46 results match your criteria: "National Institute of Water and Atmospheric Research Ltd (NIWA)[Affiliation]"

Quality of cellulose and biostimulant extracts from Oedogonium calcareum cultivated during primary wastewater treatment.

Bioresour Technol

July 2024

Coastal Marine Field Station, School of Science, University of Waikato, Tauranga, New Zealand; Environmental Research Institute, The University of Waikato, Tauranga, New Zealand.

A practical two-product cascading biorefinery was developed to extract a biostimulant and cellulose from the freshwater filamentous macroalga Oedogonium calcareum grown while treating primary wastewater. Biostimulant production provides a valuable extract with production of disinfected residual biomass for further product development. Both Escherichia coli and F-specific RNA bacteriophage, indicators of human pathogens contamination, were absent from the residual biomass.

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Elucidating phosphorus removal dynamics in a denitrifying woodchip bioreactor.

Sci Total Environ

March 2024

Environmental Research Institute, School of Science, Faculty of Science and Engineering, University of Waikato, Kirikirioa Hamilton, New Zealand; Lincoln Agritech Ltd, Ruakura, Kirikirioa Hamilton 3214, New Zealand. Electronic address:

Denitrifying woodchip bioreactors (DBRs) are an established nitrate mitigation technology, but uncertainty remains on their viability for phosphorus (P) removal due to inconsistent source-sink behaviour in field trials. We investigated whether iron (Fe) redox cycling could be the missing link needed to explain P dynamics in these systems. A pilot-scale DBR (Aotearoa New Zealand) was monitored for the first two drainage seasons (2017-2018), with supplemental in-field measurements of reduced solutes (Fe, HS/HS) and their conjugate oxidised species (Fe/SO) made in 2021 to constrain within-reactor redox gradients.

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Filamentous algae nutrient scrubber (FANS) operating parameters can strongly influence algal biomass productivity and nutrient removal. However, few studies to date have investigated the effects of FANS operating parameters such as initial standing crop, harvesting frequency and influent flow rate on biomass productivity and nutrient removal performance, especially for FANS that cultivate a single species of algae. Therefore, the overall aim of this study was to investigate how operating parameters affect the biomass productivity and nutrient removal performance of Oedogonium sp.

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We investigated the effect of algal contact time (ACT) and horizontal water velocity (HWV) on the performance of pilot-scale Filamentous Algae Nutrient Scrubbers (FANS) treating river water during the NZ summer. The FANS floways were seeded with a mixture of four New Zealand native filamentous algal species (Oedogonium sp., Cladophora sp.

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A decision-theoretical approach was used to evaluate strategies to rebuild a severely depleted scallop (Pecten novaezelandiae) populations in the Tasman Bay and Golden Bay of New Zealand. These strategies were: no intervention, cessation of seabed bottom contact fishing, and reduction of sediment and nutrient runoff from surrounding land through on-farm practices. Our approach combined outputs of estimated effects of on-farm practices on erosion and nutrient reduction with a stochastic dynamic model of the scallop populations.

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Article Synopsis
  • The concentration of dissolved oxygen in lakes affects biodiversity, nutrient cycling, greenhouse gas emissions, and drinking water quality, yet long-term changes remain largely unexplored compared to oceans.
  • A study of 45,148 profiles from 393 temperate lakes reveals widespread declines in dissolved oxygen levels, particularly in deep waters due to thermal stratification and loss of clarity, while surface waters show varied results.
  • Declines in freshwater oxygen levels are significantly higher than those in oceans, raising concerns about the impact on essential lake ecosystem services amidst climate change and reduced water clarity.
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TanSat is the 1st Chinese carbon dioxide (CO) measurement satellite, launched in 2016. In this study, the University of Leicester Full Physics (UoL-FP) algorithm is implemented for TanSat nadir mode XCO retrievals. We develop a spectrum correction method to reduce the retrieval errors by the online fitting of an 8 order Fourier series.

