Factory Visit

Human Practice

• Questionnaire
• Factory Visit
• Practical Analysis
• Team Communication

With help of the Bureau of Environmental Protection in Beijing, we visited a printing factory that uses aromatic-containing ink. There is a need for synthetic biology technologies in dealing with aromatic waste from industrial manufacture.

In August 1st, we visited a printing factory, which mainly prints newspaper and brochures. It was raining heavily outside, while it swelted inside the factory. Printing press was roaring, giving off heat.
Volatilization of toluene and xylene during ink-jetting process is the major source of aromatics pollution in this workshop,introduced the Manager.

The factory owns Volatile Aromatic Hydrocarbons Content treatment device which acquires enormous investment. The device contains an incinerator with automatic control system. Toluene and xylene volatilize from printer are collected and transported to the incinerator and then burnt steadily at 800 degree centigrade. The control valves regulate inlet air volume. Burning chambers has the temperature control system,which can most effectively save energy. Finally,the toluene and xylene are burnt into carbon dioxide and water and then emitted into atmosphere.

However, printing factories that can afford the expensive device, like the one we visited, are few. The pollution following is of even more concern.

Then we consulted professor XIE Shuguang from College of Environmental Sciences and Engineering, Peking University. Why does aromatic contamination haunt towns and villages?

As two essential solvent and lubricant of varnish and inks, toluene and xylene are common emissions from small printing workshops and varnish factories in China. Besides, aniline is discharged by dyeing mills in effluence. However, in sewage treatment plants, there exists no specific process to treat toxic aromatic waste. Limited by financial situation, small factories tend to be incapable of purchasing waste-treating devices. So detection and degradation of aromatics are badly needed.

The most common way of aromatics detection is GC-MS (Gas chromatography and Mass spectrometry). However, sample handling is inconvenient. The expensive device is prohibitive in rural areas in China as well, for which factories and government departments step back. Waste water with aromatic compounds may leach into groundwater, run into the streams and be taken into human body. And the volatile aromatics may rise into atmosphere and then be absorbed into our body.

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