sampling-identification-characterization-microplastics-release-from

Sampling, Identification and Characterization of Microplastics Release from Polypropylene Baby Feeding Bottle during Daily Use

Microplastics (MPs) are becoming a global concern due to the potential risk to human health. Case studies of plastic products (i.e., plastic single-use ...

Trinity College Dublin

Microbial lipids are considered as the starting material for production of second-generation biofuels and their polyunsaturated fatty acids are rich sources of neutraceuticals. Exploring cheap feedstock for producing microbial lipids is necessary. The present study examined the potential of microbial lipids and γ-linolenic acid (GLA) production by two oleaginous fungi, Aspergillus flavus I16-3 and Mucor rouxii, with potato processing wastewater as a low-cost or no-cost nutrient source.

Utilisation of potato processing wastewater for microbial lipids and γ-linolenic acid production by oleaginous fungi.

Peatlands cover ∼3% of the world's landmass and large expanses have been altered significantly as a consequence of land use change. Forestry activities are a key pressure on these catchments increasing suspended sediment and nutrient export to receiving waters. The aim of this study was to investigate stream dissolved oxygen (DO) and metabolic activity response following clearfelling of a 39-year-old lodgepole pine and Sitka spruce forestry in an upland peat catchment. Significant effects of clearfelling on water temperature, flows, DO and stream metabolic (photosynthesis, respiration) rates were revealed. Stream temperature and discharge significantly increased in the study stream following clearfelling. Instream ecosystem respiration increased significantly following clearfelling, indicating an increase in the net consumption of organic carbon. 

Forest clearfelling effects on dissolved oxygen and metabolism in peatland streams.

Ptaquiloside, along with other natural phytotoxins, is receiving increased attention from scientists and land use managers. There is an urgent need to increase empirical evidence to understand the scale of phytotoxin mobilisation and potential to enter into the environment. In this study the risk of ptaquiloside to drinking water was assessed by quantifying ptaquiloside in the receiving waters at three drinking water abstraction sites across Ireland and in bracken fronds surrounding the abstraction sites. We also investigated the impact of different management regimes (spraying, cutting and rolling) on ptaquiloside concentrations at plot-scale in six locations in Northern Ireland, UK. Ptaquiloside concentrations were determined using recent advances in the use of LC-MS for the detection and quantification of ptaquiloside. The results indicate that ptaquiloside is present in bracken stands surrounding drinking water abstractions in Ireland, and ptaquiloside concentrations were also observed in the receiving waters. Furthermore, spraying was found to be the most effective bracken management regime observed in terms of reducing ptaquiloside load. Increased awareness is vital on the implications of managing land with extensive bracken stands. 

Ptaquiloside in Irish Bracken Ferns and Receiving Waters, with Implications for Land Managers.

Ireland reported the highest non-compliance with respect to total trihalomethanes (TTHMs) in drinking water across the 27 European Union Member States for the year 2010. We carried out a GIS-based investigation of the links between geographical parameters and catchment land-uses with TTHMs concentrations in Irish drinking water. A high risk catchment map was created using peat presence, rainfall (>1400 mm) and slope (<5%) and overlain with a map comprising the national dataset of routinely monitored TTHM concentrations. It appeared evident from the map that the presence of peat, rainfall and slope could be used to identify catchments at high risk to TTHM exceedances. Furthermore, statistical analyses highlighted that the presence of peat soil with agricultural land was a significant driver of TTHM exceedances for all treatment types. PARAFAC analysis from three case studies identified a fluorophore indicative of reprocessed humic natural organic matter as the dominant component following treatment at the three sites. Case studies also indicated that (1) chloroform contributed to the majority of the TTHMs in the drinking water supplies and (2) the supply networks contributed to about 30 μg L of TTHMs.

National scale assessment of total trihalomethanes in Irish drinking water.

Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants.

Minimal climate change impacts on natural organic matter forecasted for a potable water supply in Ireland.

