the activated sludge process is the most widely used biological wastewater treatment for both domestic and industrial plants in the world. one of the drawbacks of conventional activated sludge (cas) processes is high sludge production. excess sludge treatment and disposal currently represents a rising challenge for wastewater treatment plants (wwtps) due to economic, environmental and regulatio...

The purpose of this work was to examine the settling properties of activated sludge from a sequencing batch reactor (SBR). The experiments were carried out in a bench-scale reactor, fed with wastewater from the University of Olsztyn treatment plant. Concentrations of the examined activated sludge varied between 2.5 and 6.0 kg SS m. Laboratory analyses of the sludge comprised: sludge concentrati...

In the processes of wastewater treatment, significant amounts of iron phosphate containing sludge is discharged. One of the recycling methods of this sludge, alkalization treatment is investigated. aq. solution of sodium hydroxide is added to the dehydrated sludge. Iron phosphate in the sludge react with sodium hydroxide, forming sodium phosphate and iron hydroxide containing-sludge at room tem...

Introduction :By ever-increasing of population, shortage of water resources and the necessity of wastewater treatment, huge volumes of sludge that is a byproduct of wastewater treatment, requires to be disposed in environmentally secure ways. The target of specifying strategic preferences of reuse of sludge has been to find the correct way of disposal or beneficial use of sludge. Material and ...

in this study, activated sludge process for wastewater treatment in a refinery was investigated. for such purpose, a laboratory scale rig was built. the effect of several parameters such as temperature, residence time, effect of leca (filling-in percentage of the reactor by leca) and uv radiation on cod removal efficiency were experimentally examined. maximum cod removal efficiency was obtained...

A novel microwave treatment of sewage sludge was developed as part of the ongoing studies for enhancing the recovery of phosphorus from municipal wastes. The microwave treatment provided a rapid and efficient process to release phosphate from sewage sludge. By using the microwave treatment for only 5 min, up to 76% of the total phosphate in the sludge could be released into the solution. No che...

Anaerobic digestion is widely applied for the recovery of energy from waste activated sludge. Pre-treatment methods are of high interest to increase the biodegradability of the sludge and to enhance the digestion efficiency. This paper studies the application of a microwave pre-treatment. An experimental set-up of two pilot scale semi-continuous digesters was used. During a long term experiment...

Conditioning of an alum-based water treatment sludge by single and dual polymers was investigated in this study. Capillary suction time (CST), specific resistance to filtration (SRF) and settling rate of conditioned sludge were used to evaluate the sludge dewatering characteristics. Sludge dewaterability resulting from single and dual polymer conditioning were compared for the purpose of explor...

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and i...

Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability ...