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...

The objective of this study is to evaluate the occurrence of fungi in aerobic and anoxic activated sludge from membrane bioreactors (MBRs). Thirty-six samples of both aerobic and anoxic activated sludge were taken from 2 MBR treating domestic wastewater. Over a period of eight months 2 samples from each plant were taken per month. The samples were prepared for count and definition of fungi. The...

During the last years, the efficiency of pollution removal and sludge treatment processes are major concerns because of the more restrictive legislation related to nutrient discharge. A key point in the field of activated sludge wastewater treatment plants (WWTPs) is the secondary settler efficiency. This paper presents a benchmark study to control, using fuzzy algorithms, the sludge height in ...

High-frequency ultrasounds have recently gained interest as oxidative technique for sonochemical degradation of organic contaminants in water. In this study an innovative approach applying 200 kHz ultrasounds to improve both sludge anaerobic biodegradability and decontamination is proposed. Digestion tests were performed on batch reactors fed either with untreated or sonicated sludge, at differ...

Earthworms feed readily upon sludge components, rapidly converting them into vermicompost, reduce the pathogens to safe levels and ingest the heavy metals. Volume is significantly reduced from 1 m³ of wet sludge (80% moisture) to 0.5 m³ of vermicompost (30% moisture). Earthworms have real potential both to increase the rate of aerobic decomposition and composting of organic matter and also to s...