Groundwater provides the main source of water supply in most semi-arid areas of the Mediterranean and the Arabic peninsula. Overexploiting the groundwater resources in such areas results in drawdown of the groundwater level and deteriorating groundwater quality. One of the regions of scarce water resources where urgent action is required is the Lower Jordan Valley, where Israel, Westbank and Jordan share their border. The local overexploitation of the water resources leads to salt water intrusion and contamination with sewage effluent.
In the frame of the BMBF-research program „Integrated Water Resources Management (IWRM)“ the federal research project SMART (Sustainable Management of Available Water Resources with Innovative Technologies / www.iwrm-smart.org) is concerned in the development of a cross-national integrated water resources management program for the catchment basin of the lower Jordan Valley as a model region for arid to semi-arid areas.
Within a SMART-related BMBF-research project at the TZW (departments of Environmental Biotechnology, Technology and Chemical Analysis) options of waste water reuse for groundwater recharge are under investigation. The coordination of waste water treatment technologies with natural purification processes in the vadose zone during groundwater recharge is one main focus of the research activities. In particular membrane bioreactors (MBR) of our partner Hans Huber AG will be operated as a first treatment step to prepare the waste water for subsequent groundwater recharge without deteriorating the natural groundwater quality.
The identification of potentially problematic waste water compounds is one important prerequisite for the design of a suitable treatment technology for groundwater recharge. Persistent organic trace compounds such as pesticides, pharmaceuticals, endocrine disruptors or organic phosphorus compounds, which are documented as world wide ubiquitous substances, whose elimination by conventional sewage treatment is mostly insufficient, have the potential to infiltrate into groundwater. Also hygienic important parameters have to be regarded during waste water treatment and groundwater recharge.
Aerobic and anaerobic batch experiments as well as experiments in unsaturated soil columns will be operated to identify boundary conditions of the biological degradation processes in order to coordinate different waste water treatment steps. With combined waste water reclamation by membrane bioreactors and soil treatment both, the elimination of persistent xenobiotics and hygienic important microorganisms have to be achieved to allow the reuse of stored groundwater after recharge. In cooperation with partners in the Jordan Valley (Jordan’s Ministry of Water and Irrigation, Palestinian Hydrology Group) field experiments in Jordan and
