background: the biological solids produced during wastewater treatment processes are called sludge. as sludge contains various sickening microorganisms such as pathogens, organic and inorganic substances and has adverse effects on human and environment, therefore it should be treated and processed entirely prior to disposal and then disposed in line to the environmental regulations. thermal tre...

This paper presents three new approaches to reduce excess sludge production in activated sludge systems: 1) modification of conventional activated sludge process with insertion of a sludge holding tank in the sludge return line; 2) chlorination of excess sludge so as to minimize excess sludge production; and 3) utilization of a metabolic uncoupler, 3, 3', 4', 5-Tetrachlorosalicylanilide (TCS) t...

aerobic digestion was useful for mixed sludge of west ahwaz sewage treatment plant. results showed that after 12 days 38% of tvs reduced. this meets the environmental standards. after 19 days detention time in the bioreactor, cod, vss, tvs, tss, ts, were 40 ,56, 54.5 ,50.4 ,44.7 percent respectively. kd coefficient was,0.173day-1. aim of this bench scale study is determination of aerobic digest...

Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. Application of aquatic worm is an approach to decrease the amount of biological waste sludge produced in wastewater ...

In this study, sludge treatment and dewatering alternatives for a selected leather tanning wastewater treatment plant were evaluated by evaluating the best available technology for sludge management. In addition, different combinations of sludge treatment alternatives were compared on the basis of investment and maintenance costs.

Integrated Fixed-Film/Activated Sludge (IFAS) technologies have been gaining wide popularity as an innovative and efficient treatment process for achieving nitrification in refining and petro-chemical wastewater treatment plants. IFAS technologies are sometimes referred to as Hybrid systems as the process combines the benefits of fixed film systems into the suspended growth activated sludge pro...

Wastewater treatment with activated sludge is the most common way of treating wastewater. The process relies on bacteria converting nutrients, BOD and COD into biomass, CO2 and N2. Even though the configuration of activated sludge processes and wastewater treatment plants varies there are common problems which are shared. Filamentous bulking sludge is one problem that is widespread and disturbs...

The literature on reduction of excess sludge production by ozonation is summarized. Two sequencing batch reactor experiments where sludge is ozonated for this purpose are performed. The purpose of these is to evaluate the prospects of using ozonation to reduce excess sludge production in two different kinds of sludge. Urban sewage sludge is used in the first, and paper mill sludge in the second...