Team:ZJU-China/HumanPractice/BeyondTheTale/AnInterviewtoAHerbicideCompany

Interviews to herbicide factories

Overview

We have designed a system which can seek and destroy herbicide atrazine by two reprogrammed bacteria. To bridge the gap between laboratory and industries, we interviewed several companies which produce herbicide, such as Zhongshan Chemical Industry, Changxing First Chemical Industry, Xintong Chemical Industries and so on. Our primary goals are:

1. We aim to search the information of the history and the development of herbicide ,especially atrazine;
2. We try to find out the process of producing atrazine in industries and their consideration of environment;
3. We try to develop a functional way to apply our system to the industry;
4. We want to measure the effect of transgenic crop on the atrazine.

History and Development of Herbicide

Until 2007, 0.56 million herbicide are made in China, including 0.26 million export, and 0.3 million on domestic market, which increases eight times compared with 1978. The form below characterizes pesticide produced in November 2012 in China, in which is from National Statistics Bureau of China, growth rate 1 is comparing November 2012 with October 2012, growth rate 2 is comparing November 2012 with 2011.

November 2012(t) October 2012(t) November 2011(t) Growth rate 1(%) Growth rate 2(%) pesticide 336131 303043 281408 10.9 19.4 insecticide 73917 70124 95946 0.1 -23.0 herbicide 161621 145482 113532 0.1 42.4 bactericide 12869 11717 11775 0.1 9.3

To get more information, we searched other data of pesticide production in China in 2012 and 2011.

Total from Jan.~Nov 2012(t) Total from Jan.~Nov 2011(t) Growth rate(%) Pesticide 3204429 2676181 19.7 insecticide 733610 812879 -9.8 herbicide 1484945 1043206 42.3 bactericide 129737 149775 -7.8

These data shows that the pesticide production in China is increasing rapidly, and the herbicide production increases more rapidly, which means herbicide will take more proportion in pesticide. There is information suggesting that 45% of the herbicide produced in China are export.

Atrazine is widely used herbicide in the world. It is an organic compound consisting of an s-trazine-ring, which was discovered 60 years ago. According to secretary of the party committee of Changxing First Chemical Industry, having been developed for 60 years, atrazine has been a main herbicide using in dry farm, especially in corn field. There are 70 percents to 80 percents of corn field using atrazine as herbicide. The atrazine production in Changxing First Chemical Industry is 5000t every year, including 70% for export and 30% mainly sold to north China.

Also, there are many companies and researchers trying to improve the efficiency of atrazine and lower its poisonousness. For example, Zhongshan Chemical Company, which produces atrazine as their major business, has developed a series of technologies awarded by both government of Zhejiang province and Ministry of Science and Technology of China on manufacturing and using atrazine in the last decade.

Environment Consideration and Assessment

We interviewed several chemical companies to ensure they take environment protection into consideration in their manufacture.

According to Xintong Chemical Industry, they have several methods to measure the poisonousness of pesticide, such as feeding mice with pesticide. To measure the effect on environment, they feed bees, birds, and fish with pesticide, then get the information from their behavior. To measure the residual of pesticide, they will feed the mice with leaves which were sprayed with pesticide for some time. Also, they detect the residual in soil, water, air in lab directly.

As for Changxing First Chemical Industry, which mainly produces active compound of atrazine, they follow the toxicity information provided by National Standard instead of measuring those data by themselves. Atrazine is considered to be a low toxicity, both the product and raw material. They have never got any information or complaint about atrazine residual doing harm to human or animals. But to take environment protection into consideration and assessment, their production is limited to 5000t atrazine every year, and they have to deal with their industrial wastes carefully, which accounts for their 20% in total degression. Both chemical and biological methods are used to deal their wastes. Here is schematic diagram. The secretary of the party committee of Changxing First Chemical Indsutry told us,”The government of Zhejiang Province is strict to environment protection.”

Application for Our Seek & Degrade System

To make sure whether our Seek & Degrade System can be used in industry, we interviewed those industries’ staff and managers, and stepped into their factories to do researches. Our system may be used in both degrading the atrazine residual in soil and factory sewage. The manager of Xinnong Chemical Industry recommended that we should make our bacteria into dry powder, which can be used more conveniently.

It is a big challenge to apply our system into industry. First, we have to make sure that our bacteria is safe to environment, which has been taken into consideration by E-coli suicide design and CaCO3 shell. Secondly, we have to ensure that our bacteria can be stored long enough and are easy to be switched from stored to working state. To solve these problems, we hypothesize that we can package our bacteria into a shell, such as CaCO3 or macromolecules, which can be made into dry powder. Bacteria are released if we change the pH of solution, by which they can be turned into working state. The last question is that when should we use our elves system to degrade atrazine after atrazine used. The half life of atrazine is considered to be seven days, and we need to measure how long enough for atrazine working is. We are trying to mix our bacteria powder with atrazine, and design a system for releasing our bacteria in a specific period of time after atrazine used. It is very regretful for our missing Phd Wang, the scientific research team leader of Zhongshan Chemistry Industry. Feasibility of our design was not evaluated by experts.

Perspectives of Atrazine

We try to find out the effect of transgenic crop on atrazine development. According to the secretary of the party committee of Changxing First Chemical Industry, atrazine develops smooth and steady in recent years. Maybe transgenic crop will have negative effect on traditional herbicide, such as atrazine and drive researches to develop new specific herbicide. At present, these effects are not remarkable. We believe that atrazine will not be weeded out in the coming decades and more methods to make it more environmental friendly will be developed.