This research aimed to develop biomarkers for estimating ammonia (NH3) emissions from dairy cattle manure over a 15-day in vitro incubation system. To generate different levels of NH3 emissions, the experiment utilized four manure experimental groups: 1 urinary nitrogen (U) to 1 faecal nitrogen (F) ratio (CT), 2 U to 1 F ratio (2U1F), and CT and 2U1F with lignite application (CT + L and 2U1F + L, respectively). The addition of lignite to ruminant manure aimed to enhance environmental sustainability through its beneficial properties. Three biomarkers, nitrogen (N) isotopic fractionation (δ15N), N: potassium (K) ratio, and N: phosphorus (P) ratio, were investigated. Manure δ15N increased linearly when NH3 emission increased in CT and 2U1F groups (R2 = 0.79 and 0.90, respectively; P ≤ 0.001), while manure N: P decreased when NH3 emission increased in CT + L and 2U1F + L groups (R2 = 0.73 and 0.85, respectively; P ≤ 0.001). No useful relationship was found between N: K and NH3 emission, apart from in 2U1F group (R2 = 0.84; P ≤ 0.001). The experiment found manure δ15N and N: P are complementary biomarkers to predict NH3 emissions, from non-lignite and lignite groups, respectively.

This article analyses the endogenous choice of farmers to be organic or conventional in a groundwater evolutionary model when a tax on fertiliser on conventional farmers is implemented by a regulatory agency. The analysis of the model shows that the coexistence of both type of farmers only occurs when the decrease in productivity due to organic production is relatively low and the price premium for organic products is relatively high. However, even if conversion is welfare improving, our results show that this conversion may be done at the expense of the water resource with a lower water table. An application to the Western la Mancha aquifer (Spain) illustrates the main results.

The washing of synthetic materials has been named as the largest contributor of microplastic pollution to our oceans. With the consumption of petrochemical-based synthetic materials expected to grow, due to an increased demand, the release of microplastic fibres to our environments is expected to also accelerate. To combat microplastic fibre release, this study explores source-directed interventions within the design and manufacturing process of textiles to reduce the amount of pollution released from the surface and the edges of the fabric structure. Using standardised wash tests and polyester fabric swatches that were created in-house with systematic structural adjustments, single jersey knit fabrics were shown to release over three times more microplastic pollution than twill woven fabric. This illustrates that increasing the tightness of a fabric could be implemented within the design of fabrics for environmental benefits. Additionally, the laser cutting technique reduced microplastic fibres released by over a third compared to scissor cutting and overlock serging, showing that the edge of the fabric is a significant source of microplastic pollution released during laundering. This research highlights the adaptable and innovative eco-design approaches to clothing production which is necessary to help the sector reach international sustainability targets and regulations.

In recent decades, the proliferation of single-use plastic products has significantly contributed to a surge in plastic pollution on a global scale. Researchers have extensively investigated the impacts of plastic pollution across various regions, yet a comprehensive holistic and location-based understanding of these impacts in the West African context is lacking. This study addresses this gap through a systemic assessment of the impacts of plastic pollution, in West Africa, particularly Ghana. Employing a qualitative system dynamics causal modelling approach, this study establishes linkages between pollution effects at the macro level, constructing a hierarchical outline of both high- and low-level impacts. The significance of this research lies in the application of pertinent systems thinking techniques to comprehend the broader impacts of plastic pollution. The outcomes of this study will inform the development of effective policies aimed at preventing or mitigating plastic pollution in Ghana, and potentially the wider West African context.

Reactions of smectite with phenols were investigated to understand the role of clay minerals in abating transport of these organic pollutants to ground water. Sorption of o-methylphenol, o-chlorophenol, and m-methylphenol by the clay with different exchange cations was accomplished by passing phenol vapors in a slow stream of air or nitrogen through the samples. The resulting products, extracted with methanol and analyzed by using mass spectrometry, included monomers, dimers, trimers, and tetramers of the parent phenol and of the corresponding quinones, the oxidation product of the phenols. In extracts from the Fe-clay-phenol complexes formed in air, traces of the phenolic pentamers were also detected. Both sorption and polymerization were much higher in air than in nitrogen. The greatly reduced polymerization in nitrogen suggests that anaerobic environment of the landfill sites may facilitate phenol transport to ground water. The degree of polymerization and its magnitude was in the order Fe- > Al- > Ca- > Na-clay.

The Black Sea is an enclosed sea surrounded by six coastal countries, of which Bulgaria and Romania are EU Member States. The Convention for the Protection of the Black Sea Against Pollution was ratified in 1994 by all coastal countries. This Convention is the only European regional sea convention to which the EU is not a Party. While Romania and Bulgaria are in favor of EU accession to the Convention, Turkey, Russia and Ukraine thus far have blocked accession. In this paper, we develop a negotiation model with endogenous enforcement and exogenous fraud to analyze the different positions of groups of coastal countries relative to EU accession to the Convention. Our model contributes to defining a proposal that the EU could make to the opposing states such that they accept the EU as a Party to the Convention. In that context we investigate also whether Romania and Bulgaria might be better off delegating their decision power to the EU, rather than retaining their individual voting rights.

Hong Kong is one of the busiest metropolises, and the Eurasian otter Lutra lutra is one of its most threatened species. We collected published data for 1890–2020 to document changes in local otter abundance and distribution over time. The 108 records revealed new distribution data and showed that decline began as early as the 1930s. The local Eurasian otter is strongly associated with coastal and alluvial wetlands, and its last refugium, the Yuen Long floodplain draining the Mai Po Inner Deep Bay Ramsar Site, has always been a critical habitat. Our analysis suggests that hunting is unlikely to be a major cause of the otter's decline. Rather, dependence on lowland wetlands makes it particularly susceptible to habitat loss caused by increasing urbanization. Auxiliary infrastructures and water pollution have also exacerbated wetland degradation to the detriment of otters and their prey. There is a need for greater cooperation amongst government agencies and landowners to guarantee otter survival: priority steps include the establishment of additional and interconnected wetland reserves, better stakeholder engagement and enforcement efficiency to tackle entrenched pollution problems, and flood prevention schemes that preserve or restore functional riverine ecosystems within critical otter habitats. The current otter distribution range has been earmarked for development in a government-led mega urbanization plan; the plight of the local Eurasian otter needs to be widely publicized to garner stakeholders' support and galvanize immediate conservation actions across society.

The importance of buoyancy relative to free-stream flow is described using an adapted Froude number $Fr' = U/f_0^{1/3}$, where $U$ is the flow speed and $f_0$ is the exhaust buoyancy flux per unit length. We varied $Fr'$ by changing the free-stream flow rate, the exhaust flow rate and the buoyancy of the exhaust. We have experimentally identified two flow regimes, depending on the value of $Fr'$. For high $Fr'$ (low buoyancy), dispersion is driven by inertial forces in the wake and the amount of a pollutant in the wake is independent of $Fr'$. For moderate $Fr'$, a wall plume develops up the back of the step, directly feeding the pollutant into the shear layer, but without altering the shape of the wake. This wall plume reduces the amount of pollutant trapped behind the step. We developed an analytic model to describe the quantity of pollutant trapped behind the step. The model predicts the transition from buoyancy being negligible to being the dominant transport mechanism within the wake. We have hypothesised and observed some evidence of a third regime at low $Fr'$, when the buoyancy is sufficient to distort the macrostructure of the shear layer and wake.