Session chairs: Ma. Catalina Alfaro and Mario Villalobos

Exchange of solutes and particles between the water and sediments, and prevailing geochemical conditions at the sediment-water interface, affect the diffusion of dissolved oxygen and internal cycling of nutrients, the chemical stabilization of organic and inorganic pollutants, AND the fate and availability of substances for the benthic organisms and plants. Before being effectively stabilized and accumulated, pollutants entering surface waters participate in several bio-geochemical processes. Even after pollutants are controlled at the sources, sediments may act as secondary sources, releasing substances upon changing biogeochemical conditions through molecular diffusion, particles resuspension, bioturbation and/or bioirrigation. Among these processes, diffusion fluxes at the sediment-water interface may control the magnitude and direction of geochemical processes, affecting the nutrient and pollutant cycle, and their environmental fate, which are crucial to evaluate the implementation of remediation actions and their effectivity. Works in this thematic are welcome, of particular interest are those related to the containment of polluted sediments or dredged materials.

Session chairs: Teresa Alarcón-Herrera and Víctor Luna-Pabello

Advanced practices based on new technologies, improved processes, and evolving science allows to clean up contaminated sites in a more efficient and sustainable manner while achieving one of our challenges of protecting human health and the environment. The goal of remediation is to restore the site to its pollution-free state. Natural attenuation, is rapidly becoming a widely used approach to manage soil contamination by hazardous substances in product releases by different accidents or leaks and leachate from many different sites including among others, mining waste sites, industrial and hazardous waste sites and landfills. In this session, the idea is to bring together parties from all aspects of the remediation of contaminated sites community, to exchange ideas and experiences on the management of soil, groundwater, and sediment. Including the current methodologies needed by groundwater scientists and engineers in their efforts to evaluate subsurface contamination problems, to estimate risk to human health and ecosystems through mathematical models, and remediation strategies approached. Works in these thematic are welcome.

Session chairs: Nadia Martínez Villegas and Perla Alonso

Sediment monitoring and characterization are activities of major importance for the comprehension of concentrations of contaminants, and biogeochemical and ecological processes that occur in the water-sediment interface in both spatial and temporal scales. The availability and behavior of organic and inorganic contaminants, the physical, chemical, and microbiological interactions, and their effects on benthic biota will heavily depend on the composition and structure of these matrices. The theme of this session is intended to attract papers that help to understand the importance of sediment monitoring and characterization in a multidisciplinary perspective in order to provide new insight in this topic as well as methodological and application bases

Session chairs: Graciela Herrera and Blanca Prado

Sediment-driven reactions and transport of pollutants is often referred to as “reactive transport modelling” (RTM), and it represents the culmination or coming together of theoretical and empirical chemical and physical data to generate predictive models of system behaviors, often in very complex multicomponent, multiphase systems. The requirement for RTM is growing, especially in the fields of carbon storage, unconventional hydrocarbon extraction and mineral exploration and mine development. This session looks to bring together the researchers whose work has direct implications to RTM and those who utilize RTM. The objective is to explore the capabilities, the growing requirements for data and data production, and to find the gaps and enhance the future of RTM based research.

Session chairs: Joselina Espinoza and Moisés Berezowsky

Hydraulic structures include a broad spectrum of applications in engineering practices such as: dams, river flood controls, piers, protection works on rivers, like borders or dikes. The flow around hydraulic structures is complex, three dimensional and highly turbulent with sediment transport. Pier scour is influenced by flow structures, and sediment factors, as the vortices and turbulence structures around the piers, and sediments in water bodies. The dams in the rivers interact giving rise to upstream degradation and downstream erosion. Study of the interaction between hydraulic works, water and sediment is focused to understand of the effects of hydraulic structures on natural systems, through laboratory experiments, field campaigns, physical and numerical modeling, analysis of occurred events, and to obtain criteria, methods, to improvement in the design, construction, operation and maintenance of hydraulic structures. Works in this thematic are most welcome.

Session chairs: Antonieta Gómez and Pilar Saldaña

Dealing with sediments is becoming an increasingly urgent task due to the importance of natural processes and the impact of anthropogenic activities. At the basin level, it is important to preserve connectivity among ecosystems as well between riverbed and flooding areas. Sediment transport and deposition is a limiting factor for the conservation of wetlands of international concern due to its importance as substrate, nutrients source, and water residence areas during floods. Dams have interrupted sediments fluxes and dredging is an increasing activity worldwide, with effects barely known and regulated. Besides, while solving hydrological cycles by mimicking temporal and historical variations through environmental flows, registration of sediments are rare at hydrometric gauges, and it is therefore not possible to identify patterns, alterations and trends. Sediments as means of transportation, transformation and final fate of pollutants are issues of great concern and advances in modelling and regulation are of benefit in this context. Examples on guidelines, approaches and regulations are highly welcome to help in advancing in this topic, still unsolved in many parts of the World.

