1 SPATIO-TEMPORAL MECHANISTIC MODELING OF HYDRODYNAMIC, TRANSPORT, AND PHOSPHORUS CYCLING PROCESSES IN LARGE-SCALE CONSTRUCTED TREATMENT WETLANDS By RAJENDRA PAUDEL A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2011