In this research, hydrogel biocomposites were prepared from whey protein isolate (WPI), reduced graphene oxide (rGO), and synthetic polymers in varied ratios. Their physicochemical properties were evaluated by FTIR, SEM, TGA, AFM, and TEM. FTIR spectra revealed significant peaks at 1167 cm −1 for C-O-C peak and at 1449 cm −1 for O-H bending for WPI and rGO, respectively. The hydrogels were loaded with proguanil hydrochloride and chloroquine diphosphate and in vitro release kinetics of individual drugs from the biocomposites were studied. The SEM images of the biocomposites after drug release confirmed that they are biodegradable. The drug release was controlled, pH-dependent which further confirmed that the hydrogels are pH-sensitive. The release of proguanil from the hydrogels was slow when compared to chloroquine, suggesting that the solubility of the drug influenced their rate of release. The drug release from the biocomposites fitted the Korsmeyer-Peppas model with n values for chloroquine between 0.46 and 0.49 at pH of 1.2 and between 0.72 and 1.41 at pH of 7.4. The n values for proguanil were between 0.66 and 0.83 at pH 1.2 and 0.85-0.92 at pH 7.4. The results obtained suggested that the biocomposites are potential systems that can be tailored for controlled delivery of bioactive agents.

Over the decades, corrosion has resulted in loss of lives accorded with damage costs in almost all engineering fields. Thus, it is seen as an environmental threat with catastrophic attributes, which calls for day-to-day research on its final resolution. Recent studies have proven organic green corrosion inhibitors (OGCIs) from plant extracts with biodegradable, environmentally accommodative, relatively cheap, and nonharmful features as the most perfect approach of tackling the problem. This review gives succinct discussion on the mechanisms, classifications, and active functional groups of OGCIs. Measuring ways and factors influencing their efficiency are presented. Also, various plant extracts used as OGCIs in preventing material corrosion in corrosive media coupled with their respective findings, applied characterization techniques, and future challenges are presented. The significance of values obtained from simulating presented mathematical models governing OGCI kinetics, adsorption isotherm, and adsorption thermodynamics is also included. In conclusion, recommendations that will broaden the usage of OGCIs from plant extracts for inhibiting corrosion of materials are presented for prospective researchers in the field of corrosion.

This paper gives detailed comprehensive review of atmospheric assessment of particulate matter and heavy metals. Previous research works executed on this subject matter in the past four decades were adequately scrutinized. Various equipments for assessing atmospheric particulate matter and heavy metals were presented. Mathematical modeling equations for source apportionment and characterization, deposition rate prediction and health risk characterization of PM 10 were also presented. However, the following conclusions were made: (1) there is need for improvement on the mathematical models by reducing the number of assumptions made in developing them. (2) Comparative analysis of concentrations of heavy metals in the atmosphere under the same environment for different methodologies should be executed for accuracy purposes. (3) Cost implication of assessing, monitoring and controlling these unfriendly substances should be examined, and hence, involvement of cost engineers may be of immense help. (4) Further research works should be done on Air-Q 2.2.3 model currently identified as a new methodology for provision of quantitative data on the impact of particulate matter exposure on the health of people. (5) Compliance monitoring networks should be designed to ease data collection for the observables, locations and time periods that allowed receptor models to be applied. (6) There is need for much more research works that enable optimal control and regulation of emission of heavy metals into the atmosphere in order to reduce health effects of these inhalable substances.

This study investigated groundwater quality collected from two industrial and residential locations in each of Lagos metropolis. Prescribed standard procedures of American Public Health Association were used to measure physico-chemical parameters of each of the groundwater samples which include pH, EC, DO, TDS, BOD, COD, anions (Cl − , NO 3 − , SO 4 2− , PO 4 3− ) and heavy metals (Cu, Zn, Pb, Mn, Fe, Co, Cd and Cr). From laboratory analysis, measured physico-chemical parameters were within the permissible ranges specified by the WHO and NSDWQ except pH, TDS, EC, Pb, Mn and Fe for groundwater samples from industrial locations and pH, Pb, Mn and Fe for residential locations. Higher concentrations of TDS and EC reported for groundwater samples from industrial locations were attributed to heavy discharge of effluents from industrial treatment plants as well as dissolution of ionic heavy metals from industrial activities of heavy machines. Statistical Pearson's correlation revealed physico-chemical parameters of water quality to be moderately and strongly correlated with one another at either p < 0.05 or < 0.01.

