Sustainable agriculture is currently trendy. It is supported not only for the urban environment but also as an innovation of conventional practices in order to increase the efficiency and quality of agricultural production. This study presents the results achieved within selected soil-less (hydroponic and aeroponic) systems. Then, it compares them, using the tool of comparative life cycle assessment (LCA), with the results of soil cultivation. The attention is directed towards biomass production and the content of bioactive substances, which can compensate for higher operating costs of soil-less cultivation systems. Coffea arabica has shown a significant increase of caffeine and theobromine contents, both in leaves and roots, as well as higher biomass yield during the aeroponic cultivation. On the contrary, Senecio bicolor evinced the results of a considerably increased growth in the hydroponic system, with no higher contents of alkaloid or flavonoids, except for the rutin concentration. The LCA results of the compared soil and soil-less systems showed that the consumption of fertilizers, diesel, and water in soil systems and of conventional electricity in aeroponics and hydroponics contributed mostly to their environmental burden. The major environmental impact categories are terrestrial ecotoxicity, human non-carcinogenic toxicity, and global warming. Therefore, in order to make the soil-less cultivation systems sustainable, these environmental aspects need to be considered deeply.
Volatile organic compounds are a broad and important class of pollutants affecting the indoor air quality. They are emitted from commercial products, building materials, furniture, occupant activities and even occupants, etc., and can participate in the indoor chemistry reacting with oxidants or being formed from secondary reactions. Some VOCs are classified as carcinogens and are associated with a variety of health effects. Characterizing and quantifying the VOCs in the indoor environments is of paramount importance in order to implement preventive measures to minimize the human exposure. A correct assessment of human exposure or characterization of emission sources and indoor activities requires appropriate and efficient methods for sampling and analysis. Therefore, this review focuses on the different methodologies for monitoring VOC that must be selected when a sampling plan is designed considering the objective of the measure. Selecting the most suitable procedures for assessing VOCs requires proper knowledge on the existing standards and off-line (including the selection of the sorbent media) and online instrumentation. Knowing the advantages and drawbacks of the different techniques available can help to plan future studies.
1 December 2017 in Science of The Total Environment
This study is focused on technology development for microplastic removal from wastewater using a sorption process, which would be suitable not only as a tertiary stage of purification in wastewater treatment plants but also for other waters, e.g., process water and surface water. Therefore, cheap natural materials such as zeolites and bentonites were tested as possible sorbents. This study aims not only at sorbent selection but also at their possible modification by a special water regime improving sorption efficiency and lifetime. Microplastic particles of the majority of common types of plastics were prepared by a newly developed abrasion technique from various plastic items used at home, thus microplastic particle sizes and shapes corresponded to the real microplastics found in waters. Based on results with high reproducibility, a novel method for microplastic characterization based on Raman spectroscopy in combination with SEM/EDX was developed. The removal of microplastics from waste water was tested not only at the laboratory scale but also in a developed semi-operational sorption unit at a real wastewater treatment plant throughout the year with the efficiency of over 90%.