HUBER Disc Filter RoDisc
- Retention of filterable solids from the secondary clarifier effluent - Reduction of micropollutants using powdered active carbon (PAC)- Preliminary filtration in drinking water recovery from surface waters and in UV disinfection applications
➤➤➤ The challenge
High hydraulic loads, insufficient tank depth and poor settling behaviour of the activated sludge are the most common causes for the poor performance of secondary clarifiers. Frequently, second ary clarifiers are even unable to reliably ensure the solids retention required. Overflow of flocks increases COD, BOD and phosphorus loads in the effluent and receiving watercourse with the result of higher wastewater fees.
Due to improved methods of analysis micropollutants
(pharmaceutical residues) are increasingly detected in water and soil in Germany. Some of these substances have a high damaging effect on the environment. Adsorption using powdered active carbon is a physical-chemical separation process to remove such substances. It is however of vital importance to prevent the ingress of contaminated powdered active carbon into the water.
A subsequently installed filtration system is a quick, efficient solution in order to achieve separation of suspended material, such as sludge flocks or powdered active carbon.
Combined with preceding precipitation and flocculation a micro screen provides an easy-to-implement means for the reduction of phosphorus in effluents to very low concentrations. This prevents eutrophication of waters and excessive growth of algae and water plants.
➤➤➤ The solution
Our RoDisc® Rotary Mesh Screen is a filtration plant and consists of up to 35 vertical discs installed on a horizontal shaft. Up to 65% of the disc surface is submerged in the filtrate during operation.
Each filter disc consists of 12 individual plastic segments equipped with two filter plates each. The filter plates are covered with filter mesh on both sides. A thermal process is applied to fix the mesh. Each segment can be exchanged individually in case the mesh should be damaged. The finest available mesh size is as small as 10 µm.
Due to its small space requirement and modular design the RoDisc® Rotary Mesh Screen can be tailored to suit any specific site require ments.
➤➤➤ The function
The RoDisc® Rotary Mesh Screen is a gravity-flow filtration system. The wastewater to be treated flows into the horizontal shaft and from there through openings into the filter discs which the water passes from inside to outside. The filter discs remain in rest position at first during the filtration process. The solids are retained on the inner disc surfaces, which leads to gradual blinding of the mesh, resulting in an in creasing pressure differential. An overflow weir ensures that the water level in the tank