---
title: "Sludge volume from sedimentation tank, 10 MLD"
subject: "Sanitary Engineering"
chapter: 8
key: "semester_6/sanitary_engineering:sludge-volume-10mld-250"
source: https://www.bctengineer.com/q/semester_6/sanitary_engineering/sludge-volume-10mld-250
site: BCT Engineering
---

# Sludge volume from sedimentation tank, 10 MLD

Sanitary Engineering · Chapter 8: Sludge Treatment and Disposal

- Asked in: 2072 Asoj, 4 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/sanitary_engineering/sludge-volume-10mld-250
- Whole chapter: https://www.bctengineer.com/md/semester_6/sanitary_engineering/chapter-8

## Question

Determine the volume of sludge produced in a sewage sedimentation tank from the following data: Flow rate = 10 million liters/day; Suspended solids content in raw sewage = 250 mg/l; Sedimentation tank removes 60% of suspended solids; Specific gravity of sludge = 1.02; Moisture content of sludge = 95%.

## Short answer

Dry solids removed: 1500 kg/d. Sludge volume at 95% moisture and sp. gr. 1.02 is 29.4 m³/d.

## Answer

Volume of sludge $V = \dfrac{W_s}{\rho_w \, G_{sl}\,(1-p)}$

- Solids in raw sewage: $10\times10^6\ \text{L/d} \times 250\ \text{mg/L} = 2500$ kg/d
- Solids removed (60%): $W_s = 1500$ kg/d
- Solids fraction of sludge: $1 - 0.95 = 0.05$

$$
V = \frac{1500}{1000 \times 1.02 \times 0.05} = 29.41\ \text{m}^3\text{/d}
$$

**Answer: volume of sludge $\approx 29.4\ \text{m}^3$ per day.**

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Dry solids removed in the sedimentation tank are
   A. 2500 kg/d
   B. 1000 kg/d
   C. 150 kg/d
   D. 1500 kg/d
   Answer: D. 10 x 10^6 L/d x 250 mg/L = 2500 kg/d; 60% removal gives 1500 kg/d. (Key point: Solids removed)

2. The volume of sludge produced is
   A. 1.5 m3/d
   B. 29.41 m3/d
   C. 588 m3/d
   D. 1470 m3/d
   Answer: B. V = 1500/(1000 x 1.02 x 0.05) = 29.41 m3/d. (Key point: Sludge volume)

## Related in Sanitary Engineering

- [Sludge volume and digester, 4 MLD](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Asludge-volume-4mld-digester) — Sanitary Engineering, chapter 8
- [Sludge digestion tank, 6.5 MLD](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Asludge-digestion-tank-6p5mld) — Sanitary Engineering, chapter 8
- [Yearly sludge volume, 6 MLD](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Asludge-volume-yearly-6mld) — Sanitary Engineering, chapter 8
- [Sludge digestion tank, 812.5 m³ sed. tank](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Asludge-digestion-tank-812) — Sanitary Engineering, chapter 8
- [Sludge volume from PST and SST](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Asludge-volume-pst-sst-20mld) — Sanitary Engineering, chapter 8
- [Standard rate filter, 3 MLD, 175 mg/l, NRC](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Atrickling-standard-3mld-175-nrc) — Sanitary Engineering, chapter 7

## Related in other subjects

- [Rectangular sedimentation tank for 10 MLD](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ased-s71) — Water Supply Engineering, chapter 6
- [Rectangular sedimentation tank, 9 million L peak demand](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ased-c75) — Water Supply Engineering, chapter 6
- [Sedimentation tank 6 m x 18 m x 3 m, 4 ML/day](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ased-a76) — Water Supply Engineering, chapter 6
- [Rectangular sedimentation tank, 8x10^6 L/day](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ased-as67) — Water Supply Engineering, chapter 6