Flex-O-Star® Industrial Wastewater Pretreatment & Filtration System
Industrial wastewater does not always start as thick sludge. Many facilities need to remove dissolved metals, fine suspended solids, oils, grease, pigments, or insoluble contaminants from rinse water, wash water, and process wastewater before discharge. The problem is that conventional systems often demand settling tanks, heavy polymer programs, or filter presses that blind, bottleneck, and consume floor space.
The ALAR Flex-O-Star® is an industrial wastewater pretreatment system that solves these challenges by combining automatic chemical pretreatment with Auto-Vac™ rotary vacuum drum precoat filtration in one skid-mounted unit. Instead of waiting for solids to settle in a clarifier or building a heavy floc for a DAF or filter press, the Flex-O-Star® chemically separates contaminants, keeps them suspended through mixing, and filters them directly. The result is treated, non-potable water for sewer discharge or reuse, plus dry, dewatered solids for disposal.
In many applications, the system accomplishes this with simple pH or ORP adjustment and without large polymer doses. That makes the Flex-O-Star® a strong fit for low-solids wastewater streams such as metal finishing rinse water, as well as higher-solids wash waters, slurries, and production waste streams. ALAR offers more than sixteen Flex-O-Star® sizes to match your wastewater volume, contaminant loading, and operating schedule.
How the Flex-O-Star® Works
The Flex-O-Star® uses a two-step liquid-solid separation process: chemical pretreatment and separation, followed by Auto-Vac™ filtration and solids dewatering. This combination allows facilities to treat wastewater in batch or continuous-batch operation without relying on sludge settling.
Step 1: Chemical Pretreatment and Separation
The Flex-O-Star® uses a PLC-controlled treatment tank with a turbine mixer and automatic chemical feed systems. Depending on the wastewater, the system can dose pH adjusters, ORP reagents, coagulants, flocculants, or other pretreatment chemicals as needed.
This chemical step separates contaminants from the water. In many applications, a simple pH adjustment is enough to precipitate metals and other dissolved solids so they become filterable. Fats, oils, and grease can also be de-emulsified for removal. The key difference: solids do not need to settle. The mixer keeps the separated contaminants suspended, and the Auto-Vac™ filter removes them directly from the liquid. That means the Flex-O-Star® can often avoid the extra footprint, time, and maintenance associated with settling tanks, clarifiers, DAF systems, and large polymer programs.
Step 2: Auto-Vac™ Filtration and Solids Dewatering
After chemical pretreatment, the wastewater pumps to the Auto-Vac™ rotary vacuum drum precoat filter at a controlled rate. The drum is precoated with microfiltration-grade diatomaceous earth or perlite filter aid. As the drum rotates, vacuum pulls treated water through the filter media while solids collect on the filter cake surface. The Auto-Vac™ captures particles larger than one micron and produces high-quality, non-potable filtrate.
As solids build up, an adjustable-speed Stellite blade shaves away the blinded layer with lathe-like precision. This exposes clean filter media and allows the system to keep filtering without cloth blinding or manual plate scraping. Filtered water discharges to sewer or moves to a clean water tank for non-potable reuse. Dewatered solids drop into a dumpster, drum, or roll-off container for compliant landfill disposal. This gives the Flex-O-Star® sludge dewatering capability without making wastewater sludge dewatering the only purpose of the system.
Designed for Low-Solids Wastewater, Wash Water, and Slurries
The Flex-O-Star® is not limited to thick sludge or high-solids waste streams. It is often a strong fit for low-solids industrial wastewater where contaminants are dissolved, emulsified, or present as fine suspended particles. This includes metal finishing rinse water, plating rinse water, parts washer wastewater, floor scrubber water, flexographic ink wash water, paint and coating wastewater, and other production wash waters.
For metal finishing and plating applications, the incoming wastewater may have very low percent solids by weight. The problem is not visible sludge. The problem is dissolved or suspended metals that need to be chemically precipitated and filtered before discharge. The Flex-O-Star® is built for that type of application because it does not need a thick floc or concentrated settled sludge to work properly. For heavier waste streams, the same system can also process slurries, ink wash water, pigment waste, and other high-variability industrial liquids. The chemical program and filter size are selected based on the waste stream, flow rate, solids loading, and discharge target.
Why Facilities Choose the Flex-O-Star®
No settling step required. Chemical pretreatment separates or precipitates contaminants, mixing keeps them suspended, and the Auto-Vac™ removes them directly from the liquid.
- Less dependence on heavy polymer programs. In many applications, pH or ORP adjustment handles most of the chemical separation. Coagulants and flocculants are available when the wastewater requires them, but the system does not always need large polymer doses to produce a filterable solid.
