Five-day biochemical oxygen demand

BOD Bochemical oxygen demand BOD5 Five-day biochemical oxygen demand COD Chemical oxygen demand CSTR Completely stirred tank reactor DDT Dichloro diphenyl trichloroethane DNA Deoxyribonucleic acid... 

Table I shows the five-day biochemical oxygen demand (BOD5 ) of some poly(sodium carboxylate)s and poly(vinyl alcohoDs (PVA). The BOD5 test according to JIS K 0102 is only an indication of susceptibility of products to biodegradation, but the test is often an useful tool for rapid screening. As shown in Table I, PMLA and...

Table I. Five-day biochemical oxygen demand (BODs) by oxygen consumption method (Japanese Industrial Standard, JIS K 0102)...

In this equation, if the incubation period is five days, the BOD is called the five-day biochemical oxygen demand, BOD5. It is understood that unless it is specified, BOD5 is a BOD measured at the standard temperature of incubation of 20°C. If incubation is done for a long period of time such as 20 to 30 days, it is assumed that all the BOD has been exerted. The BOD under this situation is the ultimate therefore, it is called ultimate BOD, or BOD . 

Kumaresan et al. [96] studied the apphcabihty of ELMs in the treatment of distillery wastewater. These types of wastewaters are generally toxic to microflora, because of the high content of several phenohc compounds [93]. The optimum ELM composition was as follows (v/v) 4% of xylene, 10% of CRESLOX, and 85% of hquid paraffin, while the optimum ELM/ treated wastewater ratio was 0.8. At this ratio, the chemical oxygen demand (COD) of the distillery wastewater was reduced from 6800 mg dm in the feed solution to the final effluent concentration of 927 mg dnrf At the same time, the five-day biochemical oxygen demand (BOD5) decreased from 3500 to 96.5 mg dm The recovery of acetic acid was 44.2%. These results indicate that ELMs can be quite effective in the reduction of the pollution of distillery wastewaters. 

Experiments in aquaria containing 4 inches of lake sediment were conducted to determine rate of oxygen consumption by the benthic load. These experiments indicated that the five-day biochemical oxygen demand (BOD5) of the sediment would be satisfied in 350 to 450 days. This slow rate of biodegradation indicates anaerobic decomposition and the presence of a reducing environment. 

Biochemical oxygen demand (BOD)- Amount of dissolved oxygen consumed in five days by biological processes breaking down organic matter. 

The Biochemical Oxygen Demand (BOD) is an important parameter for waste-water monitoring. It gives information about the biodegradable organic pollution in wastewater. The main disadvantage of the conventional BOD-method is the required extended investigation time, which for example takes five days for... 

Also the traditional BOD5 tests (e.g. the EU C.5 test) may demonstrate whether a substance is readily biodegradable. In this test, the relative biochemical oxygen demand in a period of 5 days is compared to the theoretical oxygen demand (ThOD) or, when this is not available, the chemical oxygen demand (COD). The test is completed within five days and consequently, the pass level defined in the proposed hazard classification criteria at 50% is lower than in the ready biodegradability tests. 

Biochemical oxygen demand is calculated by keeping a sample of water containing a known amount of oxygen for five days at 20 °C in the dark. The oxv-gen content is measured again after this time. 

Biochemical Oxygen Demand at Five Days (BODg)... 

---