| While subsurface aquifers deliver and purify one of Florida's most critical natural resource, freshwater, our understanding of the biogeochemical processes occurring there is relatively undeveloped. The proposed research is a set of laboratory experiments that will examine the biogeochemical interactions between natural dissolved organic matter (NDOM), nutrients, microbes and minerals in a laboratory system that models Florida's groundwater. The rationale for this research was driven by three environmental concerns: 1) Aquifer storage and recovery (ASR), a process by which water is recharged through wells to an aquifer and extracted for human use at some later time, is proposed as a major component in the Comprehensive Everglades Restoration Plan (CERP). While, 333 CERP wells have been proposed, at present, only a few pilot ASR wells have been implemented. The water to be injected may, in some cases, be agricultural or treated sewage water. However, very little is known of the effects this high nutrient or high NDOM (respectively) water may have on subsurface ecology, aquifer integrity, or the chemical changes that may occur prior to water retrieval; 2) Both natural weathering processes and, increasingly, anthropogenic activities produce and deliver nutrients and NDOM to Florida's rivers, springs, and coastal zone where they are known to cause serious ecological damage. We wish to study the biogeochemical and abiotic processes that transform NDOM and nutrients in the subsurface so that we can better understand and predicatively model the transport, delivery, and consequences of these contaminants; 3) Organic carbon stored in the subsurface represents a large reservoir of organic carbon which, if bioavailable, would be the largest dynamic carbon reservoir on the planet. But carbonate rock itself contains more carbon than all other reservoirs of the planet combined, including marine, atmosphere, biomass and fossil fuels. Surprisingly, relatively little study of the natural processes and human-related practices that may enhance or inhibit the release of this carbon has been carried out. This research addresses the important issue of water quality as it relates to water scarcity and proposed water storage practices. |
