This chapter is a review of literature concerning the fate of chloro-s-triazine herbicides, particularly atrazine, in the environment. It addresses the distribution of such herbicides and their metabolites in the soil and in water bodies, including the conditions that affect their transport mechanisms. The biodegradation pathways regarding the microbial degradation are presented as well as modification mechanisms of the compounds in plants capable of tolerating their action. Studies on the influence of the compounds on animal and human physiological processes and health, that is distribution of atrazine in the animal organisms, effects on the regulatory platform in the liver, possible carcinogenesis and endocrine disruption risks are assessed. Toxicity tests used for evaluation of the toxicity of the compounds are critically reviewed. Possible methods for atrazine degradation, including advanced oxidation procedures (AOP techniques), are outlined.
Part of the book: Herbicides
Xenobiotics in the environment include a wide variety of compounds, e.g. pesticides, drugs, textile dyes, personal care products, stabilisers, and many others. These compounds enter natural waters by rain washing of treated areas, via leaching through soil from places of application and via waste waters of manufacturing facilities or municipal waste waters (excretion of unmetabolised drugs, disposal of unused drugs). In natural waters, physical, chemical, and biological processes contribute to the decrease of xenobiotics concentrations. For substances resistant to biological degradation processes and the chemical reactions such as hydrolysis, photoinitiated processes may represent important degradation pathways. Photochemical processes can be categorised in connection with the environmental fate of xenobiotics into two fundamental groups: those that may occur in natural waters and those that have been tested for decontamination of waste waters. The first group is focused mainly on photosensitization and homogeneous photocatalysis. The second class comprises advanced oxidation processes (AOPs) of which especially heterogeneous photocatalysis on semiconductors is the most investigated technique. The chapter covers all these processes and brings examples of their applications.
Part of the book: Photochemistry and Photophysics