Session chairs: Gabriela Mantilla and Guillermo Quijano

One of the main challenges during water and wastewater treatment is the management of the produced sludge. The sustainability and economic feasibility of water and wastewater treatment plants are strongly impacted by the technologies used for sludge management. In the 21th century conception, the sludge could be considered as a raw material to produce added-value products, including fertilizers, soil conditioners, and renewable energy, among others. The main characteristics of the resulting sludge depend on the composition of water and/or wastewater and the treatment technology used, which in turn will determine the possible benefit obtained from the sludge. Contributions to this subject are most welcome, especially those related with (i) biogas production, (ii) pathogens characterization in digestates and challenges towards the reuse in agricultural activities, (iii) added-value products, and (iv) recovery of chemical products

Session chairs: Margarita Eugenia Gutiérrez and Yann René Ramos

The role of the industry in the management of sediments is an important issue worldwide. Every year, rivers and other water bodies are impacted by industrial pollutants, representing a potential risks for aquatic life and for soil quality when affected by the river floods and deposits of dredged sediments. The perspective of the metallurgic and mining industries on the proper management of affected sediments varies widely from one country to another. Two visions prevail: 1) the fulfillment of regulations without more information; or 2) carrying out assessment evaluations or case studies, which apply recent engineering developments to protect populations and resources. The environmental risk is related not only with hazardous substances behavior, but also with the environment vulnerability (including human population). The environmental fate of the pollutants and the routes of exposure are mainly dominated by the physico-chemical process in water and sediments, and the prevailing geochemical conditions. Therefore, multidisciplinary scientific studies play a significant role in sediment management studies. The point of view of relevant stakeholders, like the industry, regarding the different options to properly manage sediments, can help development of environmental regulations and policies, as well as related private programs.

Session chairs: José Luis Arellano M. and Silke Cram

The soil erosion and sedimentation are processes related to hydrological processes and environmental degradation. The soil erosion-sediment relation affecting the environmental hydrological services. In tropical and subtropical regions, soil erosion and sedimentation processes are often associated with extreme rainfall and runoff events, soil conditions, steep land slopes, and management practices. All these factors are of very high importance in most Latin American countries. This thematic session includes measurement and evaluation of soil erosion, nutrimental losses in agricultural lands, sedimentation processes, and implementation of techniques of soil erosion and sedimentation control in watersheds, rivers, lakes, and wetlands.

Session chairs: Vinicio Macias and Maria de los Angeles Calixto

Sediment cores obtained under conditions such as fine-grained sediments, non-disturbed by physical or biological perturbations, are excellent candidates to determine historical pollutant deposition and accumulation in water bodies such as lakes and reservoirs. The use of radiometric dating of sediment cores are useful tools to describe chronological sediment accumulation. Pollutants are typically transported from their sources to water bodies in high-altitude or latitude regions due to the grasshopper effect. Here they accumulate in sediments or ice that act as destination for many contaminants. No permanent sediments monitoring programs have been implemented in most countries, and there are therefore no formal inventories of pollutants or evaluation of their exposure risks. Therefore, sediments cores are excellent matrices for the reconstruction of historical contamination through the sampling and chronological and chemical characterization. The analyses of these matrices represent a powerful tool to reconstruct historical changes in contaminants concentrations. Papers addressing such issues are very welcome for this session.

Session chairs: Alfonso V. Botello and Teresa Álvarez

The oil spills, ships accidents, ruptures in transport lines, natural seeps and discharges from urban waters, introduce an important quantity of petroleum into marine and coastal areas, whose final destination are the surrounding sediments. The more conspicuous examples are the spills of Ixtoc-I well (Bay of Campeche) and the Macondo well (Lousiana) both occurred in waters of the Gulf of Mexico. Once the oil is trapped in sediments, it remains there for long periods of time, being a risk for benthic and marine organisms interacting with them, and affecting local fisheries. In others big spills around the world ( Alaska, USA: Spain, Saudi Arabia) the spilled oil had the same destination but different behavior. Regarding the management and regulations in different countries, these are very variable and depend on the enforcement of national laws and perhaps regional agreements, but actually there is a lack of action in this matter. Finally, it seems to be an excellent matter of discussion for this session.