Biological treatment of waste water

Waste water in the produetion of polyester is mainly reaction water. This water is treated either on site or externally. An external method for the treatment of reaction water is leading or transporting it to a biological waste water treatment plant (WWTP) or in an anaerobic digester. 

Depending on the composition of reaction water. The biodegrability has to be tested. 

Less expensive than burning of water (depends on the transportation distance). 

Driving force for implementation Environmental and economic reasons. 

Ashland Finland Oy, Porvoo, Finland Reference literature 

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In water, neither volatilization nor sorption to sediments and suspended particulates is expected to be an important transport mechanism. Using the Henry s Law constant, a half-life of 88 days was calculated for evaporation from a model river 1 m deep with a current of 1 m/second, and with a wind velocity of 3 m/second (Lyman et al. 1982). The biological treatment of waste water containing phenol has shown that less than 1% of phenol is removed by stripping (Kincannon et al. 1983 Petrasek et al. 1983). 

Measurement of toxicity (biological analyses) The development of toxicity during chemical/biological treatment of waste waters was seldom assessed. Only in the last few years has the application of toxicity testing been reported more frequently (e. g. Diehl et al., 1995 Moerman et al., 1994 Jochimsen, 1997 Sosath, 1999). Moerman etal. (1994) showed that a toxicity balance around the whole process is important for combined chemical/biological treatment. It is not sufficient to assess the effect of ozonation alone (cf. chapter A 1). 

For mixed culture microorganisms used for biological treatment of waste water, the general range of values used are BOD 1.43 X BOD5 Approximately 1.4-1.5 kg Oj/kg BOD5. 

Precisely the same fate can be seen in neighboring area, the biological treatment of waste water and solid wastes (Fig. 1.1). The pressure of environmental problems has grown so great that here too the methods of thinking that have been successfully used in conventional biotechnical processes are being applied. One can now speak of the biotechnology of waste water treatment. 

M. A Winkler, Biological Treatment of Waste-Water, Ellis Howard, Ltd., New York, 1981, Chap. 7. 

An understanding of the nature of the physical, chemical, and biological characteristics of waste water is essential in the design and operation of collection, treatment, and disposal facilities, and in the engineering management of environmental quality. 

BAC is also a known medium fiir of removal TOC from waste waters. As reported [120], BAC employed for treatment of waste waters from wood treatment plants, after 64 bed volumes was able to reduce TOC ty at least 80% or 50% at TOC content in influent 320 mg dm or 900 mg dm" , respectively. Improved uptaking of perchlorates and metals by biological carbon filters was also reported [121-122] and the efficiency of BAC filters was recognized as dependent on the inlet contaminants concentrations [123]. Removal of dyes in the BAC process was recognized [112] as more effective than a combination of individual carbon adsorption and biological processes (Table 8). 

Waste disposal Assure that the plan for each laboratory operation includes plans and training for waste disposal (230). Deposit chemical waste in appropriately labeled receptacles and follow all other waste disposal procedures of the Chemical Hygiene Plan (22, 24). Do not discharge to the sewer concentrated acids or bases (231) highly toxic, malodorous, or lachrymatory substances (231) or any substances which might interfere with the biological activity of waste water treatment plants, create fire or explosion hazards, cause structural damage or obstruct flow (242). 

Several biological and chemical methods such as filtration, coagulation, oxidation, and ion-exchange have been used for the treatment of waste water, but the continuing increase in the variety and amount of hazardous chemicals present in our lakes rivers and sometimes ground water reserves make these conventional methods inefficient and sometimes even ineffective. Consequently, the development of new and more effective technologies becomes essential. Many laboratory tests and field... 

Cold-pressed essential oils from the peel are some of the most important by-products recovered during the processing of Citrus fruits. The presence of limonene in the aqueous discharges, with its antimicrobial activity [1], decreases the effectiveness of the waste treatment system and increases the time necessary for the biological breakdown of the organic matter produced in the peel oil recovery system [2,3]. Additional recovery of essential oils from waste water would increase industry s returns and reduce the pollution problems associated with the disposal of waste water [4,5]. Several methods for reducing the levels of residual essential oils in the aqueous effluent have been developed over the years [6-11]. 

Dague, R.R. (1972), Fundamentals of odor control, J. Water Poll. Control Fed., 44, 583—595. Dobbins, W.E. (1956), The nature of the oxygen transfer coefficient in aeration systems. In B. J. McCabe and W. W. Eckenfelder Jr. (eds.), Section 2.1 of Biological Treatment of Sewage and Industrial Wastes, Reinhold Publishing Corp., New York, pp. 141-148. 

Mudder TI, Whitlock JL. 1984. Biological treatment of cyanidation waste waters. Miner Metallurg Proc, Aug, pp. 161-165. 

Selivanovskaya, S.Yu. Maslov, A.P. Naumova, R.P. Toxicological testing of waste water subjected to biological treatment by means of ciliate infusoria. Chem. Technol. Water 1993, 15, 286-290 (in Russian). 

Olive WE Jr., Cobb HD, Atherton RM. 1976. biological treatment of cresylic acid laden waste water. In Sharpley JM, Kaplan AM, eds. Proceedings of the 3rd International Biodegradation Symposium, Barking, England. Appl Sci 381,388. 

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