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There is a growing awareness of the valuable nutrients (nitrogen and phosphorus) being lost in conventional wastewater treatment systems. Although the removal of these nutrients has been well addressed, efforts for nutrient recovery have seen little development. As the emphasis on sustainability in the wastewater treatment industry increases, conventional wastewater treatment processes are being re-evaluated and new treatment systems developed. A possible nutrient recovery mechanism is the precipitation of magnesium ammonium phosphate hexahydrate (MgNH4PO4·6H2O), commonly known as struvite. Human urine has been identified as a rich source of nutrients in wastewater; hence the separate collection of urine is considered a viable method of enabling struvite recovery. Since dilution of urine to a certain degree is inevitable, reconcentration of urine beyond the solubility limit of struvite is critical. Currently available methods for reconcentration (e.g., evaporation, freeze-thaw, reverse osmosis and electrodialysis) are relatively expensive with high energy demand. Thus, the research here aims to demonstrate nutrient reconcentration from diluted urine and simultaneous organic removal by using the principles of microbial desalination cells (MDCs), where energy released from organic oxidation is partially used for the separation of nutrient ions. With reduced energy demand, a sustainable method for the utilization of source-separated urine is examined. The performance of bioelectrochemical systems relies on the activity of exoelectrogenic bacteria to transfer electrons to the anode. An examination of exoelectrogen sensitivity at various wastewater treatment conditions (i.e. ammonia and oxygen) is an important component of this research. Methanogenesis is considered the greatest challenge in achieving practical applications in anaerobic bioelectrochemical systems. An electrolytic oxygen production method is suggested for effective control of methanogenesis in a feasible and cost-effective manner. / Thesis / Master of Applied Science (MASc)

Livestock wastewater contains a large amount of nutrients that are available for recovery. In this study, a proof of concept process based on forward osmosis (FO) was proposed and investigated for in-situ formation of struvite from digested swine wastewater. This FO system took advantage of a drawback reverse solute flux (RSF) and used the reversed-fluxed Mg^{2+} for struvite precipitation, thereby accomplishing recovery of both water and nutrient. With 0.5 M MgCl2 as a draw solution, high purity struvite formed spontaneously in the feed solution and the water flux through the FO membrane reached 3.12 LMH. The precipitated struvite was characterized and exhibited a similar composition to that of commercial struvite. The FO system achieve >50% water recovery, >99% phosphate recovery (given sufficient magnesium supply), and >93% ammonium nitrogen removal from the digested swine wastewater. The recovered products (both struvite and water) could potentially generate a value of 1.35 $ m^{-3}. The results of this study have demonstrated the feasibility of nutrient recovery from livestock wastewater facilitated by FO treatment. / Master of Science / Forward Osmosis (FO) effectively separates water from dissolved solutes with a semi-permeable membrane. This separation feature can be used in real water body to recover nutrients, concentrate wastewater for further treatment and produce energy for power plant. And the water body rich in nutrients induces the plants growth. These plants consume tons of oxygen in the water which decrease biodiversity in the water body, cause new species invasion and economical lose. The nutrients-rich water has caused trouble to our human being for decades, and one of them is livestock wastewater. Specifically, in this study, the piggery wastewater was used to be treated by FO system. FO has not been used to treat piggery waste/wastewater without additive from previous literature review. In this study, a FO reactor was built up for in-situ nutrient recovery as struvite, which is a valuable slow-release fertilizer. The experiments from this study proved the concept for in-situ struvite recovery from digested livestock wastewater via FO treatment with simultaneous water recovery, and will encourage further exploration of FO promoted resource recovery form wastes.

Published Article / A reference carrier signal should be regenerated from a received partial response (PR) signal in order to facilitate optimal demodulation of the received signal. This paper describes the development and evaluation of such a carrier recovery system using DSP techniques. The relative phase of a free-running local oscillator at the receiver is synchronized with the carrier signal of a received 49 quadrature partial response signal (49QPRS). Synchronization is achieved and maintained by means of a process of cross-correlation.

