Treatment of Agricultural Waste Using a Combination of Anaerobic, Aerobic, and Adsorption Processes

The generation of waste in agricultural and livestock industries, followed by inadequate treatment and uncontrolled disposal to natural recipients, results in significant environmental pollution. Thus, the efficient and integrated management of high-organic-load waste produced in such activities is a key factor for sustainability and the protection of aqueous matrices. In this work, we investigate an integrated management approach for the treatment of agricultural, high-organic-load waste via a combination of processes, with an ultimate goal to improve the characteristics of the final waste and enhance the valorization of the nutrients contained in it. Towards this direction, a waste mixture comprising pig waste, cheese dairy, and food residues was sequentially treated in a laboratory scale by anaerobic digestion, followed by activated sludge (aerobic–anoxic treatment), and last by adsorption using natural zeolite. The efficiency of two different adsorption routes was examined (magnetically agitated zeolite or packed zeolite column), while the effect of the granule sizes of zeolite (0–1 mm or 1.5–3 mm) was also evaluated with regards to the remediation of the final effluent. Excellent adsorption capacities were observed in all cases, with the larger-sized zeolite exhibiting a superior performance, while the granule size of zeolite significantly affected the lifetime of the packed columns, as the smaller-sized zeolite columns reached their saturation point faster than the larger-sized zeolite analogue. The average ammonium nitrogen removal in the column experiment was ~92%, while total phosphorus was ~68%, respectively. Overall, an almost complete remediation of the final effluent was observed when compared with the physicochemical parameters of the initial waste, with a ~96% chemical oxygen demand, ~79% total nitrogen, ~96% total phosphorus, and ~82% phenols concentration decrease, signifying the high performance of the sequential treatment strategy proposed herein

Treatment of Agricultural Waste Using a Combination of Anaerobic, Aerobic, and Adsorption Processes

The generation of waste in agricultural and livestock industries, followed by inadequate treatment and uncontrolled disposal to natural recipients, results in significant environmental pollution. Thus, the efficient and integrated management of high-organic-load waste produced in such activities is a key factor for sustainability and the protection of aqueous matrices. In this work, we investigate an integrated management approach for the treatment of agricultural, high-organic-load waste via a combination of processes, with an ultimate goal to improve the characteristics of the final waste and enhance the valorization of the nutrients contained in it. Towards this direction, a waste mixture comprising pig waste, cheese dairy, and food residues was sequentially treated in a laboratory scale by anaerobic digestion, followed by activated sludge (aerobic–anoxic treatment), and last by adsorption using natural zeolite. The efficiency of two different adsorption routes was examined (magnetically agitated zeolite or packed zeolite column), while the effect of the granule sizes of zeolite (0–1 mm or 1.5–3 mm) was also evaluated with regards to the remediation of the final effluent. Excellent adsorption capacities were observed in all cases, with the larger-sized zeolite exhibiting a superior performance, while the granule size of zeolite significantly affected the lifetime of the packed columns, as the smaller-sized zeolite columns reached their saturation point faster than the larger-sized zeolite analogue. The average ammonium nitrogen removal in the column experiment was ~92%, while total phosphorus was ~68%, respectively. Overall, an almost complete remediation of the final effluent was observed when compared with the physicochemical parameters of the initial waste, with a ~96% chemical oxygen demand, ~79% total nitrogen, ~96% total phosphorus, and ~82% phenols concentration decrease, signifying the high performance of the sequential treatment strategy proposed herein

