Mechanical Wastewater Treatment System
- Mechanical bucket grating, sand traps and percolator
- Mechanical bucket grating in SPS
- Tangential sand trap
- Percolators
Mechanical Wastewater Treatment System
Mechanical treatment is pre-treatment of incoming wastewater preparing it for biological treatment. At this stage, coarse insoluble impurities are removed. Mineral pollutes are removed up to 70% and BOD (Biochemical oxygen demand ) is reduced by 30 %.
Depending on the size, composition of the wastewater, and requirements of the customer, Bioxica uses trash baskets, mechanical gratings, sand traps, and drum percolators in its wastewater treatment plants Bioks.
Depending on the specific conditions of industrial effluents of poultry, meat, and dairy processing, they may be pretreated for discharge to residential drains (residential wastewater treatment) or surface water.
If the existing treatment facilities were not originally designed to accept industrial wastewater, the effluent must be pretreated to the standards set for residential drains. The extent of treatment is coordinated with all involved urban municipal organizations and those organizations that carry out the design and operation of wastewater treatment plants and sewer systems of a particular locality.
One of the major problems of environmental protection is the purity of water reservoirs. Hence, regulatory agencies set strict requirements as to the composition of wastewater discharged into water (water reservoirs ).
Wastewater effluent from Bioks by Bioxica plants fully satisfies these requirements.
Read MoreMechanical bucket grating is set in the SPS and serves for pre-treatment of wastewater from the rough mechanical medium and small scrum with subsequent washing, pressing, and transportation in the waste container.
Mechanical bucket grating
Шнек со щеткой – screw with brush
Фильтрующий элемент - filter element
Отражающие экраны - reflective screens
Привод шнека - screw drive
Зона выгрузки - discharge area
Зона промывки и отжима - washing and pressing area
Транспортирующая зона - conveying area
Зона фильтрации - filtration area
The grating is made of stainless steel, and is mounted in the canal inclined screw perforated screen or welded slit canvas. To clean the filter cloth from delayed waste scrum, a screw is provided. It is a without axial helix with variable pitch, equipped with a brush along the periphery. Above the filter, the diameter of the helix decreases, and it becomes an axial screw.
In this zone, the auger is in a closed housing, protected against abrasion by a resistant polymer removable liner. Inclined housing rests on the stand. At the top of the housing, nozzles are provided for washing of waste taken from grating and discharge area. The screw is driven by a reduction geared motor mounted in the upper part of the grating.
Scum, retained on the filter cloth screw grating, are removed from the cloth and moved up the body of the screw by rotating helix, wherein the filter cloth is cleaned with brushes arranged around the periphery of the screw.
Spin waste is due to the reduction of the flight of a screw. In the upper part of the housing, the scrum are washed from organic impurities with water from the nozzles. Pressed water and wastewater from washing through conduit is directed into the channel before the grating. In the discharge area, scrum, washed and pressed to 35% of the original volume, are thrown to the waste container through the special opening.
The tangential sand trap is the most common type of sand trap.
Tangential sand trap
The tangential sand trap has a cylindrical shape.
Wastewater flows into it tangentially, causing a rotational movement of the water, which promotes the separation of large mineral slurries and their deposition on the bottom of the sand trap, where they are periodically removed by airlifts (special pumps) or in some other way. After the removal of large mineral slurries, the sewage flows for further purification of organic substances.
A drum percolator is part of mechanical wastewater treatment equipment. They are used without primary settling tanks, removing scum, sand, and larger suspended solids. Bioxica’s Bioks, drum percolators made by Bioworks (Germany) are used.
Drum percolator Bioworks (Germany) with screw conveyor percolators and press waste
Fine filters are used instead of gratings here, which are designed as a rotating drum with press and waste disposal system. There are 4 drum gratings (3 operating and 1 spare), a conveyor, and a press for compacting waste. The diameter and length of the drum is designed in accordance with a peak input flow. Drum drive is designed as a geared motor and is automatically controlled with a built-in water level gauge. The drum is equipped with an automatic cleaning device.
At the bottom of the device, an output for discharges of treated effluent into the open channel is made.
The whole device is made of stainless steel, which significantly extends its service life. It is equipped with a built-in system for emergency overflow and an alarm contact.
Filtered material is separated from the drum through the special scraper system and diverted to a screw press or directly into the container.
