Types of waste water treatment / sludge drying, slurry drying, waste drying

Waste water quality standard is established for waste water discharged from factory or manufacturing sites. In case of effluent into public waters (rivers, lakes, etc), it is regulated by Water Pollution Prevention Act, and the act has effluent standards which are “effluent standard about Harmful Substances” and “effluent standard about living conditions”. Also, effluent into a sewerage is regulated by Sewerage Act.
Some kinds of water treatment are necessary to satisfy these standards and there are various methods. After water treatment process, solid material called sludge which includes large amount of water after going through condensation and dehydration processes is discharged. The sludge normally costs to be treated by industrial waste disposal companies though, the cost is getting higher and higher, and also space of final disposal site is getting less and less. By drying the sludge by our KENKI DRYER, amount of sludge can be decreased, cost of industrial waste disposal can be reduced, and also cost of the dryer can be payed back in short term. It can be said that reducing amount of industrial waste is a contribution to global environment as well.

■ Types of effluent water treatment

1.The followings are classifications sourced from Ministry of the Environment in Japan about wastewater treatment facilities for manufacturing industries.


Activated sludge (floating)

2)Activated sludge (contact oxidation)

Biological denitrification


Coagulating sedimentation (surfacing)


Activated carbon






Oil separation


Other advanced treatments



The most spread method in this classification is activated sludge followed by coagulating sedimentation. It seems that the coagulating sedimentation is mainly used in inorganic wastewater treatment.

Source:Ministry of the Environment Site


2.  From “Mechanism of the sewer system” issued by Ministry of Land, Infrastructure, Transport and Tourism, Japan. 

Wastewater treatment methods in sewage treatment are shown in the table below.
Activated sludge is used as wastewater treatment method in most of sewage treatment plants, and there are a lot of types for this method. Also, the plankton method below suggests the activated sludge method.

1)Plankton method
(Activated sludge method)

It is a method that decomposes organic matter by creating a cluster of microorganisms (activated sludge) that floats within sewerage water.


Sessile organism method (biofilm method)

It is a method that decomposes organic matter by generating a biological slime on the surface of the solid floating layer and having it come in contact with sewerage water.



Plankton method

(Activated sludge method)

Standard activated sludge method

Circulation denitrification method (denitrification)

Anaerobic anoxic aerobic method (nitrogen/phosphorus removal)
Anaerobic aerobic activated sludge method (phosphorus removal)

Oxygen activated sludge method

Oxidation Ditch method (OD method)

Prolonged aeration method

Batch-wise activated sludge method


Sessile organism method
(biofilm method)

Contact oxidation method

Aerobic filter method


Source:Ministry of Land, Infrastructure and Transport Site


The following is a mechanism of final treatment site of the sewer system. This is a wastewater treatment with plankton method (Activated sludge method)
The solid material discharged after effluent process such as condensation and dehydration processes are normally disposed as sludge containing a lot of water, however, it can be utilized as fuel or charcoal by carbonizing or gasifying with a system consists of KENKI DRYER and a pyrolyzer BIOGREEN.

waste water treatment sludge drying KENKI DRYER 16/9/2018

Source:Ministry of Land, Infrastructure and Transport Site


No matter how sticky, adhesive and viscous the material is, KENKI DRYER of International Patent can dry it without clogging inside of dryer and with stable operation that no operational trouble occurs because of its unique mechanism.
Sludge after dehydration process of waste water treatment is often affected by flocculants and forms large lumps, and it frequently happen that only surface is dried but inside are not when sludge is discharged as large lumps.
In the drying process of KENKI DRYER certificated as International Patent, the material to be dried are moved forward into the dryer’s main body smoothly by being heated and crashed with a feeder at inlet. The materials get smaller and smaller since they are continuously sheared and agitated during being conveyed and heated. As the material get small, heat reaches to inside more smoothly and surely, and quality of outputs becomes stable.
Since KENKI DRYER has simple structure, initial cost is low and is estimated to be repaid with cost of industrial waste disposal for about 2 -3 years.


Sludge drying




Self-cleaning screw


Please consider KENKI DRYER for drying of sticky materials, adhesive materials and materials in liquid state that no other dryer can deal with.
Initial, running and maintenance costs are low because of its simple structure based on internationally patented technology.
For sludge drying, costs of our dryers are estimated to be retrieved within 2, 3 years by reducing industrial waste disposal cost.
For raw material slurry drying, laborious works of manual operation will be decreased significantly by replacing box shaped compartment tray dryer with our dryer
In case of organic wastes drying, the waste can be recycled as fuel, fertilizer, soil conditioner and feedstuff after being dried.



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Pyrolyzer Biogreen
A pyrolyser with internationally patented technology which use no fire