Chapter 6 - Common Academic Text Structures

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Chapter 6: Common Academic Text Structures

6c: Procedure/Sequence

iii) Text Organisation

"Procedure/sequence" can be used as an overall organisational framework for a single text (e.g. recipes, instructions) or used within a paragraph or a longer text as below.

Heading

Introduction
to introduce the topic and facilitate the listing or elaboration of details

Main Body
to list the steps in chronological order (may include more than one paragraph for more complex processes)

Conclusion
to show the outcome(s) and sum up key points

Water Treatment in Hong Kong

[1] Water in Hong Kong comes from either the rainfall collected in local catchments or the Dongjiang in Guangdong, Mainland China. For the raw water to become drinking water, it has to undergo a series of treatment steps, including pre-treatment, clarification, filtration and disinfection, to ensure that the treated water is in full compliance with the Hong Kong Drinking Water Standards.

[2] Every day, a total capacity of 4.68 million cubic metre of raw (untreated) water is treated in 20 water treatment works to supply fresh water to a population of more than 7 million in Hong Kong. Firstly, raw water is pre-treated by dosing with chemicals. Various chemicals are added to facilitate the subsequent treatment process. For example, alum is added to coagulate impurities and hydrated lime is used to control the pH. (e.g.) Following the pre-treatment process, the treated water is (a) passed to the clarifiers for removal of relatively large particles and impurities in water through the adoption of different technologies such as 'Multi-deck Sedimentation’ and 'Solids Contact Clarification’. When the larger flocs are removed, clarified water then flows into filters for filtering out the more finely divided particles by 'Rapid Gravity Filtration’ or 'Biological Filtration’. (b) , the filtered water is disinfected by adding chlorine or ozone to contact tanks before supply to the public.

[3] (c) disinfection, the treated water is fit for human consumption. It will then be conveyed to reservoirs for consumption by the public. A small amount of residual chlorine is maintained in the water to prevent bacterial growth in the rest of its journey and fluoride is added for dental protection.

Adapted from:
https://www.wsd.gov.hk/en/core-businesses/operation-and-maintenance-of-waterworks/water-treatment/index.html

6a 6b 6c 6d

Activity 6

Study the text in which "procedure/sequence" is illustrated in the second and third paragraphs. Answer the questions below.

How many key steps does water need to go through in the treatment works?

Some of the time and sequence words in the text are missing. Choose the most appropriate words from the word box below to complete the text. Each word can be used ONCE only. Capitalise where necessary. One example has been provided in the text.

after before during finally following then when

Para. 2	(a)
Para. 2	(b)
Para. 3	(c)

Arrange the following water treatment steps in chronological order.
- A. Larger particles in water are removed.
- B. Alum is added to coagulate impurities.
- C. Chlorine or ozone is added to contact tanks.
- D. Smaller particles are filtered out.

Match the main ideas with the paragraphs. Put the letters (A, B, C and D) in the appropriate boxes.

Paragraph 1		A. Consequences of water treatment
Paragraph 2		B. Water supply to the public after treatment
Paragraph 3		C. The importance of water treatment
		D. How raw water is treated in treatment works