The Evac ORCA IV B electrolytic wastewater treatment plant is designed to treat black and gray wastewater aboard vessels. The Evac ORCA IV B is a purely electrolytic wastewater treatment plant that fulfills the requirements of IMO MEPC 227 (64) and is also U. S. Coast Guard (USCG) approved.
The compact, modular design makes it ideal for both installation on new vessels and retrofitting existing vessels. It operates on a batch basis but is basically continuous, is fully automatic in normal operation, and only requires low maintenance. Depending on the model, the hydraulic load for black and gray vacuum wastewater treatment ranges from 1,350 to 63,000 liters / 357 to 16,643 gallons per day.
The operation of the Evac ORCA IV B is based on electrochemistry, with most of its processes being electrolytic. This makes operation easy, reduces sludge production, and removes the need to store and handle chemicals. The fully automatic system requires just ﬁve minutes of time each day for sampling and system check-ups. Wastewater is collected via gravity in a sewage holding tank, which serves as a buffer tank. The sewage is then conveyed from the holding tank to a reaction tank, where the processes are carried out sequentially.
The system operates at ambient temperatures of 5–40°C and at inﬂuent temperatures of 2–32°C. The toilet system can operate with both fresh and seawater, but the system needs seawater with a minimum salinity of 32PSU in order to operate.