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: Organising for Advertising Creativity: Differential Effects of Agency Structure, Absorptive Capacity, and Abrasion on Originality and Appropriateness

authors: O'Connor, Huw

subjects: Advertising

abstract: The aim of this thesis has been to extend our understanding of creativity.  Creativity is an area that is vital to society, but most commentators agree is a complex area that has been under researched. The setting for this research was the advertising industry. This industry was chosen as it is one of the few industry’s that focuses primarily on the creative thinking process and has highly specialist personnel concentrating on creative ideation. However, unlike the majority of research on creativity, the aim of this thesis was to shed light on a range of interactive, processing capacity, and knowledge elements, in the creative thinking process, rather than looking at divergent thinking processes in isolation.

This thesis is made up of four articles in Chapter’s Two to Five. The first of these articles is a replication and extension of the seminal study made by Koslow, Sasser and Riordan (2006) “Do Marketing Clients Really Get the Advertising They Deserve: Agency Views of How Clients Influence Creativity.” The article extends the findings from this seminal work in a different country context.

The next article looks into a number of structural elements driving creativity in the agency-client relationship and found a number of key interactions affecting the creativity of outcomes.
 
The third article delved into the area of absorptive capacity. In the creative thinking process a key limit is the ability of an organisation or individual to absorb the knowledge required to generate highly creative ideas. Research enabled the development of a model that illustrates the creative frontier, which is also the absorptive capacity frontier. The model indicates the trade-off that occurs between updating our beliefs with continuing to maintain these beliefs. The final article provides a model that summarises many of the key findings from the thesis. Using Agency Theory a new conceptual model that applies this in the context of absorptive capacity is developed. This model begins the process of trying to identify the key variables driving creative outputs in an agency setting and their complex interactions. Each article discusses the very real managerial implications of the findings for both advertising agencies and their clients, as well as the implications for managers as a whole. Additionally it is acknowledged that there is significant complexity in the creative thinking process and this is addressed in areas for further research.

text: Organising for Advertising Creativity: Differential Effects of Agency Structure, Absorptive Capacity, and Abrasion on Originality and Appropriateness The aim of this thesis has been to extend our understanding of creativity.  Creativity is an area that is vital to society, but most commentators agree is a complex area that has been under researched. The setting for this research was the advertising industry. This industry was chosen as it is one of the few industry’s that focuses primarily on the creative thinking process and has highly specialist personnel concentrating on creative ideation. However, unlike the majority of research on creativity, the aim of this thesis was to shed light on a range of interactive, processing capacity, and knowledge elements, in the creative thinking process, rather than looking at divergent thinking processes in isolation.

This thesis is made up of four articles in Chapter’s Two to Five. The first of these articles is a replication and extension of the seminal study made by Koslow, Sasser and Riordan (2006) “Do Marketing Clients Really Get the Advertising They Deserve: Agency Views of How Clients Influence Creativity.” The article extends the findings from this seminal work in a different country context.

The next article looks into a number of structural elements driving creativity in the agency-client relationship and found a number of key interactions affecting the creativity of outcomes.
 
The third article delved into the area of absorptive capacity. In the creative thinking process a key limit is the ability of an organisation or individual to absorb the knowledge required to generate highly creative ideas. Research enabled the development of a model that illustrates the creative frontier, which is also the absorptive capacity frontier. The model indicates the trade-off that occurs between updating our beliefs with continuing to maintain these beliefs. The final article provides a model that summarises many of the key findings from the thesis. Using Agency Theory a new conceptual model that applies this in the context of absorptive capacity is developed. This model begins the process of trying to identify the key variables driving creative outputs in an agency setting and their complex interactions. Each article discusses the very real managerial implications of the findings for both advertising agencies and their clients, as well as the implications for managers as a whole. Additionally it is acknowledged that there is significant complexity in the creative thinking process and this is addressed in areas for further research.

year: 2016

title: The role of mānuka (Leptospermum scoparium) riparian plantings in the mitigation of diffuse agricultural nitrogen

authors: Adamson, Olivia María

subjects: Manuka

abstract: The disruption of nutrient cycles in agricultural settings, particularly pastoral farming, is responsible for up to 70% of the nitrogen (N) loads entering streams in New Zealand (NZ) — resulting in the widespread degradation of freshwater ecosystems. Riparian plantings are one strategy to mitigate the losses of N from land to water, removing N by denitrification and plant uptake. Some types of vegetation are more effective than others at intercepting N, due to their ecology, impact on soil quality and root exudates. Mānuka (Leptospermum scoparium) is a plant native to NZ, and the species could be a good candidate to mitigate N losses due its ability to tolerate high N loads and co-benefits such as farm diversification through apiculture or essential oil production. Previous work also suggests that L. scoparium could be a biological nitrification inhibitor (BNI), limiting nitrate (NO₃⁻) production in soil.

The aim of this study was to investigate the potential of mānuka to intercept and remove N in an experimental riparian buffer in Lake Waikare. Currently, the lake is eutrophic due to high nutrient and sediment inputs. Significant restoration efforts have been made in recent years, led by many hapuu around the lake. All are very passionate and determined to recover the mauri of this ecosystem and reconnect the people to the lake, as well as provide economic opportunities. The riparian band had been established for four years and was set up as a series of experimental plots with different vegetation types, including plots solely in mānuka, and grassed controls. The plots are on a Perch- Gley Ultic Soil underlain by a slowly permeable clay layer— the Hamilton Ash. Further, the study sought to explore the relationship between soil physical properties and N cycling, and to identify influences expected by the local hydrology— as there was evidence of perching and lateral flow in the site. A series of suction-cup lysimeters were installed and pore water was sampled seven times between May and July 2021. Samples were analysed for total N (TN), total Kjeldahl N (TKN), NO₃⁻ and ammonium (NH₄⁺).

