Grit Separation and Treatment
Our comprehensive product range offers you the best solution for any grit separation application, with longitudinal or circular grit traps and also by means of complete plants for complete mechanical wastewater treatment in a single and compact unit.
Based on our wide ranging experience and expertise, HUBER Engineers will design your customised, complete grit treatment system for your specific needs. All grit treatment process steps can be reliably fulfilled by state-of-the-art HUBER equipment.
Systems
Grit Separation
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 from the digestable organic material. Separation of grit, gravel and other mineral matter is required to increase the reliability of wastewater treatment plant operation. Good grit separation prevents operational problems, such as grit sedimentation in aeration tanks and digestors, reduces wear of equipment, such as pumps or sludge dewatering plants, and avoids clogging of sludge hoppers and sludge lines. While as much as possible of the mineral matter should be removed, as much organic matter as possible should remain in the wastewater. Testing of the grit capture rate is usually done with a grit particle size of 0.2 mm. In combined sewer systems, approximately 60 l of grit can be removed from 1,000 m³ of wastewater. The most common grit separating systems in use are grit channels, circular grit traps and vortex grit traps. Grit is either separated by gravity sedimentation (grit channels) or centrifugal force (circular and vortex grit traps).
Grit treatment
Grit treatment
Grit from grit traps of wastewater treatment plants and grit from sewer and road cleaning are heavily contaminated with organic matter and debris. The high content of organic material, the wide volatile solids ratio of 10 to 80 %, is the reason why such grit slurries do not dewater well. The solids concentration remains somewhere between. The common performance criteria for the quality of grit removal are: The capture rate of 0.2 mm diameter grit particles; and the volatile solids concentration of the removed grit.
The end product of excellent grit treatment is a reusable product with a volatile solids ratio of less than 3 % and a water content of below 10 %. Such grit treatment not only reduces the volume and mass of the removed grit, but also the disposal costs. If the clean grit product is reused, e.g. for road bedding, costs for grit disposal could be avoided.
For the treatment of grit from grit traps on wastewater treatment plants, HUBER grit washers have proven to be the unrivalled best option. HUBER grit washers achieve an outstanding grit product containing less than 10 % water and below 3 % volatile solids. It is so clean that beneficial use is easily possible. Equally important is that HUBER grit washers have a 0.2 mm grit particle capture rate of about 95 %. Over a thousand HUBER grit washers are successfully operating worldwide. They have easily met all governmental regulation requirements and will most likely do so in the future, because they have defined the industry standards.
The characteristics of grit from sewer flushing and from gully and road cleaning can vary widely. Their treatment must be customized, depending on required capacity, input material composition, output material quality, etc. Main process steps are: storage and balancing, debris separation, grit classifying and grit washing. Where there is no wash water supply available, wash water treatment and recirculation is an option. All these steps can be reliably fulfilled by state-of-the-art HUBER equipment.
