• Effect of Illuviated Deposits on Infiltration Rates and Denitrification During Sewage Effluent Recharge

      Montgomery, Errol L.; Korkosz, Emily; Dalton, Russell O., Jr.; DeWitt, Ronald H. (Arizona-Nevada Academy of Science, 1977-04-16)
      This study, conducted to determine the interrelationships among nitrogen transformations, infiltration rates, and development of the black layer found in the Santa Cruz River downstream of the Tucson (Arizona) sewage treatment plant, tested these interrelationships by percolating sewage effluent through clear acrylic columns uniformly packed with river sand for the first run, with gravel for the second run. Sewage effluent was continuously applied to three of the columns for 28 and 64 days during the first and second runs respectively. The remaining column was continuously flooded with tap water to serve as a control. Infiltration rates decreased rapidly upon application of the sewage, and within a few days a black layer developed, its thickness inversely related to the infiltration rate but not a cause of reduced flow, which is attributed, rather, to clogging of the surface by suspended solids. There was an average reduction in total nitrogen of 62.9% for the first run, and 15.9% for the second. The mechanisms of removal for run 1 were predominately absorption and denitrification, whereas the predominate removal mechanism in run 2 was filtering of organic nitrogen with adsorption and denitrification also playing an important role.
    • Rehabilitation of Copper Mine Tailing Slopes Using Municipal Sewage Effluent

      Verma, Tika R.; Ludeke, Kenneth L.; Day, A. D.; School of Renewable Natural Resources, The University of Arizona, Tucson; Cyprus Pima Mining Company, Tucson; Plant Sciences, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1977-04-16)
      The suitability of treated municipal sewage effluent for the irrigation of deep- rooting plant material for the rehabilitation of copper mine tailings was studied at the Cyprus Pima Mining Company. The effectiveness of treated sewage effluent was compared with well water on the growth and survival of trees, legumes and grasses. The species studied were eucalyptus (Eucalyptus rostrata), native mesquite (Prosopis juliflora), palo verde (Cercidium floridum), desert tobacco (Nicotiana lauca) barley (Hordeum vulgare), perennial rye grass (Lolium perenne), alfalfa (Medicago sativa), and blue lupine (Lupinus augustifolius). Sprinkler and tree -well irrigation methods were used to apply the treated sewage effluent and well water to steep tailing slopes. The treated municipal sewage effluent was found to be a practical irrigation substitute for well water and a good source of plant nutrients such as nitrogen and phosphorous. Effluent produced better survival and growth than did well water with or without augmentation.