Reduction of Coliforms presents in domestic residual waters by
Air-Ozone Micro-Nanobubbles In Carhuaz city, Peru
Peru generates approximately 2 217 946 m3 per day of wastewater discharged
to the sewagesystem and only 32% receive treatment. The rest of the waters
are discharged to the rivers, whichhave presence of fecal coliforms. Preliminary
analyzes of the domestic wastewater of the Carhuaz district were carried out,
with total coliforms (at 35ºC) of 240,000 CFU / 100 mL and thermotolerant
coliforms (at 44.5ºC) of 130,000 CFU / 100mL at pH 7 , 17 exceeding the environmental
standard values. The treatments were carried out with the air-ozone micro-nanobubbles
generator with awater flow rate of 4.67 L/min and a pressure of the air-ozone mixture
of 90 PSI, achieving a reduction of total coliforms up to 100 CFU/100 mL (99.96%)
and fecal coliforms up to 100 CFU/100mL (99.92%).
Conclusion
• There are reductions of fecal and total coliforms presents in domestic wastewater.
The initial fecal coliform concentration was 130000 CFU /100 mL and total coliforms
240000 CFU /100 mL, after applying the airozone micro-nanobubbles, the coliforms
concentration was reduced. The reduction of fecal- and total coliforms in Treatment 1
was 1000 CFU / 100 mL and 4500 CFU / 100 mL, in Treatment 2 the reduction was
500 CFU / 100 mL and 2500 CFU / 100 mL, in Treatment 3 the reduction was
100 CFU / 100 mL and 100 CFU / 100 mL, respectively.
• The three treatments were obtained from different measures. The fecal coliforms
in T1, T2 and T3 were within the Water’s Environmental Quality Standard (EQS) for
category 3 (in vegetables irrigation), which is 1000 CFU/100mL and the total coliforms
in T1 and T2 were out of the Water’s Environmental Quality
Standard (EQS) for category 3, which is 1000 CFU/100mL. However T3 was within the EQS.
• The best treatment reduction Efficiency of fecal- and total coliforms in domestic wastewater
was in T3 by applying air-ozone micro-nanobubbles. It was obtained 99.58% for fecal
coliforms and 99.01% for total coliforms
