Biosorptive capacity of yam peels waste for the removal of dye from aqueous solutions

Removal of ultramarine blue dye from aqueous solution using yam peels waste was well investigated in this study. The effect of adsorbent concentration, dye concentration, time and pH were evaluated. Maximum adsorption occurred at pH of 10.There was a general increase in adsorption with increase in adsorbent concentration, dye concentration, time and temperature, respectively. The pseudo second order model with R2 of 0.98, provided a better description for the adsorption process than the first order, showing that adsorption occurred mainly by  intra-particle diffusion. The Freundlich and Langmuir isotherms were found suitable for describing the adsorption.  Maximum  adsorption capacity(qm) was obtained as 0.940(mg/g).The separation factor SF was obtained as 0.72 is less than unity, indicating that yam peels waste adsorption of ultramarine blue dye is quite favourable. Keywords: Ultramarine blue, Biosorption, Adsorption kinetics, Adsorption isotherm

Evaluation of biogas yield and kinetics from the anaerobic co-digestion of cow dung and horse dung: a strategy for sustainable management of livestock manure

In this study, investigation was done to deter�mine the optimum combination of cow dung (CD) and horse dung (HD) for enhanced biogas production and plant stability. Anaerobic co-digestion of CD and HD at varying percentage combination was carried out in five (5) identical 25 L cylindrical digesters (A–E) for a retention period of 37 days, at an average ambient temperature of 33 �C. Using the Microsoft excel solver function, 2010 version,the modified Gompertz model was applied to predict the relevant kinetic variables of the digestion process. Result obtained shows that digester D with 25% CD and 75% HD produced the highest daily biogas, followed by C (50% CD and 50% HD), B (75% CD–25% HD), A (100% CD) and E (100% HD). Digester D also had maximum biogas pro�duction potential (A) of 13.8 L/gVS, maximum biogas production rate (l) of 0.69 L/gVS/day and shortest lag phase (k) of 5.20 days. Digester E with 100% HD, though had a short lag phase of 5.72 days, had the least total biogas yield of 5.1 L/gVS. The closeness of the coefficients of determination (R2) to 1 reflects a good fit, between experimental and simulated data. The study found that increase in the amount of cow dung beyond 25% led to decrease in biogas yield. It has also shown that biogas production from CD and HD is feasible and can serve as way of removing CD and HD from the environment while serving as a source of bioenergy. Further study on best ways of pre-treating the substrates for greater biogas yield is recommended

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Concentrations and exposure risks of some metals in facial cosmetics in Nigeria

The concentrations of nine metals (Cd, Pb, Ni, Cr, Co, Cu, Fe, Mn and Zn) were determined in lip sticks, lip glosses, lip balms, eye pencils, eyeliners, eye shadows, blushes, mascaras and face powders. The study was aimed at providing information on the risk associated with human exposure to metals in these facial cosmetic products. The concentrations of metals in the samples were measured by atomic absorption spectrometry after digestion with a mixture of nitric acid, hydrochloric acid and hydrogen peroxide. The mean concentrations of metals in these facial cosmetics ranged from 3.1 to 8.4 μg g−1 Cd, 12–240 μg g−1 Pb, 9.1–44 μg g−1 Cr, 18–288 μg g−1 Ni, 1.6–80 μg g−1 Cu, 7.9–17 μg g−1 Co, 2.3–28 mg g−1 Fe, 12–230 μg g−1 Mn, and from 18 to 320 μg g−1 Zn. The concentrations of Ni, Cr and Co were above the suggested safe limit of 1 μg g−1 for skin protection, while Cd and Pb were above the Canadian specified limits. The systemic exposure dosage (SED) values for these metals obtained from the use of these facial cosmetic products were below their respective provisional tolerable daily intake (PTDI)/or recommended daily intake (RDI) values. The margin of safety values obtained were greater than 100 which indicated that the concentrations of the metals investigated in these facial cosmetics do not present considerable risk to the users except in the case of face powders. Keywords: Metals, Facial cosmetics, Systemic exposure dosage, Margin of safety, Allergic contact dermatiti

Simulation Analysis of Benchmark Axial Velocity After Sudden Expansion using Computational Fluid Dynamics

Computational Fluid Dynamics (CFD)- ANASYS 2020R1 was used for the analysis of food and drug administration (FDA) benchmark study for biomedical flow transition. An idealized medical device is presented within this study and the CFD predictions of pressure and velocity are compared against experimental measurements of pressure and velocity. The fluid flow transition considered for Reynold numbers(s) 500, 2000, and 6500 with turbulent fluid flow models- laminar, k-omega, k-omega SST and k-epsilon based on throat Reynolds number Reth. 500, 2000 and 6500. Mesh independence K-omega SST model used at 0.0008, 0.0004 and 0.0002 element sizes showed good matched velocity of 5.9m/sec. This converged at 0.0002, which is 2% of total pressure drop. Axial velocity at centreline for Reth 500, 2000 and 6500 at line X =0, showed maximum difference of 77.4% velocity centerline at 0.08m and 19% wall pressure at -0.09m sudden expansion laminar region of Re = 500. Besides, 65.6% and 17.2% obtained at transition Re =2000, showed good agreement between CFD simulations and experimental measurements, at turbulent region Re = 6500, all models were in good agreement at 49.6% velocity centerline and 8.10% pressure drop in laminar region. Also, downstream of the simulation of Reth =6500, other models disappeared which demonstrated K-epsilon model is best at higher Reynolds region. The result revealed negligible pressure gradient at the center line of the wall pressure, and dropped at the normalization point of the experimental pressure data range of 0 to -120n/m2 and balanced at the throat Reynolds number of Reth = 500. &nbsp

Concentrations and Health Risk of Polycyclic Aromatic Hydrocarbons in Some Brands of Biscuits in the Nigerian Market

<div><p>ABSTRACT</p><p>Concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in 40 brands of biscuits in the Nigerian market. The analyses were performed by gas chromatography-flame ionisation detection (GC-FID) after Soxhlet extraction of the sample with hexane/dichloromethane and clean-up of the extract. The concentrations of Σ16 PAHs in these biscuit samples were in the range of 35.7–645.3 μg kg⁻¹, 75.9–490.7 μg kg⁻¹, 91.5–537 μg kg⁻¹, 18.4–522.2 μg kg⁻¹, 123.5–393.8 μg kg⁻¹, 167.2–880 μg kg⁻¹, 136.5–316 μg kg⁻¹, and 135.5–241.6 μg kg⁻¹ for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The concentrations of Σ8 carcinogenic PAHs in the samples ranged from not detected (nd)–323.3 μg kg⁻¹, 15.7–138 μg kg⁻¹, 9.7–312.9 μg kg⁻¹, nd–331.7 μg kg⁻¹, nd–220.9 μg kg⁻¹, nd–53.3 μg kg⁻¹, 18.4–56.6 μg kg⁻¹, and 6.6–170.8 μg kg⁻¹ for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The margin of exposure (MOE), based on PAH8 as an indicator for the occurrence and effects of PAHs in food, was less than 10,000, the serious health effects value, in 30% and 8% of the brands for the child and adult scenarios, respectively.</p></div