An island research station needs to produce 1000 L of potable water from saline groundwater. It tests two desalination methods. The table shows the energy used and the volume of concentrated brine produced by each method for this amount of water.
| Method | Energy used (kWh) | Concentrated brine produced (L) |
|---|---|---|
| Distillation | 9 | 100 |
| Reverse osmosis | 4 | 250 |
Evaluate which method the station should use.
101 exam-style questions on Edexcel GCSE Biology 9.3 Material cycles and decomposition, covering 9.3.1 Cycling of materials through ecosystems, 9.3.2 The carbon cycle, 9.3.3 The water cycle, 9.3.4 The nitrogen cycle, 9.3.5 Indicator species and pollution, 9.3.6 Decomposition in preservation and composting, and 9.3.7 Rate changes in decay of biological material. Each one has a worked solution and a mark scheme showing where the marks go.