A free engineering reference · since 2009

Water & wastewater treatment, explained by people who run the plants.

A practical field reference for students and engineers — process theory, plant design, worked examples and the day-to-day judgement that textbooks leave out.

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0: in-depth guides
0: topic areas
1995: publishing since
Free: no paywall, ever

Start with a topic

Nine areas, from raw-water chemistry to full plant design. Each opens a curated set of guides.

66 guides

Sewage Treatment

Primary, secondary and tertiary treatment of municipal and industrial wastewater.

33 guides

Water Treatment

Filtration, coagulation and the unit processes that make water potable.

27 guides

Water

Sources, chemistry and the physical properties behind every process.

16 guides

Water Analysis

Sampling, testing and reading the parameters that define quality.

13 guides

Disinfection

Chlorination, UV and ozone at the final barrier.

9 guides

Softener

Removing hardness with ion exchange and lime–soda.

6 guides

Desalination

Reverse osmosis and thermal routes to fresh water.

7 guides

Corrosion

Why plant and pipework fail — and how to slow it.

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A rotating selection of articles pulled at random from the library, with brief summaries so you can dive straight into the right guide.

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Disinfection

EFFICIENCY OF DISINFECTION

The efficiency of the disinfection depends upon the following factors: Nature of the disinfectant, Dose of the disinfectant, Length of contact time with the…

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Water

Source of Water Supply

Sources of water supply In nature water occurs abundantly as: water vapour in the atmosphere, as liquid water in inland waters and the ocean,…

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Water Analysis

Toxic Heavy metals in Sewage

Sewage Water Treatment Some metals compounds level only are essential to live for animal, Plant and human being. Out of that metal compounds are …

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The treatment train

From raw water to the tap, in six stages

Every plant is a sequence of barriers. Follow the flow — each stage links to the guides that explain it.

01
Intake & Screening

Raw water enters; bar screens and grit channels remove debris.
02
Coagulation

Coagulants destabilise fine particles into settleable floc.
03
Sedimentation

Floc settles out under gravity in clarifiers.
04
Filtration

Rapid sand and media beds polish the remaining turbidity.
05
Disinfection

Chlorine, UV or ozone inactivate the remaining pathogens.
06
Distribution

Treated water is pumped to storage and the network.

Featured reading

Hand-picked starting points and the guides engineers return to most.

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Editor’s pick Water Treatment Process Water Treatments Method : Reverse Osmosis (RO) water treatment process involves water being forced under pressure ( Osmotic Pressure ) through a semipermeable RO water treatments… Read the guide →

01 Sewage Treatment Water Treatment Coagulation 02 Water Treatment Rapid Sand Filters 03 Disinfection Test for Residual Chlorine 04 Sewage Treatment Clariflocculator

20+ years on plant

Why trust this site

Written from the plant floor, not the textbook.

The Water Treatments is maintained by a practising water-treatment engineer with two decades of experience designing, commissioning and troubleshooting potable, sewage, boiler, chiller and industrial treatment plants across the Middle East.

Every guide is written in plain language with the worked examples, diagrams and rules of thumb that practitioners actually use — so students can follow along and engineers can move fast.

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