Written by: Xuân Phi, 25/12/2023
Supported by: Ex-BC Examiner, 26/12/2023
Question: The diagram below shows a simple system that turns dirty water into clean water. Summarise the information by selecting and reporting the main features and make comparisons where relevant.
(IELTS Academic – 23/12/2023)
The given diagram illustrates how to produce drinking water by using a simple water-filter assembly device. Overall, the system consists of two storage drums arranged to filter and then store the water. There are four main stages in the process, starting with pouring in unclean water, followed by filtering and storage, and culminating with opening of the tap for clean water.
In the first two stages, after the lid has been removed, unpurified water is poured into an initial, elevated plastic drum. The water then penetrates downwards through three filtering layers. Initially, the water undergoes a sand filtration process to eliminate impurities, subsequent to a further filtration step involving a layer of charcoal, and purification through the utilization of gravel. A pipe system with one end at the bottom of this drum then leads the purified water down to the less elevated storage drum.
In the final stages, the filtered water is stored in the lower drum with a closed lid. A tap near the bottom of this drum allows users to utilize the cleaned drinking water.
(Word count: 177)
|Undergo a filtration process
|Trải qua quá trình lọc
|Tiếp theo là