| Clogging as a function of effluent quality was investigated in very slowly permeable CasaGrande-La Palma association soils of Gila River Indian Reservation which offers problems for conventional on-site liquid waste disposal in arid and semiarid lands. Columns filled with these soils were subjected for more than 460 days to constant ponding with water and simulated septic tank effluents. No Suspended Solids and very low BOD and COD were held constant during all experimentation time. Column influents and effluents were monitored daily. At the end of this first stage, a very remarkable clogging process was established, fluctuating between 37.61% and 56.85% of infiltrative capacity. In the second stage of this study, different dosages of sulfuric acid were added to water and sewage effluents for more than 350 days. This stage was also monitored daily. At the end of this final stage, a remarkable porous media increase was noticed and the optimum dosage of sulfuric acid was found. In general, augmenting in percolation rate, fluctuated between 3.98% and 19.05%. |
