Diagnosis of Low-Carbon Permeable Pavements: Bearing Capacity and Long-Term Clogging Behaviour

The need to encourage sustainable construction practices to conserve the rapidly diminishing natural resources increases. Moreover, increases in impermeable areas in urban regions increase flood risk and impose significant stresses on stakeholders. The research presented here was conducted on using recycled low-carbon materials in permeable pavement systems (PPS) to address this issue. Despite the worldwide usage of PPS, uncertainty and a knowledge gap remain regarding the impact of recycled materials on their structural and long-term clogging performance. To this end, the load-bearing capacity and long-term clogging behaviour of four 0.2 m2 permeable pavement rigs made up of varying natural and recycled sub-base materials were evaluated in the laboratory. The recycled materials selected were crushed concrete aggregates (CCA) and cement-bounded expanded polystyrene beads (C-EPS), and the natural materials were basalt and quartzite aggregates. Accelerated 10-year clogging simulation with yearly hydraulic conductivity measurements was used to evaluate the long-term clogging behaviour of the rigs, whilst portable falling weight deflectometer (PFWD) testing was used to evaluate the load-bearing capacity. The results of the clogging simulation found that the hydraulic conductivity of all rigs declined exponentially and were of a similar pattern. This confirmed that the sub-base materials had little influence on the clogging behaviour of permeable pavements. The PFWD test, however, demonstrated that the sub-base materials impacted the load-bearing capacity of the rigs, but both CCA and C-EPS were suitable to be used in permeable pavements under different loading restrictions

AC-TC back in black: Restoring environmental water in the Douro Basin, Spain

Abatement costs (AC) and transaction costs (TC) are involved in motivating and implementing changes in public and private policies and programs. For example, Coase is best-known for his work on transaction costs, clearly stating that they matter. Both individual private and institutional public transaction costs are invested with abatement (production) costs to generate change through policy, program interventions, or incentives (e.g., regulation that minimizes or compensates those affected by smoke generated by neighbours). This compensation suggests some potential benefit to offset the losses caused by the negative event—funded, administered, monitored and possibly updated via abatement and transaction costs. Yet approaches to identifying, collecting data, measuring and describing abatement and transaction benefits remains missing from prior research. In fact, abatement or transaction benefits are almost unheard of. Because of this, standard benefit-cost analysis commonly used to economically evaluate and assess private and public investments does not feature in abatement or transaction cost research, limiting assessment and monitoring targets and a better understanding of more efficient future policy gains. As the demand and expectations for benefit-cost analysis grow in future to become more comprehensive and complex, finding ways to accommodate such analysis and test that approach is increasingly important globally. We describe such an attempt using a water management case study from northern Spain to show that not only is it possible to measure and report on coupled abatement and transaction benefits, but that prior theoretical interpretations may also be further explained and understood, providing private and public investment choices and water resource management narrative advantages

Teaching and Research as a ‘Trans-world activity’: A Decolonial Approach to Development Studies and Research

This paper contributes to decolonial horizons that challenge development studies and research within the neoliberal academy. It relies on autoethnographic positioning analysis, and a reflective reading of Freire’s critical pedagogy, and Lugones’s theory of active subjectivity and multiple selves, to explore Hull’s proposition of teaching and research as a trans-world activity. This involves reflexivity and analytical methods that incorporate questions of self and subjectivity in teaching and research. It offers trans-world teaching and research as a (1) a playful and loving way of being in the ‘world’, (2) an inversion of research and knowledge encounters and (3) a means to facilitate a sense of becoming

SUSTAINABILITY CHALLENGES IN WATER MANAGEMENT

• Water is a unique and finite resource that all users (humans, agriculture, and the environment) need to survive. However, supply is both diminishing and highly uncertain in the future due to climate change, driving intense competition between users. This situation demands we urgently teach and adopt sustainable water management for the benefit of all. • Successful sustainable water management depends on careful measurement, good quality information, high levels of caution, and flexible arrangements that are challenging to design and implement. However, most of us are also unwilling to give our water up. • Innovative sharing and reallocation of water resources offer a modern basis for teaching sustainable outcomes condensed to supply and demand concepts. Yet these concepts also face problems, which we discuss here for structuring effective teaching. • Sustainable water management is a shared problem requiring shared adjustment, which has proven challenging to achieve in the past. However, the current pressures on inequitable supply, increasingly variable supply, and uncertainty are increasing the urgency for reform

Isolation and identification of components of mother liquor sugar from Stevia rebaudiana Bertoni with nematicidal activity

