Municipal Wastewater treatment works- Is it a hub for multidrug resistant human pathogens?

Dr. Sheena Kumari | 16 May 2016

The answer is yes. Are we taking it seriously? No. Where are we heading to- in terms of wastewater treatment in our country?

Considering the amount of antibiotics we consume everyday (South Africa is listed as one among the top antibiotic consumed nations across the globe along with India, Brazil and China), our wastewater treatment works can be a dangerous reservoir for many of these fatal drugs and resistant pathogens!

Wastewater treatment plants provide an ideal “home” for a plethora of microorganisms to thrive, by providing nutrients and other favourable conditions. For example, take a municipal wastewater treatment plant. It receives wastewater from diverse habitats such as households, hospitals, and animal production farms which are often rich in nutrients; contain both pathogenic microbes and pharmaceutical compounds.

What happen to these pharmaceutical compounds when they enter a wastewater treatment process? Are our Wastewater treatment plants designed to treat these compounds?

The answer is again, no. Most of our conventional wastewater treatment plants are not designed to degrade pharmaceutical compounds. Traces of these compounds get adsorbed to the activated sludge floc surface, which are then removed by wasting sludge.  However, a portion of this sludge is recycled back. These recycling processes and the longer exposure of pathogens to certain drugs will lead to multidrug resistant strains. Another potential threat is the horizontal exchange of antibiotic resistance genes between different microbial species that can develop into new strains which can be even more dangerous than its parental strain.  

Can we control it? The answer is no! However, an optimally operating wastewater treatment plant can control the spread or dissemination of these pathogens to an extent by implementing proper tertiary treatment (disinfection) methods. A poorly operated wastewater treatment plant therefore can be extremely dangerous to the environment and the human community at large!  This may lead to many fatal water born disease outbreaks in the near future!!!

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