2.3. Pilot plant description
Fig. 2 shows a flowchart of the pilot plant used in the experiments
with RIA liquid wastes. Feed solution from the feed tank (1) firstly
flows through a filter (4) to remove any particle in suspension. Then
pressure of the liquid is increased by a variable speed pump (5). Before
entering the module (9) temperature and pressure of the liquid are
measured by a thermometer (7) and a pressure gauge (8), respectively.
At the exit of the module, a rotameter measures concentrate flow (11)
and pressure is measured by another pressure gauge (8′). The pressure
difference between two gauges allows controlling pressure loss in the
module. Operation pressure was fixed by the regulation valve of the
concentrate line (10). In the ultrafiltration tests, a 4″ vessel was used,
whereas in the reverse osmosis tests a 2.5″ one was used, both for
spiral-wound elements from Hydranautics. The rest of the elements of
the plant were the same in both cases. Each stage was prolonged until
maximum volume reduction in the feed tank was achieved. The proper