Causes, kinetics and reversal of clogging in injection wells

• Applicant: Dr.-Ing. Hartmut Holländer
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 32172610

Overexploitation of aquifers and depletion of groundwater quality is becoming more and more important worldwide. Artificial recharge can help to avoid these problems. Worldwide injection wells are used to infiltrate surface water into aquifers. The main problem using this technique is clogging of the well screen, filter and the nearby aquifer which results into a decrease of hydraulic conductivity of the aquifer. Clogging is mainly caused by physical deposition of fine particles at the aquifer matrix, by geochemical reactions, air entrapment and growth of biofilms. The pore volume is reduced by these processes and therefore the hydraulic conductivity of the aquifer. A possibility for redevelopment of the aquifer is back-washing which allows rising the hydraulic conductivity again. More or less each process has been investigated experimentally but the interactions of all processes are rarely addressed. A numerical model is necessary to analyse all the different effects causing clogging. The model will allow taking precautions in terms of quality of infiltration water and how to redevelop already clogged wells as important criteria for the selection of appropriate measures for groundwater recharge. Keywords: artificial recharge, clogging processes

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Dr. Peter Dillon