title: Cost and Performance Comparison of a Membrane Bioreactor (MBR) Plant and a Bardenpho Plant for Wastewater Treatment

authors: Rachmani, Asaf

abstract: Rotorua District Council constructed a membrane bioreactor (MBR) system to work in parallel with the existing Bardenpho system, to improve the overall capacity and removal efficiency of the wastewater treatment plant. The aim of this research was to examine and compare the performance of the MBR and the Bardenpho systems, as well as the operating costs and the net present value. The MBR showed a higher removal rate of TKN, TSS, COD, DRP and organic nitrogen than the Bardenpho system, with average removal efficiencies of 94.52%, 99.05%, 94.04%, 67.43% and 92.75% respectively. These removal rates were shown to be 0.62%, 15.47%, 8.51%, 5.72% and14.74 % better than the Bardenpho system. Furthermore, the MBR removal rate remained stable over a range of flows, while the Bardenpho removal rate fluctuated with a change in flow. The total energy consumption of the treated wastewater in the MBR and the Bardenpho systems were 0.53 kWh/m3 and 0.25 kWh/m3 respectively. Major contributors to the total operational costs were the disposal cost of sludge, the cost of ethanol and aeration. In the MBR, the cost percentage of sludge disposal was 22.11%, and the total aeration cost was 20.25%, while the cost of disposal of sludge was 45.15% and aeration 7.22% in the Bardenpho. The capital cost to construct the MBR and the Bardenpho systems was calculated to be similar when the cost of land is not taken into account, however, the size of the Bardenpho required to treat the same volume of wastewater is found to be 2.2 times bigger than a MBR system. It was concluded that from a cost point of view, the Bardenpho system is more economical; however, the low cost of running the Bardenpho comes with lower removal efficiencies in comparison to the MBR.

text: Cost and Performance Comparison of a Membrane Bioreactor (MBR) Plant and a Bardenpho Plant for Wastewater Treatment Rotorua District Council constructed a membrane bioreactor (MBR) system to work in parallel with the existing Bardenpho system, to improve the overall capacity and removal efficiency of the wastewater treatment plant. The aim of this research was to examine and compare the performance of the MBR and the Bardenpho systems, as well as the operating costs and the net present value. The MBR showed a higher removal rate of TKN, TSS, COD, DRP and organic nitrogen than the Bardenpho system, with average removal efficiencies of 94.52%, 99.05%, 94.04%, 67.43% and 92.75% respectively. These removal rates were shown to be 0.62%, 15.47%, 8.51%, 5.72% and14.74 % better than the Bardenpho system. Furthermore, the MBR removal rate remained stable over a range of flows, while the Bardenpho removal rate fluctuated with a change in flow. The total energy consumption of the treated wastewater in the MBR and the Bardenpho systems were 0.53 kWh/m3 and 0.25 kWh/m3 respectively. Major contributors to the total operational costs were the disposal cost of sludge, the cost of ethanol and aeration. In the MBR, the cost percentage of sludge disposal was 22.11%, and the total aeration cost was 20.25%, while the cost of disposal of sludge was 45.15% and aeration 7.22% in the Bardenpho. The capital cost to construct the MBR and the Bardenpho systems was calculated to be similar when the cost of land is not taken into account, however, the size of the Bardenpho required to treat the same volume of wastewater is found to be 2.2 times bigger than a MBR system. It was concluded that from a cost point of view, the Bardenpho system is more economical; however, the low cost of running the Bardenpho comes with lower removal efficiencies in comparison to the MBR.

year: 2013

title: A Population Model of the Thalamus and its Wave Interactions with the Cortex

authors: Müller, Eli Justin

subjects: Thalamus

abstract: In this thesis we construct a population model of the thalamus based on the mean-field cortex developed by Steyn-Ross et al. and Liley et al. We allow interactions between the thalamus and cortex via damped wave equations and show spindle-like oscillations (10-15 Hz)  propagating from the thalamic reticular population into the cortical populations.
We first consider a mean-field model of a cortex that is isolated from time-dependent sub-cortical inputs. The model is a continuum theory based on the electrical activity of a neural mass called the macrocolumn, containing groups of excitatory and inhibitory neurons. We demonstrate induction of 'unconsciousness' in the macrocoulmn under propofol-like general anaesthetic, and show there is a hysteretic separation between points of 'loss of consciousness' and 'recovery of consciousness'.
The thalamus, a sub-cortical structure important to the relay of sensory input into the cortex, is described using a revised set of equations based on the mean-field cortical model. We define two neuron types within the thalamus: the specific group, assumed to be excitatory, and the reticular group, assumed to be inhibitory. A new bimodal mapping function is developed to relate mean membrane potentials to mean firing rates within the thalamic macrocolumn. This bimodal function is generated by combining two sigmoidal functions, and is a representation of the observed increase in the firing rates of reticular neurons at hyperpolarized membrane potentials. In contrast, the mapping function for specific population is modelled by a standard sigmoid. We investigate the isolated dynamics of the mean-field thalamus, using parameters from Robinson et al., and find spindle-like oscillations emerge following a transition from unstable equilibrium states to stable states consistent with the linear stability analysis.
A coupling of the isolated cortical and thalamic systems is accomplished using four damped wave equations. We investigate the stationary states of the thalamo-cortical model and find the spindle-like oscillations present in the thalamus propagate into the cortical populations.

