Electrocoagulation technology for superior wastewater treatment

Electrocoagulation is a primary wastewater treatment method similar to the widely used chemical coagulation technology. Chemical coagulation itself is a highly versatile process removing a major part of the commonly occurring contaminants in wastewater. The process is usually carried out in large basins. The term ‘coagulation’ refers to the ability of multiply charged metal ions to form hydroxocomplexes attracting dissolved contaminants to adsorb onto the surface of the complex in a significantly sub-stoichiometric manner and then adding a flocculation polymer to form larger complexes.

In chemical coagulation, the coagulation is achieved by means of the addition of a strongly acidic and corrosive aqueous solution of e.g. ferric or aluminium chloride followed by a neutralization using sodium hydroxide. In electrocoagulation, the coagulation is achieved by means of letting a direct current dissolve a sacrificing electrode made of metal over time. In this process hydroxide ion is formed as the counter-ion, thus omitting the need for neutralization and not adding any chloride ion to the solution as is usually the case in chemical coagulation. Hydrogen gas is also formed in the electrochemical process.

By avoiding harsh chemicals and producing fewer byproducts, electrocoagulation technology aligns with the growing demand for sustainable wastewater treatment methods. It is an ideal choice for industries seeking efficient, environmentally friendly solutions to meet strict environmental regulations while maintaining cost-effectiveness.

Electrocoagulation: Benefits compared to chemical coagulation

• Handling of the corrosive aqueous solution for chemical coagulation is omitted together with the need for large storage tanks
• It is easy to store replacement electrodes/reactors and to do so requires very little space, which is important from a preparedness perspective as well as in remote areas such as islands
• The contaminants gather in an easily dewatered high dry solids floc, calling for low costs for further handling
• The cleaned water yield is higher which, as well as the absence of chloride addition, facilitates recirculation

The benefits of AxoPur

AxoPur is Mellifiq’s engineering adaption of the electrocoagulation technology. The AxoPur reactor ensures all wastewater to actually pass through the reactor and be subjected to an electric field and to a homogenous treatment. Additional cleaning mechanisms integral to AxoPur include effects by the electric field and the formation of hydrogen gas in the electrochemical reaction. Overall the result is an extraordinarily efficient broad-spectrum wastewater treatment – a one-stage purification.

Many electrocoagulation systems operate batch-wise and require significant treatment times, limiting their capacity. Contrary to this, the reaction in the AxoPur reactor is instant and the system designed for continuous operation, although intermittent operation is always an option, should the flow not be there. Since the reaction is instantaneous, the system has a compact footprint. It also means the water will keep its temperature throughout the process.

AxoPur: Benefits compared to general electrocoagulation

• Wastewater treatment turns into wastewater purification since all water is forced through the reactor and cleaned with higher efficiency
• More different contaminants are removed thanks to the additional mechanisms benefitted from, including oil/fat, microbes, PFAS etc.
• The process can be controlled via a simple and rapid change in current
• The heat of the water is kept throughout the process enabling heat recovery if e.g. the purified water is recirculated