Cationic graphene-based polymer composite modified with chromium-based metal-organic framework [GP/MIL-53(Cr)] for the degradation of 2,4-dichlorophenol in aqueous solution

Owing to its remarkable water stability, chromium-based metal-organic framework (MIL-53(Cr) has the capacity to remove 2,4-dichlorophenol (2,4-DCP) from aqueous solutions, but the weak adsorptive capacity of the adsorbent limits its utilization. In this work, cationic graphene-based polymer composite (GP) was successfully synthesized with (MIL-53(Cr)) [GP/MIL-53(Cr)] through one-step solvothermal technique and characterized with XRD, SEM, BET, XPS, TEM, and FTIR. Adsorbent dose, pH, initial concentration, and contact time were enhanced to improve the performance of GP/MIL-53(Cr). GP/MIL- 53(Cr) displayed a marginal adsorptive performance relative to MIL-53(Cr) and GP. The adsorption of 2,4- DCP mainly depends on the nature of MIL-53(Cr) and the electrostatic attractions of the functional groups on GP surface. Due to the high magnetic properties of GP/MIL-53(Cr), effective solideliquid separation can be easily achieved. The adsorbate mineralization process stabilizes at 200 min. The pseudo-second-order model adequately fits the adsorption kinetic data, while the Freundlich and Langmuir models gave a good fit with the equilibrium data. The maximum adsorptive capacity of the adsorbents for the adsorbate as calculated from the Langmuir isotherm are 64.9 (GP), 28.2 MIL-53(Cr), and 98.4 mg/g (GP/MIL-53(Cr). The thermodynamic studies revealed that the adsorption process is spontaneous, feasible, and endothermic. Additionally, the excellent performance of GP/MIL-53(Cr) shows that the adsorbent has potential application in treating wastewater

Advances in the Use of Ethers and Alcohols as Additives for Improving Biofuel Properties for SI Engines

Commercialization of biofuels as alternative fuels to conventional diesel fuel for application as transport-fuels for diesel engines is fast becoming attainable owing to the merits offered by the inclusion of significant quantities of an alcohol (ethanol) and a member of the “ether” group (dimethyl ether) as additives or property-improvers for biofuels obtained from biomass. These additives are fuels in kind, but have lower viscosities, flash points, flammability etc., hence they infuse some measures of atomization and moderation in the densities and viscosities of biofuels towards ensuring their suitability for use in Internal Combustion Engines (ICEs). Biofuels need be improved in terms of fuel quality such as performance, emission and combustion characteristics to meet market specification. This then informs the need for suitable fuel-modifiers which must be tested for their compatibilities with different biofuel-sources before they are used as fuels in ICEs. The mixing ratio of the added components with the biofuels is also to be given utmost attention as an alcohol such as ethanol and an ether (dimethyl ether), are known for their high volatilities which in turn regulate the BTEs and combustion potentials of the fuels, all aimed at improving the cetane numbers or indices of the blended fuels. Owing to the relative abundance of bioresources as precursors for biofuels relative to other sources of ethers and alcohols, literature has it that some prospective alcohols and ethers have been admixed with biofuels as means of upgrading their properties towards ensuring their high suitability for diesel engines with little or no modifications; this then implies that there might be need to begin to look into reconfiguring some diesel engines in order to abate engine wear, fuel degradation as well as catalyst-poisoning towards ensuring/maintaining high engine-compatibilities with these fuels. Therefore, this chapter is proposed for inclusion in Book 1 “Engine and fuels for future transport”, and its focus will be on the effects of using lone ethanol, dimethyl ether or biofuels as well as their blends for use as future transport fuels

Occurrence of Microplastics in Borehole Drinking Water and Sediments in Lagos, Nigeria

We investigated the occurrence of microplastics in samples of borehole drinking water and sediments obtained from borehole sites in Lagos Island, Nigeria. The samples were digested with hydrogen peroxide, pretreated, and filtered through a polytetrafluoroethylene membrane. The filtered microplastics were examined/analyzed under an attenuated total reflection Fourier-transformed infrared device, to quantify the microplastics. The results showed the presence of microplastics in drinking water and sediments from the sites, with plastic concentrations ranging from 206 to 1691 items m−3 and 9–47 items kg−1 for drinking water and sediments, respectively; polypropylene was the most common and was approximately 61.9% for borehole drinking water. In terms of shape distribution, plastic fragments were the highest, at 73.02%. The detected microplastics had a size range of 0.02–0.5 mm. In addition, sites with a lower percentage of microplastics had lower population densities and lower industrial activity, whereas areas of high industrial activity had high amounts of microplastics. Environ Toxicol Che

Production of fuel-blends from waste tyre and plastic by catalytic and integrated pyrolysis for use in compression ignition (CI) engines

