this research was conducted in continuous flow bench scale fixed activated sludge (fas) and anaerobic filter (af). the main objective of the research was to study the feasibility and efficiency of the mentioned systems for cr (vi) removal. in fas reactor, cr (vi) was adsorbed from influent to mlss in the range of 89 to 99 percent and the adsorption followed freundlich isotherm. in af reactor, c...

Most coupled or combined processes use a fixed film reactor in series with a suspended growth reactor. In combined processes, the fixed film reactor usually consists of a biological tower. The suspended growth reactor is generally an aeration basin or small contact channel. Other types of combined processes have been used where rotating biological contactors (RBC’s), lagoons, or other treatment...

Fixed film biological wastewater treatment processes, such as trickling filters, biological fluidized beds, and rotating biological contactors (RBC), have gained more attention recently due to their less energy consumption, ease of operation and low maintenance requirements. However, the dynamic nature of biofilms and their kinetic characteristics have not been fully understood. Designs of the ...

There are many domestic wastewater treatment processes in use today. Generally, they are all biological systems and they may be broadly categorized as either fixed film processes or suspended growth processes. During the 1970s and early 1980s, the rotating biological contactor process (RBC), a particularly efficient fixed film process, became popular. However, the primary manufacturer of RBCs i...

Combined processes are a hybridization of the activated sludge and attached growth systems, including packed beds, suspended carrier materials, and rotating biological contactors. In general, having an fixed film component has a buffering effect in the event of a process disturbance. Process disturbances may include extreme hydraulic overloading, discharge of toxic compounds into the system, or...

The Science and ‘art’ of wastewater engineering stretches only slightly beyond one hundred years. Within this period, the applied technology has certainly made significant strides in promoting disease control and environmental protection. Fixed-film treatment unquestionably plays an important role in this history, particularly since it represented the original biological mechanism. Beginning wi...