Abstract

Sewage treatment generates sludge from the physical–chemical and biological treatment stages that must be stabilized and disinfected for later reuse. The management of sludge has associated risks due to its composition in organic matter, pathogenic microorganisms, heavy metals, and emerging pollutants, such as antibiotics and disinfectants. The stabilized and disinfected sludge could be used as by-products, for example, amendment as soil improvers. However, even in these by-products, high concentrations of pathogenic microorganisms have been detected that could cause health problems in people through contact with food and also through the transmission of multi-resistant bacteria to antibiotics, which can be spread by inappropriate treatments. It is described that in stabilized sludge there may be horizontal gene transfer mechanisms that confer resistance to antibiotics among bacteria. Therefore, the management and treatment of these sludge must be efficient in the inactivation of pathogens, considering their disposal and final applications. On the other hand, the application of sludge already treated as soil improvers, due to the nutritional properties and physical characteristics, in addition to the efficiency of the sludge remediation technologies, should consider a correct application load to the soil to maintain soil biodiversity. Is necessary all that of these practices are aligned with the sustainable development objectives proposed by the United Nations in order not to generate impacts on soil and water resources.