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This study compared light and dark disinfection of faecal bacteria/viral indicator organisms (E. coli and MS2 (fRNA) bacteriophage) and human viruses (Echovirus and Norovirus) in Wastewater Treatment Pond (WTP) mesocosms. Stirred pond mesocosms were operated in either outdoor sunlight-exposed or laboratory dark conditions in two experiments during the austral summer.

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Developing a Framework for Public Involvement in Mathematical and Economic Modelling: Bringing New Dynamism to Vaccination Policy Recommendations.

Patient

July 2021

The Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, School of Life Sciences and Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK.

Objectives: The Mathematical and Economic Modelling for Vaccination and Immunisation Evaluation (MEMVIE) programme aimed to explore, capture and support the potential contribution of the public to mathematical and economic modelling, in order to identify the values that underpin public involvement (PI) in modelling and co-produce a framework that identifies the nature and type of PI in modelling and supports its implementation.

Methods: We established a PI Reference Group, who worked collaboratively with the academic contributors to create a deliberative knowledge space, which valued different forms of knowledge, expertise and evidence. Together, we explored the key steps of mathematical and economic methods in 21 meetings during 2015-2020.

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Understanding the environmental and behavioral factors that influence how organisms maintain energy balance can inform us about their potential resiliency to rapid environmental changes. Flexibility in maintaining energy balance is particularly important to long-lived, central-place foraging seabirds that are constrained when locating food for offspring in a dynamic ocean environment. To understand the role of environmental interactions, behavioral flexibility and morphological constraints on energy balance, we used doubly labeled water to measure the at-sea daily energy expenditure (DEE) of two sympatrically breeding seabirds, Campbell () and grey-headed () albatrosses.

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Unvegetated, intertidal sandflats play a critical role in estuarine carbon and nutrient dynamics. However, these ecosystems are under increasing threat from anthropogenic stressors, especially nitrogen enrichment. While research in this area typically focuses on sediment-water exchanges of carbon and nutrients during tidal inundation, there remain significant gaps in our understanding of GHG (Greenhouse Gas) fluxes during tidal emergence.

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Long-distance dispersal plays a key role in evolution, facilitating allopatric divergence, range expansions, and species movement in response to environmental change. Even species that seem poorly suited to dispersal can sometimes travel long distances, for example via hitchhiking with other, more intrinsically dispersive species. In marine macroalgae, buoyancy can enable adults-and diverse hitchhikers-to drift long distances, but the evolution and role of this trait are poorly understood.

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Swimming is a popular activity in Aotearoa-New Zealand (NZ). Two variables that strongly influence swimming suitability of waters are faecal contamination, as indicated by the bacterium Escherichia coli, and visual clarity as it affects aesthetics and safety with respect to submerged hazards. We show that E.

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Wastewater treatment ecotechnologies such as constructed wetlands and denitrifying bioreactors are commonly perceived as robust and resilient to shock loading, but this has proved difficult to quantify, particularly when comparing different systems. This study proposes a method of quantifying and comparing performance resilience in response to a standard disturbance. In a side-by-side study we compare the treatment performance of four different configurations of wetlands and denitrifying bioreactors subjected to hydraulic shock loads of five times the standard inflow rate of primary treated sewage for five days.

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Enhanced pond systems (EPS) consist of a series of ponds that have been designed to work in synergy to provide both cost-effective enhanced wastewater treatment and resource recovery, in the form of algal biomass, for beneficial reuse. Due to the limited number of full-scale EPS systems worldwide, our understanding of factors governing both enhanced wastewater treatment and resource recovery is limited. This paper investigates the seasonal performance of a full-scale municipal wastewater EPS with respect to nutrient removal from the liquid fraction, microalgal biomass production and subsequent removal through the system.

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Multiscale scenarios for nature futures.

Nat Ecol Evol

October 2017

PBL Netherlands Environmental Assessment Agency, 2500 GH, The Hague, The Netherlands.

