Расположите предложения согласно логике изложения

Закончите предложения.

Ответьте на вопросы.

■ What stages does conventional sewage treatment involve?

■ What does primary treatment consist of?

■ What does secondary treatment require?

■ What is tertiary treatment?

■ What does pretreatment lead to?

■ What other wastewater treatments do you know?

5. Выберите ответ на вопрос ‘Why should sewage go through ter­tiary treatment?'

> because more than one treatment process should be used at any plant to remove all existing contaminants or considerably reduce the concentration of such contaminants so the water becomes fit for its desired end-use.

> because primary secondary treatment is not sufficient, and part­ly clarified sewage does contain many decomposable substances.

> because secondary treatment requires a separation process to remove microorganisms.

■ Treated water is sometimes disinfected...

■ After treatment wastewater is either reused or...

■ The object of all treatment processes is...

■ Highly treated wastewater effluent from municipal wastewater treatment plants...

■ If not reused, treated water...

1. If it is sufficiently clean, it can also be used for groundwater re­charge or agricultural purposes. 2. First, the solids are separated from the wastewater stream. 3. The final effluent can be discharged into a stream, river, bay, lagoon or wetland, or it can be used for the irriga­tion of a golf course, green way or park. 4. Finally, the biological sol­ids are neutralized and disposed of or reused, and the treated water may be disinfected chemically or physically (for example by lagoons and micro-filtration). 5. The sewage treatment involves three stages, called primary, secondary, and tertiary treatment. 6. Then, dissolved biological matter is progressively converted into a solid mass by means of indigenous, water-borne microorganisms.

8. Переведите письменно, обращая внимание на 'to'-формы.

ü Pretreatment removes substances to be easily collected from raw wastewater before they spoil or clog pumps and skimmers of pri­mary treatment clarifiers.

ü Since primary treatment is not sufficient, partly clarified se­wage, still containing decomposable substances, is to go through sec­ondary treatment.

ü Secondary treatment requires a separation process to get rid of either present dissolve or suspended biological matters.

ü To remove completely or to decrease the concentration of all existing contaminants is an obligatory task of any treatment process.

ü Highly treated effluents are known to be a reliable source of water for agricultural and landscape irrigation, industrial recycling as well as non-potable or even potable reuse.

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