sludge drying bed is preferred to mechanical methods due to the need for very simple technology. due to restriction of natural dewatering, we tried to eliminate some of these limitations by the tests and studies of assumptions. in this study, the effect of hydrostatic suction and sludge chemical conditioning has been studied in the natural sludge dewatering optimization. at first, hydrostatic s...

Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent a...

A lab-scale expanded granular sludge bed (EGSB) reactor was operated at 20°C with low strength wastewater (0.6-0.8 g COD/L) for over 200 days. Reactor was inoculated with mesophilic granular sludge. The up-flow velocity was set to 5 m/h by effluent recirculation. The COD loading was increased up to 12 kg COD/m3/day until the day 76, resulting in hydraulic retention time of 1.5 hours. Physical p...

utilization authorities in sewage companies considered to sludge dewatering methods due to problems and challenges in this field. dewatering by sludge drying beds is considered in present study. this method is preferred to mechanical methods due to the need for very simple technology. due to restriction of natural dewatering, we tried to eliminate some of these limitations by the tests and stud...

in biological wastewater treatment large quantities of sludge are produced. this sludge is highly putrescible.for disposal and safe usage should be stabilized. the anaerobic digestion is a standard technique for stabilization. due to the rate imiting step of sludge hydrolysis, anaerobic degradation is a slow process with high digestion time. due to high retention time and sludge dewatering prob...

Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge and determining the effect of process variables were the main issues of t...

the evaluation of treatment characteristics and sludge properties of an upflow anaerobic sludge blanket (uasb) process was investigated using a pilot-scale 1.15 m3reactor. the uasb, inoculated with digester sludge, was operated at a hydraulic retention time of 8 h at sewage temperatures ranging from 10.6 to 27.7 °c for more than 1100 days. the stable removal efficiencies for total codcr and ss...

the evaluation of treatment characteristics and sludge properties of an upflow anaerobic sludge blanket (uasb) process was investigated using a pilot-scale 1.15 m3reactor. the uasb, inoculated with digester sludge, was operated at a hydraulic retention time of 8 h at sewage temperatures ranging from 10.6 to 27.7 °c for more than 1100 days. the stable removal efficiencies for total codcr and ss ...