Aquaculture Sludge treatment

Customized solutions within aquaculture sludge treatment and complete systems for heavy metal removal.

Aquaculture sludge treatment systems designed for easy installation and the ability to turn sludge into a valuable resource

Alumichem product range offers customised turnkey solutions for treatment of sludge from aquaculture regardless of species. Our energy optimized solutions for sludge treatment have the following advantages:

Turning sludge into a valuable resource

Sludge from aquaculture is a potential fertilizer, however it cannot be used directly as fertilizer due to the content of heavy metals and chemical polymers and is generally regarded as a waste product.

Alumichem offers unique sludge treatment solutions without the use of chemical polymers, by removing heavy metals and without creating hazardous by-products turning sludge into a valuable resource.

Sludge from aquaculture is classified as quality class 1 due to the content of zinc and cadmium. Our innovative solutions offer the ability to remove the heavy metals from the sludge.

This advanced process turns the sludge from quality class 1 into quality class 0, which allows the sludge to be used as fertilizer with limited restrictions compared to sludge classified as quality class 1.

Alumichem offers unique solutions which combine power ultrasound and electrolysis, dewatering and without introducing polymer (chemical flocculants) into the process at any stage. This innovative process removes particles, phosphates, organics, ammonia and particulates from the sludge and produce a polymer free effluent which is ideal for recycling and reuse in the fish tanks.

Customized solutions for sludge treatment

Alumichem offers various customized solutions for aquaculture sludge treatment. Our solutions are designed, engineered, and combined according to any given customer requirement.

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Treatment process

The typical process utilizes polymer to flocculate the sludge and make dewatering possible. The flocculated sludge is separated in a filtration or sedimentation process, before being further dewatered and dried.

The solutions listed below are not standard solutions, but examples of some of the different possibilities we offer.

Lexinite solution

Lexinite and IntenseOx are unique options, which each can be added to any systems within our range of innovative sludge treatment solutions.

Lexinite reduces the amount of heavy metals in liquids and sludge. The goal is to bind the heavy metals in the Lexinite filter, to de-classify the sludge. The sludge can thereby be used directly as a fertilizer, even when it is concentrated. The heavy metals are bound in the Lexinite and can be disposed of as inert waste.

Alumichem Sludge system has been successfully installed at fish farms where it effectively removes the contaminants from the waste stream, producing clean, recyclable water and a contaminant-free sludge which can then be further processed to form a dry material that is easy to handle and store, allowing the owners to turn contaminated fish sludge into a usable fertilizer, and so turning an expensive waste product into a valuable commodity.

Flocculants – gravity belt filter – decanter

It is essential to use a flocculant on gravity belt. The flocculant will accelerate the drainage of water and allow it to flow through the sludge and the filtration belt. The flocculated sludge flows over a filtration belt that is conveyed at a certain speed.

The water freed by the flocculation step is drained through the pores of the belt. This elimination of water leads to a thickening of the sludge at the end of the conveyer belt. Nozzle sprays cleans the pore of the belt to prevent plugging.

The filtrate is returned to the beginning of the process while the thickened sludge is sent to a temporary storage tank before it is pumped to the decanter for further dewatering.

Flocculants – Drum dewatering unit

The principle is identical to the gravity belt. Sludge conditioning with a flocculant, liberation of interstitial water in the sludge, gravity drainage of the free water through a grid of the drum dewater unit. A drum dewatering unit is preferred when the requirement to the dry matter content is higher than the belt filter.

Electrolysis – ultrasound – separator – decanter – drying

The flocculation process of the sludge is a combined process of electrolysis and power ultrasound. The flocculated sludge flows to the separator, which removes the flocs, before the dewatered sludge is pumped into the decanter. From the decanter the semi-dried sludge is let through a drying unit as final stage of the sludge treatment.

Explore the Processes we work with in Aquaculture

Sludge treatment

Alumichem supply sludge treatment chemicals and equipment and the expertise to optimize the sludge...

Heavy metal removal

Products and solutions for removal of all types of heavy metals from wastewater...


Complete range of coagulants. we are experts in optimising coagulation processes in the treatment...

Polymer / flocculation

We have unique and vast experience in the supply and use of polymers, which benefits our customers in particular.