Biological Wastewater Treatment With BIOBLOK®

As a result of many years of R&D, a structured filtermedia has been developed. The media has provedextremely efficient in biological treatment of domesticsewage, industrial wastewater and process waterwithin the aquaculture field.

The media is made from the environmentally friendlymaterial polyethylene and consists of net tubes, whichare welded together to form a square block. Theunique surface structure of the many net tubesprovides a large accessible surface area for enhancedbiological growth on the filter media.

The filter media is called BIO-BLOK® and the surface acts as a substrate for specialised bacterialstrains, which are able to treat and degrade a wide range of wastewater qualities. The treatmentcapacity of a biological filter depends on the quantity of bacteria that the filter can sustain. Thelarger a specific surface area is, the larger the bacterial population.

Future construction, refurbishment or upgrading of biological wastewater treatment plants is merelya matter of creating optimal ‘living conditions’ for the bacteria. BIO-BLOK® has excellent propertiesin this respect, and the result is an increase in treatment capacity.

Type BIO-BLOK100

BIO-BLOK150 HD

BIO-BLOK200

Surface (m2/m3) 100 150 200Flow area 70% 64% 60%Void percentage 90% 88% 82%Tube diameter 70mm 55mm 55mmDimensions, standard module 54x54x55 cm 55x55x55 cm 55x55x55 cm

Cross-section of a BIO-BLOK® thread

A biological wastewater treatment plant in which BIO-BLOK® filter media has been installed hasthus unique flexibility and, if necessary, the ability to increase its capacity to handle flow variationsand load changes, which inevitably occur in the inlet to all waste water treatment plants.

Thickness of bio-filmFilter type Dry condition1mm 2mm 3mm 4mm

BIO-BLOK 100 100m2/m3 165m2/m3 233m2/m3 299m2/m3 366m2/m3

BIO-BLOK 150HD 150m2/m3 268m2/m3 387m2/m3 507m2/m3

BIO-BLOK 200 200m2/m3 312m2/m3 426m2/m3

A “thin” bio-film results in arelatively low specificbiologically active surface area

Development of bio-film

Activated Sludge Systems vs. Fixed Film TechnologyActivated sludge systems came into use around 1920 as a new and effective process forwastewater treatment. The principle is based on the formation of flocs of micro-organisms thatcirculate freely in the water column due to the inejction of large volumes of air. The flocs have aclose to optimal contact surface towards the wastewater and excellent treatment results can beachieved when using this technology.

The operation of activated sludge system is, however, potentially unstable, as the process requiresa stable and homogenous supply of process water in order to work optimal. Since the supply ofwastewater (both quantity and quality) from the industry and urbancommunities varies tremendously, the inlet conditions of wastewater toactivated sludge plants is controlled by implementing expensive andcomplicated monitoring systems. Volumes of wastewater larger thannormal are often by-passed without treatment, which clearly is un-acceptable from an environmental point of view.

The capacity of activated sludge plants can easily be improved byupgrading the plant to a combination with submerged aerated filters ortrickling filters based on fixed film technology with BIO-BLOK®. The riskof flushing out active bacteria is also minimised as a large part of thesebacteria is fixed onto the filter media. The larger number of activebacteria in the same tank volume will increase treatment capacitiessignficiantly. Improvements by up to 400% have been achieved usingthe same tank volume as before.

Reduce the Volume of Biological Sludge with BIO-BLOK® Fixed FilmTechnologyIt is a well-known fact that activated sludge systems produce large amounts of biological sludge. Itis also acknowledged that handling and treatment (incl. De-watering, conditioning, storage, transportand disposal) of the sludge is expensive and time consuming. Thus, a lot of money can be savedby choosing the correct type of biological treatment system before refurbishing or upgrading existingwastewater treatment plants or constructing new systems.

Biological sludge reducing systems, based on BIO-BLOK® fixed filmtechnology, are now in operation in a number of countries. The systemsare designed to treat a variety of different types of wastewater.

Biological lamella sedimentation is based on the following principle:Process water from biological filters or other treatment systems containsflocs and other suspended solids. The solids are attracted (electricalforces) to the active bio-film growing on the BIO-BLOK® filter media.The particles will eventually settle in the bottom cone. A controlledhydraulic surface load thus facilitates a natural filtration/polishing of thedischarge water and excellent results can be achieved.

Biological lamella sedimentation with BIO-BLOK® can be installed in all existing circular or squaresedimentation basins. Construction of new systems should always be designed with two identicalchambers working in parallel.

BIO-BLOK modules are easyto handle when retrofitting/upgrading existing plants orinstalling new systems

BIO-BLOK 80 HD G

Clean water outlet

Inlet

Sludge out

Inlet from bio-reactor

Sludge out

Water Level

BIO-BLOK 150HD

Outlet

CAP TECHNOLOGYUnit 4a Hampton Heath Industrial Estate, Malpas, Cheshire, SY14 8LU

Telephone: 01948 820317 Fax: 01948 820578 E-mail: enquiries@captechnology.co.uk

BIO-BLOK® filter mediaA filter media for wastewater treatment of unprecedented quality

12 good reasons why you should choose BIO-BLOK for your next installation

CAP TECHNOLOGYUnit 4a Hampton Heath Industrial Estate, Malpas, Cheshire, SY14 8LU

Telephone: 01948 820317 Fax: 01948 820578 E-mail: enquiries@captechnology.co.uk

Very resistant to deformation,so strong that you can walk and

work freely on the material

made from theenvironmentally friendly

material – Polyethylene 100%recyclable

high porosity ensuressufficient aeration

contains no PVCcompounds nor glue

UV resistant

self supporting

easy to handlemodular andlightweight

self cleaning,does not clog

biologically andchemically

non degradable

easy to install and fit into any sizeor shape of bio-reactor or tank

unique design and surfacestructure enhances

development of biological film

extremely efficient, stable &reliable during operation

UV resistant