An alternative on-site wastewater treatment and disposal system (OSWTDS) consisting of a soil infiltrator with low pressure distribution was evaluated in a soil that was unsuitable for a conventional OSWTDS under current Commonwealth of Virginia Sewage Handling and Disposal Regulations, due to a shallow seasonally perched water table and low hydraulic conductivity. The absorption field consisted of two subsystems numbered as 1 and 2 with effluent design loading rates of 5.1 and 10.2 Lpd/m2, respectively (actual loading rates of 2.4 and 4.9 Lpd/m2, respectively). Soil matric potentials compared seasonally for each subsystem and indicated that both provided similar hydraulic performance. Background water quality was generally improved by subsurface movement through the absorption fields. A bacterial tracer was found in shallow (45.7 cm) and deep (213.4 cm) sampling wells within 24 h in the two subsystems (but in low numbers) over both summer and winter sampling periods. A viral tracer was detected within 48 h in both shallow and deep wells, but only in subsystem 2 in the winter. In evaluating denitrification potential, the addition of glucose to soil core samples did increase quantitatively, although not significantly, nitrous oxide production in each subsystem, at each depth, during each season. Overall, the performance of both subsystems was very similar. The soil infiltrator functioned very well, as designed for the site and soil limitations. It appears to be a potential alternative OSWTDS for use in problem soils. / Master of Science

Deep well injection into non-potable saline aquifers of treated domestic wastewater has been used in Florida for decades as a safe and effective alternative to ocean outfall disposal. The objectives of this study were to determine the fate and transport of injected wastewater at two deep well injection sites in Miami Dade County, Florida, USA. Detection of ammonium in the Middle Confining units of the Floridan aquifer above the injection zone at both sites has been interpreted as evidence of upward migration of injected wastewater, posing a risk to underground sources of drinking water. Historical water quality data, including ammonia, chloride, temperature, and pH from existing monitoring wells at both sites from 1983 to 2008, major ions collected monthly from 2006 and 2008, and a synoptic sampling event for stable isotopes, tritium, and dissolved gases in 2008, were used to determine the source of ammonium in groundwater and possible migration pathways. Geochemical modeling was used to determine possible effects of injected wastewater on native water and aquifer matrix geochemistry. Injected wastewater was determined to be the source of elevated ammonium concentrations above ambient water levels, based on the results of major ion concentrations, tritium, dissolved noble gases and 15N isotopes analyses. Various possible fluid migration pathways were identified at the sites. Data for the south site suggest buoyancy-driven vertical pathways to overlying aquifers bypassing the confining units, with little mixing of injected wastewater with native water as it migrated upward. Once it is introduced into an aquifer, the injectate appeared to migrate advectively with the regional groundwater flow. Geochemical modeling indicated that CO2 -enriched injected wastewater allowed for carbonate dissolution along the vertical pathways, enhancing permeability along these flowpaths. At the north site, diffusive upward flow through the confining units or offsite vertical pathways were determined to be possible, however no evidence was detected for any on-site confining unit bypass pathway. No evidence was observed at either site of injected wastewater migration to the Upper Floridan aquifer, which is used as a municipal water supply and for aquifer storage and recovery.

No description available.

No description available.

The survival of three enteroviruses (polio 1, coxsackie B3 and echo 1) and a rotavirus (SA-11) was studied under laboratory conditions. The effects of temperature, dissolved oxygen, detention time, sludge source and virus type on virus inactivation were determined. Temperature was the single most important factor influencing the rate of virus inactivation. No significant differences were found for virus inactivation rates at dissolved oxygen levels between 0.9 and 5.8 mg/l. However, the inactivation rate of the viruses under aerobic conditions was found to be significantly greater than the inactivation rate under anaerobic conditions (−0.77log10/day vs −0.33 log10/day). Sludge source, detention time and virus type did not significantly influence the rate of virus inactivation.

No description available.

