with mean values of 0.8 and 0.6, respectively. The identified bacterial isolates namely, Bacillus subtilis, Salmonella sp, Pseudomonas sp, Proteus sp, Enterobacter sp, Chromobacterium sp Bacillus spp. and Escherichia coli were found to be involved in the solubilization of phosphate, nitrogen fixation, ammonia production and induction of indole acetic acid. Specifically, feedstocks amended with vegetable (green) waste was found to have a significant influence on microbial growth (bacterial and fungal loads) between week 1 and 4. This suggests that digestate amendment is a crucial recipe for microbial growth which has considerable benefits in nutrient enhancement and increase in carbon levels

Anaerobic co-digestion of cattle rumen content and food waste for biogas production:Establishment of co-digestion ratios and kinetic studies

This study investigated the batch co-digestion of cattle rumen content (CRC) and food waste (FW) for biogas production in different ratios (CRC:FW) to assess biogas production and process stability. The results showed that CRC and FW possess characteristics that are desirable for biogas production as seen in their respective total solids (10.85 and 26.53%), volatile solids (89 and 86.83%) and carbon to nitrogen ratio (23.7 and 15.7) values. Co-digestion improved carbon to nitrogen ratio, biogas yield and pH of the co-substrate compared to individual substrates. The 50:50 co-digestion ratio was found to be optimum as it gave the maximum cumulative biogas yield of 320.52 ml/gVSadded. Co-digestion also improved the pH, volatile fatty acid (VFA) and total ammonia nitrogen (TAN) characteristics during digestion. The cone model was able to adequately represent the kinetics of the process. These findings have provided very useful insights into the co-digestion of CRC and FW