This powerpoint presentation begins by providing a brief overview of the City of Plantation, Florida's search for alternative water sources. After considering several alternative strategies, Plantation decided on indirect potable reuse -
aquifer recharge, which required consideration of several important factors including: nutrient control; aquatic organism impact; micro-constituents; recharge modeling; sustainability; public outreach; and, cost. The Plantation pilot plant is presented with information concerning it's membrane bioreactors (MBR) and conventional treatment schemes including: total nitrogen (TN) and total phosphorus (TP) removal of
MBR and reverse osmosis (RO) Pilot Units; and, TN and TP removal of
Deep Bed Filter and RO Pilot Units. Presentation conclusions concerning nutrient removal include:
both pilots met stringent TN and TP limits;
RO membranes are necessary to meet TP limit; and,
membranes alone (UF/RO) with no chemical addition met
TN and TP limits. Micro-constituent removal by RO membranes is presented, along with toxicity to aquatic organisms. Presentation summary includes the following: the pilot demonstrated to meet stringent nutrient
limits at different test conditions;
RO membranes are necessary for surface water
discharge due to stringent TP limits; almost all micro-constituents were removed by
RO system;
RO permeate could be toxic, re-stabilization/re-mineralization
is necessary; and,
the observed toxicity to aquatic organisms was likely
caused by chloramines. Other forms of RO pretreatment
should be evaluated. Includes figures.