Potential Recovery of Biogas from Lime Waste after Juice Extraction Using Solid–Liquid Extraction Process

A large percentage of fruit mass is left as waste after the consumption or processing of citrus fruits. The inappropriate disposal of these wastes directly leads to environmental and economic concerns. However, scientific investigations have demonstrated that citrus wastes, due to their high concentration in soluble sugars, can be a source of cellulosic biomass for biogas recovery. d-Limonene, the major constituent of essential oils present in citrus wastes, is however, known to hamper the conversion process of citrus wastes to biogas. With the aim of improving biogas production, a study on the pre-treatment of lime fruit waste to reduce the e�ect of d-limonene was carried out. The pretreatment process was done using hexane as the solvent in a solid–liquid extraction process to leach out essential oils from lime wastes. Solid–liquid extraction was carried out in a Soxhlet apparatus with pulverized lime waste at 68 �C for 180 min; then the residue was washed and aerated. From the pre-treatment procedure, 21.3 mL of essential oil was recovered, indicating an oil yield of 3.8%. Substrates of untreated and pre-treated lime waste were digested in batches under mesophilic conditions for a period of 28 days. The biogas yield of each substrate was evaluated and the results compared. Substrate of untreated lime waste yielded 66.9 mL/g VS. biogas after the digestion period. In comparison, pre-treated lime waste gave a better biogas yield of 93.2 mL/g VS. after 28 days, indicating an improvement in biogas yield by about 40%. The findings of this research show that there is a viable recovery option of biogas from lime waste, and recommendations of this research can be further explored to develop an economically viable biogas plant process that e�ciently utilizes citrus wastes. This would boost the drive of government towards alternative sources of energy and also fulfil two of the sustainable development goals presented by the United Nations

COVID-19: Impacts and implications on waste management, the Nigeria economy and the way forward

The coronavirus disease, popularly known as COVID-19, is a new infectious disease and Nigeria is one of the 213 countries and territories affected by its pandemic. The pandemic has practically affected every sector of the economy with substantial impacts and implications. The current waste management practice at all health care and isolation centres during this period also calls for concern. This paper focuses on the effects of COVID-19 on Waste Management Practices, the Nigeria Economy, and the Way Forward. Responses at the three tiers of government are identified; the involvement of private and public sectors with the role of international organizations, donors, public participation, and the impact of religion on COVID-19 response in Nigeria are also considered. The implications on Sustainable Development Goals, Agriculture, Manufacturing, Trade, Mining and Quarrying, and Education Sectors are discussed. SWOT analysis of waste management processes in Nigeria during the pandemic is presented. Based on the study, it is recommended that concerted effort on the part of the government be focused on maximizing welfare policy programs that would erase the sufferings of the people as regards access to primary health care and other social infrastructure that could enhance peoples' living standard. Effective responses and recovery plans in the short-, medium and long-term should also be prioritized and consider the pandemic's different dimensions, as a measure to grow truly necessary extraordinary change toward a sustainable society

Assessment of Biogas Generation Potential of Mixed Fruits Solid Waste

Increase in the demand for fruit has led to more wastes to contend with. The build-up of this waste typically signifies an economic and environmental nuisance owing to disposal problems. This study focuses on assessing biogas generation potential of mixed-fruit solid waste comingled with cow dung for biogas production. Fruit wastes consisting of pineapple peels, watermelon peels, banana peels, and orange peels were used for the experiment. Comparison between the mixture of pineapple peels, banana peels, and cow dung with the mixture of watermelon peels, banana peels, and cow dung was carried out in an experiment by anaerobic digestion at a laboratory scale. Tyre tube storage method was used to measure the amount of the biogas yield. The result from the experiment indicated that pineapple peels, banana peels, and cow dung produced more yield of biogas of (1.4 kg) than that of watermelon peel

Physico-Chemical Properties of Yellow Oleander (Thevetia peruviana) and their effects on the Qualities of Biodiesel

This study investigated the effects of physico-chemical properties of Yellow oleander (Thevetia peruviana) on quality of biodiesel. The seeds were processed and extraction of oil was carried out using solvent extraction method. Biodiesel was produced from the extracted oil using trans esterification process. Physical and chemical properties of Thevetia peruviana biodiesel were determined using the ASTM standard test procedures. Results showed that the biodiesel contained little sulphur (3.0 mg/kg) and exhibited a high cetane number of 55 that exceeded the standard limit of 47 and 51 prescribed for EN 14214 and EN 590 respectively, which is a good indication of fuel’s ignition and combustion quality. Kinematic viscosity of the biodiesel at 40°C was 4.81 mm2/s, which was within the range specified by EN 14214. The density at 15°C was found to be 0.89g/cm3 which was well within the range specified by EN 14214. 0.16 mg/g of acid level was obtained for the bio-diesel, which conformed to the standard set by  Calorific value of the biodiesel produced from Yellow oleander seed oil was obtained as 40.42 kJ/g which indicated good fuel properties such as density, ignition quality, viscosity, cetane number, heating value and flash point. Carbon residue of the biodiesel was 0.14 mass %. Quality of the biodiesel produced conform to biodiesel and petroleum diesel standards of EN14214 and EN590 respectively

Determination of Hardness and Tensile Properties of Dissimilar Phase Structured Steel Weld

