TBU

A biological sewage treatment plant fully approved by DNV according IMO resolution MEPC 159 (55).

Capacity 10 to 800 persons

BR-7400G

The BIOCOMPACT G&O Bioreactor represents the next generation of Biological Sewage Plants and is able to handle grey and black water from any Ship or Offshore construction. The plant is an “Aerated Submerged Fixed Film Unit" which operates by use of the “Matrix Technology". The BIOCOMPACT G&O Bioreactor system provides an excellent growth environment for our bacteria media. The tank is fitted with a rigid PP/PVC matrix. By this we obtain a 125 times larger internal surface where the bacteria media can adhere compared to any traditional Active Sludge Plant/tank. In this manner we secure any operator full operational freedom all around the globe with a system that exceeds any known or expected future environmental demands.

News

The guidelines, outlined in the MARPOL 73/78 rules under the IMO MEPC 159(55) Resolution, restrict treated sewage contents of BOD5, TSS, COD, thermo-tolerant coliform bacteria and chlorine.

Shipowners may run into both heavy fines and imprisonment as a consequence of lacking international rules for organic load in sewage plants. Many sewage plants may simply be too small.

This issue was a topic at the Royal lnstitution of Naval Architects (RINA) conference in London (March 2010). As of Jan. 1, 2010, much stricter guidelines on treatment of black water have placed equally stricter demands on shipowners.
At first sight, the stricter guidelines should not pose a problem to sbipowners with a sewage plant approved by a major classification society such as DNV or Bureau Veritas.
At second sight, however, the new guidelines pose a significant threat as even shipowners with newly approved sewage plants run the risk of both fines and imprisonment. The reason is that there is a significant risk that the sewage plant is too small.
A quote for a sewage treatment plant is normally requested by specifying the number of persons onboard. However, a sewage plant is not approved based on the number of persons, but rather on hydraulic load (litres per day) and organic load (kg of BOD5 per day).
"The problem arises as there are no rules governing the conversion of these loads into number of persons, and that same manufacturers exploit this regulatory void to target low prices rather than low effluents.
The resulting sewage plant may have been cheap but is very likely not efficient enough and thus leaves the shipowner little leeway when the inspection comes" said Jakob le Fevre, Product Director at Gertsen & Olufsen in Denmark.
Size and extent of the punishments depend on the waters: imprisonment under Danish law can be up two years, and in Canadian waters, under the Canada Shipping Act, the penalty for violation is a fine of up to $1 million, imprisonment for up to three years, or both.

Biocompact is the distributor for Gertsen & Olufsen in the BeNeLux and supplier of the G&O Bioreactor, a fully biological sewage treatment plant for offshore and ship use. Le Fevre explained, that a sewage plant, despite its official approval, may be grossly undersized due to a liberal attitude when converting the organic load and BOD5 into the specified number of persons.

"With shore-based sewage treatment plants, the minimum amount of BOD5 to use in calculations is 600mg per litre of black water. The organic load of the inlet for marine applications, however, is not mentioned in any rules or by any authorities," le Fevre said.

The German sewage treatment plant testing facility, Prüfinstitut für Abwassertechnik, PIA, in Aachen, has suggested using 750mg of BOD5/litre of black water as a minimum when putting together a sewage plant designated for marine use.
"If you combine PIA’s organic load minimum with the values for hydraulic load, the result is a minimum of 75 grams of BOD5 per person per dav for grey and black water and 53 grams when treating black water alone. Some manufacturers, however, specify organic loads as low as 13.5 grams BOD5 per person per day," le Fevre said.
The ensuing calculation says it all, explained le Fevre: a sewage plant to treat black water from 25 persons based on the low figure will have a capacity of 25 x 13.5 = 337.5 grams of BOD5, whereas an equally requested plant based on the PIA minimum will be able to handle 25 x 53 = 1325 grams of BOD5 on a daily basis, almost four times as much.
“The first plant will simply not be able to live up to the demands. In my opinion, the reason that same manufacturers use the low conversion factor for organic load is dear enough: they can come across as very cost effective compared to suppliers with plants based on more realistic figures," le Fevre said.

Historically onboard sewage treatment has not been at the centre of attention for shipowners.This may have to do with the fact that there has been no control.
"This has changed, though, after Jan. 1. The regulations in MEPC 159(55) very explicitly state that the authorities must insure that the sewage plants continue to function properly after installation. In practical measures, this means that samples are to be handed over during Port State Control and that the shipowner is responsible if effluents are above the limits," le Fevre said.
Until then the only thing shipowners and designers can do is to ensure that their sewage plant is in order, is to specify organic and hydraulic loads.