A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet–Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square (v2) and normalized standard deviation (Dq). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich (DKR), Halsey, Harkin–Jura and Flory–Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity (Qmax = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression (R2[0.90). The values of the thermodynamic parameters: standard enthalpy change DH_ (?50.27848 kJ mol-1), standard entropy change DS_ (203.5724 J mol-1 K-1) and the Gibbs free energy change DG_ revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution

Effect of operational parameters, characterization and antibacterial studies of green synthesis of silver nanoparticles using Tithonia diversifolia

Background: There is a growing interest in the green synthesis of silver nanoparticles (AgNPs) using plant extract because the technique is cost effective, eco-friendly and environmentally benign. This is phasing out the use of toxic and hazardous chemical earlier reported. Tithonia diversifolia is a wild sunflower that grows widely in the western part of Nigeria with a proven medicinal benefit. However, several studies carried out have left doubts on the basic operational parameters needed for the green synthesis of AgNPs. The objective of this work was to carry out green synthesis of AgNPs using T. diversifolia extract via an eco-friendly route through optimization of various operational parameters, characterization, and antimicrobial studies. Method: Green synthesis of TD-AgNPs was done via bottom-up approach through wet chemistry technique using environmentally benign T. diversifolia plant extract as both reducing and stabilizing agent. Phytochemical Screening of the TD plant extract was carried out. Experimental optimization of various operational parameters—reaction time, concentration, volume ratio, and temperature was investigated. TD-AgNPs were characterized by UV–Vis spectroscopy, FTIR Spectroscopy, SEM/energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Antimicrobial studies against multi drug resistant microorganisms (MDRM) were studied using the agar well diffusion method. Results: This study reveals the importance of various operational parameters in the synthesis of TD-AgNPs. Excellent surface plasmon resonance peaks (SPR) were obtained at optimum experimental factors of 90 min reaction time under room temperature at 0.001M concentration with the volume ratio of 1:9 (TD extract:Ag ion solution). The synthesis was monitored using UV– Vis and maximum wavelength obtained at 430 nm was due to SPR. The morphology and elemental constituents obtained by TEM, SEM, and EDX results revealed a spherical shape of AgNPs with prominent peak of Ag at 3.0 kV in EDX spectrum. The crystallinity nature was confi rmed by XRD studies. FTIR analysis proved presence of biomolecules functioning as reducing, stabilizing, and capping agents. These biomolecules were confi rmed to be fl avonoid, triterpenes, and saponin from phytochemical screening. The antimicrobial studies of TD-AgNPs were tested against MDRM— Escherichia coli, Salmonella typhi, Salmonella enterica, and Bacillus subtilis. Discussion: The variation of reaction time, temperature, concentration, and volume ratio played substantive and fundamental roles in the synthesis of TD-AgNPs. A good dispersion of small spherical size between 10 and 26 nm was confirmed by TEM and SEM. A dual action mechanism of anti-microbial effects was provided by TD-AgNPs which are bactericidal and membrane-disruption. Based on the antimicrobial activity, the synthesized TD-AgNPs could find good application in medicine, pharmaceutical, biotechnology, and food science

Seasonality of violent and property crime in Nigeria: Some Preliminary Findings

This study examines seasonal patterns of crime in two Nigerian cities with varying weather conditions. Using residents’ perception of crime data, break-ins are perceived to occur more frequently in the low quality neighbourhoods in Benin City, whereas in Minna, it is perceived to occur regularly in the high quality neighbourhoods. Overall results show that Minna, with warmer climate has higher levels and seasonal variations for violent crime (assaults) while Benin City, with colder climates has higher levels and seasonal variations for property crimes (break-ins). It is apparent from this study that seasonal patterns of crime in one place may not translate effectively into another. Hence, continuous researches into seasonal analysis of crimes are justifiable in the security planning efforts to ensure an environment that is suitable for living, working and recreating

EFFECT OF TILLAGE METHODS ON SOIL PHYSICAL AND STRENGTH PROPERTIES UNDER AMARANTHUS HYBRIDUS PRODUCTION IN A SANDY-LOAM ENVIRONMENT

Amaranthus hybridus (African Spinach) production is a common vegetable in many southwestern parts of Nigeria. Many farmers grow it for its high source of protein and vitamins under different soil conditions without taking into consideration the tillage method that best gives the highest yield. A field study was conducted on a sandy loam soil in the National Centre for Agricultural Mechanization, Ilorin. Nigeria during the raining season of 2017 to investigate the effect of tillage methods on soil physical properties, penetration resistance and shear strength under Amaranthus hybridus production. The experiment was a completely randomized design with three replications. Tillage methods were disc plough (DP), disc harrow (DH), combination of disc plough and disc harrowing (DPH) and zero tillage (ZT). Soil physical parameters investigated during the growth stages of the crop were soil bulk density, soil moisture content, penetration resistance, shear stress and total porosity. Average bulk density for DP, DPH, DH and ZT were 1.33, 1.30, 1.25 and 1.50 g/cm3 respectively. Shear stress increased with depth in all the plots. Maximum values at the 14-21 cm depth were 132, 104, 166 and 16 mPa for DP, DPH, DH and ZT respectively. The average penetration resistance on the DP, DPH, DH and ZT at the 14-21cm depth were 84.3, 82, 178 and 97 kPa respectively. Amaranthus hybridus yield was highest on the DPH plots with an average weight of 10 stands weighing 108g.  Disc ploughed + harrowing was the best tillage practice considering the soil physical properties, penetration resistance and shear stress of the plots for the optimum yield of Amaranthus hybridus on the sandy loam field

