74 research outputs found
Co-liquefaction of Macroalgae with Common Marine Plastic Pollutants
Macroalgal blooms are environmentally problematic and costly to remediate, but they also represent a vast untapped resource for the production of renewable chemicals and fuels. The responsible exploitation of such marine resources will become increasingly prominent in the transition away from the crude oil economy that currently dominates global productivity. However, crude oil-derived plastic pollution is now a ubiquitous presence in the marine environment, which hampers the effective conversion of marine feedstocks. If the full potential of macroalgae is to be realized, any large-scale industrial process will need to accommodate the presence of this plastic. This study, for the first time, aimed to assess the effect of several common marine plastic pollutants on the hydrothermal liquefaction (HTL) of four UK macroalgae species and determine the impact on the major HTL products and biocrude oil quality. Coliquefaction of polyethylene and polypropylene with L. digitata, U. lactuca, F. serratus, and S. muticum led to modest synergistic effects for plastic conversion. Under hydrothermal conditions, polyethylene underwent fragmentation to olefinic species, as well as oxidative depolymerization to form ketones. Modest synergistic effects on biocrude production were also observed for polypropylene, which depolymerized more readily in the presence of biomass to form gaseous propylene as well as oil-phase products. In both cases, the presence of plastics increased total biocrude carbon content, decreased nitrogen, and boosted higher heating value (HHV), constituting an overall improvement in biocrude fuel properties. Alternatively, nylon-6, typically originating from fisheries debris, depolymerized almost entirely under HTL conditions to form caprolactam, which partitioned mainly to the aqueous phase. While this is not favorable for biocrude production, the reclamation of marine nylon debris for hydrothermal processing to monomers may present a promising revenue stream in future biorefineries. The results demonstrate that plastic contaminants may well represent an opportunity, rather than a threat, to the successful development of an HTL macroalgal biorefinery
Assessing hydrothermal liquefaction for the production of bio-oil and enhanced metal recovery from microalgae cultivated on acid mine drainage
The hydrothermal liquefaction (HTL) of algal biomass is a promising route to viable second generation biofuels. In this investigation HTL was assessed for the valorisation of algae used in the remediation of acid mine drainage (AMD). Initially the HTL process was evaluated using Arthrospira platensis (Spirulina) with additional metal sulphates to simulate metal remediation. Optimised conditions were then used to process a natural algal community (predominantly Chlamydomonas sp.) cultivated under two scenarios: high uptake and low uptake of metals from AMD. High metal concentrations appear to catalyse the conversion to bio-oil, and do not significantly affect the heteroatom content or higher heating value of the bio-oil produced. The associated metals were found to partition almost exclusively into the solid residue, favourable for potential metal recovery. High metal loadings also caused partitioning of phosphates from the aqueous phase to the solid phase, potentially compromising attempts to recycle process water as a growth supplement. HTL was therefore found to be a suitable method of processing algae used in AMD remediation, producing a crude oil suitable for upgrading into hydrocarbon fuels, an aqueous and gas stream suitable for supplementing the algal growth and the partitioning of most contaminant metals to the solid residue where they would be readily amenable for recovery and/or disposal
Risk factors for the development of bronchopulmonary pathology in workers producing synthetic polyacrylonitrile fiber
Aim of the study was to assess the risk of bronchopulmonary pathology in workers of the production of synthetic polyacrylonitrile fiber as a result of exposure to harmful chemicals and smoking tobacco products. Material and methods. During the periodic medical examination, the function of external respiration and adherence to smoking in 137 employees were studied, medical records were analyzed (025/u accounting form). Hygienic assessment of working conditions was carried out on the basis of the results of in-situ sanitary and hygienic studies. Results and discussions. As a result of a hygienic assessment of working conditions, it was found that workers engaged in the production of polyacrylonitrile fiber are subject to the combined intermittent effects of harmful chemicals of hazard classes 1–3 (acrylonitrile, methyl acrylate, hydrocyanide, ammonia, sodium rhodanide, sulfuric acid, methanol, isopropyl alcohol, ethylene glycol), the content of which in the working area exceeded the maximum permissible concentrations in 1.6% of samples. The occupational risk of developing bronchopulmonary diseases in groups of workers who smoke is assessed as unacceptably high, while in people exposed to harmful chemicals, its level is 28.46 times higher than in people who are not exposed to these effects. The risk of the formation of ventilation disorders in groups of smoking workers is unacceptably high, while its level is 2.46 times higher in workers exposed to harmful chemicals than in non-workers in such conditions. In groups of workers exposed to harmful chemicals, the occupational risk of obstructive disorders is unacceptably high, in the group of smokers the risk is 2.32 times higher. Conclusions. Among the employees of the enterprise producing synthetic polyacrylonitrile fiber, the influence of tobacco smoking on the development of bronchopulmonary pathology is higher than the influence of harmful working conditions, and the use of smoking tobacco products significantly increases the negative effect of chemical pollutants
Towards a marine biorefinery through the hydrothermal liquefaction of macroalgae native to the United Kingdom
Hydrothermal liquefaction (HTL) is a promising biomass conversion method that can be incorporated into a biorefinery paradigm for simultaneous production of fuels, aqueous fertilisers and potential remediation of municipal or mariculture effluents. HTL of aquatic crops, such as marine macro- or microalgae, has significant potential for the UK owing to its extensive coastline. As such, macroalgae present a particularly promising feedstock for future UK biofuel production. This study aimed to bridge the gaps between previous accounts of macroalgal HTL by carrying out a more comprehensive screen of a number of species from all three major macroalgae classes, and examining the correlations between biomass biochemical composition and HTL reactivity. HTL was used to process thirteen South West UK macroalgae species from all three major classes (Chlorophyceae, Heterokontophyceae and Rhodophyceae) to produce bio-crude oil, a bio-char, gas and aqueous phase products. Chlorophyceae of the genus Ulva generated the highest bio-crude yields (up to 29.9% for U. lactuca). Aqueous phase phosphate concentrations of up to 236 mg L−1 were observed, obtained from the Rhodophyta, S. chordalis. Across the 13 samples, a correlation between increasing biomass lipids and increasing bio-crude yield was observed, as well as an increase in biomass nitrogen generally contributing to bio-crude nitrogen content. A broader range of macroalgae species has been examined than in any study previously and, by processing using identical conditions across all feedstocks, has enabled a more cohesive assessment of the effects of biochemical composition
Logistic outsourcing in pharmacy. the theory and practice
Today, the introduction and application of a logistics approach to resource management allows pharmaceutical companies to increase their social, environmental and economic efficiency.