This Review describes the objectives and methodology of the DairyWater project as it aims to aid the Irish dairy processing industry in achieving sustainability as it expands. With the abolition of European milk quotas in March 2015, the Republic of Ireland saw a surge in milk production. The DairyWater project was established in anticipation of this expansion of the Irish dairy sector in order to develop innovative solutions for the efficient management of water consumption, wastewater treatment and the resulting energy use within the country's dairy processing industry. Therefore, the project can be divided into three main thematic areas: dairy wastewater treatment technologies and microbial analysis, water re-use and rainwater harvesting and environmental assessment. In order to ensure the project remains as relevant as possible to the industry, a project advisory board containing key industry stakeholders has been established. To date, a number of large scale studies, using data obtained directly from the Irish dairy industry, have been performed. Additionally, pilot-scale wastewater treatment (intermittently aerated sequencing batch reactor) and tertiary treatment (flow-through pulsed ultraviolet system) technologies have been demonstrated within the project. Further details on selected aspects of the project are discussed in greater detail in the subsequent cluster of research communications.

DairyWater: striving for sustainability within the dairy processing industry in the Republic of Ireland.

The studies described in the Research Communication aimed to describe the feasibility of using coal fly ash to synthesize nano-zeolite, and the ammonium and phosphate adsorption efficiencies of the nanomaterial in dairy wastewater. Chemical treatment of coal fly ash was conducted and changes observed. Samples treated with NaOH had an increased cation exchange capacity and P sorption index compared to the initial fly ash, due to particle modification from smooth surface to plate- and rod-shape crystals, referred to as nano-zeolite. Batch experiments were conducted by mixing coal fly ash and nano-zeolite with synthesized wastewater to study the effect of sorption time, pH values and dosage of nano-zeolite on ammonium and phosphate removal efficiency. The adsorption process reached equilibrium in a very short time (less than 60 min), which suggests a potential for fast immobilization of pollutants. The concentration of ammonium decreased from 118 to 35 mg/l (71% removal) while the concentration of phosphate decreased from 52 to 45 mg/l. The removal efficiency of ammonium was 36·6, 51·8 and 70·9% at pH 3, 7 and 10, respectively whilst that of phosphate increased dramatically with decreased slurry pH (92·1, 47·3 and 12·3% at pH 3, 7 and 10, respectively). Nano-zeolite could be a potential absorbent for fast immobilization of ammonium but not phosphate. Surface modification of nano-zeolite could be introduced in order to enhance the pollutants removal efficiency.

Potential of using synthesized nano-zeolite for ammonium and phosphate immobilization in dairy wastewater.

Iron sulphides, mainly in the form of mackinawite (FeS), pyrrhotite (FeS, x = 0-0.125) and pyrite (FeS), are the most abundant sulphide minerals and can be oxidized under anoxic and circumneutral pH conditions by chemoautotrophic denitrifying bacteria to reduce nitrate to N. Iron sulphides mediated autotrophic denitrification (ISAD) represents an important natural attenuation process of nitrate pollution and plays a pivotal role in linking nitrogen, sulphur and iron cycles in a variety of anoxic environments. Recently, it has emerged as a promising bioprocess for nutrient removal from various organic-deficient water and wastewater, due to its specific advantages including high denitrification capacity, simultaneous nitrogen and phosphorus removal, self-buffering properties, and fewer by-products generation (sulphate, waste sludge, NO, NH, etc.). This paper provides a critical overview of fundamental and engineering aspects of ISAD, including the theoretical knowledge (biochemistry, and microbial diversity), its natural occurrence and engineering applications. Its potential and limitations are elucidated by summarizing the key influencing factors including availability of iron sulphides, low denitrification rates, sulphate emission and leaching heavy metals. This review also put forward two key questions in the mechanism of anoxic iron sulphides oxidation, i.e. dissolution of iron sulphides and direct substrates for denitrifiers. Finally, its prospects for future sustainable wastewater treatment are highlighted. An iron sulphides-based biotechnology towards next-generation wastewater treatment (NEO-GREEN) is proposed, which can potentially harness bioenergy in wastewater, incorporate resources (P and Fe) recovery, achieve simultaneous nutrient and emerging contaminants removal, and minimize waste sludge production.

Iron sulphides mediated autotrophic denitrification: An emerging bioprocess for nitrate pollution mitigation and sustainable wastewater treatment.