The results show that the riparian buffer is effectively removing N from subsurface flows, with TN declining from an average of 9.32 mg/l at 1 m into the buffer to 2.03 mg/l at 7 m. Although N concentrations were higher under mānuka, the total amount of N extracted from those plots was 21% less due to high rainfall interception by the canopy (63.9%), limiting the transport of the solute. Indicators of soil physical quality, bulk density (ρb) and macroporosity (MP), were investigated as potential causes for differences in the movement of N. There was a 17% improvement in ρb, and 38% improvement in MP relative to 2017 measurements, before the riparian band was established. No appreciable differences in soil physical properties were found between vegetation types at this early stage in the inception of the riparian buffer, although changes are likely to occur as the mānuka trees mature and the impact of roots is more developed. Shallow wells were deployed to monitor the dynamics of the water table, as there was evidence of winter perching. Dip wells demonstrated the existence of a short- lived perched water table, resulting in lateral flow, and likely impacting the degree of soil gleying in different parts of the riparian band. Water and contaminants are likely to move laterally over the Hamilton Ash towards the drain, supported by the accumulation of NO₃⁻ at the boundary with the clay layer.
Future work should be devoted to better quantifying NO₃⁻ leaching from the riparian plot by incorporating a drainage model, as well as further investigating the relative importance of N removal pathways at this site (i.e. denitrification and plant uptake)— including the potential for the lower part of the riparian band, closest to the drain, to become a hotspot for nitrous oxide (N₂O) emissions. It would also be of value to revisit this study in 4-10 years to explore how the buffer impacts soil quality and N dynamics in the subsurface as it matures.

text: The role of mānuka (Leptospermum scoparium) riparian plantings in the mitigation of diffuse agricultural nitrogen The disruption of nutrient cycles in agricultural settings, particularly pastoral farming, is responsible for up to 70% of the nitrogen (N) loads entering streams in New Zealand (NZ) — resulting in the widespread degradation of freshwater ecosystems. Riparian plantings are one strategy to mitigate the losses of N from land to water, removing N by denitrification and plant uptake. Some types of vegetation are more effective than others at intercepting N, due to their ecology, impact on soil quality and root exudates. Mānuka (Leptospermum scoparium) is a plant native to NZ, and the species could be a good candidate to mitigate N losses due its ability to tolerate high N loads and co-benefits such as farm diversification through apiculture or essential oil production. Previous work also suggests that L. scoparium could be a biological nitrification inhibitor (BNI), limiting nitrate (NO₃⁻) production in soil.

The aim of this study was to investigate the potential of mānuka to intercept and remove N in an experimental riparian buffer in Lake Waikare. Currently, the lake is eutrophic due to high nutrient and sediment inputs. Significant restoration efforts have been made in recent years, led by many hapuu around the lake. All are very passionate and determined to recover the mauri of this ecosystem and reconnect the people to the lake, as well as provide economic opportunities. The riparian band had been established for four years and was set up as a series of experimental plots with different vegetation types, including plots solely in mānuka, and grassed controls. The plots are on a Perch- Gley Ultic Soil underlain by a slowly permeable clay layer— the Hamilton Ash. Further, the study sought to explore the relationship between soil physical properties and N cycling, and to identify influences expected by the local hydrology— as there was evidence of perching and lateral flow in the site. A series of suction-cup lysimeters were installed and pore water was sampled seven times between May and July 2021. Samples were analysed for total N (TN), total Kjeldahl N (TKN), NO₃⁻ and ammonium (NH₄⁺).

The results show that the riparian buffer is effectively removing N from subsurface flows, with TN declining from an average of 9.32 mg/l at 1 m into the buffer to 2.03 mg/l at 7 m. Although N concentrations were higher under mānuka, the total amount of N extracted from those plots was 21% less due to high rainfall interception by the canopy (63.9%), limiting the transport of the solute. Indicators of soil physical quality, bulk density (ρb) and macroporosity (MP), were investigated as potential causes for differences in the movement of N. There was a 17% improvement in ρb, and 38% improvement in MP relative to 2017 measurements, before the riparian band was established. No appreciable differences in soil physical properties were found between vegetation types at this early stage in the inception of the riparian buffer, although changes are likely to occur as the mānuka trees mature and the impact of roots is more developed. Shallow wells were deployed to monitor the dynamics of the water table, as there was evidence of winter perching. Dip wells demonstrated the existence of a short- lived perched water table, resulting in lateral flow, and likely impacting the degree of soil gleying in different parts of the riparian band. Water and contaminants are likely to move laterally over the Hamilton Ash towards the drain, supported by the accumulation of NO₃⁻ at the boundary with the clay layer.
Future work should be devoted to better quantifying NO₃⁻ leaching from the riparian plot by incorporating a drainage model, as well as further investigating the relative importance of N removal pathways at this site (i.e. denitrification and plant uptake)— including the potential for the lower part of the riparian band, closest to the drain, to become a hotspot for nitrous oxide (N₂O) emissions. It would also be of value to revisit this study in 4-10 years to explore how the buffer impacts soil quality and N dynamics in the subsurface as it matures.

year: 2021