Waste treatment processes, survey

A Survey of Some Industrial Waste Treatment Processes... 

In regard to water treatment, the Section 308 data base, as previously mentioned is the best collection of information on waste treatment processes by plant site and industrial category. The data base was developed through plant visits, sampling and analysis projects, surveys, and questionnaires. It is, unfortunately, not easily available to those outside the EPA Effluent Guidelines program because of industry s confidentiality claims. 

Production processes used in the pharmaceutical/fine chemical, cosmetic, textile, rubber, and other industries result in wastewaters containing significant levels of aliphatic solvents. It has been reported that of the 1000 tons per year of EC-defined toxic wastes generated in Ireland, organic solvents contribute 66% of the waste [27]. A survey of the constituents of pharmaceutical wastewater in Ireland has reported that aliphatic solvents contribute a significant proportion of the BOD/COD content of pharmaceutical effluents. Organic solvents are flammable, malodorous, and potentially toxic to aquatic organisms and thus require complete elimination by wastewater treatment systems. 

Foam separation process involves the selective adsorption of the surface-active pollutants at the gas-liquid interfaces of fine air bubbles in a foam separation column. The surface-active pollutants, which are adsorbed on the surfaces of the rising bubbles, can be carried upward to the top of the foam separation column and thus removed from the aqueous system as condensed foam. Foam separation can be used for both waste treatment and water purification. This section presents the data on the feasibility of removing various organics and inorganics by the foam separation processes. A general survey of foam separation process and its fundamental principles are also presented. 

Depolymerizing modification of starch usually involves the use of enzymes, acid- (and less frequently base-) catalyzed hydrolysis, and thermolysis alone and thermolysis combined with acid-catalyzed hydrolysis (see a recent survey in this Series2). Despite several studies, the physical treatment of starch has not yet resulted in major practical applications. The aim of this Chapter is to review physical methods as tools for the treatment of starch which deliver amounts of energy suitable for depolymerizing starch to target products. It should be noted that the duration of such processes does not need to exceed that for conventional, namely enzymic, chemical, and thermal modifications. Moreover, a potential advantage of nonconventional physical treatments is the fact that they generate no waste products. 

The best approach is to make a comprehensive wastewater survey that will (1) determine the quantity of wastewater discharge, (2) locate the major sources of waste within the plant, (3) determine wastewater composition, (4) explore in-plant or process changes to minimize the waste problem, (5) establish the basis for wastewater treatment, and (6) evaluate effect of wastes on the receiving stream. 

---