text: A Population Model of the Thalamus and its Wave Interactions with the Cortex In this thesis we construct a population model of the thalamus based on the mean-field cortex developed by Steyn-Ross et al. and Liley et al. We allow interactions between the thalamus and cortex via damped wave equations and show spindle-like oscillations (10-15 Hz)  propagating from the thalamic reticular population into the cortical populations.
We first consider a mean-field model of a cortex that is isolated from time-dependent sub-cortical inputs. The model is a continuum theory based on the electrical activity of a neural mass called the macrocolumn, containing groups of excitatory and inhibitory neurons. We demonstrate induction of 'unconsciousness' in the macrocoulmn under propofol-like general anaesthetic, and show there is a hysteretic separation between points of 'loss of consciousness' and 'recovery of consciousness'.
The thalamus, a sub-cortical structure important to the relay of sensory input into the cortex, is described using a revised set of equations based on the mean-field cortical model. We define two neuron types within the thalamus: the specific group, assumed to be excitatory, and the reticular group, assumed to be inhibitory. A new bimodal mapping function is developed to relate mean membrane potentials to mean firing rates within the thalamic macrocolumn. This bimodal function is generated by combining two sigmoidal functions, and is a representation of the observed increase in the firing rates of reticular neurons at hyperpolarized membrane potentials. In contrast, the mapping function for specific population is modelled by a standard sigmoid. We investigate the isolated dynamics of the mean-field thalamus, using parameters from Robinson et al., and find spindle-like oscillations emerge following a transition from unstable equilibrium states to stable states consistent with the linear stability analysis.
A coupling of the isolated cortical and thalamic systems is accomplished using four damped wave equations. We investigate the stationary states of the thalamo-cortical model and find the spindle-like oscillations present in the thalamus propagate into the cortical populations.

year: 2014

title: Engaging Māori in Biobanking and Genetic Research: Legal, Ethical and Policy Challenges

authors: Beaton, Angela

subjects: Indigenous

abstract: Publically funded biobanking initiatives and genetic research should contribute towards reducing inequalities in health by reducing the prevalence and burden of disease. It is essential that Maori and other Indigenous populations share in health gains derived from these activities. The Health Research Council of New Zealand has funded a research project (2012-2015) to identify Maori perspectives on biobanking and genetic research, and to develop cultural guidelines for ethical biobanking and genetic research involving biospecimens. This review describes relevant values and ethics embedded in Maori indigenous knowledge, and how they may be applied to culturally safe interactions between biobanks, researchers, individual participants, and communities. Key issues of ownership, privacy, and consent are also considered within the legal and policy context that guides biobanking and genetic research practices within New Zealand. Areas of concern are highlighted and recommendations of international relevance are provided. To develop a productive environment for "next-generation" biobanking and genomic research,"‘next-generation" regulatory solutions will be required.

text: Engaging Māori in Biobanking and Genetic Research: Legal, Ethical and Policy Challenges Publically funded biobanking initiatives and genetic research should contribute towards reducing inequalities in health by reducing the prevalence and burden of disease. It is essential that Maori and other Indigenous populations share in health gains derived from these activities. The Health Research Council of New Zealand has funded a research project (2012-2015) to identify Maori perspectives on biobanking and genetic research, and to develop cultural guidelines for ethical biobanking and genetic research involving biospecimens. This review describes relevant values and ethics embedded in Maori indigenous knowledge, and how they may be applied to culturally safe interactions between biobanks, researchers, individual participants, and communities. Key issues of ownership, privacy, and consent are also considered within the legal and policy context that guides biobanking and genetic research practices within New Zealand. Areas of concern are highlighted and recommendations of international relevance are provided. To develop a productive environment for "next-generation" biobanking and genomic research,"‘next-generation" regulatory solutions will be required.

year: 2015