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Category: Utility System

Where Does Wastewater Come From

Rifka Aisyah Leave a comment

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  

Rifka Aisyah 3 Comments

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

Rifka Aisyah 4 Comments

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

Rifka Aisyah Leave a comment

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

Rifka Aisyah 1 Comment

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

BONUS!

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

Rifka Aisyah 2 Comments

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 demand. Maximum 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

Cooling Tower Makeup Water Calculation with Example

Rifka Aisyah 15 Comments

It’s been a while since the last time I write an article about utility system. In this post I want to share you how to calculate cooling tower makeup water.

Cooling tower must be made up because the water level decrease by the time during operation. There are aspect that contribute to calculation of cooling tower makeup water. Those are:

  • Evaporation loss
  • Drift loss
  • Blow down

Total cooling water makeup water requirement = evaporation loss + drift loss + blow down.

Let’s take a look one by one how to calculate each component.

Evaporation Loss

Evaporation loss is loss of water due to evaporation. It is calculated by this equation:

Evaporation loss = 0.00085 Wc (T1-T2)

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Water Treatment Plant Capacity Calculation

Rifka Aisyah 1 Comment

In this post, I want to share you how to calculate water treatment plant capacity. I used this term to avoid misunderstanding.

  • Raw water is untreated water coming from water source, such as from wellwater, river, or seawater
  • Utility water is raw water which has been treated and used in plant, such as for personal hygiene (flushing), utility station, cooling tower make up
  • Potable water is sufficiently high quality water which is provided for drinking, cooking, laundry, and safety shower/eye wash
  • Demineralized water is treated water which is usually used as chemical dilution of MDEA or boiler feed water

Water treatment plant capacity calculation begins with demin water demand, potable water demand, utility water demand, and the last is raw water demand. Read More