Phytoremediation of persistent organic pollutants

Toxicity, chemical stability, bioaccumulation, and long-range transport of persistent organic pollutants (POPs) cause environmental and human health hazards, and demand the cleanup of remnants from previous applications. Phytoremediation uses living higher plants for the removal and biochemical decomposition of environmental pollutants and became a front-runner among cleanup technologies. The efficiency of plants as detoxifiers, filters or traps has been proven in cleaning up soils polluted with crude oil, explosives, landfill leachates, metals, pesticides, and solvents. Although phytoremediation of POPs is made very difficult by their low bioavailability, recent literature indicated that some plants (primarily those belonging to the Cucurbitaceae family) are capable of taking up significant amounts of POPs and accumulate them in their tissues. A joint French-Hungarian research project will investigate the possibility of phytoremediation of POP

Glutathione Is a Key Player in Metal-Induced Oxidative Stress Defenses

Since the industrial revolution, the production, and consequently the emission of metals, has increased exponentially, overwhelming the natural cycles of metals in many ecosystems. Metals display a diverse array of physico-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can lead to toxicity and oxidative stress when taken up in excessive amounts, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants possess defense strategies in which glutathione (GSH; γ-glu-cys-gly) plays a central role as chelating agent, antioxidant and signaling component. Therefore, this review highlights the role of GSH in: (1) metal homeostasis; (2) antioxidative defense; and (3) signal transduction under metal stress. The diverse functions of GSH originate from the sulfhydryl group in cysteine, enabling GSH to chelate metals and participate in redox cycling

Coupled aquaponics systems

Coupled aquaponics is the archetype form of aquaponics. The technical complexity increases with the scale of production and required water treatment, e.g. filtration, UV light for microbial control, automatic controlled feeding, computerization and biosecurity. Upscaling is realized through multiunit systems that allow staggered fish production, parallel cultivation of different plants and application of several hydroponic subsystems. The main task of coupled aquaponics is the purification of aquaculture process water through integration of plants which add economic benefits when selecting suitable species like herbs, medicinal plants or ornamentals. Thus, coupled aquaponics with closed water recirculation systems has a particular role to fulfil. Under fully closed recirculation of nutrient enriched water, the symbiotic community of fish, plants and bacteria can result in higher yields compared with stand-alone fish production and/or plant cultivation. Fish and plant choices are highly diverse and only limited by water quality parameters, strongly influenced by fish feed, the plant cultivation area and component ratios that are often not ideal. Carps, tilapia and catfish are most commonly used, though more sensitive fish species and crayfish have been applied. Polyponics and additional fertilizers are methods to improve plant quality in the case of growth deficiencies, boosting plant production and increasing total yield. The main advantages of coupled aquaponics are in the most efficient use of resources such as feed for nutrient input, phosphorous, water and energy as well as in an increase of fish welfare. The multivariate system design approach allows coupled aquaponics to be installed in all geographic regions, from the high latitudes to arid and desert regions, with specific adaptation to the local environmental conditions. This chapter provides an overview of the historical development, general system design, upscaling, saline and brackish water systems, fish and plant choices as well as management issues of coupled aquaponics especially in Europe

Hydroponic technologies

This open access book, written by world experts in aquaponics and related technologies, provides the authoritative and comprehensive overview of the key aquaculture and hydroponic and other integrated systems, socio-economic and environmental aspects. Aquaponic systems, which combine aquaculture and vegetable food production offer alternative technology solutions for a world that is increasingly under stress through population growth, urbanisation, water shortages, land and soil degradation, environmental pollution, world hunger and climate change.Hydroponics is a method to grow crops without soil, and as such, these systems are added to aquaculture components to create aquaponics systems. Thus, together with the recirculating aquaculture system (RAS), hydroponic production forms a key part of the aqua-agricultural system of aquaponics. Many different existing hydroponic technologies can be applied when designing aquaponics systems. This depends on the environmental and financial circumstances, the type of crop that is cultivated and the available space. This chapter provides an overview of different hydroponic types, including substrates, nutrients and nutrient solutions, and disinfection methods of the recirculating nutrient solutions

Rola wiedzy i technologii w zakresie bezpieczeństwa żywności w szkole gastronomicznej na Węgrzech

Providing the population with safe and good quality food is one of the most important objectives of every country. The outbreak and spread of foodborne diseases is independent of a country’s location or development level, and may occur everywhere. As most children spend their days at educational institutions, we shall focus on their food safety. Not only for their present state of health, but also because childhood nutrition and diet will basically determine their health in their adulthood and thus, influence the future economic and social performance of their society. This paper introduces background information about school catering in Hungary, based upon the results of an overall food safety survey. The results of our research showed that the food safety level of the different kitchen units is mostly determined by the level of food processing activities. The technical and technological level of the school kitchens did not significantly influence the food safety level of the kitchens. According to the results of our survey, improving the knowledge and the attitudes of employees in school kitchens is more important than technical and technological conditions.W pracy przedstawiono informacje na temat żywienia w placówkach szkolnych na Węgrzech, oparte na wynikach ogólnej ankiety dotyczącej bezpieczeństwa żywienia. Zapewnienie ludności bezpiecznej żywności o dobrej jakości jest najwyższym priorytetem każdego kraju. Ponieważ większość dzieci spędza swoje dzieciństwo w placówkach dydaktycznych należy skupić się na bezpieczeństwie serwowanej w nich żywności. Nie tylko ze względu na obecny stan zdrowia dzieci, ale również dlatego że odżywianie w znacznym stopniu determinuje zdrowie młodych ludzi, co wpływa na przyszłe osiągnięcia ekonomiczne i socjalne danej społeczności. Wyniki badania wykazały, że poziom bezpieczeństwa żywienia w różnych stołówkach zależaqł przede wszystkim od poziomu przetworzenia żywności. Poziom techniczny i technologiczny kuchni szkolnych nie wpłynął w znaczący sposób na poziom bezpieczeństwa żywności w nich przygotowywanej. Zgodnie z wynikami ankiety, zwiększanie wiedzy i świadomości pracowników szkolnych kuchni było ważniejsze niż warunki techniczne i technologiczne

Protecting plants from pests and diseases in aquaponic systems

This paper gives an overview on aquaponics - a new, emerging food production technology. We point out to the social, economic, and environmental advantages of aquaponic systems, as well as to their complexity, in relation to plant nutrition and fish and plant health, and pest control. Furthermore, environmental aspects and connections to circular economy based on sustainable ecological cycles in aquaponic systems is discussed. We conclude that, in order to produce healthy plants in aquaponic systems, 1) special care has to be taken via uninterrupted measurements of the chemical composition of the circulating water, to maintain proper levels and proportions of nutrients, 2) special consideration has to be given to the potentially toxic constituent, ammonia, and 3) the prevention, monitoring, and rapid identification of the pest(s) and disease(s), and their efficient control have to be prioritized. Application of aquaponic systems in urban agriculture might be both environmentally and economically profitable by enhancing local production, utilizing unused, often derelict buildings, creating jobs and recirculating water and other natural resources linked to renewable energy production and waste management