Ozone as a selective disinfectant for nonaseptic fungal cultivation on corn-processing wastewater.
Treatment of wet corn-milling wastewater with filamentous fungi was investigated as a means of obtaining fungal biomass as an additional byproduct. Competitive bacterial growth is a common problem during this nonaseptic treatment process. Selective disinfection with ozone was evaluated for eliminating bacterial populations during fungal cultivation. Three laboratory-scale continuous flow aerated reactors were operated under nonaseptic conditions at 38 degrees C, hydraulic retention time of 8h and pH of 4. The bacterial population was reduced by one log with respect to the control when ozone was dosed at a concentration above 47+/-2mg/L. An ozone dosage of about 57mg/L was found to be most effective in improving both fungal biomass production and soluble chemical oxygen demand (SCOD) removal (up to 90%). Fungal biomass concentration increased from c. 1.45g/L (control) to c. 1.75g/L at a 57-mg/L ozone dosage. Higher and lower dosages of ozone resulted in poorer fungal growth and lower SCOD removal.
Sankaran
Sindhuja
S
Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50011, USA.
Khanal
Samir Kumar
SK
Pometto
Anthony L
AL
van Leeuwen
J Hans
JH
D001419:Bacteria / Q000187:drug effects; D018533:Biomass; D002244:Carbon / Q000302:isolation & purification; D004202:Disinfectants / Q000494:pharmacology*; D005374:Filtration; D005658:Fungi / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development*; D007220:Industrial Waste; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000494:pharmacology*; D012044:Regression Analysis; D012995:Solubility / Q000187:drug effects; D013242:Sterilization; D014865:Waste Disposal, Fluid; D003313:Zea mays / Q000378:metabolism*
D004202:Disinfectants; D007220:Industrial Waste; D010126:Ozone; D002244:Carbon; D010100:Oxygen