Οι ροές φλεβών άνωσης έχουν πολύ μεγάλο ενδιαφέρον στην περιβαλλοντική υδραυλική και στη μηχανική των ρευστών, επειδή παρουσιάζονται σε αρκετά φαινόμενα που σχετίζονται με τη διάθεση υγρών αποβλήτων ή θερμών νερών σε υδάτινους αποδέκτες καθώς επίσης και την εκπομπή αερίων ενώσεων από καμινάδες στην ατμόσφαιρα. Στην παρούσα διατριβή διπλώματος ειδίκευσης μελετήθηκε η ανάπτυξη ενός μοντέλου που περιγράφει το φαινόμενο της αλληλεπίδρασης φλεβών από διαχύτη τύπου ροζέτας. Η ροζέτα προσομοιώνεται με ένα κύκλο στον οποίο είναι εγγεγραμμένο κανονικό πολύγωνο Ν πλευρών, στις κορυφές του οποίου εδράζονται τα Ν κατακόρυφα ακροφύσια. Λόγω γεωμετρικής και υδραυλικής συμμετρίας του φαινομένου, μελετάται η μία φλέβα από την ομάδα των Ν φλεβών που συμμετέχουν. Η μέση ροή και η μεταφορά μάζας σε μία τέτοια φλέβα περιγράφονται από την ολοκλήρωση των εξισώσεων συνέχειας, ορμής και διάχυσης. Επίσης, έγινε η σύγκριση μεταξύ του συγκεκριμένου μοντέλου και δεδομένων από τη σχετική βιβλιογραφία. Σκοπός της εργασίας, είναι η ανάπτυξη ενός μοντέλου που να περιγράφει το πεδίο ταχυτήτων και διάχυσης που δημιουργείται από την αλληλεπίδραση φλεβών, όταν αυτές εκρέουν από μια ροζέτα. Η αναγκαιότητα και χρησιμότητα της προσέγγισης του φαινομένου, είναι η εξαγωγή συμπερασμάτων για την εφαρμογή τους στην ολοένα αυξανόμενη χρήση διαχυτών τέτοιου τύπου. Στο πρώτο κεφάλαιο της εργασίας παρουσιάζεται η περιγραφή του φαινομένου της εκροής μιας φλέβας. Δίνονται κάποια εισαγωγικά στοιχεία που προσδιορίζουν τις ανωστικές φλέβες και τα γενικά χαρακτηριστικά τους και γίνεται αναφορά στο φαινόμενο της τύρβης που αποτελεί βασικό κομμάτι της ροής σε μία φλέβα. Στο δεύτερο μέρος του κεφαλαίου, παρουσιάζονται οι βασικές εξισώσεις, της συνέχειας, της ορμής και της διάχυσης, που περιγράφουν τη ροή μίας φλέβας με άνωση και εξάγονται οι ίδιες εξισώσεις για την τυρβώδη ροή φλέβας, χρησιμοποιώντας τους κανόνες μεσοποίησης του Reynolds, ολοκληρωμένες σε μία εγκάρσια διατομή της φλέβας. Στο δεύτερο κεφάλαιο περιγράφεται το φαινόμενο της αλληλεπίδρασης των φλεβών. Δίνεται σχηματικά το πεδίο που προκύπτει από την αλληλεπίδραση και γίνεται αναφορά σε μεθόδους που έχουν χρησιμοποιηθεί για την αντιμετώπισή του. Στο τρίτο κεφάλαιο, αναπτύσσεται το μοντέλο για την αλληλεπίδραση φλεβών από διαχύτη τύπου ροζέτας. Αρχικά, παρουσιάζεται συνοπτικά το μοντέλο των Yannopoulos & Noutsopoulos (2005) για την αλληλεπίδραση φλεβών σε σειρά, στη λογική του οποίου αντιμετωπίζεται το πρόβλημα της αλληλεπίδρασης φλεβών από ροζέτα. Στη συνέχεια παρουσιάζεται η εξέλιξη του φαινομένου. Χρησιμοποιώντας την ολοκληρωματική μεθόδο και τη Μέθοδο Περιορισμού της Συμπαράσυρσης, επιλύεται το σύστημα των εξισώσεων ορμής στη διεύθυνση z και της εξίσωσης διατήρησης της μάζας του χημικού δείκτη. Από την επίλυση του συστήματος εξάγονται οι εξισώσεις που περιγράφουν την κατανομή των μέσων αξονικών ταχυτήτων και των συγκεντρώσεων των Ν φλεβών. Για την καλύτερη απεικόνιση των αποτελεσμάτων, δίνονται οι λόγοι της κατανομής της ταχύτητας και της συγκέντρωσης των Ν φλεβών ως προς την κατανομή της ταχύτητα και της συγκέντρωσης, αντίστοιχα, της μιας κυκλικής κατακόρυφης ανωστικής φλέβας. Στο τέταρτο κεφάλαιο παρουσιάζονται τα αποτελέσματα της εφαρμογής του μοντέλου που έχει αναπτυχθεί, για τις περιπτώσεις ροζετών με Ν=3, 4, 6, 8, 10, 12, 16, 24 και με άπειρο αριθμό ακροφυσίων. Στο δεύτερο μέρος του κεφαλαίου, γίνονται οι συγκρίσεις με τα δεδομένα από τη βιβλιογραφία. Τα αποτελέσματα της εφαρμογής του μοντέλου για άπειρο πλήθος ακροφυσίων, συγκρίνονται με τα αποτελέσματα του μοντέλου για αλληλεπίδραση απείρων φλεβών των Yannopoulos & Noutsopoulos (2005). Σε αυτή τη σύγκριση δεν παρατηρήθηκαν αποκλίσεις μεταξύ τους. Ακόμη, συγκρίνονται τα αποτελέσματα της εφαρμογής του μοντέλου της παρούσας εργασίας για ροζέτα με 8 και 12 ακροφύσια με τα αντίστοιχα πειραματικά αποτελέσματα των Roberts & Snyder (1993). Οι αποκλίσεις είναι μικρότερες του πειραματικού σφάλματος το οποίο υπεισέρχεται στα πειράματα. / Buoyant flows are of great interest in environmental fluid mechanics and hydraulics, because they occur in many phenomena related to wastewater or heat disposal into water bodies. Similar flows take place when chimney or cooling tower emissions of smoke and other air pollutants or heat are released into the atmosphere. In this project a model was developed which describes the phenomenon of