The increase in energy demand and depletion of oil reserves has prompted researchers to seek alternative fuels for compression ignition engines. In this study, the characteristics of the fuels obtained from waste tyres/plastics were determined and compared with those of diesel fuel. The waste plastic oil was obtained from polyethylene terephthalate, polypropylene, high-density polyethylene, polystyrene, low-density polyethylene, and poly (vinyl chloride), thereafter, they were each blended with distilled waste tyre oil from used Dunlop tyres, in different ratios, for use as substitute fuels in a CI engine. The engine (Kirloskar, TAF 1 model) performance was studied based on its combustion, brake thermal efficiency (BTE) and emission characteristics when run on the fuels obtained from the waste-tyres/plastics. The test results showed the engine gave a higher performance in terms of BTE for E (33.9%) and F (36.9%) whereas, others gave lower performance (A- (31.9%), B (30%), C (29.7%), D (32.4%) with respect to diesel fuel. The pyrolyzed Polystyrene/tyre blends gave the highest BTE of 36.9%, with low emission. Although lower emissions were recorded for the blended fuels relative to the diesel fuel, the resulting peak emissions for the blends are in the following increasing order: unburnt HC (B (30.1) < D (30.1) <F (30.2) < A(30.4) < E (30.7) < C(31 ppm), NOx (F (1001) < B (1100) < D (1107) < C (1107) < E (1108) <1150 ppm) and CO (F (0.003) < E (0.004) < B (0.005) < A(0.006) < C(0.007) < D (0.008) ppm

Production of fuel-blends from waste tyre and plastic by catalytic and integrated pyrolysis for use in compression ignition (CI) engines

The increase in energy demand and depletion of oil reserves has prompted researchers to seek alternative fuels for compression ignition engines. In this study, the characteristics of the fuels obtained from waste tyres/plastics were determined and compared with those of diesel fuel. The waste plastic oil was obtained from polyethylene terephthalate, polypropylene, high-density polyethylene, polystyrene, low-density polyethylene, and poly (vinyl chloride), thereafter, they were each blended with distilled waste tyre oil from used Dunlop tyres, in different ratios, for use as substitute fuels in a CI engine. The engine (Kirloskar, TAF 1 model) performance was studied based on its combustion, brake thermal efficiency (BTE) and emission characteristics when run on the fuels obtained from the waste-tyres/plastics. The test results showed the engine gave a higher performance in terms of BTE for E (33.9%) and F (36.9%) whereas, others gave lower performance (A- (31.9%), B (30%), C (29.7%), D (32.4%) with respect to diesel fuel. The pyrolyzed Polystyrene/tyre blends gave the highest BTE of 36.9%, with low emission. Although lower emissions were recorded for the blended fuels relative to the diesel fuel, the resulting peak emissions for the blends are in the following increasing order: unburnt HC (B (30.1) < D (30.1) < F (30.2) < A(30.4) < E (30.7) < C(31 ppm), NOx (F (1001) < B (1100) < D (1107) < C (1107) < E (1108) < 1150 ppm) and CO (F (0.003) < E (0.004) < B (0.005) < A(0.006) < C(0.007) < D (0.008) pp

Performance evaluation of Nannochloropsis oculate–carbon nanoparticle blend as fuel in compression ignition engine

In this study, multiwalled carbon nanotubes (MWCNTs) were used as a property improvers for fuel obtained from Nannochloropsis oculate for application in a compression ignition engine. The engine's performance was monitored in accordance with its newly induced characteristics. The fixed biodiesel ratio was blended with different proportions of MWCNTs. The nanotubes were ultrasonicated with the biodiesel in different doses of 50,75, 100 and 150 ppm, respectively, and the resulting fuels were subjected to performance tests as compared with conventional diesel-fuel in a Yanmar Model-TF120M diesel engine. It was observed that cylinder pressure and heat release rates were higher under full load condition as compared with those obtained for the diesel fuel. Furthermore, the results compared favorably for both fuels in terms of combustion, emissions and engine performance. The brake thermal efficiency of the blended fuel improved by 2.72, 2.81, 3.07 and 2.24% for BC-50, BC-75, BC-100 and BC-150 as compared with that of diesel fuel. The release of CO2, NO x , hydrocarbons and carbon monoxide decreased in favor of the blends. From the analysis, a dosing level of 100 ppm MWCNTs in the biofuel is recommended for best engine performance and combustion, with optimal emission reduction. © 2021 Society of Chemical Industry and John Wiley & Sons, Lt

Decaffeination of wastewater using activated carbon produced from velvet tamarind-pericarp (Dialium Guineense)

