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Primary Treatment of Wastewater

Aims of primary treatment of wastewater is to separate suspended solids and greases from wastewater. What does primary treatment of wastewater remove? Sedimentation remove both organic and inorganic suspended solids. In addition, skimming, as part of sedimentation tank, remove grease, oil, scum, and floating solids.

Primary treatment of wastewater includes primary sedimentation (also called clarification), microscreen, Imhoff tanks. In most facilities, primary treatment is used as preliminary step ahead of biological treatment. Read More

Wastewater Treatment – How Wastewater is Treated

In earlier posts, we learned sources of wastewater, which are domestic wastewater, industrial wastewater, and infiltration/inflow. In this post, I want to share to you how wastewater is treated.

Wastewater is treated at wastewater treatment plants before it is permitted to be discharged to the environment/water bodies. Basic function of wastewater treatment is to speed up the natural processes of water purification. Read More

Where Does Wastewater Come From

Where does wastewater come? This basic question shall be answered if we want to design a wastewater treatment system. Source of wastewater, its characteristics, and its flow rate, will influence the type of technology to treat the wastewater.

Components that make up the wastewater depend on the type of collection systems. Urban wastewater that contribute to a wastewater treatment is originated from the following three main resources:

  • Domestic (also called sanitary) wastewater. This type of wastewater is discharged from residential districts, commercial districts, institutional facilities, or recreational facilities.
  • Industrial wastewater. Wastewater which predominantly consists of industrial waste.
  • Infiltration/inflow.
    • Infiltration is water entering a sewer system including service connections, defective pipes, pipe joints or manhole walls.
    • Inflow is the water discharged into a sewer system from roof leader, cellar, yard and area drains, foundation drains, cooling water discharges, drains from springs and swampy area, manhole covers, cross connections from storm and combined sewers.

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What Is Wastewater Treatment  

After a quite long absence of updating this blog, I want to begin this March’s post with refreshing our knowledge about wastewater treatment. Let’s begin with one fundamental question: what is wastewater treatment?

In general, wastewater treatment is a process converting wastewater into effluent that can be discharged back into the environment. This terms contains at least four keywords, which are wastewater, effluent, converting process, and environment.

Sewage wastewater

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Cooling Pond Sizing

In this post, I want to share to you how to size cooling pond. Cooling pond is used to remove heat from water by means of air. Example of application of cooling pond is to remove heat from brine water in geothermal power plant facilities.

To design cooling pond, you need process data and environment data. Process data are flow rate of liquid to be cooled, initial temperature, final temperature, and density of liquid. Environent data are relative humidity, wind velocity, average air temperature, and solar heat gain. Here is example of cooling pond sizing. Read More

Sedimentation basin

Visiting Drinking Water Treatment Plant in Tirtawening

On December 2017, I got an opportunity to visit drinking water treatment plant in Tirtawening, Bandung, which is near my college. It was a very amazing experience, because this is my first experience visiting water treatment plant. And also, experience like this is very rare after I entered working environment.

This site visit is actually a part of water treatment plant training. I will share you about this training in different post.

Drinking water treatment facility in Tirtawening is actually the biggest one in Indonesia. It processed 2000 liter/second water, from two trains (rate of each trains is 1000 liter/second). 1900 liter/second water is sent to customers and 100 liter/second water is own used. Read More

My First Javascript Online Calculator – Instrument Air and Compressor Sizing

For a long time, I want to post something more advance in this blog. I always want this blog like or I want to make online calculator just like did.

Due to my limitations, at this point I cannot create online calculator. To compensate that, I tried to make useful spreadsheet.

But, today I did it! I made my first online calculator, which is instrument air sizing calculator. Please click this link to access to instrument air and air compressor online calculator. I hope you find it useful.

It is better for you to check two of previous post related with the calculator. Calculation basis used in this calculator is based on those two post.

Read Sizing of Compressor and Instrument Air Capacity

Read Spreadsheet of Air Compressor and Air Dryer Calculation


I already replaced spreadsheet attached in this post : Spreadsheet of Air Compressor and Air Dryer Calculation. So you can trace how the calculation works.


Fire Water Pump Capacity Calculation Part 1 – Fire Zones Determination

Process safety and pressure relieving and depressuring system are two areas that I want to master. Since the topic is quite big, in this post I want to share you what I learnt about fire water pump capacity calculation, specifically how to determine fire zones.

Fire water pump capacity calculation begins with fire zones determination. The whole pictures of fire water pump capacity calculation is expressed in figure below.

Fire water pump capacity calculation
Fire water pump capacity calculation

To determine fire water pump capacity, we can say we determine fire water demandMaximum fire water demand is summation of fire water required for fixed system (water spray, foam, sprinkler) and fire water required for manual fire fighting equipment (fire hydrant, fire monitor, and hose reel). Read More