New water treatment process hailed as more efficient
processors clean their water effluent more efficiently, says the
machine's manufacturer.
Food plants typically use a large volume of water to process products and to clean plant equipment. The process yields large amounts of wastewater that must be treated before it is discharged.Finding the best method of cleaning its water inputs is often a cost saver for plants in meeting food safety and environmental regulations.
Novasys' Compact Dynamic Bioreactor is an automated water treatment plant that uses a combined anaerobic-aerobic method along with aflocculation process.
By combining both aerobic and anaerobic steps in the one process, the Bioreactor will result in an efficient reduction of pollutants and total nitrogen in the wastewater, Novasys claims.
The technique produces a minimum of sludge and no odours, the company stated. Flocculation or the aggregation of particulate suspensions using other materials is used widely in bioprocessingdrinking and wastewater.
In most cases, flocculation is achieved in agitated tanks or similar devices that bring a flocculent in contact with the particles to be flocculated.
Novasys says the key innovative feature of its Compact Dynamic Bioreactor is its use of small cubes (14 x 14 x 7 mm) of an open, polymer foam. The foam cubes, called Variopure, are dropped into theeffluent and provide a large surface area for the micro-organisms that break down the pollutants.
The open structure of the foam guarantees that the micro-organisms are adequately supplied with nutrients and organic compounds, Novasys claims.
"Compared with conventionally used flocs of micro-organisms, which are active mostly at the surface only, the carrier is much more efficient," the company stated in anannouncement.
The CDB is especially suitable for seasonal food and beverage processing such as wineries. The micro-organisms in the foam can be kept alive or restarted depending on seasonal demand.
Although the Compact Dynamic Bioreactor was originally designed for small communities, Novasys says the Bioreactor can be used for food and beverage processors, who typically have water effluentshigh in biochemical and chemical oxygen demands (BOD/COD).
The terms are a standardised means of estimating the degree of contamination of water supplies, especially those which receive contamination from organic sources.
The process of cleaning effluent begins with screening for coarse material. Then the effluent is moved to the cleaner's reactor. The effluent is then mixed in the reactor with the foam cubes.
The effluent is then aerated from one side of the bottom of the reactor, resulting in a rapid circulation of water together with the carrier cubes. The aeration treatment saves on energy costssince no stirrer is required for mixing.
The supplied air is retained for a longer time in circulation, thus increasing the exchange of oxygen from the air into the water.
Different varieties of micro-organisms will find a habitat on the foam carrier material. Those on the surface of the cube will oxidise ammonia to nitrate, while simultaneously degradingorganic compounds.
The micro-organisms inside the carrier cube will consume the reduced nitrate to gaseous nitrogen while at the same time further degrading the organic compounds.
By combining both aerobic and anaerobic steps in the one process, this method of effluent treatment will result in an efficient reduction of BOD/COD and total nitrogen, Novasys claims.
The company says it can supply containers of a modular standard design with a small footprint for a reactor with throughputs as low as 500 litres per hour.
Food and beverage plans will not have to carry out any construction as all that is required is a firm and level base. Standard polypropylene pipes and fittings can be used for inlets and outlets tothe reactor.
It also does not require a large clarification basin, because the biomass on the cubes is held back just by a grid. The process is therefore stable even during high flow events and the biomass isnot washed out.
The cleaned, clear effluent leaving the plant is of high quality and can be used for irrigation or recycling, the company stated.
"Changes in flow rate, temperature, or salinity have no negative influence on the high stability of this treatment process," the company stated. "Successful results haveeven been obtained for industrial wastewater with very high salinity where conventional biological treatment does not work."
