title: Use of high-rate filamentous algal ponds for primary municipal wastewater treatment

authors: Novak, Indira

abstract: High-rate filamentous algal pond (HRFAP) systems offer a promising alternative to conventional municipal wastewater treatment. Research on selecting filamentous algal species for municipal wastewater bioremediation is currently limited. Chapter 2 introduces a screening protocol aimed at identifying robust cultivars suitable for HRFAP monoculture systems. Evaluating eleven cultivars under local seasonal ambient and extreme conditions played a crucial role in cultivar selection. Based on their consistent biomass productivity and bioremediation performance across ambient and extreme conditions, Klebsormidium sp. (KLEB B), Stigeoclonium sp. (STIG A) and Ulothrix sp. were identified as target cultivars for nutrient bioremediation of primary municipal wastewater.

The identification of target cultivars has previously been based on laboratory conditions, which are insufficient for practical applications. Chapter 3 assessed the biomass productivity and nutrient bioremediation performance of three cultivars - Klebsormidium flaccidum, Oedogonium calcareum, and Oedogonium sp. – in outdoor HRFAP mesocosms. K. flaccidum had the highest biomass productivity and bioremediation performance, while O. calcareum had complete die-off. Competition experiments at varying stocking densities highlighted K. flaccidum dominance at lower densities (0.25 and 0.5 g FW L-1), positioning it as the preferred cultivar for nutrient bioremediation in primary municipal wastewater within HRFAP systems.

Effective management of operational parameters is crucial for optimising wastewater treatment in HRFAP systems. Therefore, in Chapter 4 the effects of hydraulic retention time (HRT), stocking density, and harvest frequency on the growth and nutrient bioremediation performance of K. flaccidum in primary municipal wastewater in outdoor HRFAPs were examined during summer and winter. Seasonal conditions impacted biomass productivity, which was 48.3% higher in summer compared to winter. A HRT of 4 days was optimal for both seasons based on bioremediation of total ammoniacal-nitrogen (TAN). Lower stocking densities of 0.25 and 0.5 g FW L-1 demonstrated enhanced bioremediation efficiency, while higher densities were preferable during slower growth periods to mitigate potential toxicity risks from primary wastewater. Harvest frequencies of two, four and six days did not significantly affect nutrient removal rates across different treatments and seasons. These results highlight the importance of seasonal optimisation of HRFAP systems to maximise biomass production and nutrient bioremediation. 

Wastewater treatment plants (WWTPs) are major sources of per- and polyfluoroalkyl substances (PFAS) pollution entering the environment. Certain algal species have demonstrated the ability to bioaccumulate PFAS compounds, indicating their potential for removing PFAS from wastewater. Therefore, in Chapter 5 a laboratory study was conducted to assess the ability of K. flaccidum to reduce concentrations of PFAS and PFAS precursors in primary municipal wastewater under two HRTs. K. flaccidum maintained stable productivity in the wastewater. Removal rates of PFAS and PFAS precursors, however, varied considerably. Specifically, reductions were observed in three individual PFAS and in all measured PFAS precursors present in the wastewater. Despite these reductions, PFAS was not detected in the algal biomass of K. flaccidum, making it suitable for a range of biomass applications provided it remains free of other contaminants.

Overall, this thesis has demonstrated that HRFAP systems are an effective alternative treatment for nutrient reduction in primary municipal wastewater. Application of the screening protocol to select target species, and seasonal optimisation of HRFAP operating parameters will enable more consistent and effective year-round nutrient bioremediation and algal biomass productivity to be achieved.

text: Use of high-rate filamentous algal ponds for primary municipal wastewater treatment High-rate filamentous algal pond (HRFAP) systems offer a promising alternative to conventional municipal wastewater treatment. Research on selecting filamentous algal species for municipal wastewater bioremediation is currently limited. Chapter 2 introduces a screening protocol aimed at identifying robust cultivars suitable for HRFAP monoculture systems. Evaluating eleven cultivars under local seasonal ambient and extreme conditions played a crucial role in cultivar selection. Based on their consistent biomass productivity and bioremediation performance across ambient and extreme conditions, Klebsormidium sp. (KLEB B), Stigeoclonium sp. (STIG A) and Ulothrix sp. were identified as target cultivars for nutrient bioremediation of primary municipal wastewater.

The identification of target cultivars has previously been based on laboratory conditions, which are insufficient for practical applications. Chapter 3 assessed the biomass productivity and nutrient bioremediation performance of three cultivars - Klebsormidium flaccidum, Oedogonium calcareum, and Oedogonium sp. – in outdoor HRFAP mesocosms. K. flaccidum had the highest biomass productivity and bioremediation performance, while O. calcareum had complete die-off. Competition experiments at varying stocking densities highlighted K. flaccidum dominance at lower densities (0.25 and 0.5 g FW L-1), positioning it as the preferred cultivar for nutrient bioremediation in primary municipal wastewater within HRFAP systems.

