CONTIFLOW® Sandfilter CFSF

The CONTIFLOW® Sandfilter is an upflow filter with a continously cleaned filter bed, making shutdowns for backwashing of the filter bed unnecessary. Also the reservoirs for wash water and sludge liquor can be spared. Feed is introduced at the top of the filter and flows downward through an opening between the feed pipe and airlift housing. The feed is introduced into the bed through a series of feed radials which are open at the bottom. As the influent flows upward through the moving sand bed, the solids are removed. The filtrate exits at the top of the filter. Simultaneously, the sand bed, along with the accumulated solids, is drawn downward into the airlift pipe, which is located in the centre of the filter. The sand and the solids are transported through the airlift into the washer / separator with central reject compartment. As the sand falls through the washer, which consists of several concentric stages, a small amount of filtered water passes upward, washing away the dirt, while allowing the heavier, coarser sand to fall through to the bed.By setting the reject weir at a lower level than the filtrate weir, a steady stream of wash water is assured. The continuous reject exits near the top of the filter. By variation of the weir height, optimal adjustment of the wash water volume is possible. The method allows continuous filtration of the water and wastewater without shutdowns for backwash cycles.

Grit Separation

For reasons of operating reliability of wastewater treatment plants it is necessary to separate the grit transported with the wastewater and other mineral materials (approx. 60 l / 1000 m³ of wastewater) from the digestible organic material. Grit separation from wastewater can prevent operational troubles, such as grit sedimentation (in aeration tanks and digestors), increased wear (of pumps or stirrers) and clogging (of removal hoppers or pipelines). In addition, wear reduction of mechanical equipment (e.g. a centrifuge, etc.) can be achieved. The aim is to separate as much as possible of the grit and inorganic material up to 0.20 mm grain diameter and at the same time separate the mineral and organic particles in the grit trap. The grit separating systems used today are divided into longitudinal grit traps, circular grit traps and vortex grit traps, depending on their design and process layout. They separate the grit either by gravity (longitudinal grit traps) or centrifugal force (circular and vortex grit traps). For longitudinal grit removal scrapers or screw conveyors are frquently used. Solids removal in the further course of the process is effected by pump, grit classifier or integrated grit classifying screw. Due to the significant organics content in the classified grit longitudinal grit traps are today additionally aerated to at least partly avoid settling of organic material in the grit trap and cause floating material (grease) to rise to the surface. According to Kalbskopf, aerated grit traps are generally laid out on the basis of the residence time of wastewater in the grit trap. However, even aerated grit traps are unable to ensure reliable separation of grit from organics. This can only be achieved by well performing grit washing plants.

Grit Treatment

Grit and mineral material from wastewater treatment plants or sewer and road cleaning are usually more or less contaminated with organic particles or other foreign matter similar to domestic waste. Such contamination in the heterogeneous mixture results in a relatively low dry substance content [DR], ranging between 40 % and 70 %, and in a relatively high loss on ignition [GV] in the range of 10-80 %. The purpose of a well performing grit treatment system is removal of grit up to 0.20 mm grain size and subsequent separation of the valuable grit and mineral fraction from the contamination material. The end product of grit treatment is a valuable product with a low loss on ignition (< 3 %) and a high DR (> 90 %). Grit treatment thus reduces on the one hand disposal costs and on the other hand produces a secondary raw material that can be reused. As the composition of the polluted grit to be treated can be vary greatly, depending on its source of production, the decisive factor when planning a treatment plant is the selection of the best suited treatment system. Treatment of grit from wastewater treatment plants If the grit to be treated is material from the grit trap of a wastewater treatment plant, the worldwide best proven solution is the HUBER Grit Washing Plant. The HUBER Grit Washing Plant ensures that the organics in the grit are washed out to such a degree that the treated grit has a loss on ignition of below 3 %, which allows low-cost grit disposal or direct reuse of such grit. Many countries meanwhile have an according legislation that defines the requirements for washed grit. In practice, not only the effective separation of organic and mineral material is decisive, but also the retention of fine grit. The HUBER Grit Washing Plant takes this fact into account. Treatment of grit from sewers and road refuse Grit from sewers or road sinks or road refuse requires individually designed grit treatment systems. Depending on the system capacity, input material composition, requested material output, etc., the treatment technology has to be tailored to meet specific requirements. The main process steps: acceptance tank, foreign matter separation, wash drum for pre-classification, grit washing plant for separation of organic material. If the external supply and treatment of the wash water required for grit treatment cannot be provided, an additional wash water treatment unit can optionally be supplied for recycling of the required water. On the basis of its wealth of experience in developing complete grit treatment systems, HUBER is able to provide a tailored concept and solution for each individual grit treatment project.

Screenings Treatment

The complete HUBER program for screenings treatment systems: screenings washing, dewatering, compaction, transport and disinfection Optimal systems for any application High dewatering efficiency >li>Maximum washout degree Reduced disposal costs

Storm & Sewer Equipment

Advanced combined and stormwater treatment in municipal combined sewers is a main issue with regard to sustainable environmental and water protection. The quality of many watercourses has significantly been increased meanwhile by building new wastewater treatment plants and upgrading or refurbishing continuous wastewater discharges. Despite all these efforts, however, there are still ecological deficits caused by floating and coarse material that is discharged from the sewer system into waters in the event of stormwater overflow discharge in combined and separated sewer systems. For the purpose of specific environmental protection appropriate measures will have to be taken in future to minimise these deficits.

Wastewater Screens

The mechanical preliminary treatment: Indispensable as a first process step ! Reliable screens for any application Fine and micro screens for separation of fine suspended material Innovative technology from one source