No abstract

No abstract

The availability of mineral fertilizers is becoming more challenging in the future. In source separated human urine, nutrient ratio is suitable for fertilizer use and nutrients are readily available for plants. In this study the aim was to acquire scientific data of the environmental impacts and nutrient potentials of wastewater separating systems, i.e. urine and blackwater source separation. At the same time, general acceptance on the use of human urine in agriculture wanted to be improved. In addition, the value of urine as a fertilizer was calculated. The focus of the study was on rural areas but comparison between different systems included also the nutrient potential of urban areas as well. Based on the results, human urine was found to be an environment friendly fertilizer. Applying source-separation systems in rural areas, four times more phosphorus and over thirty times more nitrogen could be recovered compared to the current wastewater treatment system. Furthermore, eutrophication impact is reduced to one fifth. However there is a risk of increased soil acidification but it can be minimized with advanced spreading techniques, like deep injection. The results of this study support the use of source-separation technologies for nutrient recovery.

Several time-use studies in engineering education have shown that students use less time studying than has been allocated in the curricula. It is questionable whether a scarce use of time can lead to deeper understanding and the ability to apply knowledge in problem-solving. The alarming results from earlier time-use studies led to a search for answers to the following questions: How much time do first-year engineering students use for their studies and other activities? Do they spend enough time on studying and other learning activities? Is their time use in agreement with the curriculum? What learning outcomes and grades do students achieve from their studying efforts? Factors that influence student time use and approaches to learning are discussed. A deep approach to learning is desirable and is seen to support comprehension and lead to better learning outcomes. Learning approaches that students choose are both student-related and influenced by the learning environment. How can the learning environment be designed so that students are motivated to assume a deep approach to learning and devote more time and effort to out-of-class studying? Answers to these questions will be helpful for teachers, tutors, teacher educators and designers of curricula, as well as students themselves.

No abstract