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The powerful El Niño event of 2015-2016 - the third most intense since the 1950s - has exerted a large impact on the Earth's natural climate system. The column-averaged CO dry-air mole fraction (XCO) observations from satellites and ground-based networks are analyzed together with in situ observations for the period of September 2014 to October 2016. From the differences between satellite (OCO-2) observations and simulations using an atmospheric chemistry-transport model, we estimate that, relative to the mean annual fluxes for 2014, the most recent El Niño has contributed to an excess CO emission from the Earth's surface (land + ocean) to the atmosphere in the range of 2.

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In the last decade, studies have focused on identifying the most suitable microalgal species for coupled high rate algal pond (HRAP) wastewater treatment and resource recovery. However, one of the challenges facing outdoor HRAP systems is maintaining microalgal species dominance. By increasing our understanding of the environmental drivers of microalgal community composition within the HRAP environment, it may be possible to manipulate the system in such a way to favour the growth of desirable species.

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Sediment carbon and nutrient fluxes from cleared and intact temperate mangrove ecosystems and adjacent sandflats.

Sci Total Environ

December 2017

National Institute of Water and Atmospheric Research Ltd (NIWA), Hamilton, New Zealand; Institute of Marine Science, University of Auckland, Auckland, New Zealand.

The loss of mangrove ecosystems is associated with numerous impacts on coastal and estuarine function, including sediment carbon and nutrient cycling. In this study we compared in situ fluxes of carbon dioxide (CO) from the sediment to the atmosphere, and fluxes of dissolved inorganic nutrients and oxygen across the sediment-water interface, in intact and cleared mangrove and sandflat ecosystems in a temperate estuary. Measurements were made 20 and 25months after mangrove clearance, in summer and winter, respectively.

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Wastewater treatment high rate algal pond biomass for bio-crude oil production.

Bioresour Technol

January 2017

Chemical and Materials Engineering Department, University of Auckland, New Zealand. Electronic address:

This study investigates the production potential of bio-crude from wastewater treatment high rate algal pond (WWT HRAP) biomass in terms of yield, elemental/chemical composition and higher heating value (HHV). Hydrothermal liquefaction (HTL) of the biomass slurry (2.2wt% solid content, 19.

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Biodiesel production potential of wastewater treatment high rate algal pond biomass.

Bioresour Technol

December 2016

Chemical and Materials Engineering Department, University of Auckland, New Zealand. Electronic address:

This study investigates the year-round production potential and quality of biodiesel from wastewater treatment high rate algal pond (WWT HRAP) biomass and how it is affected by CO addition to the culture. The mean monthly pond biomass and lipid productivities varied between 2.0±0.

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Detrital subsidies from marine macrophytes are prevalent in temperate estuaries, and their role in structuring benthic macrofaunal communities is well documented, but the resulting impact on ecosystem function is not understood. We conducted a field experiment to test the effects of detrital decay on soft-sediment primary production, community metabolism and nutrient regeneration (measures of ecosystem function). Twenty four (2 m(2)) plots were established on an intertidal sandflat, to which we added 0 or 220 g DW m(-2) of detritus from either mangroves (Avicennia marina), seagrass (Zostera muelleri), or kelp (Ecklonia radiata) (n = 6 plots per treatment).

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A water quality index for recreation in Brazilian freshwaters.

J Water Health

April 2016

Geosciences Institute, Universidade Federal de Minas Gerais (UFMG), Av. Antônio Carlos 6627, Belo Horizonte, Brazil E-mail:

Use of water for leisure activities has long been prevalent in human societies, especially where the climate is favorable. Water resources with appealing conditions for primary contact recreational activities include rivers, waterfall plunge pools, dams and lakes, as well as sea coasts. Recreational use has specific demands for water quality, particularly as regards risks to human health such as exposure to pathogenic organisms, toxic substances, and submerged hazards.

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Carbon limitation in domestic wastewater high rate algal ponds is thought to constrain microalgal photo-physiology and productivity and CO2 augmentation is often used to overcome this limitation in summer. However, the implications of carbon limitation during winter are poorly understood. This paper investigates the effects of 0.

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