Life cycle analysis for buildings and environmental impact

Περίληψη: Η παρούσα διπλωματική εργασία έχει τρεις στόχους: (α) Ο αρχικός στόχος επικεντρώνεται στην διεξαγωγή αποτελεσμάτων που αντικατοπτρίζουν τις περιβαλλοντικές επιπτώσεις που επιφέρει ένα κτίριο καθ’ όλη την διάρκεια ζωής του. (β) Ο δευτερεύον στόχος επικεντρώνεται στην αξιολόγηση των αποτελεσμάτων αυτών και συγκεκριμένα στον εντοπισμό τμημάτων του κτιρίου που πιθανολογείται ότι συμμετέχουν σε μεγάλο ποσοστό στην δημιουργία των περιβαλλοντικών επιπτώσεων αυτών. (γ) Ο απώτερος στόχος όμως, της διπλωματικής εργασίας επικεντρώνεται στην αντικατάσταση υλικών των τμημάτων που συνεισφέρουν περισσότερο στην δημιουργία επιπτώσεων, με σκοπό, την εύρεση του βέλτιστου συνδυασμού υλικών της κτιριακής κατασκευής προκειμένου να μειωθούν οι περιβαλλοντικές επιπτώσεις του κτιρίου. Ως μελέτη περίπτωσης χρησιμοποιήθηκε μία διώροφη μονοκατοικία η οποία σχεδιάστηκε στην περιοχή της Πολυτεχνειούπολης στον νομό Χανίων της Ελλάδας. Το εργαλείο ανάλυσης κύκλου ζωής που χρησιμοποιείται για την διεξαγωγή αποτελεσμάτων είναι το Athena Impact Estimator for Buildings. Με βάση αυτό το εργαλείο, ο χρήστης έχει την δυνατότητα να αναλύει τις επιπτωσεις της κατασκευής στο περιβάλλον. Οι επιπτωσεις προκύπτουν αθροιστικά, από όλα τα στάδια ζωής του κτιρίου, δηλαδή από το στάδιο παραγωγής που περιλαμβάνει την εξαγωγή της πρώτης ύλης από το περιβάλλον, την μεταφορά των πρώτων υλών, την διαδικασία οικοδόμησης του κτιρίου, την διαδικασία εγκατάστασης, την συντήρηση, τις επισκευές, την αντικατάσταση κάποιων υλικών, την ανακαίνιση, την λειτουργική ενεργειακή χρήση, την λειτουργική χρήση νερού έως το στάδιο λήξης ζωής του κτιρίου που περιλαμβάνει την αποκατάσταση κατεδάφισης, την μεταφορά, την επεξεργασία αποβλήτων και την απόρριψη. Πιο αναλυτικά, παρουσιάζεται η συνεισφορά του κάθε τμήματος στις συνολικές περιβαλλοντικές επιπτώσεις όσον αφορά τα κύρια περιβαλλοντικά προβλήματα του πλανήτη. Τα κύρια περιβαλλοντικά φαινόμενα είναι το δυναμικό θέρμανσης του πλανήτη, η κατανάλωση ορυκτών καυσίμων, το δυναμικό οξίνισης, η ρύπανση από αιωρούμενα σωματίδια, το δυναμικό καταστροφής του όζοντος και το δυναμικό πρόκλησης του ευτροφισμού. Με την παρουσίαση της συνεισφοράς του κάθε τμήματος ξεχωριστά στο συνολικό περιβαλλοντικό αποτύπωμα του κτιρίου έγινε αντιληπτό ποια επιμέρους στοιχεία του κτιρίου ήταν τα λιγότερο φιλικά προς το περιβάλλον και έτσι έγιναναλλαγές των υλικών κατασκευής με διάφορους συνδυασμούς, μέχρι να βρεθεί η καλύτερη δυνατή λύση. Η μοντελοποίηση για την λήψη δεδομένων της κατανάλωσης ενέργειας μετά την ολοκλήρωση του αρχιτεκτονικού σχεδιασμού και την επιλογή υλικών για την κατασκευή του κτιρίου πραγματοποιήθηκε με το λογισμικό OpenStudio.Summarization: The objective of this diploma thesis has triple importance. (a) The primary target focuses on conduction results that reflect the environmental impacts that any building can bring throughout its life. (b) The secondary objective focuses on assessing these results, and in particular identifying parts of the building which are very likely to be involved in creating these environmental impacts. (c) The ultimate aim of this document is associated with replacement of materials of the most impact-intensive parts and, more general, with the discovery of the optimum combination of construction materials, which are contributed to reduction of the environmental impact of the building. This building consists of two-storey detached house, which has been designed in the area of ​​the Technical University of Crete in Chania, Greece. The Life Cycle Analysis tool used to conduct the results is Athena Impact Estimator for Buildings. Based on Life Cycle Analysis tool, the user has the ability to simulate a building after designing it. The actions taken by the user concern the registration of dimensions, building materials and energy consumptions. The geometry of the building was created using the SketchUp and the Autocad software. In addition, the house was modeled in OpenStudio to receive energy consumption data after the architectural design has been completed and the materials used for the construction of the building were selected. Furthermore, after the data entry and the simulation of the building in software the charge of the building against the environment was resulted.This burden arises cumulatively for all life building stages, concluding the production stage, which includes the extraction of the raw material from the environment, the transport of raw materials, the process of construction of the building, the installation process, the maintenance, repair, replacement of threadbare materials, refurbishment, functional energy use, functional use of water up to the end-of-life stage of the building including demolition restoration, transportation, waste treatment and disposal. More specifically, it contains the contribution of each department to the overall environmental impact of the building towards to environmental problems of the planet. The main environmental phenomena are global warming, fossil fuel consumption, acidification, particulate potential, ozone depletion and the Eutrophication potential. By presenting the contribution of each section separately to the overall environmental impact of the building, it is perceived which "parts" of the building were the least environmentally friendly and thus were made some changes according to the building materials. Those were found in these parts of the building in various combinations until the best possible solution was found