The laboratory scale studies had been carried out regarding the possibility of electron beam application for sludge hygienization. Experimental system with nozzle type sludge feeder and stainless steel belt conveyor was constructed for irradiation under continuous feeding conditions of sludge cakes with electron beam of dose rate of 40kGy/s. Survival curves of microbial population for total col...

This study investigated the integrated removal of heavy metals, organic matter and nitrogen from landfill leachate using a novel laboratory scale constructed wetland system. The main objectives of this study were: (i) to assess the overall effectiveness of the constructed wetland system for treating landfill leachate; (ii) to examine the interactions and impact of key leachate constituents (hea...

A large amount of paper is recycled in China, that generates a significant amount of sludge and residue during the paper production process. Energy recovery by means of combustion in Waste-to-Energy (WTE) plants can be a possible candidate for sludge elimination. Currently, two incineration methods, distinguished as either direct incineration of partially dewatered sludge (generally 80% water c...

This research has two eventual goals: (1) To optimize performance of subsurface constructed wetlands for removal of phosphorus (P) (2) To demonstrate that dewatered alum sludge (a by-product), can be reused as a constructed wetland substrate. To achieve these, alum sludge from a water treatment plant was characterized and used as main substrate in four experimental vertical sub-surface flow con...

In this study, dewatered alum sludge cakes were used as substrate in a laboratory scale tidal vertical flow reed bed system treating animal farm wastewater. Tidal flow operation was employed to enhance oxygen transfer into the system while dewatered alum sludge cake was used to enhance phosphorus (P) removal through ligand exchange. Except for the removal of P which was consistently high throug...

Phosphorus (P) recovery from liquid swine manure is an attractive technology when on-farm application of liquid swine manure is not an option. We developed a technology that enables separation of this P, but its high moisture content makes transportation difficult. In this work, we investigated dewatering procedures to concentrate the P product. Sludge rich in calcium phosphate (> 20% P2O5) was...

The recycling of organic wastes is required from the viewpoint of environmental issues. Sewage sludge makes up about 30% of the organic wastes in Japan, and at present, the ratio is increasing (Study group on bio-waste recycling, 1999); therefore, it is important to treat and utilize the sewage sludge. Conventional treatment methods such as land filling and ocean dumping have been regulated to ...

This work has evaluated the effects of a thermally dried or composted dewatered sewage sludge on glucosidase activity, total (TCH) and extractable (ECH) carbohydrate content, microbial biomass carbon (MBC) and basal respiration (BR) of soils from limestone quarries under laboratory conditions. Two doses (low, L and high, H) of the dewatered sludge (DS), or of the respective thermally dried (TD...

Dewatered sludge cakes from bench scale anaerobic digesters operated at mesophilic temperatures and solids retention times (SRT) ranging from 10 days to 40 days were evaluated for their sulfur odor generation potential. Extracellular Polymeric Substances (EPS) extraction for digested sludge samples was also carried out. Static headspace sulfur gas analysis was successfully used to compare diffe...

Belt filter presses represent an economical means to dewater the residual sludge generated in wastewater treatment plants. In order to assure maximal water removal, the raw sludge is mixed with a chemical conditioner prior to being fed into the belt filter press. When the conditioner is properly dosed, the sludge acquires a coarse texture, with space between flocs. This information was exploite...