Industrial Wastewater Treatment Equipment and Complete Systems
Quick answer: A complete industrial wastewater treatment system combines pre-treatment, physical-chemical treatment, biological treatment and sludge dewatering. Senjie builds these as packaged plants, with the filter press or screw press handling the final sludge stage. Typical delivered capacity runs from 5 m³/day skid units to 5,000 m³/day civil-works plants.
What a complete wastewater treatment system contains
Buyers often ask for “a wastewater treatment machine”. In practice a plant is a chain of stages, and the equipment in each stage is chosen from the characteristics of your effluent — flow rate, COD, suspended solids, pH, oil content and the discharge limit you must meet. Skipping a stage is the single most common reason a plant fails to hold its discharge permit.
| Stage | Purpose | Typical equipment |
|---|---|---|
| 1. Pre-treatment | Remove rags, grit, coarse solids; buffer flow and pH swings | Bar screen, rotary drum screen, grit chamber, equalisation tank with mixer |
| 2. Physical-chemical | Remove suspended solids, oil, colour, phosphorus, heavy metals | Coagulation-flocculation tank, dissolved air flotation (DAF), lamella clarifier, neutralisation unit |
| 3. Biological | Remove dissolved organics (COD/BOD), ammonia nitrogen | Anaerobic (UASB/IC), aerobic activated sludge, MBBR, SBR, MBR |
| 4. Advanced / polishing | Meet strict discharge or reuse limits | Sand and carbon filters, ozone or Fenton oxidation, ultrafiltration, RO |
| 5. Sludge handling | Thicken and dewater the sludge every stage produces | Sludge thickener, multi-disc screw press, chamber or membrane filter press |
Stage 5 is where most suppliers under-deliver. Every earlier stage produces sludge, and a plant with no serious dewatering step simply moves the disposal problem downstream at a much higher cost per tonne.
Equipment ranges we supply
All figures below are typical operating ranges for the configurations we build. Exact specifications are fixed against your water analysis and are confirmed in the quotation — we do not publish fixed model specifications, because the same nominal capacity behaves very differently on 500 mg/L COD and on 20,000 mg/L COD.
| Equipment | Typical range | Where it fits |
|---|---|---|
| Chamber (recessed-plate) filter press | 1–1000 m² filter area; feed 0.6–1.0 MPa, up to 1.6 MPa high-pressure; cake moisture 40–55%; cycle 1–4 h | General sludge dewatering, the workhorse of stage 5 |
| Membrane (diaphragm) filter press | Squeeze 1.5–2.0 MPa; cake 10–15 percentage points drier than chamber; cycle 30–90 min | When disposal is charged by weight, or the cake must be landfill-ready |
| Fully automatic filter press | Auto plate shifting, auto cloth washing, PLC control; hydraulic closing 20–25 MPa | Continuous plants, limited labour, three-shift operation |
| Multi-disc screw press | Continuous, low-speed, low-noise; handles oily and greasy sludge that blinds belt presses | Municipal and food-industry sludge, 24/7 unattended running |
| Dissolved air flotation (DAF) | Removes oil, grease, fats and light suspended solids ahead of biological treatment | Food, slaughterhouse, palm oil, textile, refinery effluent |
| MBR / MBBR / SBR biological units | Packaged or civil-works; sized on COD load and required effluent quality | Stage 3, wherever dissolved organics dominate |
| RO industrial water purification | Reuse-grade or process-grade permeate | Water reuse, zero-liquid-discharge projects, boiler and process feed |
| Feed pumps | Air-operated diaphragm, progressing cavity, slurry, ceramic piston | Matched to slurry abrasiveness, solids content and required feed pressure |
Filter plates are moulded in PP rated to 90 °C, or glass-reinforced PP to 120 °C. Filter cloth is selected per application in PP, PA/nylon or PET, monofilament or multifilament, with a typical service life of 3–12 months depending on abrasion.
Applications by industry
The process chain changes shape depending on what is in the water. These are the effluent types we build for most often.
| Industry | Dominant problem | Typical chain |
|---|---|---|
| Electroplating & surface finishing | Heavy metals, extreme pH, cyanide or chromium | Segregated streams → reduction/oxidation → neutralisation → precipitation → chamber filter press |
| Textile dyeing & printing | Colour, high COD, temperature, surfactants | Cooling → coagulation → DAF → anaerobic + aerobic → membrane filter press |
| Food, beverage & slaughterhouse | Fats, oil and grease; high BOD; shock loads | Screen → DAF → equalisation → UASB + aerobic → screw press |
| Palm oil mill effluent (POME) | Very high COD, high temperature, oil | Cooling ponds → anaerobic digestion → aerobic → filter press |
| Mining & mineral processing | Fine abrasive solids, high throughput, water recovery | Thickener → high-pressure chamber or membrane filter press → water reuse |
| Stone cutting, ceramics & construction | Very fine inert slurry, rapid settling | Settling → thickener → filter press → closed-loop water reuse |
| Chemical & pharmaceutical | Variable, often toxic or inhibitory to biology | Segregation → pre-oxidation → biological → advanced oxidation → filter press |
| Municipal & industrial-park plants | Mixed load, strict permits, sludge volume | Full chain with MBR polishing → screw press or membrane filter press |
How to size and select a system
Five numbers decide almost everything. Have them ready and a realistic proposal takes days rather than weeks.
