introduction: the presence of pathogenic microbial agents and pathogens in organic fertilizers causes health problems and disease transmission. the aim of this study was to evaluate the efficiency of vermicomposting process in improve the microbial quality of the compost produced. methods: this experimental study was conducted as a pilot-scale one, in the laboratory of school of health. in orde...

Introduction: The presence of pathogenic microbial agents and pathogens in organic fertilizers causes health problems and disease transmission. The aim of this study was to evaluate the efficiency of vermicomposting process in improve the microbial quality of the compost produced. Materials and Methods: This experimental study was conducted as a pilot-scale one, in the laboratory of school of...

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...

When primary domestic sewage sludge was combined with settled sewage or secondary-treatment plant effluent, synergism resulted. The activity (measured by oxygen uptake, and the removal of Kjeldahl nitrogen and orthophosphate from solution) which resulted from incubating sludge together with settled sewage exceeded the sum of the activities when these components were incubated separately. A simi...

The performance of an EGSB (expanded granular sludge bed) reactor type using flocculent sludge was evaluated for the post-treatment of effluent from UASB reactor treating domestic sewage. A pilot-scale 157.5-L EGSB reactor was monitored during a 331-day period. The original concept of the EGSB reactor was based on the granular sludge use and by applying high upflow liquid velocities (vup). Howe...

Biosolids are solid, semi-solid, or liquid materials resulting from the treatment of domestic sewage sludge. The term “biosolids” was introduced by the wastewater treatment industry in the early 1990’s and has been adopted by the United States Environmental Protection Agency (U.S. EPA) to distinguish high quality, treated sewage sludge from raw sewage sludge and from sewage sludge containing la...

The nature and behavior of the microbial population developed on a synthetic waste containing salts and sorbitol are compared to that of a treatment-plant activated sludge. The population of the adapted sludge developed on the synthetic waste consisted approximately of only six kinds of bacteria. Experiments with radioactive sorbitol indicate that the microbial population developed on the synth...

introduction: the present study aimed to investigate the microbial quality of the produced vermicomposts and compare them with the existing standards. methods: this experimental study was conducted as a pilot-scale one, in the laboratory school. some perishable domestic waste were mixed in a reactor, including food waste, vegetables and fruits, cow manure and sludge of wastewater treatment plan...

Three types of ponds used for treating domestic wastewater in Burkina Faso in Soudano-sahelian climate, were monitored for sludge accumulation. After five and a half years of operation, the rates of sludge accumulation in the ponds were evaluated to 0.02; 0.009 and 0.007 m 3 /capita year respectively for the anaerobic, facultative and maturation ponds. The corresponding rates of accumulation in...

in order to optimize sludge depth in sand drying beds under the climatic conditions of saudi arabia, the effect of initial sludge depth on the fate of pathogens was investigated.the investigation was carried out for one year in al-khobar wastewater treatment plant, where initial sludge depths of 10, 15, 20, 25, 30 and 35 cm were implemented. sludge samples were collected on 0, 1, 2, 4, 7, 14, a...