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PRE-TREATMENT
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SCREENING
The screen channel plays a fundamental role in the preliminary stages of processing by filtering out large solid materials from the incoming wastewater. As the untreated water flows into the treatment plant, it first passes the sand trap before entering the screen channel, where it encounters one or more automatic screens in series designed to capture and remove solid debris.
Once the wastewater flows through the screens, these solid materials, trapped by the screening system, are collected in removable dumpsters. This is accomplished by a mechanical rake or an automated cleaning system that clears away the accumulated waste to prevent clogging and to ensure continuous flow. Once the larger solids have been reoved from the water, the screened wastewater flows by gravity into the next stage.
CHARACTERISTICS & ADVANTAGES
Protects Downstream Equipment
Prevents clogging, abrasion, and damge in pumps, pipes valves, aerators, and biological reactors.
Flexibity
Screens can be adapted (different bar spacing, mechanical raking) depending on waste water characteristics.
SAND TRAP
A sand trap is used during the preliminary treatment stage to remove gritty particles like sand, silt, gravel, and other fine heavy particles from the wastewater. These materials can cause significant wear and damage to pumps, pipes, and other equipment if they are allowed to enter further treatment stages, so their early removal is essential.
As wastewater flows into the sand trap, it is slowed down to a controlled velocity, allowing heavier particles to settle at the bottom while lighter organic materials remain suspended and continue through the system. The design of the sand trap is crucial here; it must be calibrated to allow grit to settle without trapping organic matter, which should remain in the water flow for biological treatment.
Sand trap at this plant set up is a horizontal-flow non-aerated unit in the existing inlet channel. In this horizontal-flow sand trap, wastewater moves slowly in a straight path, allowing gravity to pull heavier particles to the bottom, where they accumulate. Once the grit has settled at the bottom of the sand trap, it must be removed (manually) on regular basis. During sand removal and cleaning, the incoming wastewater is by-passed via a new by-pass channel constructed in parallel with the existing grid channel by opening and closing slice gate valves installed at the inlet and outlet of the channels.
© ICR AMBIENTAL. ALL RIGHTS RESERVED.
CHARACTERISTICS & ADVANTAGES
Protects Downstream Equipment
Prevents clogging, abrasion, and damge in pumps, pipes valves, aerators, and biological reactors.
Reduces Maintenance Costs
Well-designed channels allow easy rremoval and disposal of screenings
EQUALIZATION TANK
An equalization tank is used to balance the flow and composition of incoming wastewater, creating a more consistent load for downstream treatment processes. Wastewater inflow rates and pollutant concentrations can vary significantly due to factors like changes in industrial discharges, or daily usage patterns. These fluctuations, if left unaddressed, can strain the treatment system and affect its efficiency.
The equalization tank receives wastewater from a pump station and temporarily stores it, allowing the plant to regulate flow and composition before releasing it to further treatment stages. By adjusting the flow rate, the equalization tank helps maintaining a steady, manageable rate of wastewater entering the plant, reducing the risk of overwhelming the biological processes in later stages.
Mixers are installed in the tank to keep solids suspended and to prevent settling, which can otherwise lead to issues with consistency and odor. Partial acidification of biodegradable components will occur in the equalization basin, which is beneficial for the next treatment step. Once the wastewater has been balanced in terms of volume and pollutant concentration, it is gradually pumped to the step of the treatment process.
CHARACTERISTICS & ADVANTAGES
Balances out fluctuations in efluent flow and prevents hydraulic overloads in downstream treatment units.
Flow Equalization
pH and Temperature Control
Allow for neutralization, chemical dosing, or cooling/healing of wastewater before treatment.
© ICR AMBIENTAL. ALL RIGHTS RESERVED.
© ICR AMBIENTAL. ALL RIGHTS RESERVED.
DAF - DISSOLVED AIR FLOTATION UNIT
A Dissolved Air Flotation - DAF unit is an advanced water treatment technology used to separate suspended solids, oils, grease, and other pollutants from water. The process relies on the principles of flotation, where fine air bubbles are introduced into the water, causing contaminants to rise to the surface for removal. This method is highly effective in treating industrial and municipal wastewater, particularly in applications where high levels of grease, oils, and other lightweight particles are present.
The operation of a DAF unit begins with the injection of air into a pressurized water stream. Air is dissolved into the water under pressure, creating a supersaturated solution. This pressurized water is then introduced into the main treatment tank, where the pressure is released, allowing the dissolved air to come out of the solution in the form of microbubbles. These tiny bubbles are crucial to the flotation process, as they attach to suspended particles, fats, and oils in the wastewater. The attachment of bubbles reduces the density of these contaminants, causing them to rise to the surface of the water.
As the bubbles and attached particles reach the surface, they form a floating layer of sludge. This layer is continuously or periodically skimmed off using mechanical scrapers, removing the bulk of the contaminants from the water. The floating materials are collected (by gravity) in the sludge hopper of the DAF unit and pumped with progressive cavity pumps to the sludge handling.
The clarified water beneath the surface is then directed to subsequent biological treatment stage for further purification.
The DAF unit is a fully automated "stand alone" unit equipped with feed system, internal recycle, micro bubble saturation system, sludge scraper and bottom hopper purge system.
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CHARACTERISTICS & ADVANTAGES
Excellent Removal of Light, Non-Settleable Solids
Compact and Fast Process
DAF is far superior to sedimentation for these contaminants.
Provides rapid clarification in a much smaller footprint compared to conventional primary clarifiers.
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