Adsorption of caffeine from an aqueous solution was carried out using Velvet Tamarind- Pericarp, activated with H3PO4. The adsorbent was characterized using a scanningelectron microscope and the Brunauer-Emmett-Teller. Parameters such as activating agent concentration (80 wt.% in 100 mL solution), initial caffeine concentration of 5−40 g/L, pH of 0−14, and residence time 0−90 minutes, were investigated. Improved adsorptive capacities were seen at in creased acid concentrations, with the highest removal rate obtained at a pH of 6. The highest residence time and adsorbent concentrations were obtained at 40 min and 10 g/L. The surface adsorption of the adsorbent obeyed the Langmuir Isotherm, while the regression coefficients conformed to the pseudo-second-order kinetic model for the remediation of caffeine with DG-AC. The highest amount of caffeine removed per gram DG is 72.60 mg.g−1. From the thermodynamic study, the caffeine adsorption was feasible, spontaneous, entropydriven, and endothermic. These data show that the use of DG-AC can be a good alternative to other expensive methods for caffeine remediation. The Pseudo – first/second-order kinetic results gave R2 values of 0.95 and 0.99, other parameters

Comparing the effects of Juliflora biodiesel doped with nano-additives on the performance of a compression ignition (CI) engine: Part A

In lieu of the fact that modern-day research is saddled with the responsibility of replacing/supplementing fossil fuels with biodiesel for use in diesel engines, the challenge still remains the need to improve the properties of biofuels towards stimulating high engine compatibility and performance. Despite the advances made in improving biofuels such as those sourced from Juliflora with additives, none seems to have addressed the potentials that underly the use of hybrid nano-particles as propertyimprovers of Juliflora-biofuel for use in diesel engines. This then led to the need to harness the potential use of hybrid CeO2:CuO, MnO2:Al2O3, ZnO:TiO2, and TiO2:Al2O3 in different ratios as a means of determining the best combination for improved fuel properties, high engine performance and reduced emissions. The nanoparticles were produced via sol-gel method and ultrasonicated with the biofuel before being characterized using scanning electron microscopy/atomic force microscopy. Based on the engine-test results, the brake thermal efficiency (BTE) increased from 1.11 to 2.21% for the biodiesel mixed with nanoparticles. Furthermore, the Nitrogen oxide (NOx), hydrocarbon (HC) and carbon monoxide (CO) emissions for the admixed biofuels decreased by 16.29e23.76%, 14.07e17.32% and 5.51e8.27% respectively compared to conventional diesel, thus reducing environmental pollution

Authentication of Styrax officinalis L. methyl ester nanoparticulate fuel-system’s suitability in powering CI engines

Investigation was carried out on the engine performance, combustion and emission characteristics of a CI engine using biodiesel-nanoparticulate fuel-system formulated using ultrasonicated cerium, aluminum and titanium oxide nanoparticles mixed with Styrax officinalis L. seed oil methyl esters. The nanofluids were prepared using 75, 58, and 83 ppm of aluminum, titanium, cerium dioxides. The physicochemical characteristics of the nanofuels were determined and compared with those of conventional diesel in a Lister petter engine under various engine loads. The stabilities of the nanoparticles were analyzed under static conditions. There was marginal enhancement in the engine performance where the brake thermal efficiencies (BTEs) of the biodiesel doped with 75 ppm Al2O3 (S-C), 58 ppm TiO2 (S-D), and 83 ppm CeO2 (S-E) nanoparticles were 34.1%, 37.1% and 35.9% compared to those of the neat biodiesel and conventional diesel which were 31.2% and 31.9% respectively. Furthermore, the HC, NOx and CO emissions of the nano-fuel decreased at full load. Combustion properties of the in-cylinder pressure and the heat release rate improved upon the addition of the nanoparticles to the biodiesel. Therefore, the nano-fuels improved the engine’s performance and can satisfactorily be used as fuel in an unmodified diesel engine

Catalytic reforming of tar and volatiles from walnut shell pyrolysis over a novel Ni/olivine/La2O3 supported on ZrO2

The effect of catalytic reforming of volatiles from pyrolysis of walnut shell using an innovative catalyst was investigated in this study. The analysis was conducted in a two-stage fixed bed reactor operated at 700–1100 °C. The prepared Ni/olivine/La2O3/ZrO2 catalyst had a significant performance on the catalytic tar reforming reactions. In the catalytic reforming of tar, the weight of catalyst is critical. However, it was observed that the tar reforming efficiency increased with increase in catalyst-weight and temperature. In addition, the highest tar reforming efficiency (98.9%) was attained with 20 g of Ni/olivine/La2O3/ZrO2. After 4 cycles of regeneration, tar reforming efficiency was kept stable. The product gas composition was highest at 1100 °C with a very low tar yield, which reduced from 18.1 to 2.1 wt% at 700–1100 °C. At varying reforming conditions, the product gas composition increased. The product-gas distribution varied at different steam flow rates (3–9 mL/h) as well as particle size (0.2–3.5 mm) and the highest yield was achieved with the smallest particle size (0.2 mm) of walnut shell thus confirming the superb catalytic activity of Ni/olivine/La2O3/ZrO2 for tar reformation into gases owing to high dispersion of ZrO2 in the shells