Biological treatment system improved

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

The use of filtration to polish biological treatment system effluent has become more popular in recent years because of more stringent discharge requirements. The 1977 EPA survey of petroleum refineries indicated that 27 of 259 plants used filtration as part of the existing treatment scheme and 16 others planned to install filtration systems in the near future [5]. Filtration can improve effluent quality by removing oil, suspended solids, and associated BOD and COD, and carryover metals that have already been precipitated and flocculated. Improved effluent filtration in one recent instance helped a Colorado refinery to meet the newly adopted discharge toxicity requirements [49]. 

The recent and accelerating emphasis on water pollution control has necessitated the rapid development of improved biological waste treatment systems to aid in cost and energy savings. The use of... 

Section 27.8 summarizes the feasibility and advantages of an improved biological wastewater treatment system involving the use of secondary flotation clarification. 

For effective biological treatment of dye wastewater, immobilization of bacteria under aerobic anaerobic high-rate reactors should be given special attention. The main cause of effective treatment of these xenobiotics under immobilized condition in high rate reactors is the rapid facile reduction of these compounds to products of lower toxicity [68, 69]. Moreover, the immobilization of anaerobic bacteria and maintenance of a high concentration of biomass in the high rate reactors are factors that improve the tolerance of the anaerobic system to toxic substances [70, 71]. 

J. W. Blackburn. 1989. Improved understanding and application of hazardous waste biological treatment processes using microbial systems analysis techniques. Hazard. Waste Hazard. Mat. 6(2) 173-193. 

Several different peroxygen-based systems exist, all of which are compatible with biological treatment. The peroxygen treatment can be used up- or downstream of the biotreatment unit, either as a pre-treatment to reduce toxicity and improve biodegradability or as a post/polishing treatment to remove remaining biorecalcitrant species from the effluent. All the peroxygen-based treatments can also be used as stand-alone processes for the total treatment of a waste stream. The most common AOPs are ... 

Wastewater treatment systems can be classified, in addition to pretreatment, as preliminary, primary, secondary, and tertiary (advanced) treatments. Pretreatment of industrial wastewater is required to prevent adverse effects on the municipal wastewater treatment plants. Preliminary treatment is considered as any physical or chemical process that precedes primary treatment. The preliminary treatment processes may consist of influent screening and grit removal. Its function is mainly to protect subsequent treatment units and to minimize operational problems. Primary treatment is defined as the physical or chemical treatment for the removal of settleable and floatable materials. The screened, degritted raw wastewater from preliminary treatment flows to the primary clarification tanks, which are part of the primary treatment facilities. Secondary wastewater treatment is the process that uses biological and chemical treatment to accomplish substantial removal of dissolved organics and colloidal materials. The secondary treatment facilities may be comprised of biological reactor and secondary clarification basins. Tertiary (advanced) wastewater treatment is used to achieve pollutant reductions by methods other than those used in primary and secondary treatments. The objective of tertiary wastewater treatment is to improve the overall removal of suspended solids, organic matter, dissolved solids, toxic substances, and nutrients. 

Mohamed F. Dahab (water reuse pollution prevention sustainable systems for water quality improvement including biological treatment nutrients removal biosolids and energy management use of natural systems for wastewater treatment). College of Engineering,... 

Combat medicine poses special problems. Chemical science and technology can aid in the rapid detection and treatment of injuries from chemical and biological weapons and other new weapons such as lasers. We need to develop blood substitutes with a long shelf life, and improved biocompatible materials for dealing with wounds. For the Navy, there are special needs such as analytical systems that can sample the seawater to detect and identify other vessels. We need good ways to detect mines, both at sea and on land. Land mines present a continued threat to civilians after hostilities have ended, and chemical techniques are needed to detect these explosive devices. 

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