Forest harvesting activities on peatlands have long been associated with nutrient leaching and deterioration of downstream water quality. This study aims to assess the effect of grass seeding practice on harvested blanket peatlands to immobilize N and reduce its export to water courses. First, a plot-scale field experiment was conducted by seeding with two grass species (Holcus lanatus and Agrostis capillaris) to study the N uptake potential from a harvested area. Secondly, a simulated rainfall experiment was conducted to study the effect of these grasses on reducing N leaching from surface peat using laboratory flume approach. In the end, the role of seeded grasses in removing N from nutrient-rich throughflow water was assessed using simulated overland flow experiment. The results showed that the seeded grasses had the potential to uptake over 30 kg ha of N in the first year after seeding on harvested peatlands, whereas it takes over 2.5 years to establish the same level of N uptake by natural re-vegetation (non-grassed). In the simulated rainfall experiment, the inorganic N (NH-N and NO-N) leaching in surface runoff from grassed flumes was 72% lower (453 mg m) than non-grassed flumes (1643 mg m). In the simulated overland flow experiment, the N retention by grassed flumes was significantly higher (98%) as compared to non-grassed flumes (70%) in the simulated overland flow experiment. Comparatively higher concentrations of NH-N and NO-N in soil porewaters of non-grassed flumes suggest that this N retention by non-grassed flumes is less sustainable and is likely to be leached in runoff in subsequent flow events. The results from all three experiments in this study suggest that seeded grasses are a major sink of N on harvested blanket peatland forests. Immobilization of N onsite using the grass seeding and mini-buffer practice could be an efficient and a feasible mean of reducing N export from harvested blanket peatland forests in order to protect the sensitive water courses. However, the sustainability of retention and immobilization of N by grasses needs to be studied further in long-term field-scale experiments on multiple peatland sites.

Mechanism and role of seeded native grasses to immobilize nitrogen on harvested blanket peat forests for protection of water courses.

Nitrogen removal is often limited in municipal wastewater treatment due to the insufficiency of carbon source, and using food wastes fermentation liquid as carbon source could cut down the cost of operating and recycle food wastes. Food wastes fermentation liquid production and application as external carbon source were explored in the laboratory and full-scale system in this study. In the laboratory scale, lactic acid and VFAs were the main components of fermentation liquid, and the highest total chemical oxygen demand (TCOD) production was obtained with activated sludge as inoculum. The yield of TCOD was around 794.5 mg/g TS and NH-N was 3.5 mg/g TS. The denitrification rate with fermentation liquid was slightly lower than acetic acid and butyric acid, but higher than lactic acid and starch. In the full-scale investigation, the TCOD concentration in fermentation liquid was in the range of 6.9-12.8 g/L and the ratio of TCOD/inorganic nitrogen was 210.5-504.5:1. NO-N removal increased from 52.1% to 94.2% after fermentation liquid addition, confirming the potentiality of food wastes fermentation liquid replace the commercial carbon source in wastewater treatment plants.

Article	Year
Utilisation of potato processing wastewater for microbial lipids and γ-linolenic acid production by oleaginous fungi. Journal of the science of food and agriculture\| PubMed ID: 25504420	2015
Forest clearfelling effects on dissolved oxygen and metabolism in peatland streams. Journal of environmental management\| PubMed ID: 26513323	2016
Ptaquiloside in Irish Bracken Ferns and Receiving Waters, with Implications for Land Managers. Molecules (Basel, Switzerland)\| PubMed ID: 27128893	2016
National scale assessment of total trihalomethanes in Irish drinking water. Journal of environmental management\| PubMed ID: 29428648	2018
Minimal climate change impacts on natural organic matter forecasted for a potable water supply in Ireland. The Science of the total environment\| PubMed ID: 29499542	2018
DairyWater: striving for sustainability within the dairy processing industry in the Republic of Ireland. The Journal of dairy research\| PubMed ID: 30088465	2018
Potential of using synthesized nano-zeolite for ammonium and phosphate immobilization in dairy wastewater. The Journal of dairy research\| PubMed ID: 30101729	2018
Iron sulphides mediated autotrophic denitrification: An emerging bioprocess for nitrate pollution mitigation and sustainable wastewater treatment. Water research\| PubMed ID: 32413614	2020
Mechanism and role of seeded native grasses to immobilize nitrogen on harvested blanket peat forests for protection of water courses. Environmental science and pollution research international\| PubMed ID: 33156503	2021
Fermentation liquid production of food wastes as carbon source for denitrification: Laboratory and full-scale investigation. Chemosphere\| PubMed ID: 33423004	2021

Liwen Xiao

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