The MBR Book: Principles and Applications of Membrane

266 The MBR Book
5.4.5.2 Other Millenniumpore plant
A Millenniumpore MBR plant of very similar design to that used at the Eden Project
site was installed for treating highly concentrated organic waste from a beverage
production factory, owed by VitaSoy International Holdings Limited, in Hong Kong in
2003. The effluent, which has a COD varying between 500 and 20 000 mg/L, is partially
clarified by coagulation/DAF to produce a feed to the MBR of 320–17 000 mg/L
COD. The MBR is operated at an MLSS of 7–9 g/L, and six MT modules provide
sufficient capacity for the flow of 88 m 3 /day. The effluent COD level is between 11
and 93 mg/L.
5.4.6 Novasep Orelis
5.4.6.1 The Queen Mary II WWTP
Background Legislation concerning water discharged to sea has recently been
tightened. In the past, the practice had been to employ conventional wastewater
treatment for foul waters and discharge grey water to the sea. The latter is no longer
considered acceptable; a number of pieces of legislation applied to different geographical
regions have been promulgated which effectively disallow grey water discharge,
the most restrictive being the Alaskan regulations which limit both TSS and
BOD to 30 mg/L, faecal coliforms to 20 per 100 ml and undetectable levels of heavy
metals. Some commercial cruise ship companies have adopted targets which are even
stricter than the legislation, since (a) the marine conservation lobby is likely to bring
about ever more stringent standards and (b) only slightly more rigorous treatment
would permit water reuse for general purposes such as cooling and sluicing down.
Ship-board wastewater treatment presents a number of challenges. The deck
height, the floor-ceiling distance in which the MBR has to be located, is normally
around 2.5 m. This limits the aeration tank depth and prohibits inserting the membrane
module into or lifting it from the tank in situ. The plant has to run with very
little maintenance, since marine crew generally have little or no experience of
wastewater treatment. Full plant automation is thus required, and in the case of the
Queen Mary II (QM2) staff training has also been provided. Lastly, and perhaps most
importantly, accurate effluent water data is at a premium in the ship industry.
The QM2 is the world’s largest passenger ship and is owned by the Carnival Group.
A total of around 1.1 MLD of wastewater is generated on board the ship from four
main sources, these being:
● Grey water from accommodation (0.65 MLD) and laundering operations
(0.150 MLD).
● Galley water (0.2 MLD) from the kitchens and food waste drainage.
● Black (or foul) water (0.100 MLD).
● Recreational pool and sauna wastewater (�0.01 MLD).
These flows can be segregated into two streams of black and grey water (Table 5.25).
Carnival has set targets of 10 mg/L TSS and undetectable faecal coliforms for the
treated water, thereby providing the option of reuse of the grey water stream.