Effective management of operational parameters is crucial for optimising wastewater treatment in HRFAP systems. Therefore, in Chapter 4 the effects of hydraulic retention time (HRT), stocking density, and harvest frequency on the growth and nutrient bioremediation performance of K. flaccidum in primary municipal wastewater in outdoor HRFAPs were examined during summer and winter. Seasonal conditions impacted biomass productivity, which was 48.3% higher in summer compared to winter. A HRT of 4 days was optimal for both seasons based on bioremediation of total ammoniacal-nitrogen (TAN). Lower stocking densities of 0.25 and 0.5 g FW L-1 demonstrated enhanced bioremediation efficiency, while higher densities were preferable during slower growth periods to mitigate potential toxicity risks from primary wastewater. Harvest frequencies of two, four and six days did not significantly affect nutrient removal rates across different treatments and seasons. These results highlight the importance of seasonal optimisation of HRFAP systems to maximise biomass production and nutrient bioremediation. 

Wastewater treatment plants (WWTPs) are major sources of per- and polyfluoroalkyl substances (PFAS) pollution entering the environment. Certain algal species have demonstrated the ability to bioaccumulate PFAS compounds, indicating their potential for removing PFAS from wastewater. Therefore, in Chapter 5 a laboratory study was conducted to assess the ability of K. flaccidum to reduce concentrations of PFAS and PFAS precursors in primary municipal wastewater under two HRTs. K. flaccidum maintained stable productivity in the wastewater. Removal rates of PFAS and PFAS precursors, however, varied considerably. Specifically, reductions were observed in three individual PFAS and in all measured PFAS precursors present in the wastewater. Despite these reductions, PFAS was not detected in the algal biomass of K. flaccidum, making it suitable for a range of biomass applications provided it remains free of other contaminants.

Overall, this thesis has demonstrated that HRFAP systems are an effective alternative treatment for nutrient reduction in primary municipal wastewater. Application of the screening protocol to select target species, and seasonal optimisation of HRFAP operating parameters will enable more consistent and effective year-round nutrient bioremediation and algal biomass productivity to be achieved.

year: 2024

title: Industry training organisations in changing times: New research possibilities

authors: Cochrane, William

subjects: tertiary education

abstract: The tertiary education reforms have placed considerable pressure on Industry Training Organisations (ITOs), which are now required to assume “new roles as strategic leaders in skills and training needs for the industries under their coverage" (Statement of Tertiary Education Priorities (STEP) 2003-04, P. 21). This paper argues that the STEP requirement can lead to productive relationships between ITOs and established research organizations. It considers the new context within which ITOs now operate and offers an illustrative case study of the sort of research that can result from collaborative relationships. Specifically, it reports on research commissioned by the New Zealand Industry Training Organisation (NZITO), which covers dairy manufacturing, meat processing, and leather processing, as part of' its strategic planning. The research reported includes: an analysis of the industries covered by the NZITO and their economic significance; the impact of an ageing workforce and other demographic on the labour market and its Implications for NZJTO industries; the impact of technological change on the labour market; and some of the consequences of the continuing integration of the global economy.

text: Industry training organisations in changing times: New research possibilities The tertiary education reforms have placed considerable pressure on Industry Training Organisations (ITOs), which are now required to assume “new roles as strategic leaders in skills and training needs for the industries under their coverage" (Statement of Tertiary Education Priorities (STEP) 2003-04, P. 21). This paper argues that the STEP requirement can lead to productive relationships between ITOs and established research organizations. It considers the new context within which ITOs now operate and offers an illustrative case study of the sort of research that can result from collaborative relationships. Specifically, it reports on research commissioned by the New Zealand Industry Training Organisation (NZITO), which covers dairy manufacturing, meat processing, and leather processing, as part of' its strategic planning. The research reported includes: an analysis of the industries covered by the NZITO and their economic significance; the impact of an ageing workforce and other demographic on the labour market and its Implications for NZJTO industries; the impact of technological change on the labour market; and some of the consequences of the continuing integration of the global economy.

year: 2006

title: Bay of Plenty Region and its Territorial Authorities: Demographic Profile 1986 - 2031

authors: Jackson, Natalie

subjects: Bay of Plenty Region

abstract: This report outlines the demographic changes that have occurred in Bay of Plenty Region, as well as what trends are expected in the future.

text: Bay of Plenty Region and its Territorial Authorities: Demographic Profile 1986 - 2031 This report outlines the demographic changes that have occurred in Bay of Plenty Region, as well as what trends are expected in the future.

year: 2013-12