Agricultural developments require changes in land surface and subsurface hydraulic functions as protection from floods, reclamation of flooded land, irrigation, and drainage. Drainage of agricultural land has a long history and apparently traces back to the earliest civilizations of Mesopotamia and Iran before 4000 BC. In the Eastern Mediterranean, the Minoan and Mycenaean civilizations developed techniques and strategies of drainage of agricultural lands from the middle of the 2nd millennium BC. After the collapse of the Aegean Bronze-age civilizations, society building and agricultural innovation in the archaic and Classical periods (ca. 800–300 BC) included successful attempts at controlling drainage and irrigation techniques. In addition, China, India, and Mesoamerica have extensive histories of drainage. The aim of this review paper is to trace the evolution of the main foundings on agricultural drainage technologies through the centuries until the present. This historical review reveals valuable insights into ancient hydraulic technologies as well as irrigation and drainage management that will help to find bright horizons for sustainable agriculture in future.
Water quality in San Francisco Bay has been adversely affected by nitrogen loading from wastewater treatment plants (WWTPs) discharging around the periphery of the Bay. While there is documented use of zeolites and anammox bacteria in removing ammonia and possibly nitrate during wastewater treatment, there is little information available about the combined process. Though relatively large, zeolite beds have a finite ammonium adsorption potential and require periodic re-generation depending on the wastewater nitrogen loading. Use of anammox bacteria reactors for wastewater treatment have shown that ammonium (and to some degree, nitrate) can be successfully removed from the wastewater, but the reactors require careful attention to loading rates and internal redox conditions. Generally, their application has been limited to treatment of high-ammonia strength wastewater at relatively warm temperatures. Moreover, few studies are available describing commercial or full-scale application of these reactors. We briefly review the literature considering use of zeolites or anammox bacteria in wastewater treatment to set the stage for description of an integrated zeolite-anammox process used to remove both ammonium and nitrate without substrate regeneration from mainstream WWTP effluent or anaerobic digester filtrate at ambient temperatures.
23 September 2005 in Land Degradation & Development