Measures against water pollution in industries producing petrochemicals including polymers.

Because of the breadth of the subject, the problems concerning the treatment of waste water are limited to those of (i) the production of organic chemicals which are produced on a petrochemical basis in chemical plants, (ii) the production of various derivatives selected according to their importance and (iii) the production of some of the more important vinyl polymers. Specific quantities of waste water per ton of product are derived using examples and specifying the pollutants. The waste water from these processes can be purified mainly by mechanical, physical, chemical or biological methods. Technological difficulties in waste water treatment, which arise in some cases producing highly refined products, must be eliminated by modifying the process. The term petrochemicals is variously defined. In the broadest sense it is understood to mean chemical compounds or elements (e.g. sulphur) which are produced from petroleum or natural gas or which are entirely or partly derived from the hydrocarbons of petroleum or natural gas (Rompp). According to this definition most of the products of organic chemistry and some inorganic products, such as ammonia which is produced from natural gas, are today termed petrochemicals. The following account is limited to organic primary chemicals which are produced on a petrochemical basis in chemical plants. It will include a discussion of some of the most important vinyl polymers. Using the Federal Republic of Germany and the USA as examples, Table 1 shows the most important products. The data presented in the table refer to total production, independent of the source of the raw materials. MONOMERIC HYDROCARBONS After petroleum largely replaced coal as a raw material in the chemical industry of today, ethylene became the most important starting material for organic synthesis. The production of ethylene and its higher homologues, of which the C3 and C4 compounds are the most important, is shifting more