Mother liquor sugar (MLS) is a highly prevalent by-product of processing Stevia rebaudiana Bertoni, which is an important cash crop used to prepare a natural sweetener. With an increase in demand for stevia, MLS production has also increased. However, MLS has limited applications owing to its complex sweetness profile and pronounced bitter aftertaste. To explore the potential reuse of MLS, two diterpenoid compounds were gradually separated and identified using polarity-based separation, normal-phase chromatography, reversed-phase chromatography and LH-20 separation followed by an acute toxicity tracking test in Caenorhabditis elegans. These compounds were identified as sterebins E and F using high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance. Sterebins E and F were found to be isomers, and sterebin F exhibited stronger nematicidal activity than sterebin E and fosthiazate at 24 h. The preliminary isolation of sterebin F was achieved via gradient elution using macroporous HPD-100 resin with methanol concentrations of 70 %, 90 % and 100 %. The adsorption process lasted approximately 10 h, and the desorption process was completed in 2 h. To the best of our knowledge, this is the first study to identify specific individual compounds from stevia by tracking their nematicidal activity. The insights gained into the nematicidal properties and isolation process of sterebin F from MLS provide a crucial theoretical and practical foundation for developing eco-friendly pest control solutions and natural alternatives to chemical pesticides in sustainable agriculture

Sustainable drainage systems (SuDS) for rainwater harvesting and stormwater management in temporary humanitarian settlements

Effective management of stormwater runoff is crucial in refugee camps and temporary shelters. Across the Africa, this is vital especially with the intense rainfalls due to the climate effect. Sustainable Drainage Systems (SuDS) can be implemented to provide potential sources of water resources across refugee camps and internally displaced people (IDPs). The performance of two SuDS (engineered wetlands and biofilters) was evaluated to assess their effectiveness at reducing levels of pollutants in harvested rainwater and stormwater under simulated environmental conditions of an IDP camp. The SuDS comprised a matrix of sub-surface bedding materials and filter media. Stormwater quality analysis aligned with the WHO and CIRIA standards was carried out over 61 weeks simulating environmental conditions. The SuDS significantly reduced nutrients and organics loading from the influent stormwater. The Constructed Stormwater Treatment System S1-a had an overall high performance in removing impurities (BOD – 60 %, COD – 70 %, Turbidity – 70 %, Colour – 72 %, Phosphates – 63 %, Ammonium – 57 % and Nitrates – 57 %). In addition, the Refugee Camp Engineered Stormwater Treatment System S2-d has overall well-performed impurities removal (TDS – 52 %, COD – 100 %, Turbidity – 100 %, Colour – 41 %, Phosphates – 96 %, Ammonium – 98 % and Nitrates – 88 %). The outflow samples from these SuDS found the concentrations are with high standards. However, it is recommended that the treated stormwater be reused for non-potable sources in these conditions. The implementations of this research findings can be further incorporated into the United Nations sustainable developmental goals of good health and wellbeing (SDG 3) clean water and sanitation (SDG 6), and Peace, justice and strong institutions (SDG 16)

‘This disagreeable weed’: arable plant conservation may benefit from historical publication insights

Arable plants, such as Cornflower (Centaurea cyanus), are the wild species that grow on cultivated land, having evolved alongside traditional low-intensity cropping practices. In Great Britain, approximately 150 species have been classified as arable plants, of which 54 have been recorded as threatened with extinction and at least seven as regionally extinct (i.e. extinct in GB) or extinct in the wil

Abatement and transaction costs of water reallocation

Water reallocations have costs to the users of water, or abatement costs (e.g., charges designed to marginally increase environmental water flows), but also nontrivial institutional transaction costs (e.g., costs incurred to develop institutions and organizations to support and enforce environmental reallocations). However, institutional transaction costs studies are very limited and those available do not integrate abatement costs measurements, which constrains our ability to assess the performance of water reallocation. This paper presents the first integrated analysis of abatement and transaction costs of water reallocation. The analysis is illustrated with an application to the Douro River Basin, an agricultural basin in central Spain that has recently finished its second planning cycle (2015-2021). First, we use a hydroeconomic model that accounts for the two-way feedback responses between human and water systems to estimate the abatement costs of water reallocations, as well as their effectiveness in achieving the good ecological status of water bodies. Second, we measure and monetize realized institutional transaction costs of river basin planning over time and build on this cutting-edge longitudinal dataset to assess future directions and magnitude of transaction costs. We use this information to assess and rank the performance (through cost-effectiveness) of the water reallocations considered in the latest Douro River Basin Plan under alternative climate change scenarios. We find that under the hypothesis of stationary transaction costs, these can represent between 5.7% and 8.3% of the total reallocation costs (abatement plus transaction costs). This non-trivial magnitude highlights the need to account for both abatement and transaction costs when assessing the performance of water reallocations, and environmental policy overall