Specific Gravity for a Solids Slurry
Environmental Engineering · FE Reference Handbook section
Handbook notes for this section
Definitions and conditions exactly as the handbook states them.
- The volume of waste sludge for a given amount of dry matter and concentration of solids is given by
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
specific gravity for a solids slurry of sludge and water Given fraction solids by weight (W_s) = 0.2660; specific gravity of solids (S_s) = 1.9700; specific gravity of water (S_w) = 1.0060, determine the specific gravity of slurry (SG_s).
Given
Find
specific gravity of slurry (SG_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except SG_s is given, so isolate SG_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for SG_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.2660, specific gravity of solids (S_s) = 1.9700, specific gravity of water (S_w) = 1.0060.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning SG_s = 1.1565 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.3131 — kept a factor of two that cancels in the correct rearrangement.
- 0.5783 — dropped that same factor in the other direction.
- 1.2722 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity calculation for a solids slurry from a thickener Given fraction solids by weight (W_s) = 0.1390; specific gravity of water (S_w) = 0.9980; specific gravity of slurry (SG_s) = 1.1430, determine the specific gravity of solids (S_s).
Given
Find
specific gravity of solids (S_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except S_s is given, so isolate S_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for S_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.1390, specific gravity of water (S_w) = 0.9980, specific gravity of slurry (SG_s) = 1.1430.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning S_s = 11.4260 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 22.8521 — kept a factor of two that cancels in the correct rearrangement.
- 5.7130 — dropped that same factor in the other direction.
- 12.5687 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
slurry specific gravity from percent solids and solids specific gravity Given fraction solids by weight (W_s) = 0.0770; specific gravity of solids (S_s) = 1.2400; specific gravity of water (S_w) = 0.9930, determine the specific gravity of slurry (SG_s).
Given
Find
specific gravity of slurry (SG_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except SG_s is given, so isolate SG_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for SG_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.0770, specific gravity of solids (S_s) = 1.2400, specific gravity of water (S_w) = 0.9930.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning SG_s = 1.0085 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.0169 — kept a factor of two that cancels in the correct rearrangement.
- 0.5042 — dropped that same factor in the other direction.
- 1.1093 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity for a solids slurry of sludge and water Given fraction solids by weight (W_s) = 0.2820; specific gravity of water (S_w) = 1.0100; specific gravity of slurry (SG_s) = 1.2440, determine the specific gravity of solids (S_s).
Given
Find
specific gravity of solids (S_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except S_s is given, so isolate S_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for S_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.2820, specific gravity of water (S_w) = 1.0100, specific gravity of slurry (SG_s) = 1.2440.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning S_s = 3.0333 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 6.0666 — kept a factor of two that cancels in the correct rearrangement.
- 1.5167 — dropped that same factor in the other direction.
- 3.3367 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity calculation for a solids slurry from a thickener Given fraction solids by weight (W_s) = 0.0840; specific gravity of solids (S_s) = 1.6100; specific gravity of water (S_w) = 0.9910, determine the specific gravity of slurry (SG_s).
Given
Find
specific gravity of slurry (SG_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except SG_s is given, so isolate SG_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for SG_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.0840, specific gravity of solids (S_s) = 1.6100, specific gravity of water (S_w) = 0.9910.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning SG_s = 1.0241 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.0481 — kept a factor of two that cancels in the correct rearrangement.
- 0.5120 — dropped that same factor in the other direction.
- 1.1265 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
slurry specific gravity from percent solids and solids specific gravity Given fraction solids by weight (W_s) = 0.2730; specific gravity of water (S_w) = 0.9910; specific gravity of slurry (SG_s) = 1.1710, determine the specific gravity of solids (S_s).
Given
Find
specific gravity of solids (S_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except S_s is given, so isolate S_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for S_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.2730, specific gravity of water (S_w) = 0.9910, specific gravity of slurry (SG_s) = 1.1710.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning S_s = 2.2680 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 4.5361 — kept a factor of two that cancels in the correct rearrangement.
- 1.1340 — dropped that same factor in the other direction.
- 2.4948 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity for a solids slurry of sludge and water Given fraction solids by weight (W_s) = 0.1830; specific gravity of solids (S_s) = 1.4900; specific gravity of water (S_w) = 1.0050, determine the specific gravity of slurry (SG_s).
Given
Find
specific gravity of slurry (SG_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except SG_s is given, so isolate SG_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for SG_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.1830, specific gravity of solids (S_s) = 1.4900, specific gravity of water (S_w) = 1.0050.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning SG_s = 1.0687 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.1373 — kept a factor of two that cancels in the correct rearrangement.
- 0.5343 — dropped that same factor in the other direction.
- 1.1755 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity calculation for a solids slurry from a thickener Given fraction solids by weight (W_s) = 0.2950; specific gravity of water (S_w) = 0.9970; specific gravity of slurry (SG_s) = 1.2370, determine the specific gravity of solids (S_s).
Given
Find
specific gravity of solids (S_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except S_s is given, so isolate S_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for S_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.2950, specific gravity of water (S_w) = 0.9970, specific gravity of slurry (SG_s) = 1.2370.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning S_s = 2.9125 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 5.8251 — kept a factor of two that cancels in the correct rearrangement.
- 1.4563 — dropped that same factor in the other direction.
- 3.2038 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
slurry specific gravity from percent solids and solids specific gravity Given fraction solids by weight (W_s) = 0.1420; specific gravity of solids (S_s) = 2.4200; specific gravity of water (S_w) = 1.0080, determine the specific gravity of slurry (SG_s).
Given
Find
specific gravity of slurry (SG_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except SG_s is given, so isolate SG_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for SG_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.1420, specific gravity of solids (S_s) = 2.4200, specific gravity of water (S_w) = 1.0080.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning SG_s = 1.0991 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.1981 — kept a factor of two that cancels in the correct rearrangement.
- 0.5495 — dropped that same factor in the other direction.
- 1.2090 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry
specific gravity for a solids slurry of sludge and water Given fraction solids by weight (W_s) = 0.1270; specific gravity of water (S_w) = 1.0100; specific gravity of slurry (SG_s) = 1.0790, determine the specific gravity of solids (S_s).
Given
Find
specific gravity of solids (S_s)
Start with the thinking
- The governing relation printed in this handbook section is Specific Gravity for a Solids Slurry.
- Everything except S_s is given, so isolate S_s symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Specific gravity for a solids slurry combines the specific gravities of solids and water weighted by solids fraction.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for S_s:
Step 3 — List the givens: fraction solids by weight (W_s) = 0.1270, specific gravity of water (S_w) = 1.0100, specific gravity of slurry (SG_s) = 1.0790.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning S_s = 2.0344 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 4.0687 — kept a factor of two that cancels in the correct rearrangement.
- 1.0172 — dropped that same factor in the other direction.
- 2.2378 — rounded an intermediate value before the final step.
Reference: FE Handbook — Specific Gravity for a Solids Slurry