Behaviour of inorganic substances in waters depends on the species (forms of existence) affecting their toxicity, chemical reactivity and physical-chemical properties (sorption). That is why it is necessary to examine the species forms for individual components.
Natural, utilizable and waste waters contain a range of newly occurring organic substances negatively influencing chemical and biological processes in waters. These are mainly PPCPs (Pharmaceutical and Personal Care Products), usually called pharmaceuticals or personal care products. This group includes medicinal substances and washing, cleaning and cosmetic agents. New analytical methods are needed for these new substances as well as the determination and analyses of their chemical and biological behaviour in waters, i.e. their chemical and physical-chemical properties and biodegradability under aerobic and anaerobic conditions. These properties subsequently influence their distribution and circulation in the environment and must be taken into consideration from the legislation viewpoint when defining the quality requirements for various types of water as far as the ecological aspect is concerned.
Chemical behaviour of inorganic substances and new PPCPs depends on their chemical structure. A common type of water analysis usually determined the total concentration of individual components. In fact, the individual components occur in various forms of existence (species), which result from protolytic, complex-forming, oxidation-reduction, polymerising and biodegrading reactions. It is difficult to determine the individual forms experimentally and so they are frequently calculated on the basis of the chemical thermodynamics laws. For this purpose a range of calculation programmes already exists.
Development and extended applications of various new PPCPs require preparation of suitable analytical methods for their identification and quantification. Among the methods applicable belong particularly the methods of instrumental analysis allowing detecting the presence of the PPCPs selected even at nanogram concentrations. Attention is primarily paid to selected medicaments, cosmetic preparations and surfactants. The researchers closely cooperate with the Czech Office for Standards, Metrology and Testing (ÚNMZ) in creating new regulations ÈSN. They also deal with the assessment and adaptation of new hydro-analytical directives ISO and EN.
Besides their chemical properties, behaviour of organic substances in water also depends on their biodegradability. From the perspective of ecology, the only substances acceptable in the environment are those that are biodegradable either under aerobic or anaerobic conditions. In this respect the legislative requirements are unambiguous. To be able to predict a degree and speed of biodegradation it is necessary to identify relations between the chemical structure and a tendency of organic substances to biodegrade, i.e. it is necessary to identify the dependency on individual molecular fragments, amounts and types of substitutes and their position inside molecules. This will lead to creation of the database necessary and the formation of general requirements applicable to biodegradability and acceptable for the production of new PPCPs. In this respect the department has extensive experience from defining the requirements for biodegradation of surfactants.