Biological Treatment Systems

Sludge disposal typically can be responsible for 25 to 40 percent of the operating costs of a biological treatment system. Treatment of sludge is aimed primarily at reducing its volume. This is so because the sludge is usually 95 to 99 percent water and the cost of disposal... 

Health nd SMety Factors. The lowest pubhshed human oral toxic dose is 430 mg/kg, causing nervous system disturbances and gastrointestinal symptoms. The LD q (rat, oral) is 750 mg/kg (183). Thiocyanates are destroyed readily by soil bacteria and by biological treatment systems in which the organisms become acclimatized to thiocyanate. Pyrolysis products and combustion products can include toxic hydrogen cyanide, hydrogen sulfide, sulfur oxides, and nitrogen oxides. 

Many different factors influence the performance of biological treatment systems. Although each specific biological process has special requirements, factors common to biological processes, besides biodegradabihty, include organic concentration, temperature, pH, nutrients, and oxygen (aerobic or anaerobic). 

When organics containing reduced nitrogen are degraded, they usually produce ammonium, which is in equilibrium with ammonia. As the pK for NH3 NH4" is 9.3, the ammonium ion is the primary form present in virtually all biological treatment systems, as they operate at pH < 8.5 and usually in the pH range of 6.5-7.5. In aerobic reactions, ammonium is oxidized by nitrifying bacteria (nitrosomonas) to nitrite... 

Typically, the biological treatment system operates best when a waste stream is at a pH near 7. However, waste treatment systems can operate (with some exceptions) between pH values of 4 and 10. The... 

Figure 26. Process diagram for revised groundwater and solvent wastes biological treatment system.

Skladany, G.J., J.M. Thomas, G. Fisher and R. Ramachandran. The Design, Economics and Operation of a Biological Treatment System for Ketone Contaminated Ground and Solvent Recovery Process Waters. Presented at the 42nd Annual Purdue Industrial Waste Conference, Purdue University, West Lafayette, Indiana, 1987. 

Alkanesulfonates manufactured by sulfochlorination, such as Mersolates, contain about 0.15 wt % chlorine [34]. In biological treatment systems this AOX content disappears completely. 

It requires continuous operation (a biological treatment system cannot be turned on and off frequently). 

THE IMPROVED BIOLOGICAL TREATMENT SYSTEM 27.3.1 General Principles and Process Description... 

Due to the higher amounts of organic pollutants in the food industry wastewater, conventional biological treatment systems can be used. 

Cheng HF, Kumar M, Lin JG (2010) Assessment of di-(2-ethylhexyl) phthalate (DEHP) removal in attached growth and suspended growth biological treatment systems of a municipal sewage treatment plant. Sep Sci Technol 45 221-227... 

The effectiveness of a combined reduction-biological treatment system for the decolorization of nonbiodegradable textile dyeing wastewater has been investigated. The bench-scale experimental comparison of this technique with other reported combined chemical-biological methods showed higher efficiency and lower cost for the new technique [35]. 

Colox An aerobic biological treatment system for municipal and industrial wastes. The biomass is fixed as a film on granules in a fixed bed. Developed in Texas by Tetra Technologies. 

Remediation currently continues at this site. Recovery of LNAPL will continue for the next few years. Further expansion of the biological treatment system is... 

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