interaction of jets discharging from a rosette riser. A circle in which a horizontal equilateral polygon of N sides is inscribed, has modeled the rosette riser. The N vertical nozzles are laying on the apexes of the polygon. Due to geometric and hydraulic symmetry of the phenomenon, one buoyant jet of the group of N jets was studied. The mean flow and mass transfer in a jet of this kind are governed by the integral forms of the equations of continuity, momentum at the vertical direction and mass conservation of tracer. Furthermore, the specific model was compared to experimental data. The aim of the project is the development of a model describing the mean axial velocity distribution and mean concentration distribution, which are produced of the interaction of jets when they discharge vertically from a rosette riser. The necessity of this approach is the extraction of useful results in order to design such kind of diffuser systems. In the first chapter, there is a description of the discharged effluent. Some preliminary elements that determine buoyant jets and their general characteristics are given. Also, there are some preliminary elements about turbulence that constitutes great part of jet flow. In the second part of this chapter, there are the equations of continuity, momentum and mass conservation of tracer, which describe the turbulent flow, utilizing the Reynolds’ rules. These equations are integrated across the flow. In the second chapter the phenomenon of jet interaction is described. Also, it is given, schematically, the merged flow field and the methods and techniques that have been used to face up the problem in the past. In the third chapter, it is shown the development of the model for jet merging from a rosette riser and the process of the phenomenon. Using the Integral Method and adopting the Entrainment Restriction Approach, the system of the equations of momentum and mass conservation of tracer was solved, extracting the axial velocity and concentration distributions. To better quantify the buoyant jet interaction and illustrate it in simple diagrams, these expressions were divided on both sides by the corresponding analytical expressions of the round vertical turbulent buoyant jet, determining the axial velocities and concentrations ratios. In the last chapter, we demonstrate the results from applying the model for N=3, 4, 6, 8, 10, 12, 16, 24 ports per riser. There is also an application of the model for infinite number of nozzles. In the second part of this chapter, it is shown the comparisons of the results with other data. The results of the application of the model of infinite number of nozzles were compared with the model for an infinite row of interacting buoyant jets (Yannopoulos & Noutsopoulos, 2005). There are no deviations between the models. Also, there is a comparison between the application of the model for 8 and 12 nozzles with the experimental data of Roberts and Snyder (1993). The deviations in this case were less than the experimental error, which took place in the experiments.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / With the objective of determining if sufficient water would be salvaged by a typical desert, urban-household from normally wasted sources associated with the lot and household to adequately irrigate a garden and orchard, a 2000 sq ft house on a typical one fifth acre lot in three cities having climates similar to Phoenix, Tucson, or Prescott, Arizona was hypothesized and the amount of water available for yard watering calculated, provided that (1) only rainfall was available, (2) rainfall-runoff from covered areas associated with or adjacent to the lot was salvaged (roof, street, alley etc.), (3) gray-water from the household was utilized, (4) a portion of the lot was waterproofed to concentrate the runoff on the untreated portion, and (5) various combinations of the above were utilized to increase the amount of available water. It is demonstrated that these sources could be used singly or in combination to obtain the required amount of water with the actual amount available depending upon the precipitation, runoff and runon areas, runoff efficiency of the contributing area, and the number of people in the household. A number of horticultural plants are suggested that should best fit such an irregular irrigation scheme.