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Jordan's water scarcity prompted a national plan whereby treated wastewater is utilized to amend agricultural irrigation water so as to reallocate freshwater to urban/domestic uses. The policy, however, has engendered farmers' resistance in the Northern Jordan Valley (NJV), causing a stalemate in putting new infrastructure into operation. This research investigated the socio-economic causes of farmer resistance and contestation, and examined the government's institutional approach to overcome the challenges. We found that the perceived risks of wastewater reuse such as salinization and restrictions from international markets figure prominently in the farmers resistance. As yet, farmers have managed to avoid the shift to treated wastewater use by using the political agency of elite farmers who control the Water Users Associations. These same farmers have adopted informal water access practices to overcome freshwater shortages. At the same time, small producers who don't have possibilities to access extra water and with less political clout seem more willing to irrigate with treated wastewater. We conclude that understanding the heterogeneous context in which the envisioned wastewater users operate is key to predicting and solving conflicts that arise in treated wastewater reuse projects. [ABSTRACT FROM AUTHOR]

Macroplastics are the primary contributor to riverine plastic pollution by mass, posing a wide range of serious threats for riverine systems, from adversely affecting various life forms within the riverine system, to potentially increasing flood risk, and generally resulting in adverse effects on any livelihoods. Compared to other river-related research disciplines, research into riverine macroplastics and their effects has not yet featured prominently. Various quantification methods are presently used to assess the presence of macroplastics at different locations within river systems; however, overcoming limitations and unifying methods remain an essential need. Macroplastic dynamics in rivers are subject to various factors, including both material and river characteristics. We review the diverse factors that potentially influence macroplastic dynamics in rivers, and highlight our knowledge limits. We advocate for future research that enables synergies between improved field quantification techniques, use of global protocols and data sharing, and laboratory experiments. This is needed to obtain a riverine macroplastic budget model, required for the implementation of targeted management practices. Finally, a multilayer potential management strategy is presented: (i) reducing the macroplastic supply into rivers; (ii) removing effectively and safely macroplastics from within rivers; and (iii) treating macroplastics once removed from the riverine system. [ABSTRACT FROM AUTHOR]

Recently, the rapid increase in global plastics production has caused various ecological and economic issues, worsened by poor material and waste management. Among the market-based instruments that could help mitigate the environmental impacts of plastics throughout their life-cycle, we evaluate the advantages and limitations of incorporating a cap-and-trade (CAT) system into future policy mixes. Our aim is to inspire further investigation of CAT's feasibility rather than presenting it as the ultimate solution. Drawing from past CAT implementations in domains such as water resource management and carbon emissions, we outline three key policy design considerations: (1) material and target group identification, (2) cap establishment and permit allocation, and (3) development of a competitive market environment. We explore a three-tiered approach with global, national, and sectoral caps covering the plastic lifecycle from cradle to grave. While there are viable reasons to consider a plastics CAT, significant challenges persist, which may ultimately limit its implementation. In the context of ongoing UN Plastics Treaty negotiations or future policy developments, this evaluation of CAT can be beneficial for assessing when and how this tool can address the negative externalities of plastics.

Microplastics pose numerous threats to aquatic environments, yet understanding their transport mechanisms remains limited. Drawing from natural sediment research provides valuable insights to address this knowledge gap. One key dimensionless number used to describe sediment transport is the transport stage, referring to the ratio between the flow shear velocity and the particle settling velocity. However, variations in physical properties, such as shape and density, raise concerns about the applicability of existing sediment transport theories to microplastics. To address this challenge, we employed a physical modeling approach, examining 24 different nonbuoyant microplastic particles in a turbulent open channel flow. Utilizing 3D particle tracking, a total of 720 trajectories were recorded and analyzed. Microplastic particles exhibited transport modes akin to natural sediments, including rolling/sliding, saltation, and suspension. The transport stage strongly correlated with these modes, as well as with the mean forward velocity and mean position in the water column. Notably, particle shape emerged as a critical factor influencing transport dynamics. Due to their lower settling velocity, fibers tended to stay closer to the water surface with lower forward velocities compared to spheres. Based on the laboratory results, a new phase diagram for microplastics is introduced analogous to an existing diagram for sediments.