GORMAN-RUPP VG3B3-B, Инструкция по установке, эксплуатации и обслуживанию

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Aqua UltraFiltration™ Membrane System Control Strategy
ID #107150D Page 3 of 37 Revision: 1
Augusta Correctional Center WWTP
© 2013 Aqua-Aerobic Systems, Inc.
1.0 INTRODUCTION
1.1 OVERVIEW
The Aqua Ultrafiltration™ Membrane System for the Augusta Correctional Center Wastewater
Treatment Plant is an integral part of the AquaMB
®
Process, which also includes a sequencing
batch reactor (SBR) system and a cloth media filtration (CMF) system; the control strategies for
these latter two systems are provided separately. The Aqua Ultrafiltration™ Membrane System
utilizes two (2) ultrafiltration (UF) trains, each containing sixteen (16) modules of Aqua
MultiBore™ UF membranes to treat the effluent of the SBR and CMF systems.
As illustrated in Aqua-Aerobic Systems P&ID (9107150D P&ID Sheets 1-5), the UF system
consists of the feed tank, (2) feed valve/pump skids, (2) membrane assemblies, backwash pump
skid, backwash tank, compressed air system, main control panel with programmable logic
controller (PLC) and human-machine interface (HMI), power panel with variable-frequency
drives (VFDs) and motor starters, chemical feed control panel, supervisory control and data
acquisition (SCADA) system, and IntelliPro
®
Process Management System (the latter three are
shared with the SBR and CMF systems).
Effluent from the CMF system flows by gravity to the feed tank, which supplies the water to
both of the UF trains. Coagulant is injected into the CMF effluent; the coagulant attaches to the
organic matter in the water, improving the flow through the membranes and extending the time
between backwashes. A feed pump on each train pumps the flow into the top or bottom of the
train’s membrane modules and into the membrane fibers. Treated water passes through the fiber
material and collects on the outside of the fibers (i.e., inside-out flow), where it flows through the
filtrate line and into the backwash tank. The feed pressure to the membrane is monitored, and is
expected to gradually rise throughout the filtration process depending on the degree of fouling.
With a nominal filtration pore size of approximately 0.02

m, more than 99.99% (or 4-log)
removal of viruses (including hepatitis) can be anticipated.
To clean the membrane, filtrate in the backwash tank is pumped in a reverse direction (i.e.
outside-in) to remove the accumulated foulant layer. By use of the backwashing process, the
feed pressure is reduced to the initial high permeability state.
Over a long period of operation, fouling of the membrane may result in an increasing pressure
despite backwashing. In such an event, a process using a chemical enhanced backwash (CEB)
mode can be used to clean the membranes. Hydrochloric acid is used to remove inorganic
foulants, and base is used to remove organic foulants.
To verify that no membrane fibers are broken, a manual air integrity test can be performed. In
this operation, the feed-side of the system is pressurized to a safe setting below the membrane’s
‘bubble point’ pressure (i.e. the pressure at which the capillary forces are overcome and air will
displace the water from the pores) and the line pressure is monitored over time. A rapid loss of
pressure would indicate a breach somewhere in the system, potentially implicating a membrane
fiber or seal, whereas a slow loss of pressure is indicative of diffusion and demonstrates that the
system is fully integral.