2 . SYDNEY —Australian scientists have designed a system which uses microwaves to break down plastic into an environmentally friendly by-product.
Head of Electrical Engineering at Australia’s James Cook University, Prof. Mohan Jacob revealed on Thursday that by using microwaves, plastic waste can be converted into biochar(生物炭), charcoal that can be used as a soil conditioner.
“We are developing a processing room, which could process many kinds of plastic materials, up to 5 kilograms of waste,” Jacob said. “It will be a typical example system for the development of biochars from different types of plastics under various conditions.” Jacob explained that microwave energy is used to heat the plastic waste above 600 degrees centigrade within the custom-made room, where it ends up as a biochar, which can then be used to improve the properties of soil.
Currently underway is step one of the project, testing the room, after which, step two will involve improving the energy efficiency of the system and maximizing the yield of by-products. If all goes to plan, step three will be to construct a medium scale waste processing system which is customizable and can be installed remotely.
Jacob said that with the average person using 130 kg of plastic every year, there is an urgent need for developing better ways of processing it.
“Perhaps contrary to popular opinion, plastic is an indispensable material in modern life. It is cheap, competent, lightweight, and has many benefits like maintaining food quality and safety and preventing waste,” he said.
However, “abandoned plastics endanger our marine wildlife, and have begun to enter the food chain. There is an urgent need for developing technologies to recover plastic waste.”
1. How does the system function?
| A．Microwaves are used to produce plastic. |
| B．Plastic waste is heated in the microwaves. |
| C．Plastic waste is cut into pieces and buried into the soil. |
| D．Microwaves change plastic waste into biochar by heating. |
2. Which statement is true according to Jacob?
| A．Plastic consumption now is acceptable. |
| B．Plastic should be abandoned in our life. |
| C．The system of processing plastic has come into use. |
| D．Finding better ways to deal with plastic waste is urgent. |
3. What does “recover” in the last paragraph mean?
| A．Make up for a loss in time. |
| B．Find or regain lost possession. |
| C．Extract or recycle an energy source for reuse. |
| D．Return to a normal state of health, mind or strength. |
4. What does the passage mainly tell about?
| A．3 steps of processing plastic waste. |
| B．A way of producing plastic products easily. |
| C．A new system of breaking down plastic waste. |
| D．A program designed for plastic use in the daily life. |
