Investigation into the mechanism and kinetic of bod reduction due to pressurization

Document Type

Conference Proceeding

Publication Date

12-1-1982

Abstract

Investigations concerning the application of pressure to domestic sewage and simulated sewage samples have demonstrated a decrease in the rate of biochemical assimilation of the organic matter. Also, BOD and COD values after pressurization were approximately 75 of the unpressurized samples. This suggested a change in the biochemical composition of the wastes being pressurized. A pilot plant pressure chamber was constructed where presures to 40 psi could be maintained by compressed air. Raw wastes were pressurized, aerated, and left quiescent and the BOD, COD, and microorganisms were monitored. The waste content of the pressurized samples showed greater reductions whereas the aerated and quiescent samples displayed similar changes. An investigation was made to show that the reductions which occured were due to an increased rate of hydrolysis of the large molecular weight organic fractions to their smaller counterparts. Polysaccharides, fats, and proteins were pressurized, hydrolyzed, and analyzed to their monosacchatides, fatty acids, and amino acids. In all cases the larger compounds showed an increased rate of hydrolysis due to pressure. As has been shown in the literature the decomposition constant, k 1, is proportional to the organic matter present. This is reasonable if the rate constant is assumed to be kinetically first order. As the time of exposure to pressure is increased the BOD and COD values also decrease as does the BOD rate constant which supports the argument that pressurization increased the rate of hydrolysis.

Identifier

77957000721 (Scopus)

Publication Title

Studies in Environmental Science

External Full Text Location

https://doi.org/10.1016/S0166-1116(08)71172-5

ISSN

01661116

First Page

239

Last Page

255

Issue

C

Volume

19

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