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Electrocoagulation (EC) & Electrooxidation (EO) for Wastewater Treatment

  • kunyapak
  • Oct 11
  • 5 min read
How YASA ET turns tough industrial effluent into reusable water—step by step

Why electrochemical treatment now?

Industrial wastewater is getting more complex while discharge limits are getting tighter. Electrochemical technologies—Electrocoagulation (EC) and Electrooxidation (EO)—solve the two hardest jobs in treatment:

  • EC: removes suspended solids, oil/grease, heavy metals, color, phosphates, and a good portion of COD by generating coagulants in-situ.

  • EO: destroys difficult dissolved organics (recalcitrant COD), pathogens, and traces that slip through other processes often the last mile to compliance or reuse.

Used alone or in sequence, EC and EO help plants cut chemical usage, reduce sludge volumes, and stabilize performance.



What is Electrocoagulation (EC)?

Electrocoagulation uses sacrificial metal electrodes (typically iron or aluminum) in a DC field. At the anode, metal ions are released and hydrolyze to form fresh coagulant, at the cathode, hydrogen micro-bubbles lift floc to the surface. The result is rapid destabilization and removal of emulsified oils, color, colloids, metals, and part of the dissolved organics.

Highlights

  • Coagulant is generated on demand—less chemical trucking and dosing

  • Produces dense, easily dewatered sludge compared to conventional coagulation

  • Excellent front-end step for oily, colored, metal-laden, or highly variable wastewater

  • Typical follow-up: settler, DAF, or filtration for solid–liquid separation

What is Electrooxidation (EO)?

Electrooxidation uses inert (non-sacrificial) anodes such as BDD (Boron-Doped Diamond) or MMO to create powerful oxidants (•OH radicals, active chlorine if chloride is present, sometimes ozone) right at the anode surface. These species mineralize dissolved organic pollutants and disinfect water ideal for polishing after EC, membranes, or biological treatment.

Highlights

  • Breaks down recalcitrant COD and micro-pollutants; supports ZLD strategies

  • No added oxidant handling—oxidants are generated in-situ and quenched in-line

  • Powerful disinfection without separate chlorination systems

  • Best used as a finishing step for energy efficiency


EC vs EO at a glance

Criterion

Electrocoagulation (EC)

Electrooxidation (EO)

Main action

In-situ coagulant + flotation

In-situ advanced oxidation

Targets

SS/Turbidity, oil/grease, color, metals, phosphates, partial COD

Recalcitrant COD, color residues, pathogens, odor, trace organics

By-products

Coagulated sludge (low–moderate volume)

Minimal sludge; oxidized by-products

Opex drivers

Electrode consumption + low–mid DC power

Higher DC power; inert/BDD anodes

Best use

Front-end pre-treatment / bulk removal

Polishing / last-mile compliance & reuse

Typical follow-up

Settler/DAF + filtration

Filtration/AC as needed, reuse or discharge

Rule of thumb: Use EC first to take out the “big, sticky, and shiny” stuff (solids, oils, metals, color). Use EO second to finish the COD and disinfect.

YASA ET Lab & Pilot Solutions

EC/EO Lab Test Kits (Acrylic reactors, ready to run)

Designed for universities, R&D teams, and industrial labs to find the right recipe before scaling up.

Model

Reactor Volume

Included EC Plates

Power Supply

Typical Use

S-EC-1

~1 L

4 × Al + 4 × Fe

0–24 V / 0–30 A

Quick screening, jar-test replacement

S-EC-5

~5 L

5 × Al + 5 × Fe

0–24 V / 0–30 A

Parameter optimization, repeatability

S-EC-10

~10 L

8 × Al + 8 × Fe

0–24 V / 0–30 A

Scale-up trials, continuous‐flow simulation


What’s in the kit: acrylic reactor (see-through), EC plates set, recirculation pump, tubing/valves, wiring, skid with flowmeter, and DC power. Add-on electrodes for EO: SS, Titanium, Ti/Ru-Ir MMO, BDD, Graphite, Magnesium, etc.

How-to videos (embed in Wix):

EOXCell (EO add-on with BDD)

EOXCell is our electro-oxidation module that drops into the same test platform. It comes with BDD anodes and Titanium cathodes in compact, easy-to-plumb cells—ideal for COD polishing, color removal, and disinfection.