Kinetics, mechanism, isotherm and thermodynamic studies of liquid phase adsorption of Pb2\mathplus onto wood activated carbon supported zerovalent iron (WAC-ZVI) nanocomposite

The kinetics, mechanism, isotherm, and thermodynamics of adsorption of Pb2+ onto wood-activated carbon-supported zerovalent iron (WAC-nZVI) nanocom- posite was successfully studied. WAC-nZVI was characterized by a combination of spectroscopic and analytical techniques (BET, PZC, FTIR, SEM, and EDX). BET surface area was 101.50 m 2/g and BJH Adsorption average pore diameter 116.73 Å. The adsorption of Pb2+ studied in batch process depends on various operational param- eters ranging from effect of pH to ionic strength. Kinetics data were best described by pseudo-second-order model based on high initial adsorption rate, h2 (166.67 mgg −1 min−1 ) and correlation coefficient (R2 > 0.99). The mechanism was controlled by both external and intraparticle diffusion models confirmed by Bangham and Boyd models. Equilibrium data were fitted to seven isotherm models. The Langmuir monolayer adsorption capacity (77.52 m2 /g) surpassed those previously investi- gated for adsorption of Pb2+ onto nanoadsorbents. Validity of kinetics and isotherm models was studied using three statistical models. Post-adsorption characteriza- tion by SEM, EDX, and FTIR confirmed the presence of Pb2+ on the loaded-WAC-nZVI

Mechanism and Isotherm Modeling of Effective Adsorption of Malachite Green as Endocrine Disruptive Dye using Acid Functionalized Maize Cob (AFMC)

Cationic Malachite green has been identified as a candidate of endocrine disruptive compound found in the environment. In this study, the mechanism and isotherm modeling of effective adsorption of cationic malachite green dye onto acid functionalized maize cob (AFMC) was investigated by batch technique. The operational parameters such as initial concentration (100 – 600 mg/L); contact time (10 – 120 mins) and pH (3 – 10) influenced the removal efficiency and quantity adsorbed. Maximum of 99.3% removal efficiency was obtained at optimum conditions. AFMC physicochemical properties (surface area 1329 m2 /g and particle size 300μm0.97 and consistently low values of SSE, X2, HYBRID and MSPD adsorption statistical error functions (ASEF), equilibrium data were best fitted to Freundlich isotherm. Kinetic data were best described by pseudo second-order model with consistent R2 >0.98 and validated by ASEF. The mechanism of process was better described by intraparticle diffusion. Evidence of adsorption process was confirmed by change in morphology and surface chemistry determined by SEM and FTIR respectively. The performance of AFMC enlisted it as a sustainable and promising low-cost adsorbent from agro-residue for treatment of endocrine disruptive dye polluted water

Pyrolysis of maize cob

Adopting the concept of the waste to wealth approach, agricultural waste from maize cob could be transformed into a renewable form of energy through thermo-chemical methods of treating the biomass. This method can be utilised for biochar production. The utilisation of biochar has several significant applications. These applications include the enhancement of the soil through amendment, stimulation of crop production by a variety nutrient inputs in the soil, etc. In this research work, a biochar was obtained through a slow pyrolysis process of maize cob waste. This experiment was carried out using a small-scale muffle furnace and subjecting the feedstock to heating at different temperatures (300, 400, 500 °C). The biochar was produced and characterised by a proximate analysis, scan electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, while the surface area was determined by Saer's method. The effect of the temperature on the yield of the biochar was investigated. The results show that the biochar yield decreases with increasing temperature for the maize cob biochar at 300, 400, and 500 °C. The results of the physiochemical properties showed that the temperature greatly impacts the physicochemical properties of the biochar. The biochar produced at 300 °C has the highest fixed carbon content of 60.5%. The largest surface area was (281.8 m2 ·g–1) at 500 °C

Exploring the Effect of Operational Factors and Characterization Imperative to the Synthesis of Silver Nanoparticles

The synthesis and application of silver nanoparticles are increasingly becoming attractive. Hence, a critical examination of the various factors needed for the synthesis of silver nanoparticles as well as the characterization is imperative. In light of this, we addressed in this chapter, the nitty-gritty on the operational parameters (factors) and characterization relevant to synthesis of silver nanoparticle. The following characterization protocols were discussed in the context of silver nanoparticle synthesis. These protocols include spectroscopic techniques such as ultraviolet visible spectroscopy (UV –Vis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS)

Water Pollution: Effects, Prevention, and Climatic Impact

The stress on our water environment as a result of increased industrialization, which aids urbanization, is becoming very high thus reducing the availability of clean water. Polluted water is of great concern to the aquatic organism, plants, humans, and climate and indeed alters the ecosystem. The preservation of our water environment, which is embedded in sustainable development, must be well driven by all sectors. While effective wastewater treatment has the tendency of salvaging the water environment, integration of environmental policies into the actor firms core objectives coupled with continuous periodical enlightenment on the present and future consequences of environmental/water pollution will greatly assist in conserving the water environment