Adsorptive and Photocatalytic Properties of Green Synthesized ZnO and ZnO/NiFe2O4 Nanocomposites for Tannery Wastewater Treatment

This study investigated adsorptive and catalytic behaviour of ZnO and ZnO/NiFe2O4 nanocomposites for the removal and degradation of organic pollutants in tannery wastewater. ZnO and ZnO/NiFe2O4 nanomaterials were synthesized via a green method using Zn, Fe and Ni salts precursor and leaves extract of Anacardium occidentale (linn.). Subsequently, the synthesized samples were characterized by different analytical tools. The adsorptive and catalytic performance of the prepared nanomaterial were assessed using reduction in Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Organic Carbon (TOC) in tannery wastewater as indicator parameters. High Resolution Scanning Electron Microscope (HRSEM), High Resolution Transmission Electron Microscope (HRTEM), and X-Ray Diffraction (XRD) analysis of ZnO and ZnO/NiFe2O4 confirmed the formation of hexagonal wurtzite nanoparticle and cubic spinel phase with an average crystallite sizes in the range of 13- 28 nm and 30.44 – 42.53 nm respectively. XRD analysis confirmed no change in the polymorph of ZnO upon the addition NiFe2O4. XPS spectrum showed the existence of the elements in the following oxidation state (+2) for Zn, (+1, +2) for Ni and (+2 and +3) for Fe. BET analysis revealed order of the specific surface area of ZnO/NiFe2O4 (44.61 m2/g) > NiFe2O4 (40.39 m2/g) > ZnO (8.91 m2 /g). The adsorptive and photocatalytic results revealed that 3% ZnO/NiFe2O4 exhibits higher efficiency compared to ZnO and NiFe2O4 nanoparticles alone and in the order of 3% ZnO/NiFe2O4 > NiFe2O4 > ZnO. The study revealed that the prepared nanomaterial behaved better as photocatalyst than as nanoadsorbent. Keywords: Adsorption, photocatalytic technology; ZnO; ZnO/NiFe2O4, tannery wastewate

Removal of pharmaceutical residues from water and wastewater using dielectric barrier discharge methods—A review

Persistent pharmaceutical pollutants (PPPs) have been identified as potential endocrine disruptors that mimic growth hormones when consumed at nanogram per litre to microgram per litre concentrations. Their occurrence in potable water remains a great threat to human health. Different conventional technologies developed for their removal from wastewater have failed to achieve complete mineralisation. Advanced oxidation technologies such as dielectric barrier discharges (DBDs) based on free radical mechanisms have been identified to completely decompose PPPs. Due to the existence of pharmaceuticals as mixtures in wastewater and the recalcitrance of their degradation intermediate by-products, no single advanced oxidation technology has been able to eliminate pharmaceutical xenobiotics. This review paper provides an update on the sources, occurrence, and types of pharmaceuticals in wastewater by emphasising different DBD configurations previously and currently utilised for pharmaceuticals degradation under different experimental conditions

Toxicity of Workplace Aluminum Particles: Insights from Earthworm (Eisenia fetida) Tests in Soil Mixtures

Lifestyle changes have led to increasing use of alternative materials in building construction, fabrication of furniture and household appliances. Apart from the associated light weight and aesthetics, Aluminum products endure various pressures that range from climatic factors to pest attacks; hence, they are more durable than wood and other conventional materials. Activities of fabricators are widespread in many Nigerian cities and these result in traces of Aluminum particles derived from cutting, shaping and surface filing. The resulting recalcitrant dust particles can exert adverse consequences on biota. Therefore, this study examined the effects of different levels of Aluminum particles on earthworm in soil mixtures by assessing their behaviour, mobility and mortality in a five-week ecotoxicity test. Worms became sluggish after only two-week exposure and this culminated in loss of mobility and ultimately mortality in exposed organisms. Mortality of worms was highest (80 – 100%) in soil mixtures with the most proportion of Aluminum particles and decreased correspondingly with contaminant levels. However, there was no mortality of worms in soil mixtures without any Aluminum particles. Lethal concentration (LC50) values of 2.564g/kg, 0.995g/kg and 0.851/kg were determined at two, four and five weeks, respectively. The results suggest that worms in the course of foraging in soil, can internalize contaminating Aluminum particles, which may lead to adverse consequences in exposed population. Considering the role of earthworms in breakdown of soil organic matter and nutrient cycling, indiscriminate disposal of Aluminum particles across various landscapes may have consequences on soil fertility, food security and sustainability

