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Water Quality Industrial Water Supplies 9.1 Effects The colour-causing humic and fulvic acids that make up a large fraction of organic carbon in feedwaters may cause foaming in boilers and hinder other treatment processes such as iron removal and water softening (CCREM 1987 and updates). Colour-causing constituents and suspended particulates in organic carbon can also reduce paper brightness and sheet quality because cellulose fibers readily absorb these substances, and the colour may remain in the finished product. Organic compounds are difficult to remove from pulp fibers. For the same reason, organic carbon is undesirable in textile waters because it can cause staining. Several food and beverage industries (i.e., brewing, carbonate beverages, sugar manufacture) require water free from organic matter because it can cause spoilage, rings in bottles, and carbonation problems. Water used in the semiconductor industry must be ultrapure with TOC levels below 0.05 mg/L because TOC is directly correlated with defect density (George Varkey at www.exicom.org/cew/sep96/george.htm. Note: This link no longer works.)
Water quality guidelines ranging from 0.2 to 1 mg/L TOC have been adopted by the CCME (CCREM 1987 and updates) for waters used in steam generators. The TOC guidelines are 0.2 mg/L when pressure is greater than or equal to 6.22 MPa, 0.5 mg/L when pressure is greater than or equal to 3.11 MPa and less than 6.21 MPa, and 1 mg/L when pressure is less than 3.1 MPa for industrial water tube boilers that include super heater, turbine drives or process restriction on steam purity. For steam industrial water tube boilers without super heater, turbine drives or process restriction on steam purity, the TOC guideline is 1 mg/L. For industrial fire tube boilers without super heater, turbine drives or process restrictions on steam purity, the TOC guideline is 10 mg/L.
No water quality criteria are proposed for total and dissolved organic carbon in industrial water supplies.
Organic
carbon for industrial water use are not likely necessary because
industries requiring water free of colour-causing constituents
or organic matter (e.g., production of fine paper) generally
treat the water to remove organic carbon prior to use.
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