Video: How to test with EOXCell – https://vimeo.com/1028299790

How to run great EC/EO tests (and get scale-up-ready data)

1) Pre-check & preparation

  • Screening/filtration: remove >100 µm grit to protect hydraulics

  • pH: start near 6.5–7.5; adjust if data later shows a better window

  • Conductivity: for EO, keep sufficient conductivity (add small Na2SO4/NaCl if needed)

2) EC testing (typical plan)

  • Start with Fe and Al separately, then try mixed stacks (Fe/Al alternating)

  • Current density steps (example): 10 → 30 → 50 A/m²

  • Contact time ladder: 10–20–30 minutes (batch) or set equivalent HRT for flow-through

  • Capture: Turbidity/SS, oil & grease, color, COD, PO4-P, metals, pH, conductivity

  • Observe floc formation and froth; verify settle/float behavior

3) EO testing (polishing step)

  • Use BDD anode + Ti cathode; start with modest current density (e.g., 5–20 mA/cm²)

  • Track COD/TOC decay, color removal, ORP, and disinfection where relevant

  • If chloride is present, account for active chlorine formation (beneficial for disinfection; manage residuals appropriately)

4) Optimize & lock the recipe

  • Tune pH and current density for best removal per kWh

  • Validate retention time at the lowest power that meets targets

  • Record energy per m³ and electrode consumption (for EC) → inputs for scale-up

Electrode selection cheat-sheet

  • EC anodes (sacrificial):

    • Iron (Fe): strong for phosphate, many heavy metals, color; dense sludge that settles well

    • Aluminum (Al): excellent for emulsified oils, many dyes/organics; fluffy floc that floats well

    • Mix Fe/Al when both phosphate and emulsions matter

  • EO anodes (inert):

    • BDD: premium mineralization and disinfection; best overall polishing (higher capex)

    • MMO (Ti/Ru-Ir): robust and cost-effective for many EO duties

    • PbO₂/graphite: application-specific; consult for compatibility

  • Cathodes: Titanium or SS commonly used; keep surfaces clean to minimize overpotential.

Operations & maintenance tips

  • Avoid passivation: use automatic polarity reversal (EC power supplies support configurable intervals).

  • Keep plates clean: periodic air scouring and gentle acid wash when needed.

  • Expectations (lab → plant): Fe/Al plates last months depending on load; inert EO anodes last years when operated within design limits.

  • Downstream solids handling: pair EC with DAF or a settler + filter press for simple, reliable separation.

From lab to plant: the YASA ET scale-up path

  1. Lab recipe using S-EC kit (+ EOXCell if polishing is required)

  2. Pilot at representative flows (e.g., PREDEST-100/200 pilot units, containerized options)

  3. Full-scale PREDEST EC systems with optional EO polishing and DAF/filters downstream

Typical full-scale scope (example PREDEST lines): stainless/PP reactor, modular plate stacks, auto-reversing DC supply, PLC (Siemens), instrumentation (pH, EC, level, temperature), dosing/air systems, and plug-and-play skids for rapid installation.


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Animation: PREDEST process – https://youtu.be/BmEGZwFXZRA


Case examples

Case 1 — Palm Oil Mill Effluent (POME), trial scale

Challenge: high SS, oil & grease, color, and COD. Approach: EC first with Fe/Al optimization, followed by settling and multimedia filtration. Outcome: clear permeate suitable for reuse/discharge; low chemical footprint; simple operation.


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Case 2 — Schaeffler industrial wastewater, pilot → scale

Challenge: machining effluent with oil, surfactants, high COD; tight discharge/reuse targets. Approach: PREDEST EC front-end for bulk removal, EO (BDD) polishing, plus downstream separation. Outcome: major reductions in COD and oil; >80% water recycling reported in pilot conditions; supports plant-wide ZLD roadmap.


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Frequently asked questions (FAQ)


1) EC or EO first?

Start with EC to remove solids/oils/metals and partial COD; use EO after to finish COD, color, and disinfection.

2) Do I need chemicals?

Usually, no that’s the beauty of electrochemical treatment. You may adjust pH and, for EO, add a small supporting electrolyte if conductivity is very low.

3) What current density should I use?

Begin conservative and step up: EC often 10–50 A/m² (plate reactors). EO (BDD) frequently 5–20 mA/cm² for polishing optimize with your water.

4) How do I choose Fe vs Al for EC?

Try both. Fe shines with phosphate/metals; Al shines with emulsions/color. Mixed stacks frequently win.

5) How do I handle sludge?

After EC, send to DAF or settler + filter press. Sludge volumes are generally lower than chemical coagulation.

6) Can I disinfect with EO?

Yes, EO provides strong disinfection via radicals/active chlorine (if chloride is present).

7) How do I scale up?

Use our lab kits to lock the recipe, then pilot on a PREDEST skid, then full-scale. We keep current density and HRT consistent and scale electrode area and flow.


Talk to an engineer

Send your water analysis and flow rate to info@yasa.ltd We’ll recommend an EC/EO lab plan (with plates and current settings), run a pilot if needed, and quote a PREDEST system sized for your site optionally bundled with DAF, filtration, and EO polishing for reuse/ZLD.


Optional (for the Wix editor)

  • Add a two-column section near the top: left = short explainer bullets (EC/EO highlights), right = a looping PREDEST animation embed.

  • Insert a callout box mid-page titled “How to choose EC vs EO” with a 5-point checklist.

  • End with a CTA button: “Book a 20-minute EC/EO consult”.

If you want, I can also produce a Thai version matching this layout—or tailor the case section with your exact client numbers and photos.

 
 
 

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