An assessment of the level of motivation towards the study of Anatomy among students in south-western Nigerian Universities

No Abstrac

Toxicological studies of silver nanoparticles synthesized from Calopogonium mucunoides aqueous leaf extract on Wistar rats

Increasing usage of nanosilver (AgNPs) for biomedical purposes outstrips the handiness of safety evaluation studies. This study investigates oral toxicity of biogenic AgNPs (at 50, 75, 100 and 150 μg/kg) on rats. Results analysis revealed that C. mucunoides AgNPs improved dietary intake and body weight of rats. Level of serum total protein significantly increased 9.54±0.05, 8.31±0.06, 11.31±0.41, 10.48±0.65 g/dL compared to control 6.43±0.55 g/dL while serum AST significantly reduced to 0.05±0.00 and 0.10±0.02U/L at 50 and 75 μg/mL. AgNPs did not significantly (P ˃ 0.05) altered serum chloride, urea, ALT and creatinine relative to the control. However, serum potassium (10.74±1.86 mmol/l) significantly decreased (P < 0.05) to 3.11±0.71, 3.12±2.50 4.64±1.47, 5.79±1.30mmol/L respectively. There was also a significant (P < 0.05) dose dependent upsurge in platelets (618.50±48.79, 743.50±17.68, 763.50±10.60 and 843.50±24.75) and MCV (49.50±0.71, 52.50±0.71, 53.50±0.71 and 56.00±4.24) compared to the control (617.50±79.90 and 43.00±0.00) respectively. The haemoglobin, PCV, MCHC, MCH, RBC, WBC, lymphocytes, monocytes, eosinophils and basophils values were not different (P ˃ 0.05) from the control. Results obtained suggest that AgNPs is relatively safe, although it altered serum total protein and potassium concentrations, no rat died due toxicological effect. Keywords: Alterations, nanosilver, toxicity, upsurge

Role of tolterodine in the management of postoperative catheter-related bladder discomfort: Findings in a Nigerian teaching hospital

Background: Patient discomfort secondary to an indwelling urethral catheter in the post operative period can be very distressing. These symptoms resemble the overactive bladder (OAB) syndrome. Muscarinic receptor blockers have been successful in the management of OAB. However, information on the use of these drugs in the management of the postoperative catheter-related bladder discomfort (CRBD) in sub-Saharan Africa is still relatively sparse.Objective: To assess the efficacy of preoperative oral tolterodine in the management of CRBD in surgical patients in the immediate postoperative period.Methods: This was a double-blind placebo-controlled study consisting of 56 patients in each arm who underwent general anesthesia. Each patient was given oral tolterodine or placebo 1 hour before the induction of anesthesia. The patient was later assessed at the recovery room at intervals after recovery from anesthesia. The presence of CRBD was noted and graded.Results: The overall incidence of CRBD in both the tolterodine group and the control were 85.7% and 91.1%, respectively. Overall, tolterodine prophylaxis (TP) was associated with an absolute risk reduction (ARR) of 5.4%, relative risk reduction (RRR) of 5.8%, and a number needed to treat (NNT) of 19. The incidence of moderate-to-severe CRBD in the tolterodine and control groups were 10.7% and 78%, respectively, with an ARR of 74.5% with TP.Conclusion: TP does not significantly reduce the incidence of CRBD in the immediate postoperative period but appears to be efficient in the reduction of the severity of postoperative CRBD.Keywords: Catheter-related bladder discomfort, indwelling urethral catheter, tolterodine, postoperativ

