Membrane and Desalination Technologies - TCE Moodle Website

222 L.K. Wang and R. Menon
If you were the plant’s environmental engineer responsible for WW compliance at this
coffee plant, what would be your recommended engineering solutions to the plant manager?
5.3.1. Solution
The coffee plant’s environmental engineer decided to conduct a feasibility or treatability
study, and selected an MBR pilot plant with the following specifications:
1. Skid dimensions = 13" 7" 8"H
2. Weight = 4,000 lbs. (shipping); 8,000 lbs. (operating)
3. Connections =
Influent = 1.5" hose clamp
Discharge = 2" male NPT
Water supply = 5–10 gpm (3/4" hose clamp)
4. Electrical = three phase, 240 V, 60 Hz, 100 amp, two grounds
5. Flow rate = approximately 1 gpm (depends on influent BOD/COD)
6. Automatic control system.
It was known that the MBR system is technically and economically feasible for treating
high-strength and low-flow WW streams. It was then recommended by the plant’s environmental
engineer that only the low-flow high-strength stream (representing 30% of total
combined WW flow) would require treatment in an MBR system. The remaining 70% of
untreated low-strength streams could be post-blended with the treated effluent from the MBR,
resulting in a combined or blended effluent, which would meet the discharge permit’s effluent
limitations (see Fig. 5.8).
The 1-gpm pilot plant demonstration was very successful. The above proposed engineering
solution was fully proven by the MBR performance. Accordingly, an MBR process system
was ordered, installed, started-up, and operated at the coffee plant. Figure 5.8 shows the fullscale
WWT flow schematic implemented by the coffee plant. The successful performance
data of the installed process system are shown in Table 5.4. It is seen from Table 5.4 that the
quality of the MBR effluent was very high. Critical effluent parameters were as follows:
Fig. 5.8. Coffee factory WWT flow schematic.