Removing harmful drugs from wastewater
Hospital wastewater includes drugs which are a major environmental problem. Wastewater may include cytostatic drugs such as cyclophosphamide and ifosfamide used for cancer treatment. The presence of such drugs in hospital waste not only pollutes environment but can also harm human health as these drugs often don’t break up easily. The cytostatic drugs are known to cause severe and irreversible damages to human body. The concentration of these drugs is high in the wastewaters of hospitals specializing in cancer treatment. A group of researchers from Belgium and India have developed a novel method of treating wastewater to get rid of such harmful substances from hospital waste. Components:
The method involves slurry photocatalytic membrane reactor which involves a filtration process similar to the one used to purify drinking water.
This device works with a light source like an LED.
Catalyst viz. titanium dioxide is used to breakdown drugs. Titanium is easily available, efficient, stable and not toxic. The membrane used as a barrier to stop the drugs is made up of a polymer or ceramic.
Process:
As waste water with cytostatic drugs enters photoreactor, the light source activates or ‘fires up’ the catalyst (titanium dioxide) breaking it up into two parts—titanium and ‘free’ oxygen.
The ‘free’ oxygen then combines with the cytostatic drugs in waste water and breaks them into smaller parts thus making them ‘safer’.
If any drug particles are left unchanged, the membrane prevents them from passing through.
Thereafter, the mixture goes into another part of the reactor where the catalyst is removed and re-circulated to the photoreactor.
The amount of carbon contained in the pollutants before and after the filtration process decreases with time, this indicates that the degradation process is effective.
