Nitrate Removal from Contaminated Water Supplies. Volume 1. Design and Initial Performance of a Nitrate Removal Plant

摘要

The report reviews the design, construction, and operation of a 1-mgd nitrate removal plant in McFarland, CA. The plant treats well water for domestic use. Nitrates are reduced from approximately 15.8 mg NO3-N/L to well below the maximum contaminant level of 10 mg NO3-N/L. Continuous daily (24-hr.) operation of the plant was made possible by automatic operation. Automatic nitrate monitoring of product water was performed once an hour through the use of modified ion chromatography. Daily records of flows, water quality, electrical consumption, salt usage, and manhours were kept to determine operating costs. The amount of water treated by each ion exchange vessel before regeneration was 165,900 gal. (260 bed volumes). The amount of salt used per regeneration was 6.35 lb/ft3 of resin. Capital costs totaled $355,638 for a 5-ft, bed system. Operation and maintenance costs were $0.13 per thousand gal. when the system was operating at 1 mgd. Total costs, including operations and maintenance (O&M) and amortized capital, were $0.25 per 1000 gal. when operating at design capacity of 1 mgd.