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| Nijhuis Water Technology offers a complete range of biological waste
water treatment systems. The strength of Nijhuis is designing tailor-made
solutions taking into consideration the total efficiency of a plant. In the
process design the following aspects are considered:
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The purpose of biological treatment is to reduce the pollution in the
waste water, which is indicated as :
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BOD : Biological Oxygen Demand
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COD : Chemical Oxygen Demand
TOC : Total Organic Carbon N : Nitrogen P : Phosphorus
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A
biological treatment plant is using biomass to convert pollution into
water, minerals and gasses, like carbon dioxide and nitrogen. Biological
treatment is primarily aimed to reduce dissolved materials, like sugar,
soap, organic acids, alcohol, starch, proteins, etc.
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The biological treatment can be
divided into:
The
characteristic of aerobic treatment is that bacteria are using air (oxygen) to
reduce the pollution. The removal efficiency, in terms of COD, of aerobic
treatment varies from 70% to 90% in a high loaded system and from 90% to 98% in
a low loaded system. Low loaded systems are producing relatively less sludge
compared with a high loaded system due to the complete sludge mineralisation.
This mineralisation also reduces the smell.
The batch biological plant from Nijhuis Water Technology is specifically
designed to match the production cycle in the production plant. In a
single tank the whole process takes place. The flexibility of a batch
system is enormous. A batch system is very suitable for :
Nitrification Denitrifying Phosphate
removal.
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An intermediate form between the batch
system and the system and the system and the continuous system is the double
batch system.
For
aerobic treatment systems several aeration systems can be used:
Surface aeration Fine bubble aeration Coarse bubble aeration.
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In a continuous system the biological treatment plant is continuously
fed and the sludge is separated from the waste water in a separate
clarifier. Most of the separated sludge is recycled to the aeration tank.
The excess sludge is disposed, if required, after a dewatering stage.
The sludge/water separator can be a settling tank, a bio-membrane system
or a specially designed Nijhuis Dissolved Air Flotation unit. The
advantages of the bio-membrane system and the Nijhuis DAF plant compared
with the settling tank are: they require less space, they avoid floating
sludge problems and they produce a sludge with a 4 to 10 times higher dry
solids content.
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The characteristic of the anaerobic system is that organic material in
the waste water is reduced in a situation without the presence of air. In
this situation organic material is reduced by producing biogas, which can
be used for power generation. The removal efficiency, in terms of COD, of
an anaerobic system varies from 75% to 90%. The reduction of Nitrogen is
relatively low. Anaerobic treatment is suitable for companies with highly
polluted waste water, containing mainly dissolved materials. The sludge
production of an anaerobic treatment plant is very low.
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The Aecomix is designed to treat waste water with high peak loads and
with a high dissolved pollution load, which contains difficult dissolved
compounds, like fats, gelatins, oils, etc. With these types of waste water the
Aecomix is much more efficient than any other form of anaerobic treatment.
The Aecomix is designed
in such a way that it can be constructed below ground level.
The Nijhuis High rate reactor is based on the UASB technology. The
gas/water separation system and the water inlet system are the key parts.
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Main
characteristics of aerobic and anaerobic treatment systems:
Low maintenance Space saving Low energy requirement Complete automation possible Pilot plants available Quick pay back times Computer controlled plant
operations In-house knowledge and experience in biological treatment In-house knowledge and experience in integrated systems (pre-treatment,
biological treatment, sludge treatment) Installation, commissioning and training by Nijhuis specialists New product developments by our own R&D Dept. - Worldwide after sales
service.
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Nijhuis Water Technology has a long term experience with biological
treatment systems. Our specialists will be pleased to advise you on the best
system and how this might be augmented with other high quality technology from
Nijhuis Water Technology to create a fully integrated water treatment system
which gives you the security you require.
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