Growing awareness of the long term effects of chemicals released into the aquatic environment has increased over the last decades. Pharmaceutical residues are among those emerging organic micro-contaminants due to their extensive use and their increasing occurrence in the aquatic environment. The potential sources for pharmaceutical’s pollution include chemical manufacture facilities, medical facilities and those who receive them and use them (humans/animals/plants). The acute and chronic effects of pharmaceutical compounds on the ecosystem and on human health are not yet fully understood.
Ultimately, a portion of the pharmaceuticals disposed, for example, from hospital wastewater will reach domestic wastewater treatment plants (WWTPs), which do not sufficiently remove these contaminants. As a result, effluents containing micro pollutants will enter aquatic water cycles as rivers, groundwater and drinking water by direct discharge, irrigation or artificial recharge. Persistent pharmaceuticals like Carboplatin (chemotherapy) and Absorbable Organic Halogens (AOX) are hardly removed by soil passage under aerobic conditions. Major concerns for water reuse from the hospital effluents are the survival of enteric viruses and emerging resistant bacterial and protozoan pathogens, and the potential toxic effects of nano-micro-pollutants that may be introduced to the environment. Thus, another concern, although not regulated, is the fate of micro-pollutants in the treated reused effluent, used for agricultural reuse (Israel 84%), stream/rivers rehabilitation and groundwater artificial recharge.
Several studies conducted have confirmed the occurrence of pharmaceutical residues (e.g. antiphologistic, blood lipid regulators, anti-inflammatory drugs and antibiotics) in surface and groundwater. For example, frequently used pharmaceuticals (the anti-epileptic carbamazepine) and analgesic anti-flammatory drugs (ibuprofen, diclofenac, ketoprofen and naproxen) were detected in lakes, rivers and WWTP effluents, at concentrations ranging between 5-3500 ng/l. Twenty two different compounds, including pharmaceuticals, personal care products and endocrine disrupting compounds (PPCPs and EDCs), found at various locations within the water use cycle of Ann Arbor, in Michigan.
Hospital wastewaters provide a significant source of pharmaceuticals found in the environment. In Germany, for example, during 1999, approximately 411 tons of antibiotics were used for human applications, of which 105 tons were used in hospitals. These substances were detected at much higher concentrations in hospital wastewater than in household wastewater and might reach levels as high as several milligrams per liter! due to their intensive use and lower dilution.
Furthermore, The majority of pharmaceutical compounds enter aquatic systems via the wastewater treatment network after ingestion and subsequent excretion as non-metabolized parent compounds or metabolites. The increasing use of various pharmaceutical compounds and the formation of their metabolites have led to an increase in their presence in the environment. The elimination of these compounds by WWTPs was found to be relatively low and consequently, effluent containing a mixture of pharmaceutical residues and their degradation products (DP’s) may be released to the aquatic environment and instigate genetic selection of more harmful such as antibiotic-resistant bacteria, a matter of great concern.
The hydrochemistry laboratory is a leading laboratory working on the formation of drugs DP’s formed under natural environmental conditions, therefore, we were studied the degradation of amino-penicillin, which is a widely used penicillin-type antibiotic, (Figure 1), macrolides and drugs using for chemotherapy (Figure 2), and identified several DP’s which were detected in the aquatic environments (surface and groundwater). The results of these studies should direct further research into identified and suggested DP’s, not only from these compounds but also from other drugs as well, which can potentially be obtained in various aquatic environments.
Further research is required to examine the environmental toxicity and stability of these compounds, which might, through exchange, form other DPs, depending on the many possible nucleophilic agents existing in a specific aquatic environment.
Figure 1: Suggested degradation pathway of amoxicillin in aqueous medium
(ADP3 according to Gozlan et al., 2010).
Figure 2: Diagrammatic scheme for the CPT DPs obtaining from the major DP
CPT4 under various conditions, with solar irradiation.
The Research Group
A key research group – the Hydrochemistry, of which addresses a wide range of topics and bring together scientists and research students from fields ranging from chemistry, biology, hydrology, geology and chemical engineering. This lab is unique in Israel and the leading in the field – and use advanced analytical tools with cutting edge technologies. Additionally, the research group is investing lots of effort and building collaboration to develop and optimized patented innovative technologies, which are currently in the process of implementation to improve wastewater and drinking water quality.
The hydrochemistry’s studies are published in world leading scientific journals and presented in international and national conferences. The hydrochemistry research group is conducting an outstanding studies to improve water quality and to provide a platform for excellent graduate students, which are interested in water studies.