title: Evaluation of a denitrifying bioreactor to improve water quality of tertiary treated water using DGT

authors: Dougherty, Hannah L.

subjects: denitrifying bioreactors

abstract: A proven nitrogen remediation strategy, denitrifying bioreactors are a low cost, edge-of-field approach for removing nitrate from subsurface drainage waters. The methodology to evaluate the performance of denitrifying bioreactors has remained practically unchanged for many years and is largely dependent upon grab sampling to evaluate their performance. In this study, a controlled flow denitrifying bioreactor treating wastewaters was used to evaluate a monitoring technique called Diffusive Gradients in Thin-Films (DGT) in place of grab sampling. Corbett et al., (in press) previously showed that DGT could replace high frequency grab sampling (e.g. hourly to daily) and significantly improve upon traditional low frequency sampling. Importantly, DGT provided NO3- concentrations comparable to high frequency grab sampling but require less time on site. In the current study, the bioreactor provided complete removal of nitrate within 4 meters with influent NO3- concentrations ranging from 9.7 to 15.9 mg NO3- L-1 over the four deployments. This study also demonstrated how grab samples can easily overestimate and underestimate NO3- removal with low frequency data providing a removal rate of 6.3 to 19.6 g N m-3 d-1 because of the infrequency of sampling. The time-weighted average concentrations calculated using Purolite AE520 DGT provided nitrate removal rates (NRR) that ranged from 5.7 to 9.4 g N m-3 d-1. This removal rate was higher than many other bioreactors most likely because influent wastewater contained dissolved organic carbon that could also support high denitrification. A Q10 of 3.9 was calculated using the NRR from this study and Corbett et al., (in press) illustrating that temperature was a determining factor in NO3- removal. A survey of redox reactions was also undertaken with oxygen, sulfate, methylmercury and total mercury measured. Sulfate reduction also measured for each deployment (average of 3.6 g S m-3 d-1; 1.7 to 5.10 g S m-3 d-1) via grab sampling. Methylmercury and total mercury concentrations were consistently below health guidelines. No phosphate reduction was observed. This study showed how DGT can provide more accurate NO3- removal data and were easier to use compared to traditional point-in-time grab sampling.

text: Evaluation of a denitrifying bioreactor to improve water quality of tertiary treated water using DGT A proven nitrogen remediation strategy, denitrifying bioreactors are a low cost, edge-of-field approach for removing nitrate from subsurface drainage waters. The methodology to evaluate the performance of denitrifying bioreactors has remained practically unchanged for many years and is largely dependent upon grab sampling to evaluate their performance. In this study, a controlled flow denitrifying bioreactor treating wastewaters was used to evaluate a monitoring technique called Diffusive Gradients in Thin-Films (DGT) in place of grab sampling. Corbett et al., (in press) previously showed that DGT could replace high frequency grab sampling (e.g. hourly to daily) and significantly improve upon traditional low frequency sampling. Importantly, DGT provided NO3- concentrations comparable to high frequency grab sampling but require less time on site. In the current study, the bioreactor provided complete removal of nitrate within 4 meters with influent NO3- concentrations ranging from 9.7 to 15.9 mg NO3- L-1 over the four deployments. This study also demonstrated how grab samples can easily overestimate and underestimate NO3- removal with low frequency data providing a removal rate of 6.3 to 19.6 g N m-3 d-1 because of the infrequency of sampling. The time-weighted average concentrations calculated using Purolite AE520 DGT provided nitrate removal rates (NRR) that ranged from 5.7 to 9.4 g N m-3 d-1. This removal rate was higher than many other bioreactors most likely because influent wastewater contained dissolved organic carbon that could also support high denitrification. A Q10 of 3.9 was calculated using the NRR from this study and Corbett et al., (in press) illustrating that temperature was a determining factor in NO3- removal. A survey of redox reactions was also undertaken with oxygen, sulfate, methylmercury and total mercury measured. Sulfate reduction also measured for each deployment (average of 3.6 g S m-3 d-1; 1.7 to 5.10 g S m-3 d-1) via grab sampling. Methylmercury and total mercury concentrations were consistently below health guidelines. No phosphate reduction was observed. This study showed how DGT can provide more accurate NO3- removal data and were easier to use compared to traditional point-in-time grab sampling.

year: 2019

title: Airport surface access strategies and targets

authors: Francis, Graham

subjects: airport

abstract: Airport surface access is increasingly seen as a major problem not only in the UK but worldwide given its impact in terms of both traffic congestion and environmental degradation. In 1998 the UK Government published a White Paper entitled ‘A New Deal for Transport’ (DETR, 1998) in which it introduced the idea of Airport Transport Forums to be established by UK airports in order to set targets for the reduction in the proportion of journeys to/from the airport made by car based modes. In this working paper the authors critically assess the targets developed for achieving the objective of a greater use of public transport in making journeys to airports. Evidence is presented as to how UK airports have developed targets in order to respond to the Government’s initiative.

