Microconstituents in Surface Water

Major and most frequently found microconstituents (MCs) in surface water can be classified into four groups as pharmaceutical and personal care products (PPCPs), endocrine-disrupting chemicals (EDCs), industrial chemicals, and pesticides. Sources and distribution of these four groups are highly related to human activities. The concentration of MCs in urban areas are usually higher than rural environments. Wastewater treatment plants (WWTPs) are the major source of emitting MCs to surface water from where the resulting pollutants flow along rivers, accumulate in lakes, and finally reach estuaries. Some pollutants, like pesticides, can be transported through the atmosphere because of volatilization. Adsorption, biological degradation and transformation, and photo-decomposition usually occur during transportation. Soil and Water Assessment Tool (SWAT) and Hydrological Simulation Program Fortran (HSPF) models are the most common tools to describe and predict the transportation of MCs in the water cycle. Various parameters, conditions, and limitations are also discussed in this chapter.