Diseases are treated and cured
with man-made chemicals every day – it’s a fact of life. However, scientists
and public officials have long be concerned with the question: what happens
when those chemicals (pharmaceuticals) come in contact with a healthy person?
As is often the case in science, the answer is: well …. It depends!
When a human or animal
consumes pharmaceutical products (PPs), what happens to them? These substances
are excreted, disposed from the households through sewers and released into the
aquatic environment. PPs are an important group of potential endocrine-disrupting compounds (EDCs) which have
recently attracted much attention of the international scientific community. PPs
such as analgesics, antibiotics, antiseptics, hormones and antidepressants were
detected in influents of wastewaters treatment plants, in surface water, in
ground water and even in drinking water resources across the world. Their
occurrence and persistence in the aquatic ecosystems can lead to an adverse
impact on human life and aquatic systems. Research has shown that PPs
may mimic or alter endocrine system pathways, potentially leading to forms of
gene alteration (Boberg et al., 2010; Verlicchi et al., 2012). Once in the
environment, pharmaceutically active PPs can produce a wide variety of subtle
effects on aquatic and terrestrial organisms. Thus, it is crucial to develop
efficient and cost-effective treatment technologies for removal of such
compounds from water.
Pharmaceutical products (PPs)
are a large and diverse group of compounds designed to prevent, cure and treat disease and to improve health. The
prevalence of their usage is increasing constantly due to numerous factors such
as the discovery of new diseases, the expanding population, the inverting age structure in the general population, and
expiration of patents and the consequent availability of less expensive
generics. The annual production volume of drugs has been estimated to be
several hundreds of tons. (Martinez et al., 2011; Halling Sorensen et al.,
2011).
Examples of pathways for pharmaceuticals to enter the environment |
Trace
concentrations of human and veterinary pharmaceutical compounds and metabolites
have been detected in surface water, groundwater,
and drinking water even after going through water treatment including conventional
physical and biological treatment processes. Wastewater treatment plants
are not yet efficient in removing these micropollutants (PPs) from wastewaters
so they are released to the environment. Several pharmaceutical products cannot
be oxidized even during conventional biological treatments. Other treatment
technologies such as membrane processes are being increasingly implemented in water
treatment because these technologies combine process stability with an
excellent effluent quality. However, factors such as the cost of treatment, the
tendency for membranes to foul, and for pollutants to accumulate in the reject
stream are major issues for this technology.
Currently, efforts are
directed toward environmentally friendly, less expensive, relatively simple and
efficient technologies that can oxidize persistent organic pollutants. BioLargo’s
Advanced Oxidation System (AOS) has been successfully demonstrated for oxidation
of emergent organic contaminants such as PPs. The preliminary investigation
conducted by the research team of Centre Des Technologies De L’Eau (CTE) using
the AOS was very promising. The AOS has proved to be an efficient treatment
tool for municipal wastewater (MWW) loaded with pharmaceutical pollutants such
as Carbamazepine (CBZ), Ibuprofen (Ibu) and Amoxicillin (Amox). The
contribution of the AOS to remove PPs from MWW exceeded 95%. Funded by the
Canadian ARD NSERC grant, BioLargo and CTE researchers are optimizing the AOS
technology for an efficient treatment of MWW loaded with PPs. This project aims
to establish the economic and environmental interest of the AOS process for the
treatment of persistent organic compounds such as PPs.
References:
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