Affiliations: School of Municipal & Environmental Engineering,
Harbin Institute of Technology, Harbin 150090, China | College of Environmental & Energy Engineering,
Beijing University of Technology, Beijing 100022, China
Abstract: On the basis of continuous tests and batch tests, conversion regular
patterns of acetate, propionate and butyrate in activated sludge at different
heights of the UASB reactor were conducted. Results indicated that the
conversion capacity of the microbial is decided by the substrate characteristic
when sole VFA is used as the only substrate. But when mixed substrates are
used,the conversion regulations would have changed accordingly. Relationships
of different substrates vary according to their locations. In the whole
reactor, propionate's conversion is restrained by acetate and butyrate of high
concentration. On the top and at the bottom of the reactor, conversion of
acetate, but butyrate, is restrained by propionate. And in the midst, acetate's
conversion is accelerated by propionate while that of butyrate is restrained.
It is proved, based on the analysis of specific conversion rate, that the space
distribution of the microbe is the main factor that affects substrates'
conversion. The ethanol-type fermentation of the acidogenic-phase is the
optimal acid-type fermentation for the two-phase anaerobic process.
Keywords: conversion regular pattern, VFAs, specific conversion rate, UASB reactor
