Removal of selected contaminants from water by sorption on coal

Conventional water and wastewater treatment practices have little or no effect on an increasing number of both inorganic and complex synthetic organic wastes which presently contaminate our nation's watercourses. Among the inorganics particular concern in recent years has been directed toward phosphorus containing compounds, since it is widely thought that phosphorus is the nutrient which limits the growth of large quantities of algae in lakes and other bodies of water. Concern regarding organic pollutants has been directed toward synthetic organic pesticides which in the past decade have become recognized as significant water pollutants.

In order to protect the water resources of our nation new technologies for water and wastewater treatment must be developed. One of the more promising processes to be discovered in recent years is the use of activated carbon as an adsorbent for organic pollutants. The technical feasibility of this process has been fully demonstrated. Economic considerations, however, are frequently unfavorable owning to the high cost of the activated carbon. More recently a number of processes have been suggested which utilize the properties of coal as an adsorbent, flocculent, filter aid and filter media for the purpose of facilitating treatment of a variety of wastewaters. In evaluating these processes, there is a real need for quantitative data which describe the extent of uptake of a wide variety of contaminants on coal.

The research reported in this bulletin enables the evaluation of. the sorption of selected pesticides and phosphorus containing compounds by a variety of grades of coal. The rate at which the uptake reaction proceeds is reported, and the optimum environmental conditions for sorption are noted. Information of this type helps to facilitate the proper evaluation of the various coal processes which are presently being proposed. In particular the extent to which sorption on coal may be substituted for sorption on activated carbon is discussed.