BIOAEROSOL EMISSIONS FROM WASTEWATER TREATMENT PLANTS IN DUBAI, U.A.E.ZAINAB AL ANSARI, ROBERT BOLDI AND MUNAWWAR KHAN.Abstract Waste Water Treatment plants (WWTPs) can release microbes from waste water to the ambient air in the form of bioaerosols. This study measured the concentration, microbe classification, and size distribution of bioaerosols emitted from the aeration tanks at the Jebel Ali WWTP and the Al Awir WWTP, both located in Dubai, UAE. Microbes studied were heterotrophic bacteria, contamination indicators (total and fecal coliform), and pathogens such as Pseudomonas aeruginosa and Escherichia coli. The results show that: (1) heterotrophic bacteria were detected at all sampling sites; a few samples contained coliform bacteria, but pathogens such as Pseudomonas aeruginosa and Escherichia coli were not observed at any site. (2) Observed concentrations of heterotrophic bacteria were highest when sampling directly over the aeration tanks, and decreased by a factor of two when sampling downwind 100 meters; (3) from 50% to 70% of bacteria were on particles 0.65 - 2.1 μm in diameter, which might pose a potential health hazard. Finally (4) Increasing wind speed was found to be associated with increase bio-aerosol upwind of the WWTPs, indicating re-suspension of soil-borne bacteria may occur.
Enter your contact information below to receive full paper.
|