WASTES IN RELATION* TO AGRICULTURE AND FORESTRY 



101 



too expensive at the present time. Expediting slash 

 disintegration by chemical treatment has not given 

 positive results. Likewise, fungal inoculation to 

 hasten decay appears to offer little hope. There 

 can be marked improvement in burning techniques 

 that reduce atmospheric pollution. This approach 

 appears very promising and research to this end 

 should be expedited. 



Processing Wastes 



It can be conservatively estimated that over a 

 billion pounds of milk goes into sewers annually 

 from fluid milk processing plants ; over 20 billion 

 pounds of whey and buttermilk containing over 

 1 billion pounds of solids result from cheese and 

 butter production. Over 500 million pounds of bio- 

 chemical oxygen demand are produced in cannery 

 wastes (dry weight). Neither the farmer nor the 

 processor has a direct interest in water pollution 

 from farm products. Costs for additional treat- 

 ment of these wastes must be borne by the con- 

 sumer or the general public through taxation. 



In the forest products field, processing losses 

 annually include nearly 400 million cubic feet of 

 logging residues and 230 million cubic feet of 

 coarse wood residues at manufacturing plants. 

 Progress in use of manufacturing wastes has been 

 phenomenal ; wood waste burners have almost dis- 

 appeared and 25 percent of all pulp is made of 

 chips from sawmill and veneer mill residues. Yet. 

 the pulp industry indicates that its wood require- 

 ments in 1967 will expand by 10 million cords over 

 those of 1966. The need for better utilization of 

 the resource continues to grow. 



Because of the potential economic value of agri- 

 cultural and forest product wastes for chemicals, 

 pulp, and other manufactured products, the first 

 priority of research should be in new product de- 

 velopment using available residues. 



The potential for improving processes so that less 

 waste results, or less deleterious wastes, is very 

 good. Many steps in processing were developed 

 some years ago when not much attent ion was paid 

 to stream contamination by effluents. These need to 

 be restudied and changed. Water reuse or counter- 

 current use should lower both cost and water con- 

 sumption. Completely new systems are possible; 

 "dry floor" evaporated milk operations illustrate 

 the possibilities. 



Progress in pulp and paper manufacturing 

 processes to reduce water pollution has been good, 

 and at newer plants control can be effected. No 

 economical way is as yet available to further re- 

 duce the pollution problem at older plants which 

 are not equipped to adopt new and improved 

 processes. 



The first step in increasing the efficiency of utili- 

 zation of waste from processing agricultural and 

 forest products is an evaluation of the waste's 

 physical and chemical properties and a study of 

 potential outlets or uses for these materials. Efflu- 

 ents from some food-processing plants are being- 

 used as a source of much-needed irrigation water 

 in some areas. The sugar industry effectively uses 

 filter press mud as a soil amendment and bagasse 

 as a source of cellulose for making paper or for the 

 preparation of furfural. Certain organic wastes 

 from the food- and timber-processing industries 

 are also used as soil amendments. Lignin, making 

 up one-fourth to one-third of all wood, is a by- 

 product of some pulping processes and may have 

 great potential as a source of chemical products. 

 The livestock-processing industry has made great 

 strides in efficiently utilizing many of its wastes as 

 byproducts. Increasing needs for protein in the fu- 

 ture make research on fermentation of carbohy- 

 drates more promising. 



Where wastes cannot be used directly because of 

 the presence of a detrimental characteristic or 

 component, some minor amelioration processes 

 might be developed to make the waste product 

 more compatible with a potential use. This might 

 include filtration of an effluent to remove harmful 

 solids, dilution of a saline effluent to make it more 

 suitable for irrigation, etc. Some wastes may be 

 converted to satisfactory soil amendments, bur in 

 some instances, byproducts o( greater economic 

 value may be obtained through the development of 

 new and improved technology. It is important 

 that, where possible, some of the wastes of today 

 be developed into profitable products of the future. 



Infectious Agents and Allergens 



The latter part of the L9th century has been 

 aptly called the period of "the Great Sanitary 

 Awakening" (35). The research of two outstand- 

 ing medical authorities provided the t'oundat 

 for this awakening. John Snow demonstrated to 



