Water pollution control in petroleum refineries in the United States.

The principal use of water by the petroleum refining industry in the United States of America is in the refining branch itself, and the present paper is concerned with problems arising from this use of water, and some of the measures being taken by the industry to solve these problems. The compilation oftheManualonDisposalof Refinery Wastes is briefly alludedto, and the importance ofrecirculation indicated. It is reported that cooling accounts for 97 per cent of total refinery water requirements. The use of air coolers is growing rapidly in the USA. It may well be more effective and more economical to segregate waste waters by classes and treat each class separately. Next, the use of dissolved air flotation for removal of suspended solids and oils is considered, followed by comments on ponding. Some biological treatments are briefly described, with notes on application. Examples of waste water treatment in new refineries are given, paying attention to the effects of recent legislation to control deterioration of the environment. Difficulty is likely to arise at any stage where particles have the same density as the water into which they are introduced. In future, processes will be redesigned still further to improve reuse of circulating water and reduce water usage from outside sources, coupled with more and more air cooling stages. The petroleum industry in the United States has been concerned with water use and the subsequent handling and treatment of waste water for many years. In the late 1920's, a group known as the Committee on Disposal of Refinery Wastes was formed in the Division of Refining of the American Petroleum Institute (API) to deal specifically with waste water treatment in refineries. The committee's scope was later expanded to include all pollution problems inside the refinery fence. One of the important continuing contributions of this committee has been the compilation of a Manual on Disposal ofRefinery Wastes. The various volumes which make up the Manual are kept up to date by periodic revisions. In 1969, a completely rewritten Manual on Liquid Wastes was published, combining former Volumes I and III and adding new data. The titles of the volumes are as follows: Volume on Liquid Wastes Vol. II, Waste Gases and Particulate Matter Vol. IV, Sampling and Analysis of Waste Water Vol. V, Sampling and Analysis of Waste Gases and Particulate Matter Vol. VI, Solid Wastes