Subproject: Solid Waste Disposal (SP-13) 



Disturbing Activity: Solid waste disposal 



Solid wastes from major petrochemical plants originate in feedstock 

 processing, treatment of wastewater, and storage of feedstock and 

 produced chemicals. Sediments from the bottom of the storage tanks, in 

 the form of sludges and slurries, require special handling and treatment 

 prior to disposal. Solid wastes containing potentially hazardous compounds 

 from processing and wastewater treatment procedures also require special 

 collection and disposal methods to prevent contamination of ground and 

 surface waters. Residue from the waste treatment is usually deposited in 

 a sanitary landfill. The types of wastes and their sources and 

 characteristics may vary greatly from one petrochemical complex to 

 another, depending upon the particular processes employed (Table 18). 



Subproject: Industrial Wastewater Systems (SP-14) 



Disturbing Activity: Wastewater collection and disposal 



Wastewaters from petrochemical plants vary greatly in their chemistry 

 and in the treatment required, depending on the chemical characteristics 

 and complexity of plant processes. The two major sources of contaminated 

 wastewaters (in addition to cooling waters) are boiler operations and 

 process waters. In a petrochemical plant, process waters are the most 

 highly contaminated, requiring on-site wastewater treatment (Table 19). 

 They are generated by various steps in the production of petrochemicals 

 such as acidic and caustic washes that remove contaminants from the 

 process stream, washing and scrubbing procedures that remove remaining 

 contaminants, and solvent processes that purify the feedstock and 

 products. Wastewater treatment facilities require careful monitoring be- 

 cause petrochemical production is a continuous 24-hour per day operation 

 and any malfunction of the treatment system can cause a rapid release of 

 large volumes of toxic wastes. 



Subproject: Industrial Cooling Water Systems (SP-15) 



Disturbing Activity: Cooling water treatment and discharge 



Cooling water may account for 40 to 80 percent of the wastewater 

 volume from a petrochemical plant. Cooling waters may contain con- 

 taminants from process valve and seal leaks and from additives such 

 as sulfuric acid, chromate, and chlorine, which are added to the cooling 

 water to inhibit corrosion. Once-through cooling systems use the largest 

 volumes of water, and thus produce the maximum volume of heated effluent. 

 Closed-cycle or recycling cooling systems, in which water is cooled in 

 towers or ponds and then reused, require much smaller volumes of water 

 (perhaps 10 percent or less) and consequently generate less effluent. 

 Effluents from petrochemical plants are regulated through the National 



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