ÃÛèÖÊÓƵ

Education

Ph.D., 1992, Louisiana State University (Geology)

M.S., 1979, Virginia Polytechnic Inst. and State Univ. (Physics)

B.S., 1975, Universidad de El Salvador (Chemistry)

Research Interests

Geochemistry and Hydrogeology

• Geochemical and hydrogeological modeling
• Arsenic in the environment and health
• Pesticides and health impacts
• Volcanic soil degassing
• Geochemistry of hydrothermal sytems
• Acid mine drainage

In recent years and in my future retirement, my research has taken a twist to the investigation of the environmental causes of chronic kidney disease of unknown etiology in El Salvador and problems associated to arsenic contamination in different environmental phases. In addition, I continue working with impacts of acid mine drainage in streams of Ohio. In general, my research interests include the geochemistry and hydrogeology of geothermal systems (including diffuse soil degassing and heat flow studies), and environmental problems such as acid mine drainage and arsenic contamination in water. For my research, I am using new modeling tools as artificial neural networks and geographical weighted regression and other multivariate analysis methods for assessing the relationships between the environmental variables and dependent variables as discharge, chemical composition, or the incidence of the disease according to the specific problem.  At the present time, my areas of research in geothermal systems are located in Central America (El Salvador, Honduras), and in Canary Islands, Spain. The release of gases from the magmatic environment, their incorporation to the groundwater system, and their release to the air at the soil-air interface can provide important information about the volcanic activity, fluid paths, and preferential routes of circulation in the upper crust. This information is important for geothermal energy exploitation as well as for volcanic monitoring. I am also interested in environmental problems associated with mining and resource exploitation. Within Ohio, I investigate the chemistry, fluid flow, and mass transfer associated with acid mine drainage from coal mines. The exploitation of sulfide-rich coal in this region produces mine drainage of low pH and high acidity and metal concentrations (mainly iron, aluminum, and manganese) affecting hundreds of miles of streams and aquatic life. I investigate the hydrology of abandoned coal mines and the fate of the acid mine drainage chemicals in the environment. In addition, I have also investigated a closed uranium mine in Poços de Caldas, Brazil. I am investigating arsenic in volcanic lakes and groundwaters, and acid mine drainage problems in El Salvador. I belong to the Appalachian Watersheds Research Group of ÃÛèÖÊÓƵ. This group has a multidisciplinary approach to the study of acid mine drainage problem and treatment. During the recent years we have focused in studying the relationship between the physics of the flow, the chemistry of water and sediments, and the biology of the stream in the acid mine drainage problem, especially in the response to remediation, such as alkalinity additions. My students and I have been working in the modeling of these processes in the rivers of Ohio.

Courses Taught

• GEOL 2050: Statistical Methods in Geology
• GEOL 2310: Water and Pollution
• GEOL 3/5050: Modeling and Computer Methods in Geology
• GEOL 4/5270: Water Geochemistry
• GEOL 4/5280: Physical Geochemistry
• GEOL 4/5290: Contaminant Geochemistry
• GEOL 4/5710: Advanced Environmental Geology
• GEOL 4/5810: Groundwater Flow Modeling
• GEOL 4/5820: Transport Processes in Groundwater

Professional Appointments

2008-present, Professor

2001-2008, Associate Professor

1995-2001, Assistant Professor

Representative Publications

Geochemistry of Hydrothermal Process (41 papers)

Morales-Simfors, N., Bundschuh, J., Herath, I. Inguaggiato, C., Caselli, A.T., Tapia, J., Erlingtton, F., Chequehuayta, A., Armienta, M.A., Ormachea, M., Joseph, E., López, D.L., 2019. Arsenic in Latin America: A critical overview on the geochemistry of arsenic originating from geothermal features and volcanic emissions for solving its environmental consequences, The Science of the Total Environment, November 2019, Elsevier, DOI:10.1016/j.scitotenv.2019.13556

López, D.L., Araujo, P.A., Delgado Outeiriño, I., Cid, J.A., and G. Astray, G. 2018. Geochemical signatures of the groundwaters from Ourense thermal springs, Galicia, Spain. Sustainable Water Resources Management, pp 1-14. .

Marrero-Diaz, R.,  López, D.L., Pérez, N.P., Custodio, E., Melián, G.V., Padrón, E., Hernández, Padrón, E., 2017.Fluorine in Groundwater in Central Tenerife Island (Canary Islands, Spain). 15th Water-Rock Interaction International Symposium, WRI-15. Procedia Earth and Planetary Science.  Available online at

Richardson, J., Lopez, D., Leftwich, T., Angle, M., Wolfe, M., and Fugitt, F., 2016, The characterization of flooded abandoned mines in Ohio as a low-temperature geothermal resource, in Dowling, C.B., Neumann, K., and Florea, L.J., eds., Geothermal Energy: An Important Resource: Geological Society of America Special Paper 519,  p. 19–41, doi:10.1130/2016.2519(02).

López Larios, D.L., Araujo, P.A., Delgado, I., Cid, J.A., y Astray Dopazo, G., 2015. Geochemistry of hydrothermal systems: thermal springs of Ourense. Proceedings 1st International Congress on Water Healing SPA and Quality of Life, Ourense, Spain, 23-24 September 2015. Failde Garrido, J.M. et al. editors, Campus da Auga, Vicerrectoria del Campus de Ourense, Universida de Vigo, pp. 23-26.

Marrero-Diaz, R., Alcalá, F.J., Nemesio M. Pérez, N.M., López, D.L., Melián, G.V., Padrón, E. and Padilla, G.D., 2015. Aquifer recharge estimation through atmospheric chloride mass balance at Las Cañadas Caldera, Tenerife, Canary Islands, Spain, Journal Water, v. 7, 2451-2471.

Marrero-Diaz, R.,  López, D.L., Pérez, N.P., Custodio, E., Sumino, H. Melián, G.V., Padrón, E., Hernández, P.A., Calvo, D., Barrancos, J., Padilla. G., Sortino, F., 2015. Carbon dioxide and helium dissolved gases in groundwater at central Tenerife Island, Canary Islands: chemical and isotopic characterization. Bull Volcanol vol. 77:86, pp. 1-18.

Acid Mine Drainage and Other Contaminant Problems (50 papers)

Bundschuh, J., Armienta, M.A., Morales-Simfors, N., Ayaz Alam, M., López, D.L., Delgado Quezada, V., Dietrich, S., Schneider, J., Tapia, J., Sracek, O., Castillo, E., Parra, L.M.M., Altamirano Espinoza, M., Guimarães Guilherme, L.R., Sosa, N.N., Niazi, N.K., Tomaszewska, B., Lizama Allende, K., Bieger, K., Alonso, D.L., Brandão, P.F.B., Bhattacharya, P., Litter, M.I. & Ahmad, A. (2020) Arsenic in Latin America: New findings on source, mobilization and mobility in human environments in 20 countries based on decadal research 2010-2020, Critical Reviews in Environmental Science and Technology, DOI: 

Howard, Lucas, and Lopez, D.L. Nutrient and Sulfate Variations along the Maumee River, Ohio, USA. Paper submitted to the EWRCON19 World Environmental & Water Resources Congress 2019, May 2019, Pittsburgh, PA. &nbs