AIMS To quantify the incremental exposure of root crops, at point of harvest, to enteric pathogens from sewage sludge applied to agricultural land according to current regulations and guidance (Safe Sludge Matrix). METHODS AND RESULTS A quantitative risk assessment based on the Source-Pathway-Receptor approach is developed for Cryptosporidium and salmonellas. Event trees are constructed to mo...

This work experimentally elucidates the efficiencies of sono-alkalization treatment on municipal sewage sludge. The total solids (TS) concentration of the sewage sludge was pre-adjusted at 29.7 g/L. Two parameters such as sodium hydroxide (NaOH) dosage and sonication time were considered by the central composite design (CCD) program to investigate the effect on the degradation of phthalate acid...

Municipal sewage sludge is a solid, semisolid, or liquid muddy looking residue that results after plain old sewage (human and other waste from households and industries) is treated at a waste water treatment plant. Recent restrictions on the use of sewage sludge, however, have resulted in increased disposal problems. Sludge contains a variety of organic and inorganic compounds in the waste wate...

The treatment of the sewage sludge produced in the biological treatment plants have increasingly become a serious problem. For this reason, when the reuse and the disposal of the sludge are taken into consideration, the pathogens that the sludge contains should be seriously reduced. In this study, as an alternative to traditional treatment methods for the purpose of pathogen inactivation in sew...

The purpose of the study was to determine the associations between dust, endotoxins and bacterial exposure, and health effects in sewage workers. Exposure of 19 workers handling dry sludge and 25 other sewage workers was measured. Controls were office workers from compost and sewage plants. Spirometry, acoustic rhinometry and nitric oxide in exhaled air were performed before and after exposure ...

A sanitary indicator has been proposed to gather informations about the presence of CFU (colony forming units) of bacteria capable of causing hemolysis of sheep blood cells, known as hemolytic bacteria, in a sewage sludge sample. A group of hemolytic, heterotrophic bacteria, which are differentiated in terms of their phenotypes and genotypes, includes many species and types. As follows from lit...

The composting of thermal-hydrolyzed kitchen biogas residue, either with or without sewage sludge, was compared in this study. The addition of sewage sludge increased and prolonged the temperature to a sufficient level that met the requirements for aerobic composting. Moreover, after mixing the compost materials, oxygen, ammonia, and carbon dioxide levels reverted to those typical of aerobic co...

Some treatment plants in operation have not been designed to fulfill the required standards of phosphorus removal. A possibility to upgrade the efficiency of phosphorus removal could be elimination of the phosphorus returned with sludge processing liquors by releasing and recovering from sewage sludge. The phosphorus recovery can occur from sewage sludge by chemical methods or from supernatant ...

The main objective of this study was to investigate the rheology of mixed primary and secondary sludge and its dependency on solid content and temperature. Results of this study showed that the temperature and solid concentration are critical parameters affecting the mixed sludge rheology. It was found that the yield stress increases with an increase in the sludge solid content and decreases wi...