- 1-micron filtration. The Auto-Vac™ precoat filter captures particles larger than 1 micron and produces high-quality non-potable filtrate for discharge or reuse, helping facilities maintain TSS and BOD compliance.
- Dry solids for disposal. The system produces dewatered solids for landfill disposal, supporting sludge dewatering equipment goals without requiring a separate filter press or sludge-handling process in many applications.
- Skid-mounted and factory-built. Pre-piped, pre-wired, and ready for placement. Controls, chemical feed, treatment tank, filtration, and automation are built into one package.
Standard System Features
Every Flex-O-Star® ships as a complete industrial wastewater pretreatment and filtration package:
- Structural steel skid — Welded, painted, and ready for placement
- PLC and pneumatic controls — Allen Bradley MicroLogix PLC with PanelView touch screen; automatic precoat, wash-up, chemical pretreatment, and filtration cycles
- NEMA 12 control panel — Integrated pH/ORP monitoring
- Batch treatment tank — Carbon steel, stainless steel, or fiberglass dish-bottom tank with turbine mixer and level sensors
- Automatic chemical feed — Metering pumps, make-down tanks, pH and ORP probes
- Auto-Vac™ rotary vacuum drum precoat filter — Self-cleaning filtration with one-micron particle capture and solids dewatering
- Multiple system sizes — More than 16 configurations based on wastewater volume, solids loading, and operating hours per day
The skid-mounted design reduces footprint and installation complexity compared to multi-component systems that require separate tanks, clarifiers, filter presses, and sludge handling equipment.
Common Applications
The Flex-O-Star® handles a wide range of industrial wastewater treatment system requirements. It is especially useful when a facility needs chemical treatment, fine filtration, and dry solids collection in one automated package.
Metal Finishing and Plating
Rinse water and spent bath solutions from electroplating, anodizing, and surface finishing operations contain regulated metals such as zinc, copper, nickel, and chrome. The Flex-O-Star® can precipitate and filter these metals using pH adjustment wastewater treatment or ORP control, often without requiring a clarifier, DAF, or large polymer program. This makes it a strong fit for low-solids rinse waters where heavy metal wastewater treatment is needed but the contaminants are not present as thick sludge.
Flexographic Ink and Corrugated Packaging
Flexographic ink wastewater contains pigments, binders, starches, suspended solids, and organic loading. These waste streams can plug filter presses, overload settling tanks, or require long treatment cycles. The Flex-O-Star® combines chemical pretreatment with Auto-Vac™ filtration to remove suspended and precipitated solids while producing dry solids for disposal, often reducing labor and eliminating filter press bottlenecks.
Paint, Coatings, and Pigment Wastewater
Fine pigments, latex solids, oils, resins, and suspended contaminants that resist conventional clarification are common in paint and coatings wastewater. The Flex-O-Star® chemically separates these contaminants and filters them directly from suspension, providing a repeatable wastewater filtration system without relying on large settling tanks or manual sludge handling.
Food and Beverage Wastewater
Food and beverage facilities often deal with elevated TSS, FOG, and insoluble BOD. The Flex-O-Star® reduces these contaminant loads before sewer discharge or before additional downstream treatment. It is not a biological treatment system, but it removes filterable solids, oils, grease, and insoluble organics that contribute to surcharge and discharge penalties.
Industrial Waste Hauling and Batch Treatment
Waste haulers and centralized treatment operations receive variable wastewater from multiple generators. The Flex-O-Star® can be configured for batch or continuous-batch treatment, making it useful for facilities that need to chemically adjust, filter, and dewater many different waste streams on a flexible schedule.
Flex-O-Star® vs. Settling Tanks, DAFs, Clarifiers, and Filter Presses
Many wastewater treatment systems depend on settling or thick sludge formation before solids can be removed. The Flex-O-Star® uses a different approach: it chemically separates contaminants, keeps them suspended, and filters them directly through the Auto-Vac™ precoat filter. This can eliminate the need for large settling tanks that consume floor space, clarifiers that struggle with fine particles or poor-settling solids, DAF systems that require heavy chemical programs, filter presses that blind and require long blow-down cycles, and manual plate scraping and cloth replacement. The Flex-O-Star® is not the right answer for every wastewater stream, but it is often a strong fit when the facility needs automatic pretreatment, reliable filtration, and dry solids handling in one system.
Proven Results: Flexographic Ink Wastewater
A West Coast corrugated packaging company was struggling with wastewater treatment bottlenecks at multiple facilities. Existing filter presses blinded quickly, blow-down cycles exceeded 24 hours, and wet cake required extra drying before disposal.
