one of the main disadvantages of anaerobic wastewater treatment at a low ph is the significantoperational cost due to the addition of necessary alkali. to reduce alkali supplement and thus the cost, thisstudy proposes a sequential multi-feed (sqmf) mode (distributed feeding) and effluent recycle (er) mode.experiments were conducted with a pilot-scale (2.5 m3) thermophilic (55°c) multi-staged up...

one of the main disadvantages of anaerobic wastewater treatment at a low ph is the significantoperational cost due to the addition of necessary alkali. to reduce alkali supplement and thus the cost, thisstudy proposes a sequential multi-feed (sqmf) mode (distributed feeding) and effluent recycle (er) mode.experiments were conducted with a pilot-scale (2.5 m3) thermophilic (55°c) multi-staged up...

An anaerobic digestion of palm oil mill effluent (POME) for production of biogas was carried out at pilot scale under thermophilic condition. The objective of this research is to maintain short hydraulic retention time (HRT) and high degradation of the POME to biogas by applying recycle sludge. Fresh POME from PTPN IV without further treatment was used as feed. The fermentation process occurred...

Two laboratory-scale sequencing batch reactors were used to study biological treatment of carbon and nitrogen in a new combined anaerobic-aerobic system. Piggery wastewater was used as a model effluent. The anaerobic reactor, fed with raw wastewater and nitrite/nitrate recycling from the aerobic reactor, carried out denitrification and anaerobic digestion of organic carbon. In the aerobic react...

In the paper different nitrogen control strategies are proposed and tested on a simulation model of a combined preand post-denitrification plant. The plant configuration corresponds to the DomžaleKamnik wastewater treatment plant that will be upgraded for nitrogen removal using MBBR (moving bed biofilm reactor) technology. The aim of the study is to find an optimal control strategy in terms of ...

Many industrial processes, particularly in the food industry, produce slurriesor wastewaters containing high concentrations of biodegradable organicmaterials. Before these contaminated wastewaters can be dischargedthe concentration of these pollutants must be reduced. A method which has beenextensively employed to remove biodegradable organic matter is biologicaltreatment. In this process the w...

Many industrial processes, particularly in the food industry, produce slurries or wastewaters containing high concentrations of biodegradable organic materials. Before these contaminated wastewaters can be discharged the concentration of the biodegradable organic pollutant must be reduced. One way to do this is to pass the wastewater through a bioreactor containing biomass which grows through c...

Polyvinyl alcohol-containing desizing wastewater discharged within final textile wastewater has a great impact to the environment due to its poor biodegradability. An improved lab-scale hybrid anaerobic baffled reactor was developed to treat desizing wastewater. The modification was achieved by increasing the height of hybrid anaerobic baffled reactor and application of proper effluent recycle ...

Sludge production in wastewater treatment plants is increasing worldwide due to the increasing population. This work investigated the effects of ultrasonic (ULS), ultrasonic-ozone (ULS-Ozone) and ultrasonic + alkaline (ULS+ALK) post-treatments on the anaerobic digestion of sewage sludge in semi-continuous anaerobic reactors. Three conditions were tested with different hydraulic retention times ...

A gas-phase reactor with reversible exothermic reactions is the classical example of the many tradeoffs between operating costs and capital costs. Because per-pass conversion is limited by chemical equilibrium, recycle is almost always needed, and this gas recycle is expensive because of the high capital cost and high energy cost of gas compression. At low temperatures, conversion is limited by...