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In this study, a low-cost composite adsorbent was prepared from snail shell and rice husk (SS-RH) through calcination for brilliant green dye (BGD) adsorption from aqueous solution. Six two-parameter and three three-parameter isotherm models were used to fit the experimental data by both linear and non-linear regression methods using ten error functions. Linear and non-linear regression analysis coupled with linear and non-linear fit error functions all revealed Langmuir and Sip as two- and three-parameter isotherm models well-fitted for BGD uptake from aqueous solution using calcined particles (CPs) of SS-RH. Chi-square (χ2) error function proved to be the best applicable predictive error function for the two-parameter isotherm study while sum of absolute error (EABS), hybrid functional error (HYBRID) and normalized standard deviation (NSD) are the best error functions for non-linear Redlich-Peterson, Sips and Toth three-parameter isotherm models respectively. Irregular surface texture was observed for the calcined particles of SS-RH as revealed by SEM with BGD filling the opening pores after adsorption. FTIR revealed shift in spectrum broad peaks after adsorption. EDS exhibited active mixed metal oxides formation before adsorption with the observance of weight percent change after adsorption.

In the present study, the adsorption behavior of copper-based metal organic framework (Cu-MOF) in the removal of cadmium ion (Cd 2+) from aqueous solution was investigated. The Cu-MOF prepared by solvothermal method was characterized by BET, FTIR, SEM and EDX techniques. Effect of adsorption parameters such as initial Cd 2+ concentration (20-100 mg/L), contact time (20-60 min) and adsorbent dosage (0.1-0.5 g) on the removal efficiency and equilibrium adsorption capacity was investigated at fixed pH and temperature. The results obtained from the batch mode adsorption studies revealed that at initial Cd 2+ concentration of 20 mg/L, contact time of 60 min and adsorbent dosage of 0.5 g, the removal efficiency and equilibrium adsorption capacity of Cd 2+ from the process were 98.62% and 1.9724 mg/g, respectively. The experimental data were evaluated by Langmuir and Freundlich isotherm models. The data fitted well with the Langmuir isotherm, and monolayer adsorption capacity of the Cu-MOF was 219.05 mg/g. The kinetic data were analyzed by using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The kinetic studies showed that pseudo-second-order model exhibited high correlation coefficients for all the initial Cd 2+ concentrations studied, thus indicating that the theoretical amount of Cd 2+ adsorbed agreed to the experimental values of Cd 2+ adsorbed.

In the past, lives and wealth have been lost due to corrosion in almost all engineering fields. Not only this, the cost of reviving damaged equipments in the industry due to corrosion contributed a lot to the gross domestic product of a nation. Thus, all hands must be on desk to combat this harzadous act via time to time research on its final resolution. However, current research works have revealed effective and reliable corrosion inhibitors from pharmaceutical drugs, plant extracts and ionic liquids as organic green corrosion inhibitors (OGCIs) with accommodative attributes such as being environmentally friendly, readily available, biodegradable, non-harmful, relatively cheap and many others to mention a few. This paper opens readers mind into the detailed classifications, mechanisms and active functional groups of these eco-friendly OGCIs. Not only the corrosion efficiency calculation ways but also influencing factors on efficiency were presented. Plant extracts, pharmaceutical drugs, ionic liquids and synthetic inhibitors, as among major sources of OGCIs, used in preventing material corrosion in corrosive media were separately and comprehensively examined. The significance of values obtained from simulating presented mathematical models governing OGCIs kinetics, adsorption isotherm and adsorption thermodynamics was also included. In conclusion, beneficial recommendations for both current and prospective researchers in the field of Corrosion Engineering were presented.