The article is aimed to research the essence of the concept, types and party of logistic outsourcing in practical pharmacy. To reach the aimreview of foreign and domestic scientific sources and the existing legal framework of Ukraine on this issue have been analyzed. Investigation methods were bibliographic and analytical ones.
The results of these studies indicate the today outsourcing is one of the main logistics strategies of domestic pharmaceutical companies, which is actively used in the sphere of IT-technologies and warehouse services. At the same time for ensuring high-quality providing outsourcing services, a legal and regulatory framework is needed that standardizes the interaction between firm customer and the outsourcer, also the development of standards for the provision of services of a certain type of outsourcing. Wide introduction of logistics outsourcing, as a modern form of optimization of logistics business processes, requires the formation of professional competence among future pharmacists in pharmaceutical logistics, its tools and strategies, i.e. training of competitive professionals capable of working in various directions of practical pharmacy.
Introduction of the topic «Logistic outsourcing in practical pharmacy» in the educational process of students of pharmaceutical faculties (university), pharmacists-interns and pharmacists at the postgraduate level of training is necessary. It will improve the theoretical and practical training of future specialist pharmaceutists and will allow them to apply the knowledge which would be gained in the future in logistics outsourcing in the activities of pharmaceutical companies
Improving electrocoagulation floatation for harvesting microalgae
Electro-coagulation floatation (ECF) is a foam-floatation dewatering method that has been shown to be a highly effective, rapid, and scalable separation methodology. In this manuscript, an in-depth analysis of the gas and flocculant levels observed during the process is provided, with microbubbles observed in the 5–80μm size range at a concentration of 102–103 bubbles mL−1. Electrolysis of microalgae culture was then observed, demonstrating both effective separation using aluminium electrodes (nine microalgal species tested, 1–40μm size range, motile and non-motile, marine and freshwater), and sterilisation of culture through bleaching with inert titanium electrodes. Atomic force microscopy was used to visualise floc formation in the presence and absence of algae, showing nanoscale structures on the magnitude of 40–400nm and entrapped microalgal cells. Improvements to aid industrial biotechnology processing were investigated: protein-doping was found to improve foam stability without inducing cell lysis, and an oxalate buffer wash regime was found to dissolve the flocculant whilst producing no observable difference in the final algal lipid or pigment profiles, leaving the cells viable at the end of the process. ECF separated microalgal culture had an algal biomass loading of 13% and as such wasideal for direct down-stream processing through hydrothermal liquefaction. Highbio-crude yieldswere achieved, though this was reduced slightly on addition of the Al(OH)3 after ECF, with carbon being distributed away to the aqueous and solid residue phases. The amenability and compatibility of ECF to integration with, or replacement of, existing centrifugation and settling processes suggests this process may be of significant interest to the biotechnology industry
Organic waste as a sustainable feedstock for platform chemicals
Biorefineries have been established since the 1980s for biofuel production, and there has been a switch lately from first to second generation feedstocks in order to avoid the food versus fuel dilemma. To a lesser extent, many opportunities have been investigated for producing chemicals from biomass using by-products of the present biorefineries, simple waste streams. Current facilities apply intensive pre-treatments to deal with single substrate types such as carbohydrates. However, most organic streams such as municipal solid waste or algal blooms present a high complexity and variable mixture of molecules, which makes specific compound production and separation difficult. Here we focus on flexible anaerobic fermentation and hydrothermal processes that can treat complex biomass as a whole to obtain a range of products within an integrated biorefinery concept
The tetanic depression in fast motor units of mammalian skeletal muscle can be evoked by lengthening of one initial interpulse interval
A lower than expected tetanic force (the tetanic depression) is regularly observed in fast motor units (MUs) when a higher stimulation frequency immediately follows a lower one. The aim of the present study was to determine whether prolongation of only the first interpulse interval (IPI) resulted in tetanic depression. The experiments were carried out on fast MUs of the medial gastrocnemius muscle in cats and rats. The tetanic depression was measured in each case as the force decrease of a tetanus with one IPI prolonged in relation to the tetanic force at the respective constant stimulation frequency. Force depression was observed in all cases studied and was considerably greater in cats. For cats, the mean values of force depression amounted to 28.64% for FR and 10.86% for FF MUs whereas for rats 9.30 and 7.21% for FR and FF motor units, respectively. Since the phenomenon of tetanic depression in mammalian muscle is commonly observed even after a change in only the initial interpulse interval within a stimulation pattern, it can effectively influence processes of force regulation during voluntary activity of a muscle, when motoneurones progressively increase the firing rate
- …