问题 问答题 简答题

简述活性污泥法处理工业废水的基本原理?其处理系统主要有哪几种?

答案

参考答案:

活性污泥法又称曝气法,是利用含有大量需氧性微生物的活性污泥,在强力通气条件下使废水净化的生物化学法。活性污泥法处理工业废水,就是让这些生物絮凝体悬浮在废水中形成混合物,使废水中的有机物与絮凝体中的微生物充分接触。废水中呈悬浮状态和胶态的有机物被活性污泥吸附后,在微生物的细胞外酶作用下,分解为溶解性的小分子有机物。溶解性的有机物进一步渗透到细胞体内,通过微生物的代谢作用而分解,从而使废水得到净化。

活性污泥法以其曝气方式之不同,可分为普通曝气法、逐步曝气法、加速曝气法、旋流式曝气法、纯氧曝气法、深井曝气法等多种方法。

单项选择题 A1型题
阅读理解

Wild animals seem to have escaped the Indian Ocean tsunami(海啸), adding weight to ideas they possess a “sixth sense” for disasters, experts said on Thursday.

Sri Lanka wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island’s coast seemingly missed wild beasts, with no dead animals found.

“No elephants are dead, not even a dead hare or rabbit. I think animals can sense disaster. They have a sixth sense. They know when things are happening,” H.D. Ratnayake, deputy director of Sri Lanka’s Wildlife Department, said on Wednesday.

The waves washed floodwaters up to 3 km (2 miles) inland at Yala National Park in the southeast, Sri Lanka’s biggest wildlife reserve and home to hundreds of wild elephants. “There has been a lot of evidence about dogs barking or birds migrating before volcanic eruptions or earthquakes. But it has not been proven,” said Matthew van Lierop, an animal behaviour specialist at Johannesburg Zoo.

“There have been no specific studies because you can’t really test it in a lab or field setting,” he said.

Other authorities agreed with this conclusion.

“Wildlife seem to be able to pick up certain phenomenon, especially birds. There are many reports of birds detecting coming disasters,” said Clive Walker, who has written several books on African wildlife.

Animals certainly rely on the known senses such as smell or hearing to avoid danger such as predators(食肉动物).

The idea of an animal “sixth sense” is a lasting one that the evidence on Sri Lanka’s damaged coast is likely to add to.

小题1:This passage is mainly about________.

A.the damage that was caused in the Indian Ocean tsunami

B.why animals can save them from natural disasters

C.how to protect the wildlife when disaster happens

D.the different opinions about animals’ natural power小题2:Which of the following is true according to the text?

A.It has been proved that animals have a “sixth sense”.

B.Research has been made on the special movements of animals before disasters.

C.It’s generally considered that animals can sense the coming of disasters.

D.Animals have depended on the known senses to escape the Indian Ocean tsunami.小题3:What does the term “sixth sense” in the text means?

A.It is the natural ability of animals that can save them from danger.

B.It is the animal’s imagination in the brain.

C.It is some hidden power to say in advance that something will happen.

D.It is a kind of sense that is the same as smell or hearing.小题4:Which section does the text most probably appear in a newspaper?

A.News Report.

B.Discovery.

C.Science Fiction.

D.Culture.