- Flow rate — m³/day, plus the peak hourly flow. A plant sized on daily average and fed a four-hour peak will wash out.
- Influent quality — COD, BOD, suspended solids, pH, oil and grease, ammonia nitrogen, and any heavy metals. A laboratory analysis, not an estimate.
- Required discharge limit — the actual local standard you are held to, or the reuse quality you want.
- Sludge quantity and target dryness — this sizes stage 5 and drives your disposal cost for the next decade.
- Site constraints — available footprint, power supply, ambient temperature, and whether you want a containerised skid or a civil-works plant.
For the dewatering stage specifically, see our filter press sizing calculation guide, which works through the volume-per-cycle arithmetic with a worked example.
Frequently asked questions
What equipment do I need for industrial wastewater treatment?
A complete system normally has five stages: pre-treatment (screening, equalisation), physical-chemical treatment (coagulation, DAF, clarification), biological treatment (anaerobic, aerobic, MBBR, SBR or MBR), advanced polishing where the discharge limit is strict, and sludge dewatering with a filter press or multi-disc screw press. Which stages you actually need is decided by your influent analysis and your discharge limit, not by the flow rate alone.
How much wastewater treatment capacity do I need?
Size on peak hourly flow, not daily average. Take your daily volume in cubic metres, identify the worst four-hour peak, and size hydraulic equipment for that peak while sizing biological volume on the daily organic load. A plant sized only on the daily average will wash out its biomass during peaks and lose compliance.
What is the difference between a filter press and a screw press for sludge?
A filter press works in batches at 0.6 to 2.0 MPa and produces a dry, stackable cake, typically 40 to 55 percent moisture for a chamber press and 10 to 15 percentage points drier for a membrane press. A multi-disc screw press runs continuously at low speed, handles oily and greasy sludge that blinds belt presses, and needs almost no attention, but its cake is wetter. Choose the filter press when disposal is charged by weight, and the screw press when you need unattended 24/7 operation.
Can treated wastewater be reused?
Yes, where the process is designed for it. Reuse normally requires an advanced polishing stage such as ultrafiltration followed by reverse osmosis. Stone cutting, ceramics and mining plants frequently run closed-loop water recovery because their solids are inert and settle quickly, which makes reuse comparatively straightforward.
How long does it take to deliver a packaged wastewater plant?
Lead time depends on whether the plant is a containerised skid or a civil-works installation, and on the level of automation. Provide your water analysis, flow rate and discharge limit and we will confirm a delivery schedule with the quotation.
What information do you need to prepare a proposal?
Five items: flow rate in cubic metres per day with peak hourly flow; a laboratory influent analysis covering COD, BOD, suspended solids, pH, oil and grease and ammonia nitrogen; the discharge standard you must meet; estimated sludge quantity and target dryness; and site constraints such as footprint, power supply and ambient temperature.
Do you supply the sludge dewatering equipment separately?
Yes. Many buyers already have a working biological plant and only need to solve the sludge stage. We supply chamber, membrane and fully automatic filter presses, multi-disc screw presses, filter plates, filter cloth and the matching feed pumps as standalone equipment.
Which feed pump should be used for a filter press?
It depends on the slurry. Air-operated diaphragm pumps suit low to medium solids and are simple to maintain. Progressing cavity pumps handle viscous and shear-sensitive sludge. Slurry pumps are built for abrasive, high-solids duty. Ceramic piston pumps are used where high feed pressure is required, typically on high-pressure and membrane presses.
Related equipment
- Chamber filter press — the standard dewatering unit for most industrial sludge
- Membrane filter press — for the driest cake and the lowest disposal weight
- Multi-disc screw press — continuous, unattended dewatering for oily sludge
- RO industrial water purification systems — for reuse and zero-liquid-discharge projects
- Filter cloth and filter plates — consumables and spares
- Feed pumps and auxiliary equipment — diaphragm, progressing cavity, slurry and ceramic piston pumps
- Buyer FAQ hub — 30 questions on specification, sizing, operation and procurement
Send your flow rate, water analysis and discharge limit and we will come back with a process proposal and equipment list: request a wastewater treatment proposal.