RESUMEN

Rapid drying, cost-effective and safe, will increase the viability of using microalgae for several bio-industrial applications. In this study, five different drying techniques of microalgal biomass were investigated. These include freeze drying, oven drying, air drying, sun drying, and microwave drying. Morphology, metabolite content, FAME profiling, chlorophyll content, total organic carbon, and total nitrogen were analyzed. Results showed that the freeze-drying technique preserves the highest amounts of chlorophyll, proteins, and lipids. Oven drying underperformed as it retained the lowest amount of chlorophyll, protein, and lipid content. More importantly, FAME profiling results showed that air drying was the best technique in maintaining the highest amount of polyunsaturated fatty acids and more specifically docosahexaenoic acid (DHA). Furthermore, this process requires the least capital and energy needs. The findings from this study confirmed that the drying technique affects the microalga biomass quality.

RESUMEN

Rapid industrial development, mega construction projects and increased immigration are some of the reasons that the State of Qatar has recently generated an unprecedented amount of construction and demolition (C&D) waste in the country. The State is racing towards the Fédération Internationale de Football Association World Cup 2022, a fact that requires additional construction, for which it is expected to increase its rate of waste generation. Compared to other regions, there are relatively few studies in the literature that report on the C&D waste management issues of Qatar. The present work begins to address this gap by providing insights into the current state of C&D waste management practices in Qatar and by providing a mini-review on the benefits of using recycled aggregates which have only recently been allowed locally by Qatar Construction Standards. A Strengths, Weaknesses, Opportunities, and Threats analysis has been implemented, using data and information from various sources including governmental reports, industries, local waste management companies, as well as reported interviews with relevant stakeholders. Finally, several strategies were proposed and developed that could potentially be implemented by stakeholders and decision-makers, so as to improve the current status by encouraging more sustainable and viable practices.

Asunto(s)

Industria de la Construcción , Administración de Residuos , Materiales de Construcción , Residuos Industriales , Reciclaje

RESUMEN

The Qatar's national vision (QNV2030) underlines an unequivocal commitment to maintaining harmony between the three inter-dependent pillars of sustainable development: economic growth, social development and environmental management. Nonetheless, it seems that the country is set on a trajectory of unparalleled and rapid development that most waste management and environmental experts would, possibly, characterise as unsustainable; in addition it seems to repeat many of the "errors" that have been made in other parts of the world, including, for example, a lack of developed recycling and waste management infrastructure. The average Municipal Solid Waste (MSW) generation rate per capita in the Gulf Co-operation countries (GCC) reaches almost 1.5 kg/person/d, with the State of Qatar being close to 1.4 kg/person/d during the past years, thereby ranking the Gulf States as some of the highest waste generating countries globally. Plastics, accounting for approx. 13-14% of the total MSW (in these countries), present both a significant amount as well as a valuable resource to be recovered. In the present work, the authors attempt to delineate the plastic recovery status, based on the current waste management and recycling infrastructure existing and operating in Qatar, outlying the drawbacks, but at the same time highlighting the potential opportunities and benefits in developing the waste management and recovery sector in the country.