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...

The goal of this study is to investigate the effect of inoculating granules on reducing membrane fouling. In order to evaluate the differences in performance between flocculent sludge and aerobic granular sludge in membrane reactors (MBRs), two reactors were run in parallel and various parameters related to membrane fouling were measured. The results indicated that specific resistance to the fo...

In addition to the positive effects on the physical, chemical and biological soil properties of the application of sewage sludge into the soil, there is often an increase of both organic and inorganic pollutants in the soil. One of the most popular organic xenobiotics frequently present in sewage sludge are polycyclic aromatic hydrocarbons. The aim of this study is to determine possibilities fo...

In this study two wet microalgae cultures and one dried microalgae culture were co-digested in different proportions with sewage sludge in mesophilic and thermophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of sewage sludge alone. The results showed that co-digestion with both wet and dried microal...

A fundamental study of the characteristics of a sludge refuse-derived fuel (RDF) and the combustion behaviors were done. The test data demonstrate good results for the development of energy recovery technology of organic sludge or waste. The ash deposit formation propensity has been based on pretreatment, temperature and the ratio of organic sludge to sawdust. The usage of organic sludge and wa...

In this paper, an overview on sewage sludge characteristics and recovery routes is presented. Starting from an analysis of typical sewage sludge characteristics as found in literature, the most promising disposal options are presented. A focus on incinerated sewage sludge ash (ISSA) follows. Most of the authors agree on considering pyrolysis and gasification as the most viable treatments for sl...