This work involves the use of submerged arc welding (SAW) technique in joining heat treated steel in alternate arrangement. The selected as-received steel was initially cut, machined and heat treated to develop a conventional microstructure prior to joining operation. All samples were subsequently characterized to investigate the effect of the process on the mechanical behaviors. 3360 Instron Universal Tensile testing machine was used for the tensile properties evaluation; Vickers’ microhardness testing machine was also used for the hardness evaluation at various zones. From the result, it was found that interchanging arrangement of the microstructures during welding yield better combined properties of the ultimate tensile strength, yield strength and with improvement in the strain-to-fracture of some of the samples. The adopted mechanism was also observed to yield better hardness property on the sample. This led to the recommendation of this technique to the oil and gas industry that need to transport their products via the giant water bodies to clients

Carbapenem resistance expressed by Gram-negative bacilli isolated from a cohort of Libyan patients

Background and objectives: Carbapenem-resistant Enterobacteriaceae (CRE) and other Gram-negative bacteria are among the most common pathogens responsible for both community and hospital acquired infection. The global spread of cephalosporinases in Enterobacteriaceae has led to the increased use of carbapenems resulting in the emergence and rapid spread of CRE. This has become an alarming public health concern, yet the condition in Libya remains unclear. The aim of this study was to obtain a better understanding of CRE strains prevalent in Libyan patients by investigating their phenotypic characteristics and antibiograms. Methods: Gram-negative bacterial species were collected from Misrata Central Hospital, Misrata Cancer Centre and Privet Pathology Laboratories. Clinical samples and swabs were obtained from hospitalised and non-hospitalised patients and from mechanical ventilation and suction machines. Patients who had received antibiotic therapy for at least three days prior to the study were excluded. The identification and characterization of the isolated species were achieved using the growth characteristics on MacConkey and blood agar, spot tests and API 20E or API 20NE biochemical testing systems. Screening for carbapenem resistance was performed using the disk diffusion method with carbapenem 10 μg and cephalosporin 30 μg disks and minimum inhibitory concentrations (MIC) determined using the Sensititre Gram-negative Xtra plate format (GNX2F). All strains demonstrating resistance or reduced susceptibility to one of the four carbapenems were subjected to carbapenememase activity detection using the RAPIDEC CARBA NP test, Modified Hodge test and carbapenem inactivation methods. Results: A total of one hundred and forty isolates representing fourteen bacterial species were isolated from 140 non-duplicated specimens. Clinical specimens included urine samples (96/140, 68.57%), sputum (15/140, 10.71%), surgical wound swabs (18/140, 12.85%), foot swabs from diabetes mellitus (DM) patients (6/140, 4.29%), ear swabs (3/140, 2.14%) and wound swabs (2/140, 1.43%). Thirty-four (24.29%) isolates demonstrated resistance to at least one of the four carbapenems with Klebsiella pneumoniae representing 73.53% (25 isolates) of all carbapenem resistant species, followed by 8.82% for Pseudomonas aeruginosa (3 isolates), 5.88% for both Proteus mirabilis (2 isolates) and Escherichia coli (2 isolates) and 2.94% for both Citrobacter koseri (1 isolate) and Rahnella aquatilis (1 isolate). The other isolates were either susceptible or cephalosporinase producers. Conclusion: This study has revealed the high rate of carbapenem resistance amongst Libyan patients and emphasizes the crucial need for accurate screening, identification and susceptibility testing to prevent further spread of nosocomial and community acquired resistance. This may be achieved through the establishment of antibiotic stewardship programmes along with firm infection control practices.National Research Foundation of South Africa; Libyan GovernmentWeb of Scienc

Thermoluminescence properties of potassium fluoride:

This study is designed to examine the thermoluminescence characteristics of potassium fluoride for possible use as a thermoluminescence dosemeter. Thermoluminescence measurements were carried out at doses up to 20 Gy and heating rates between 0.2 and 4°C/s. The glow curve of the fluoride, readout at 1°Cs−1, exhibited two peaks at 130 and 250 °C. In addition, two shoulder peaks appeared at 70 and 200°C

Comparative dataset on the characterization of natural polymers and nanocomposites for enhanced oil recovery

Polymer flooding is one of the most effective processes to improve crude oil recovery. However, the capacity of nat- ural polymers to displace crude oil is determined by their rheological behaviour in the face of prevailing reservoir con- ditions. Poor rheological stability of water-soluble polymers challenges their application in harsh reservoir conditions, making it important to investigate the characteristics of poly- mers and their corresponding nanocomposites for use in en- hanced oil recovery (EOR). The main objective of this work is to conduct characterization tests for three polymers (Gum Arabic, Xanthan Gum and Guar Gum) and three nanoparticles (silica, alumina and cupric), and to investigate the viscosity profile of the polymers under different conditions of tem- perature, salinity, nanoparticle weight percentage and poly- mer weight percentage. SEM was used to characterize the nanoparticles while FTIR and TGA were used to character- ize the polymers. All viscosity measurements were conducted using an OFITE Viscometer. The SEM, FTIR and TGA results are presented in figures while the viscosity results are pre- sented as raw data in tables. The data should be used to support oil recovery experiments, economic analysis of the use of polymers and nanocomposites in EOR and the study of adsorption and permeability impairment in core flooding tests

Optically stimulated luminescence and spectral emission features of radioluminescence and thermoluminescence of natural kunzite:

Features of luminescence optically stimulated from natural kunzite using 470 nm blue light are reported. Preparatory measurements of its X-ray excited radioluminescence and thermoluminescence show that the sample has two main bands centered at 360 nm and 600 nm. The optically stimulated luminescence discussed in this report was monitored in the UV region and is presumed to be the same 360 nm emission that appears in the radioluminescence and thermoluminescence spectra. The glow curve shows at least three peaks at 74, 202, 432 oC for heating at 1 oC and the third one is a composite of two. Only the first two peaks are deduced to contribute most of the optically stimulated luminescence