More stringent controls on the quality of wastewater discharges have given rise to increasing volumes of sewage sludge for disposal, principally to land, using either land-spreading or sludge-to-landfill operations. Current sludge-to-landfill methods generally involve mixing the concentrated sludge with other solid waste in municipal landfills. However, stricter waste disposal legislation and h...

Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus...

Imidazolium salts are one of the most often used and investigated groups of ionic liquids (ILs). The research concerning their ecotoxicity comprised many test organisms representing different trophic levels; however, their impact on mixed cultures of microorganisms such as activated sludge has been hardly ever investigated. Thus, in this work, the effect of imidazolium ionic liquids on dehydrog...

The methane potential of activated sludge from six Swedish pulp and paper mills was evaluated. The methane production potential of sludge samples ranged from 100-200 NmL CH4 g(-1) volatile solids (VS) and for four of the six sludge samples the potential exceeded 170 NmL CH4 g(-1) VS. The effects of sludge age and dewatering on the methane production potential were evaluated. The effects of enzy...

Sludge incineration in fluidized bed is a very complex process, producing gaseous pollutants (carbon monoxide (CO) and nitrogen oxides (NOx)). The legislative norms need to be respected in spite of variations of sludge in composition and in quantity. The NOx formation, due to lots of chemical reactions from sludge nitrogen, is partly unknown. This paper deals with the design of a dynamic model ...

A novel microwave treatment of sewage sludge was developed as part of the ongoing studies for enhancing the recovery of phosphorus from municipal wastes. The microwave treatment provided a rapid and efficient process to release phosphate from sewage sludge. By using the microwave treatment for only 5 min, up to 76% of the total phosphate in the sludge could be released into the solution. No che...

This work reports some reflections about the European and Italian regulation on sewage sludge. In Europe, the progressive augment of the production of sludge from municipal wastewater treatment plants has recently led to a growing attention about management of this type of solid matrix. European Directives and Italian guidelines stimulated reuse of sewage sludge on agricultural soils or in comp...

The objective of this work was to study the effect of sewage sludge compost on ammonia and nitrate accumulation in the olive-grove soil. This study has been conducted since 1998. To evaluate sewage sludge compost on soil-grove four treatments were set up in a clay loam soil in Seseña (Toledo, Spain). Every experiment was replicated four times. The applied treatments were sewage sludge compost (...

In lab-scale experiments at the 2-stage activated sludge pilot plant of Vienna’s central WWTP it is shown that the wastewater soluble COD concentration, which is inert to a sludge with SRT < 1 d (SIA) is about double compared to the SI concentration in sludge with SRT > 10 d (SIB). Unexpectedly the ratio of SIA/SIB is independent of the sludge age between SRTs of 0.4 and 1.0 days. The differenc...