The development of a three phase plant-wide mathematical model for sewage treatment

Includes abstract.Includes bibliographical references.To aid in finding the most cost effective methods for the design and operation of wastewater treatment plants, for minimization of energy consumption and cost while maximizing nutrient recovery and improving effluent quality, the purpose of this project is to develop three phase (aqueous-gas-solid) steady state and dynamic mathematical models for the anaerobic and aerobic digestion of sludge; including waste activated sludge (WAS) produced by biological excess phosphorus removal (BEPR) plants, within a plant-wide setting

Applying performance indices in plantwide modelling for a comparative study of wastewater treatment plant operational strategies

Achievement of good effluent quality is always the main goal for wastewater treatment plant (WWTP) systems. However, these WWTPs have developed further objectives that include efficient design and strategic control options, with the prospect of their conversion into waste resource recovery facilities (WRRFs) that operate on reduced energy costs. With all these aspects becoming an intrinsic part of waste treatment, mathematical models that simulate WWTP unit processes are becoming of increasing relevance for the achievement of WRRF goals (including good effluent quality, low energy costs and nutrient recovery). It is expected that these mathematical models will benefit potential future applications of automation process control, which have also been developing rapidly with the availability of more reliable and affordable sensors. However, simulated automation control strategies require a thorough evaluation protocol to ensure their viability prior to being adopted as efficient operation control measures. This study considers the comparison of different control strategies implemented on a standard WWTP layout, for plant optimization. The initial task was to define performance indices, effluent quality index (EQI) and operation cost index (OCI), based on a previous investigation by the International Water Association (IWA) benchmark simulation modelling (BSM) task group. These performance indices were then used to evaluate the following strategies: (i) adding a fermentation tank, (ii) dosing flocculant and (iii) implementing a balancing tank. A control strategy was only assumed to be effective with improvement or maintenance of effluent quality. Overall, the evaluation exercise proved to be useful for providing expert advice on efficiency of proposed waste treatment system layouts, towards determination of the best configuration of future WRRFs. For instance, it was notable that significant organic strength is needed for removal of nutrients recycled back from the anaerobic digestion (AD) system into the activated sludge (AS) – hence alternate methods to put the nutrient-rich outflow from the AD system to good use are required.Keywords: WWTP control strategy, activated sludge, performance index, plant wide modellin

Towards a plant-wide Benchmark Simulation Model with simultaneous nitrogen and phosphorus removal wastewater treatment processes.

It is more than 10 years since the publication of the Benchmark Simulation Model No 1 (BSM1) manual (Copp, 2002). The main objective of BSM1 was creating a platform for benchmarking carbon and nitrogen removal strategies in activated sludge systems. The initial platform evolved into BSM1_LT and BSM2, which allowed the evaluation of monitoring and plant-wide control strategies, respectively. The fact that the BSM platforms have resulted in 300+ publications demonstrates the interest for the tool within the scientific community. In this paper, an extension of the BSM2 is proposed. This extension aims at facilitating simultaneous carbon, nitrogen and phosphorus (P) removal process development and performance evaluation at a plant-wide level. The main motivation of the work is that numerous wastewater treatment plants (WWTPs) pursue biological phosphorus removal as an alternative to chemical P removal based on precipitation using metal salts, such as Fe or Al. This paper identifies and discusses important issues that need to be addressed to upgrade the BSM2 to BSM2-P, for example: 1) new influent wastewater characteristics; 2) new (bio) chemical processes to account for; 3) modifications of the original BSM2 physical plant layout; 4) new/upgraded generic mathematical models; 5) model integration; 6) new control handles/sensors; and 7) new extended evaluation criteria. The paper covers and analyzes all these aspects in detail, identifying the main bottlenecks that need to be addressed and finally discusses the aspects where scientific consensus is required

International studies of ice sheet and bedrock at Dome Fuji, East Antarctica

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / 2F Auditorium, National Institute of Polar Researc

Journey from life to death

The kind of diseases affecting Japanese people and the causes of death in Japan have changed a great deal in the last several decades due to various factors, most notably the advancement of medical technology and changes in life style. The number of people who die from life style diseases such as cancer, which are chronic and possibly need long-term hospitalization, increases every year. In the 1970s the hospice philosophy was introduced to Japan from the West. It encourages patients and their families to affirm life and to regard dying as a normal process, and offers a support system to help patients live as actively as possible and sustain a sense of selfhood, autonomy, and dignity until they die. In practice, however, the dying process is still not regarded as normal in contemporary Japan and many patients fail to die in the way proposed by the hospice philosophy. There is also disagreement between the patients and the medical professionals regarding their respective idea of good death. Hospices and PCUs, which were initially developed in order to provide humane care, have become places which provide a new form of institutionalized death, and consequently constrain the patients' dying patterns. In this thesis, I investigate the above issues from the perspectives of the anthropology and the ethnography of Japan. I demonstrate how the framework of van Gennep's rites of passage and Turner's concept of liminality can be used to analyze the current situation in Japanese hospice settings. I also perform an ethnographic analysis of Japanese attitudes towards health, illness, and death in order to illustrate the reasons why some Japanese patients fail to die a good death as proposed by the hospice philosophy.</p

Performance of upflow anaerobic sludge blanket (UASB) reactor and other anaerobic reactor configurations for wastewater treatment: a comparative review and critical updates

© 2018 IWA Publishing. With the rising cost of energy and continuously increasing pressure to be more conscious of the amount of energy used in processes, aerobic wastewater treatment methods are becoming less desirable. However, anaerobic treatment is becoming more popular, especially with the development of high-rate activated sludge processes that can handle variations in operating conditions with small energy requirements. This short review aims to summarize the characteristics of anaerobic processes, with eventual emphasis on the upflow anaerobic sludge blanket (UASB) reactor and its performance under various conditions. Modeling of processes is helpful in making design decisions, and therefore the various modeling techniques applied to UASB reactors have also been included. Specific consideration has been given to anaerobic digestion model 1 (ADM1) due to its potential to be integrated with activated sludge models (ASM) to provide a single framework to describe aerobic post-treatments of the UASB effluent. Finally, an example test case involving the modeling of a pilot-scale UASB reactor has been included to indicate the usability of ADM1 in modeling anaerobic bioprocesses.status: publishe