ALAR tested the wastewater, reviewed the treatment chemistry, and designed a Flex-O-Star® around the facility's existing sump pit and holding tank. The system processed a full day of wastewater in under five hours, produced dry solids for disposal, and eliminated the bottleneck caused by the old treatment process. The company later installed multiple Flex-O-Star® systems across its facilities.
Flexographic ink sample before and after the application of the Alar® Flex-O-Star® dewatering filter system.
The entire process of the Flex-O-Star® is automatic, which is built on a structural steel skid, pre-piped and pre-wired for easy installation.
Standard Flex-O-Star® Features Include:
System Support Skid
Structural carbon steel [welded and painted] skid that will support tank(s), mixer(s), pump(s), control cabinet, and Auto-Vac™
Skid-Mounted; Pre-Piped; Pre-Wired Components
Automatic PLC and Pneumatic Controlled
Automatic precoat filter cycle
Automatic wash-up cycle
Automatic chemical pretreatment cycle
Automatic filtration cycle
All controls programmed and mounted in Control Panel / PLC
NEMA 12 Control Panel
Automatic PLC Controls
Allen Bradley MicroLogix PLC
PanelView Touch Screen
pH / ORP Monitoring System
Treatment Tank
Carbon, Stainless or Fiberglass Dish Bottom Tank
Skid Mounted
Turbine Mixer and Support
Level Sensors
Controls Programmed into PLC
Automatic Chemical Feed System
Make-down tanks, metering pumps, or both
pH probe, ORP probe, or both
Automatic Sludge Transfer
PLC activated filter feed pump with regulator, ball valve and automatic solenoid control
Auto-Vac™ Rotary Vacuum Drum Filter Technology
Contact ALAR to discover how the easy to operate Auto-Vac™ can benefit your bottom line.
ALAR has sixteen (16) Flex-O-Star® sizes to choose from. Available in single or continuous batch systems. The solids loading, volume and amount of hours per day will factor into the equipment size.
Contact an ALAR representative to determine which Flex-O-Star® system is best suited for your industrial wastewater process.
Replacement Parts
ALAR designs each system to meet the customer's build-to specifications. ALAR begins with stock layouts, and customizes the auxiliary equipment according to the customer's specifications.
These stock layouts are available in PDF format. Contact ALAR for more information.
Frequently Asked Questions
The Flex-O-Star® automatically treats industrial wastewater using chemical pretreatment followed by Auto-Vac™ rotary vacuum drum precoat filtration. It separates contaminants from water, filters suspended and precipitated solids, and produces non-potable filtrate plus dewatered solids for disposal.
No. The Flex-O-Star® can dewater solids, but it is more than a sludge dewatering system. It is an industrial wastewater pretreatment and filtration system designed for batch or continuous-batch treatment of wastewater, rinse water, wash water, slurries, and other liquid waste streams.
No. The Flex-O-Star® does not require contaminants to settle in a tank before filtration. Chemical pretreatment separates or precipitates the contaminants, mixing keeps the solids suspended, and the Auto-Vac™ filter removes them directly from the liquid.
The Flex-O-Star® can reduce TSS, FOG, heavy metals, precipitated solids, fine suspended particles, and insoluble BOD. Common metals include zinc, copper, nickel, chrome, and other regulated metals depending on the wastewater chemistry.
Yes. The Flex-O-Star® is well suited for many metal finishing and plating rinse waters. With the right pH or ORP adjustment, dissolved metals can be precipitated and filtered without requiring a clarifier, DAF, or heavy polymer program in many applications.
Traditional plate-and-frame filter presses can require long cycle times, blow-down steps, manual plate scraping, and frequent cloth cleaning or replacement. The Flex-O-Star® uses a self-cleaning Auto-Vac™ drum precoat filter that continuously shaves away blinded solids and exposes clean filter media during operation.
A sludge dewatering system removes water from solids generated during wastewater treatment. The goal is to reduce sludge volume, lower disposal cost, and produce solids dry enough for disposal. The Flex-O-Star® supports this function by filtering chemically separated solids and discharging dewatered solids from the Auto-Vac™ filter.
ALAR offers more than 16 Flex-O-Star® sizes for batch or continuous-batch wastewater treatment applications. System sizing depends on wastewater volume, contaminant loading, solids loading, filterability, and required operating hours per day.
Yes. The Flex-O-Star® can often be integrated with existing holding tanks, sump pits, transfer systems, or downstream treatment equipment. ALAR reviews each application to match the system layout to the facility's wastewater source, available space, and operating needs.