Survivors of critical illness suffer from a range of problems affecting physical, psychological and social well-being (Needham et al 2011). Weakness, fatigue and malnutrition are highly prevalent during the months following a critical illness. Few studies have systematically and comprehensively explored the factors that influence nutritional recovery or ways to overcome them. The aim of this study was to provide a comprehensive understanding of the factors influencing nutritional recovery, and the relationship between them, in post intensive care (ICU) patients. A model of care was then developed to improve current management of nutrition for patients recovering from critical illness. Grounded theory methodology was used with a mixed method research design. Nutritional status and intake were assessed on discharge from ICU and at three months post ICU discharge. The process of nutritional recovery during the first three months post ICU discharge was explored from a patient perspective and at the level of ward organisation of care, through observation of practice and interviewing patients and staff. Seventeen patients, who had required greater than 48 hours ventilation, were recruited on discharge from the ICU. On transfer to the ward 9 of the 17 patients were assessed as well-nourished and 8 were malnourished using Subjective Global Assessment. At three months post ICU discharge 14 patients were followed up (1 lost to follow up, 1 incapacitated following illness and 1 went overseas). Seven of these were classified as well-nourished and the other 7 were malnourished. Patients universally failed to meet their nutritional targets during their ward stay and although intakes had improved by three months post ICU discharge, the majority of patients were still not achieving their nutritional requirements. Qualitative data revealed that patients' nutritional intake was influenced by interrelated system breakdowns during the recovery process; this emerged as the overarching core theme. Three sub-themes were ‘experiencing a dysfunctional body’, ‘experiencing socio-cultural changes in relation to eating and ‘encountering organisational nutritional care delivery failures’. This study identified connections and interrelations between these concepts and provided new insights into the factors that influence the nutritional care of post ICU patients. In order to optimise nutritional rehabilitation in this patient group a model of care has been developed which addresses the identified organisational and patient related factors that were shown to influence the nutritional recovery of patients after critical illness. This nutritional strategy will need to be evaluated in clinical trials or quality improvement programmes.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / A long standing problem in telemetry applications is the recovery of data which has been damaged during downlink. Data recovery can be significantly improved by telemetering information in a packet format which employs redundant mechanisms for data encapsulation. A simple statistical algorithm (known as a "merge" algorithm) can be run on the captured data to derive a "least damaged" data set.

The reserve growth potential of existing conventional oil reservoirs is huge. This research, through numerical simulation, aims to evaluate pattern size reduction as a strategy for improving waterflood recovery in undersaturated oil reservoirs. A plethora of studies have reported improvements in waterflood recovery resulting from pattern size reduction in heterogeneous reservoirs. The dependence of waterflood recovery on pattern size was attributed to factors such as areal reservoir discontinuity, preferential flooding directions, “wedge-edge” oil recovery, irregular pattern geometry, communication with water-bearing zones, vertical reservoir discontinuity, and project economics (Driscoll, 1974). Though many of these publications relied on decline curve analysis in estimating ultimate oil recovery, simulations completed in this thesis support their findings, specifically for compartmentalized reservoirs, fractured reservoirs, and layered reservoirs. Geostatistically-generated permeability fields were employed in the creation of various types of reservoir models. These models were populated with vertical production and injection wells. Sensitivity analysis was then performed on three development scenarios: 160, 40, and 10 acre five-spots. Based on assigned production and injection constraints, the quantity of oil recovered at simulation termination was used to calculate ultimate recovery efficiency. In homogeneous reservoir models, simulation results suggest that waterflood recovery was independent of pattern size. Similar results were also obtained from models with highly-variable non-zero permeabilities. On the other hand, pattern size reduction was found to enhance oil recovery from reservoir models with a high degree of permeability anisotropy. In such reservoirs, recovery was found to be highly dependent on bottom-hole injection pressures. The higher the injection pressure the larger the quantity of oil bypassed by widely spaced patterns. Likewise, high infill potential exists for reservoir models exhibiting areal discontinuity. In these types of models, the improvement in waterflood recovery resulting from pattern size reduction was directly related to the percentage of imbedded zero-permeability grid blocks. Ultimate oil recovery depended on the percolation of permeable grid blocks between production and injection wells. Increasing well density also enhanced waterflood recovery in vertically discontinuous reservoir models. In such layered reservoirs, the amount oil unswept with large patterns was considerably diminished because of the improved injection profiles associated with tighter patterns. / text