Membránové kontaktory a jejich aplikační potenciál

Nowadays, due to the scarcity of natural resources, there is more pressure on the reuse of materials and the application of circular economy principles. For this purpose, increasingly efficient and energy-saving technologies capable of extracting valuable raw materials from waste streams are needed, thus reducing energy and material dependence on primary resources. One such innovative technology is represented by membrane contactors, which enable mass sharing without the need for phase dispersion within each other, thus achieving lower operational and space requirements, as compared to conventional mass sharing devices (e.g. packed bed, tower column or stirred bed reactors). In addition, membrane contactors are very versatile and can be used not only for the recovery of valuable materials from waste streams in waste management processes (in particular recycling of metals or organics), but also as life-saving devices in biomedical applications (e.g. as extracorporeal blood oxygenation devices).

Farm to Institution to Farm: Circular Food Systems With Native Entomoculture

Edible insects recycle food waste, which can help feed a hungrier planet by making food systems more circular and diversifying protein production. The potential for entomophagy (i.e., insect cuisine) to contribute to waste recycling and lower input food production is only beginning to be explored in the U.S., although insects have been consumed by people for millennia in a wide range of cultures. In this perspective piece, we consider as a case study the potential for university foodservice programs in New England to serve as incubators for circular entomophagous food systems. Students are likely early adopters of entomophagy because they increasingly demand sustainable non-meat protein options. University foodservices meanwhile purchase large amounts of food wholesale from local producers, utilize standardized pre-processing, and generate consistent waste streams which may be valuable feed for local insect farmers. Current Farm to Institution approaches strengthen regional food systems by connecting small farmers with university foodservices; we argue that a similar model (Farm to Institution to Farm) could support establishment of local insect farms, introduce edible insects to a relatively receptive base of university student customers, and provide a more sustainable mechanism for repurposing university food waste as insect feed. But to enable this type of food system, additional requirements include: (1) research on domestication of native insect species; (2) investment in processing capacity, ensuring new insect farmers have reliable markets for raw insect products; (3) infrastructure to recirculate waste streams within existing food systems; and (4) creation of recipes that entice new insect consumers.

Fit for the Future: Garment Quality and Product Lifetimes in a CE Context

The fashion industry is one of the most polluting industrial sectors in the world and its environmental impacts are huge. Garments are produced effectively at a low price, are of low quality, and are used for a very short time before ending up in increasing textile waste streams. One critical aspect in this context is the lifetime of a garment. Short garment lifetimes are the results of low quality and consumer dissatisfaction, or consumers’ constant search for newness, resulting in the early disposal of garments. This study focused on the issue of garment quality and how it can be connected to product lifetime. The research used a case study approach, including company interviews about working for quality, and aimed to expand on the topic of how quality impacts product lifetimes. Data analysis was conducted according to the principles of descriptive analysis and the discussion expanded to the circular economy context, creating an extended understanding of garment quality in a circular economy.

Study on Spinnability of Arabinoxylan Extracted From Barley Husks

Valorisation of bio-based materials derived from agricultural and industrial side-streams or waste-streams is a basis of circular economy. However, the success of it depends on the full understanding of materials and finding their optimal way of processing. Barley husk is a side-stream waste material derived from the starch and ethanol production. This study is focused on the processability of the arabinoxylan extracted from barley husk using the electrospinning technique to produce thin xylan-poly(vinyl alcohol) fibers. As a comparison, lignin-free xylan of beech wood was used. The properties of spinning solutions and resulting nanofibrous mats were assessed by using rheological measurements, FTIR spectroscopy, scanning electron microscopy and contact angle measurements. It was found that solubility plays a crucial role in the spinnability of xylan extracts. Decrease in viscosity of arabinoxylan achieved by decreasing its concentration was found to improve the jet stability but at the same time, to reduce the diameter of spun fibre. Hydrophilicity of nanofibrous mats were strongly affected by the type of xylan and solvent used.

Methods of Thermal Treatment of Radioactive Waste

Throughout the world, and especially in the European Union, numerous technologies for the thermal treatment of radioactive waste are available or being developed. These technologies can be applied to a large range of different radioactive waste streams, including non-standard types of waste that present specific waste management challenges. Thermal treatment can result in a significant reduction in volume and hazard, which are beneficial for safe storage and disposal. Thermal treatment also removes organic material that can form complexing agents and increase the mobility of radionuclides in the landfill. In the paper, basic thermal techniques are presented, and some examples of the installations are shown. Common knowledge of these methods may result in an increased public acceptance of nuclear energy in a country just introducing it, as Poland is.

Fate of influent microbial populations during medium chain carboxylic acid recovery from brewery and pre-fermented food waste streams

Waste streams continuously introduce active and inactive microbial populations that can influence assembly of microbial communities in chain elongation systems.

Biological Desulfurization of Tannery Effluent Using Hybrid Linear Flow Channel Reactors

The tanning process generates a saline effluent with high residual organics, sulfate and sulfide concentrations. The transition from a linear to circular economy requires reimagining of waste streams as potential resources. The organics in tannery effluent have the potential to be converted to renewable energy in the form of biogas if inhibitors to anaerobic digestion are removed. Hybrid linear flow channel reactors inoculated with culture-enriched halophilic sulfate reducing bacteria from saline environments were evaluated as a novel pretreatment step prior to anaerobic digestion for the concurrent removal of sulfur species and resource recovery (elemental sulfur and biogas). During continuous operation of a 4-day hydraulic retention time, the reactors were capable of near-complete sulfide oxidation (>97%) and a sulfate reduction efficiency of 60–80% with the formation of a floating sulfur biofilm containing elemental sulfur. Batch anaerobic digestion tests showed no activity on untreated tannery effluent, while the pretreated effluent yielded 130 mL methane per gram COD consumed.