Anatomical practices of preserving, handling and management of human remains: A proposition for an act in the laws of Nigeria

The anatomical practices of handling, managing, preserving and disposing human remains should be adequately regulated. It is not uncommon to observe poor management of human remains especially with regards to preservation, handling, treatment and transportation. Deaths resulting from disasters as well as some unwholesome practices are major factors that affect the quality of practices. Yet, the management of human remains requires utmost attention for the purpose of health, ethics and environment. Outbreaks of diseases and the spread of such, for instance, the case of Ebola virus, in Liberia and Guinea are obvious pointers to the need to pay adequate attention to the management of human remains.  Though this was originally partly addressed by the Anatomy Act of 1933, currently found in the Laws of the Federal Republic of Nigeria; changes and advancements in societal life and circumstances have however limited the practicability of some aspects of the old Anatomy Act, especially as it relates to the management of human remains for non-dissection educational purposes. To this end; a conscientious review of the old act relative to the current scenarios was carried out with the aim of proposing an effective system of taking care of human remains. The result of this review is that an act will be required to address the management of human remains as well the regulation of the anatomical practices of preserving, handling and management of human remains. Human remains as used in this context includes established lifeless or dead whole human body otherwise known as corpse or cadaver, or dead organs and tissues that require disposal.Keywords: anatomical practices, human remains, mortuary and funeral homes, act     

Chemical oxygen demand removal from electroplating wastewater by purified and polymer functionalized carbon nanotubes adsorbents

This study investigated the removal of chemical oxygen demand (COD) from electroplating industry wastewater via batch adsorption by purified and polymers functionalized carbon nanotubes (CNTs) as nano-adsorbents. Bimetallic Fe-Co supported on CaCO3 was utilized to produce multi-walled carbon nanotubes (MWCNT) via the catalytic chemical vapor deposition (CCVD) technique. This was subsequently followed by the purification of the as-prepared MWCNTs by a mixture of HNO3 and H2SO4 in order to remove the support and metal particles. The purified MWCNTs was further functionalized using known mass of the following polymers: Amino polyethylene glycol (PEG), polyhydroxylbutyrate (PHB) and amino polyethylene glycol with polyhydroxylbutyrate (PEG-PHB). The purified (P-CNTs) and functionalized CNTs coded PEG-CNTs; PHB-CNTs, and PEG-PHB-CNTs were characterized by HRSEM, HRTEM-EDS, BET, XRD and XPS. The electroplating wastewater was subjected to physicochemical characterization before and after treatment with various prepared nano-adsorbents using standard methods. The adsorption process under the influence of contact time, adsorbent dosage and temperature was measured using the chemical oxygen demand (COD) as indicator parameter. The HRSEM/XRD/BET confirmed that the purified and polymer functionalized CNTs were homogeneously dispersed; highly graphitic in nature with fewer impurities and of high surface area (>145 m2/g). The order of maximum COD removal by the nano-adsorbents at equilibrium time of 70 min are as follows: PEG-CNTs (99.68%) > PHB-CNTs (97.89%) > P-CNTs (96.34%) > PEG/PHB-CNTs (95.42%). Equilibrium sorption data were better described by Freudlich isotherm with the correlation coefficient (R2>0.92) than Langmuir isotherm. The adsorption kinetics for COD removal from electroplating wastewater fitted well to the pseudo-second-order model with rate constant in the range of 4 × 10−5–1 × 10−4 (g mg−1 min−1). Thermodynamics analysis of the adsorption process revealed that the enthalpy (ΔH°) of the reaction was positive and endothermic in nature. The Gibbs free energy (ΔG°) was negative which showed the feasibility and spontaneity of adsorption process. The findings from this study support the potential use of PEG-functionalised CNTs as a nanoadsorbent to purify electroplating wastewater than others prepared sorbents