ABSTRACT
Determining the suitability of sewage sludge for land application by characterizing its properties is a necessary first step in planning and designing a land application system. This chapter describes the properties of sewage sludge to be characterized, the different types of sewage sludge, and the effects that wastewater and sewage sludge treatment processes and pre-treatment have on sewage sludge characteristics. Important properties of sewage sludge that need to be characterized include: quantity, total solids content, volatile solids content, pH, organic matter, pathogens, nutrients, metals, organic chemicals, and hazardous pollutants. Key factors affecting sewage sludge volume and mass are wastewater sources and wastewater and sludge treatment processes. Nutrients present in sewage sludge, such as nitrogen, phosphorus, and potassium, among others, are essential for plant growth and endow sewage sludge with its fertilizing properties. The chapter focuses on the broader effects of treatment on sewage sludge characteristics, highlighting the variable nature of treated sludge and thus the need for site-specific sludge characterization.
