in the present study, the effects of four factors including initial sulfide concentration (mg l-1 ), agitation speed (rpm), amount of inoculums (%) and sodium concentration (mg l-1) on removal efficiency (%r) and yield of sulfate production by thioalkalivibrio versutus from synthetic spent caustic were investigated. for this purpose, experiments are designed by design of experiments (doe) and r...

In the present study, the effects of four factors including initial sulfide concentration (mg l-1 ), agitation speed (rpm), amount of inoculums (%) and sodium concentration (mg l-1) on removal efficiency (%R) and yield of sulfate production by Thioalkalivibrio versutus from synthetic spent caustic were investigated. For this purpose, experiments are designed by design of experiments (DOE) and R...

Background & Aims of the Study: Hydrogen sulfide (H2S) is a colorless and highly toxic, easily dissolved in water, flammable and explosive gas. Hydrogen sulfide gas is the main cause of odor emissions from municipal sewage plants. One method for removal of hydrogen sulfide gas is the use of biological systems, biofilter. The aim of this study was to survey removal hydrogen sulfide provide in se...

A laboratory scale aeration treatment system was built to study the fate of nitrogen during aeration of pig slurry. For each run evaluated, the nitrogen mass balance was determined including measurement of the nitrous oxide gas emissions. Intermittent aeration led to a nitrogen removal of about 53% of the total nitrogen content of the raw slurry. About 18% of the total nitrogen content of the r...

Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transi...

The removal of ammonium (NH(4)(+)) and phosphate (PO(4)(3-)) from supernatant of anaerobic digestion by magnesium ammonium phosphate (MAP) formation was studied. To be able to find out the loss of NH(4)(+) by its transformation to NH(3), rates of NH(4)(+) removal by aeration and by MAP formation combined with aeration were compared. NH(4)(+) removal by aeration was found to be insignificant. Th...

a bench scale aerobic sequencing batch reactor (sbr) was evaluated in terms of its potential to treat synthetic dairy wastewater. the 2-l plexiglass bioreactor was supplied with oxygen via a fine bubble air diffuser, fed with synthetic dairy wastewater under various operational conditions. to analyze the process, three significant independent variables — influent chemical oxygen demand (cod), m...

−A packed bed external loop airlift bioreactor (PBELAB) was proposed as an alternative treatment system for wastewater containing ammonia and nitrate compounds. The 60L PBELAB consisted of aeration and non-aeration zones, both of which were packed with plastic bioballs to enhance the surface area for the attachment of bacteria. The system was able to achieve complete removal of all nitrogen com...

electroplating industry wastewater (eiw) characterized by high chemical oxygen demand (cod) is a big source of water and air contamination with heavy metals. the formation of cyanide complex with heavy metals is responsible for its elevated cod. the concentration of heavy metals in eiw can be removed by the use of different precipitating agents (sulfide and hydroxide). but the major bottleneck ...