This work is focused on deserts, as extreme environments, because the year 2006 has been declared Year of Deserts and Desertification by the United Nations (IYDD Program 2006). The loss of vital resources such as fresh water and soil, and the depletion of biodiversity are emerging hazards, able to transform beneficial situations into extreme environments. Desertification is generated by land degradation: the loss of biological productivity is caused by nature or by human-induced factors and climate change. Nearby the desertification process there is the increasing process of salinisation of soil and water, induced by irrigation itself, or by salt water ingress derived by tsunamis or hurricanes. Increased research on the development of salt-tolerant cultivars could, with appropriate management, result in the broader use of saline soils. Although careful application is necessary, the combination of sand, seawater, sun and salt-tolerant plants presents a valuable opportunity for many developing countries. Cooperation among plant ecologists, plant physiologists, plant breeders, soil scientists, and agricultural engineers could accelerate the development of economic salt tolerant crops. If saline water is available, the introduction of salt tolerant plants in poor regions can improve food or fuel supplies, increase employment, help stem desertification, and contribute to soil reclamation.

The challenge of the food sufficiency through salt tolerant crops

The Upper Colorado Region covers about 113,500 square miles (293,965 km 2) in parts of Arizona, Colorado, New Mexico, Utah, and Wyoming. Drainage from about 97 percent of the region is to the Colorado River. About 60 percent of the land is owned or administered by the Federal Government, and another 15 percent is in Indian trust. The predominantly arid to semiarid region is sparsely populated (averaging about three persons per square mile, or about two and one-half persons per km2) and is used chiefly for grazing, recreation, and mineral development. The water supply for the region comes from precipitation within the region, which averages about 95 million acre-feet (117, 182.5 hm3 ) per year. Development of the region's water supply has been limited almost entirely to surface water. Only about 2 percent of the total estimated volume of water withdrawn (about 5.7 million acre-ft, or 7,030.9 hm) and consumed (about 3.6 million acre-ft, or 4,440.6 hm3) in the region in 1970 came directly from ground-water sources. By the year 2020 consumptive use of water within the region and water exports to adjacent regions are expected to total more than 6.5 million acre-feet (8,017.8 hm3) per year. Use of the ground-water resources of the Upper Colorado Region in water-resources management can help to meet these water needs. A tremendous amount of water is stored iri the rocks (ground-water reservoirs) of the Upper Colorado Region. Recoverable water in just the upper 100 feet (30.5 m) of saturated rocks is estimated to be as much as 115 million acre-feet (141,852.5 hm3). That amount is nearly four times the total active storage capacity of all surface-water reservoirs in the region. The average annual replenishable supply of the ground--water reservoir is about 4 million acre-feet (4,934 hm3). This amount of water could irrigate about 1.3 million acres (526,1,10 ha) of crops 'having an annual water requirement of 3 feet· per acre (0.9 m/ha), or it could provide about 3,600 million gallons (13,627,440 m3) per day for industrial use. Most of the ground water is in consolidated rocks, which generally yield water to wells slowly .. Much of the ground water is saline and, in some places, occurs at great depths. Nevertheless, the ground water is more uniformly distributed than is surface water, both areally and with time; therefore, it can be used advantageously in overall waterresources management. Recent advancements in the field of demineralization and in evaluation and development of ground water make this possible. · Options available for use of ground water in water-resources management·in the·region include conjunctive use with surface water or development of ground water as an independent supply. The latter option could be for & perennial supply or for a time-limited supply (mining ground water), depending on the need and the existing ground-water conditions. All options can be carried out so as to meet the requirements of the Colorado River Compact. The options could be implemented to optimally develop the Upper Colorado River Basin's allocation of Colorado River water while meeting the Compact commitments to the Lower Basin. INTRODUCTION

Summary appraisals of the nation's ground-water resources; Upper Colorado Region

A water requirement model for salt gradient solar ponds

Studies were conducted to determine the applicability of photooxidat ion for the degradat ion of select ed hazardous and refractory organic compounds. These photochemical oxidation react ions occur through the trans fer of energy from elect ronically excited sensitizer molecules which attain excited states by absorbing visible light energy. Optimum conditions for photooxidation were established based on sensitizer concentration and reaction pH for four polynuclear aromatic pollutants. The rate of photooxidation was found to be independent of the initial substrate concentration for methylene blue-sensitized reactions, and dependent on substrate concentration for solutions without a sensltlzins dye. Photolysis of substrat e mixt ures established acridine and anthracene as photochemically active substrates. Photochemical reaction data suggest predictable trends in substrate reactivity based on pKa values of both sensitizer and substrate, initial substrate concentration and light absorbance characterist i'cs. The photoproducts formed during the photolysis of acridine were found to be more toxic than the parent compound. These reaction products appear to be stable and warrant further study.

/pdf/engineering-treatment-of-hazardous-wastewaters-utilizing-dye-38b6udfsnw.pdf

Engineering Treatment of Hazardous Wastewaters Utilizing Dye-sensitized Photooxidation

The potential mutagenicity of aqueous leachates from coal, raw oil shale, and the spent shale resulting from two processes was tested. Specifically, an Ames salmonella microsomal bioassay was used to test for chemical mutagenicity. Spent oil shales from the Paraho and TOSCO II processes, a raw shale from Anvil Points, and a composite coal sample from the Wasatch plateau were extracted with double deionized water and organic solvents. Of the tests, only organic solvent extraction of the TOSCO spent shale resulted in a mutagenic response.

/pdf/evaluation-of-the-potential-for-groundwater-transport-of-325zcia66i.pdf

Evaluation of the Potential for Groundwater Transport of Mutagenic Compounds Released by Spent Oil Shale

Maps were made of the Upper Colorado River Basin showing locations of coal deposits, oil and gas, oil shale, uranium, and tar sand, in relationship to cities and towns in the area. Superimposed on these are locations of wells showing four ranges of water quality; 1000 to 3000 mg/l, 3000 to 10,000 mg/l, 10,000 to 35,000 mg/l, and over 35,000 mg/l. Information was assembled relative to future energy-related projects in the upper basin, and estimates were made of their anticipated water needs. Using computer models, various options were tested for using saline water for coal-fired power plant cooling. Both cooling towers and brine evaporation ponds were included. Information is presented of several proven water treatment technologies, and comparisons are made of their cost effectiveness when placed in various combinations in the power plant makeup and blowdown water systems. A relative value scale was developed which compares graphically the relative values of waters of different salinities based on three different water treatment options and predetermined upper limits of cooling tower circulating salinities. Coal from several different mines was slurried in waters of different salinities. Samples were analyzed in the laboratory to determine which constituents had been leached from or absorbed bymore » the coal, and what possible deleterious effects this might have on the burning properties of the coal, or on the water for culinary use or irrigation.« less

Use of saline water in energy development

Information was assembled relative to future energy-related projects in the upper basin, and estimates were made of their anticipated water needs. Using computer models, various options were tested for using saline water for coal-fired power plant cooling. Both cooling towers and brine evaporation ponds were included. Information is presented of several proven water treatment technologies, and comparisons are made of their cost effectiveness when placed in various combinations in the power plant makeup and blowdown water systems. A relative value scale was developed which compares graphically the relative values of waters of different salinities based on three different water treatment options and predetermined upper limits of cooling tower circulating salinities. Coal from several different mines was slurried in waters of different salinities. Samples were analyzed in the laboratory to determine which constituents had been leached from or absorbed by the coal, and what possible deleterious effects this might have on the burning properties of the coal, or on the water for culinary use or irrigation.

C.E. Israelsen

Papers

Use of saline water in energy development

Use of saline water in energy development. Final report