Aluminum effluent limitations

Source U.S. EPA, Development Document for Effluent Limitations Guidelines and Standards for the Aluminum Forming Point Source Category, Vols. 1 2, U.S. EPA, Washington, DC, 1984 U.S. EPA, Aluminum Forming Point Source Category, available at http // www.access.gpo.gov/nara/cfr/waisidx 03/40cfr467 03.html, 2008. 

The effluent limitations of all aluminum forming operations representing (a) the degree of effluent reduction attainable by the application of the BPT currently available and (b) the degree of effluent reduction attainable by the application of the BAT economically achievable, can be found from the... 

Effluent Limitations and Performance Standards of the Aluminum Basis Material Subcategory... 

The Effluent Limitations of the Aluminum Basis Material Subcategory that Represent the Degree of Effluent Reduction Attainable by the Application of the BPT Currently Available... 

Effluent limitations attainable by application of BAT for primary aluminum smelting... 

The most commonly used inorganic polymers are the polyacrylamides. Chemical flocculant concentrations employed normally range from 100 to 500 mg/Liter. The wastewater pH may require adjustment between 4.5 and 5.5 for the ferric compounds or between 5.5 and 6.5 for the aluminum compounds using an acid such as H2SO4 or a base such as NaOH. In many applications, the DAF effluent requires additional pH adjustment, normally with NaOH to assure that the effluent pH is within the limits specified by the POTW.. The pH range of the effluent from a DAF is typically between 6 and 9. 

A very limited amount of individual plant specific data for the aluminum forming industry is available. Data available on the influent and effluent streams are discussed briefly in the following subsections for specific plants. This aluminum processing plant uses lime precipitation (pH adjustment) followed by coagulant addition and sedimentation as its treatment system. Data... 

In a pilot-scale study conducted by Raj ala and co-workers (40), rapid sand filtrahon combined with the use of poly aluminum chloride coagulation was used as a pretreatment to improve the quality of wastewater effluent before further treatment with UV irradiahon. Rapid sand hltration reduced suspended solids, turbidity, color, and microbes by about 90%, 70-80%, 20-50%, and 90-99%, respechvely, which improved the UV transmittance of water by up to 20%. The UV irradiation further reduced the number of microbes. More than 99.9% reduction of MS 2 was achieved with the dose of 140 mW-s/cm. Rapid sand hltration and the subsequent UV irradiation reduced the number of all the tested microbes to a low level, often below the detection limit. 

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