Aquatic plants for pH adjustment and removal of toxic chemicals and dissolved minerals from water supplies, 8

摘要

Microbial plant filter systems with torpedo grass (Panicum repens) and Southern bulrush (Scirpus californicus) were evaluated for their utility in adjusting pH levels and removing potassium ferric cyanide, potassium cyanide, pentachlorophenol (PCP) and dissolved minerals from contaminated water. The initial concentrations of cyanides were in the range of 0.72 to 32.8 ppm and all were reduced to less than 0.2 ppm in 24 hrs with bulrush. The initial average PCP concentration of 0.85 ppm was reduced to an average of 0.04 ppm in 24 hrs with torpedo grass. The total dissolved solids (TDS) in the torpedo grass filter system were reduced from 988 mg/L to 588 mg/L in 7 days with a 40 percent water loss due to evapotransportation. Adjustment for the water loss represents a TDS removal rate of approximately 83 percent. Plant/rock filters also demonstrated the ability to adjust pH levels from 5 to near 7 in several hours.