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Spiral-Electrocoagulation
(S-EC)

Introducing
Spiral-Electrocoagulation (S-EC)

Looking for a highly effective and sustainable solution for industrial wastewater treatment?

Spiral-Electrocoagulation (S-EC) by Spiraltec GmbH offers cutting-edge technology designed with your needs in mind. This technology is engineered to treat a diverse range of contaminants across a multitude of industries.

What makes our S-EC system special is its unique spiral electrode configuration, which optimizes flow hydrodynamics, thereby saving energy and improving contaminants removal efficiency.

Moreover, the system operates automatically and features a built-in monitoring system, enabling you to easily track key parameters such as pH, conductivity, temperature, etc. both before and after treatment.

How does Electrocoagulation (EC) work

In EC, when an external direct current voltage is applied, then different electrochemical reactions may take place at the anode and cathode of an electrolytic cell. EC involves the generation of in-situ metal coagulant by electrolytic dissolving sacrificial anode materials (aluminium or iron).
In case of aluminium, the anodic process, involves the oxidative dissolution of aluminium into aqueous solution which is presented in reaction (1). In the cathode, the reductive dissociation of water would also take place, see reaction (2).

Anode
Al(s)→Al3+(aq) + 3e
(1)
Cathode
2H2O + 2e → H2(g) + 2OH(aq)
(2)

Aluminium ions (Al3+) produced by electrolytic dissolution of the anode, which act as coagulant reagent, hydrolyze and form mono-nuclear complexes according to the following sequence:

Al3+ +H2O → Al(OH)2+ +H+
(3)
AlOH2+ + H2O → Al(OH)+2 + H+
(4)
Al(OH)+2 + H2O → Al(OH)3 + H+
(5)
Al(OH)3 + H2O → Al(OH)-4 + H+
(6)
Reference: Jafari et al., 2023
Figure 1. Sketch of Eq. 1 and Eq. 2 inside the EC reactor.
The inert electrode is usually the same material as anode

Applications

Electrocoagulation is a versatile method for wastewater treatment that finds applications across various industries, encompassing, but not limited to:
Oil refinery, gas exploration, and production
Petrochemical industry
Textile industry (e.g dyeing)
Food and beverage processing
Pulp and paper manufacturing
Mining and metal processing
Chemical and pharmaceutical production
Slaughterhouse
Landfill leachate treatment
Electronics and semiconductor manufacturing

Contaminants Removal

Electrocoagulation can effectively treat a wide range of contaminants found in various wastewater streams. Some common types of contaminants that can be treated through electrocoagulation include:

No.
Contaminant
Compounds
1
Suspended Solids
particles, colloids, and sediments
2
Heavy Metals
lead, chromium, cadmium, arsenic, and mercury
3
Organic Compounds
oils and Fats, Surfactants, Phenols, Dyes and Pigments
4
Phosphorous

orthophosphates, Polyphosphates, Organic Phosphorous Compounds

5
Bacteria and Pathogens
bacteria, viruses
6
Turbidity and Color
caused by suspended particles and dissolved substances
7
Inorganic Ions

sulfate (SO4), fluoride (F)

Process optimization through innovative electrode configuration

Process optimization through innovative electrode configuration
  • Optimized flow hydrodynamic
  • Optimized energy consumption

Three processes were integrated into one system
    1. Spiral-electrocoagulation (S-EC) with stirrer
    2. Electroflotation
    3. Sludge settling tank
Flow hydrodynamic optimization

An efficient EC configuration would preferably provide a uniform flow distribution between the electrodes. To compare the flow hydrodynamic of the spiral electrocoagulation (S-EC) with the conventional EC (vertical plates), a fluid flow simulation using Computational Fluid Dynamics (CFD) with similar dimensions and conditions was performed (see Fig 2).

As it can be seen, the uniformity and increased velocity in the spiral EC have been enhanced than the conventional EC. In the conventional EC, the vertical plate electrodes serve as a barrier against flow circulation, so then flow cannot be circulated and distributed evenly between the electrodes. This is a condition under which, fouling is anticipated to occur under the passivation of electrodes. Under such circumstances, fouling potential increases on the anode electrode and reduces the mass transfer coefficient.

Energy consumption optimization

Fig. 3, compares the voltage rise between the conventional EC and spiral EC configurations. To reduce energy consumption, the voltage should be reduced as much as possible. In general, two reasons can be expressed for increasing voltage in ECF. First, the development of a passive film on the anode, and second, the generation of hydrogen gas on the cathode.

These issues increase electrical resistance and hinder optimal removal results, requiring excessive energy consumption. To address these problems and prevent voltage rise, enhancing flow hydrodynamics around the electrodes is crucial, pushing out bubbles and improving mass transfer near the anode. The spiral EC configuration, depicted in Figure 3, shows promising results with lower voltage experienced across all concentrations, suggesting a potential solution to mitigate these challenges.

Production Capacities for Industrial Wastewater Treatment

Model
Treatment
Capacity
S-EC 10
10 m³/d
S-EC 20
20 m³/d
S-EC 30
30 m³/d
S-EC 40
40 m³/d
S-EC 50
50 m³/d

Control and Monitoring System

DC power Control Panel
  • Current: 600 – 5000 A
  • Voltage 24 V
  • Pulsing Polarity Reversal
  • Current Breaks
Control Panel
  • Level Control
  • Stirring Speed
  • Feed Pump
  • Sludge Pump
Monitoring parameters from feed solution
  • Initial Turbidity
  • Initial pH
  • Initial Conductivity
  • Initial Temperature
Monitoring parameters from treated solution
  • Final Turbidity
  • Final pH
  • Final Conductivity
  • Final Temperature

Example

Feed from metal industry

Milky Wastewater from Dairy Cattle Septic Systems and CIP Processes

Feed from Textile industry

    Proof of concept

    Publications

    Impact of operating parameters of electrocoagulation-flotation on the removal of turbidity from synthetic wastewater using aluminium electrodes
    Innovative spiral electrode configuration for enhancement of electrocoagulation-flotation

    We will be glad to help you!

    Do not hesitate to contact us to check your application (including special applications).
    Ongoing research for new areas of application.