A Biofiltration System - Winery Effluent
Biofiltration System: Simplified Clean Water
To treat wastewater in a contact reactor, a biofilm consisting of a mixed population of microorganisms has been developed to serve as a biological scrubber. After formation in the reactor, the biofilm breaks down and removes organic contaminants. When one biofilm becomes too thick to remain attached within the system, it will slough off. Simultaneously another biofilm will form, thus the operation of the system is uninterrupted.
In conventional trickling filter water treatment plants, organically contaminated water is treated by passing it through a packed bed of porous substrate material. These systems require mechanical aeration by pumps or fans. During the process microorganisms in the contaminated water forms a biofilm on the packed bed surface. Over time the biofilm thickens and will eventually slough off, and is then collected as sludge at the base of the reactor, from where the sludge needs to be removed. In this invention, a tower with a packed bed of porous substrate material is provided, designed efficiently to distribute wastewater over the substrate with the simultaneous draft of air in the opposite direction, ensuring effective aeration of the system without additional energy required to power the aeration. Contaminated water enters the tower through the water inlet and a biofilm of a mixed population of microorganisms develops on the surface of the packed bed material. The biofilm covers a large surface area and as it thickens, it serves as a biological scrubber to remove and breakdown organic contaminants. The resulting biological sludge and the solid waste matter is constantly removed by making use of a highly effective-in-line separation method provided by the invention to produce a small volume concentrated waste stream and a separate newly filtered water stream.
This invention has particular application to wineries producing cellular effluent, production facilities that produce water containing an organic waste component as well as wastewater management companies.
In conventional water filtrations systems, the biofilms that form during the filtration process are separated out or pumped to a separate collection tank. However, these conventional systems have to be stopped from time to time to manually remove sediments. This novel system described here holds the following advantage over conventional systems:
1. Biological contaminants and solid materials are continuously separated out of the filtered water without the need to disrupt operation in order to clean the packed beds.
2. There is no need to build an additional settling tank.
3. The system does not use filters that need to be cleaned or can become clogged with use.
4. Only a small amount of waste is produced from the filtration process resulting in a lower negative environmental impact. In other words, this system has a smaller footprint than conventional filters of the kind.
5. The design of the filter allows for a greater aeration rate than a conventional filter, allowing for the quicker breakdown of the organic matter.
7. The pre-fabricated components require minimal or even no construction.
8. Small capital outlay to implement, especially if an existing water cooling tower is on site.
The invention presents a continuous biofiltration system which produces a stream of waste and a stream of clean filtered water. The system seamlessly separates solid and organic waste material from water in one tank.Filters are unnecessary for this invention, which means less clogging than traditional filtration systems.
Prof T.E. Cloete, Vice-rector (Research and Innovation), Miss D.M du Plessis, Department of Biochemistry and Dr. M. Botes, Department of Microbiology.