text: Airport surface access strategies and targets Airport surface access is increasingly seen as a major problem not only in the UK but worldwide given its impact in terms of both traffic congestion and environmental degradation. In 1998 the UK Government published a White Paper entitled ‘A New Deal for Transport’ (DETR, 1998) in which it introduced the idea of Airport Transport Forums to be established by UK airports in order to set targets for the reduction in the proportion of journeys to/from the airport made by car based modes. In this working paper the authors critically assess the targets developed for achieving the objective of a greater use of public transport in making journeys to airports. Evidence is presented as to how UK airports have developed targets in order to respond to the Government’s initiative.

year: 2004-09

title: When your maunga is a mountain but your moana is not a sea; Insights from the perception of synonymy of te reo Māori loanwords and New Zealand English lexical equivalents

authors: Pohl, Alexander

abstract: Languages and their speakers are in ongoing contact with one another, which inevitably leads to a flow of words being borrowed from one language into another (Haspelmath 2009; Winford 2010). One perspective that has comparatively seen less attention in language contact research concerns how loanword relate to existing lexical alternatives. In recent years, language contact research has thus seen a paradigm shift towards an onomasiological perspective (see Anderson et al. 2017; Crombez et al. 2022; Zenner et al. 2023). Within this shift, most studies looking at lexical variation between loanwords and their near synonyms equivalents employ corpus linguistics methods (e.g. Onysko & WinterFroemel 2011; Soares da Silva 2013). 

This project presents a large-scale experimental approach from a case-study involving Māori loanwords borrowed into New Zealand English (NZE). Māori loanwords are ubiquitous, salient and probably still increasing within the NZE lexicon (Macalister 2007; Trye et al. 2019). Regarding onomasiology, Māori loanwords have been glossed and explained in different ways, and to date, there has been to our knowledge almost no research focused specifically on the relationship between loanwords and their near synonyms. 

Here, we report on a Qualtrics experiment devised to probe the perceived relationship between 60 Māori loanwords (spanning established semantic categories: flora and fauna, material culture, and social culture) and their NZE equivalents, as ascertained from published sources. The synonymy judgments were elicited for pairs (e.g. whānau – family), using an analogue slider (ranging from 0 = non-synonymous to 100 = fully synonymous; see Figure 1). Because synonymy judgements are subjective, we also included ten fillers, to help us calibrate and interpret participant judgements. The 60 words were divided into two-word lists in order avoid fatigue, resulting in a within participant design. The target demographic for our population of interest consisted of young adults (18-24 years). 

Following cleaning and exclusions (e.g. participants who ignored filler items), the final dataset contained 260 participants. Inspecting the dataset showed a skew towards female participants, and for this reason, we focus our statistical analysis on this core sample, while keeping an eye on the full dataset containing all participants. Preliminary findings suggest that young adults think Māori loanwords are (highly) synonymous with NZE lexical alternatives. These findings will be further scrutinised with regression techniques and qualitative analyses of the comments provided in an open answer section of the questionnaire.

text: When your maunga is a mountain but your moana is not a sea; Insights from the perception of synonymy of te reo Māori loanwords and New Zealand English lexical equivalents Languages and their speakers are in ongoing contact with one another, which inevitably leads to a flow of words being borrowed from one language into another (Haspelmath 2009; Winford 2010). One perspective that has comparatively seen less attention in language contact research concerns how loanword relate to existing lexical alternatives. In recent years, language contact research has thus seen a paradigm shift towards an onomasiological perspective (see Anderson et al. 2017; Crombez et al. 2022; Zenner et al. 2023). Within this shift, most studies looking at lexical variation between loanwords and their near synonyms equivalents employ corpus linguistics methods (e.g. Onysko & WinterFroemel 2011; Soares da Silva 2013). 

This project presents a large-scale experimental approach from a case-study involving Māori loanwords borrowed into New Zealand English (NZE). Māori loanwords are ubiquitous, salient and probably still increasing within the NZE lexicon (Macalister 2007; Trye et al. 2019). Regarding onomasiology, Māori loanwords have been glossed and explained in different ways, and to date, there has been to our knowledge almost no research focused specifically on the relationship between loanwords and their near synonyms. 

Here, we report on a Qualtrics experiment devised to probe the perceived relationship between 60 Māori loanwords (spanning established semantic categories: flora and fauna, material culture, and social culture) and their NZE equivalents, as ascertained from published sources. The synonymy judgments were elicited for pairs (e.g. whānau – family), using an analogue slider (ranging from 0 = non-synonymous to 100 = fully synonymous; see Figure 1). Because synonymy judgements are subjective, we also included ten fillers, to help us calibrate and interpret participant judgements. The 60 words were divided into two-word lists in order avoid fatigue, resulting in a within participant design. The target demographic for our population of interest consisted of young adults (18-24 years). 

Following cleaning and exclusions (e.g. participants who ignored filler items), the final dataset contained 260 participants. Inspecting the dataset showed a skew towards female participants, and for this reason, we focus our statistical analysis on this core sample, while keeping an eye on the full dataset containing all participants. Preliminary findings suggest that young adults think Māori loanwords are (highly) synonymous with NZE lexical alternatives. These findings will be further scrutinised with regression techniques and qualitative analyses of the comments provided in an open answer section of the questionnaire.

year: 2024