Performance and microbial community analysis of a pilot-scale UASB for corn-ethanol wastewater treatment

Abstract

The performance and microbial community structure of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor inoculated with flocculent sludge were investigated over 52 days. The characteristics of corn-ethanol wastewater were as follows: CODCr, 1,050-4,970 mg l(-1); ammonia, 14-298 mg l(-1); and alkalinity, 332-2,867 mg l(-1). The UASB could start up smoothly with a hydraulic loading rate lower than 180 l h(-1) and a ratio of volatile fatty acid versus alkalinity between 0.04 and 0.48. The maximum gas production rate was 432 l h(-1) and the highest volumetric loading rate of 7.2 kg m(-3) day(-1) was obtained after 48 days. The 1 mm granules could form a complex network and were composed of many Methanosaeta. Aceticlastic methanogens served as a dominant methanogenic group, which accounted for the relatively high resistance to shock loading.

Advanced treatment of biologically pretreated coal gasification wastewater using a novel expansive flow biological intermittent aerated filter process with a ceramic filler from reused coal fly ash

“…Meanwhile, Firmicutes were dominant in the treatment of municipal solid waste under anaerobic and microaerobic conditions. 23 Particularly, the core genus Thermomonas was the typical denitrifying bacteria under the anoxic conditions, and the relative abundance reached 5.57% which was related to reduction of TN. The core genus Methylococcus, with a 3.28% relative abundance, indicated that a micro anaerobic environment had been formed in the biolm on the carriers.…”

Simultaneous removal of sulfur and nitrogen compounds with methane production from concentrated latex wastewater in two bioreactor zones of micro‐oxygen hybrid reactor

“…These processes are responsible for various groups of microorganisms which require different conditions to support their growth and activities. Therefore several treatment units are applied, resulting in increased capital and operational costs …”

“…Apart from the aforementioned DO parameter, a COD/SO 4 2− ratio of 3:2 achieved 100% sulfate and nitrate removal efficiencies with a granule formation consisting of SRB and DNB communities . The optimal S 2− /NO 3 − ratio was found to be 5:6 for S 0 recovery with 100% NO 3 − and acetate removal efficiencies during the denitrifying sulfide removal process . Reyes‐Avila et al .…”

“…Therefore several treatment units are applied, resulting in increased capital and operational costs. 5 Simultaneous biological sulfur and nitrogen compounds have recently been developed and studied at optimal bioreactor operating conditions depending on several factors, including dissolved oxygen (DO), chemical oxygen demand (COD)/SO 4 2− ratio, S 2− /NO 3 − ratio, etc., for generating high removal efficiencies coupled with favorable products (S 0 , N 2 ). Controlled operational conditions are mandatory to prevent serious problems such as competition between microorganisms for substrates and formation of toxic compounds (HS − , NH 4 + , NO 2 − ) leading to breakdown of the treatment process.…”

“…9 The optimal S 2− /NO 3 − ratio was found to be 5:6 for S 0 recovery with 100% NO 3 − and acetate removal efficiencies during the denitrifying sulfide removal process. 5 Reyes-Avila et al 10 reported that carbon and nitrogen compounds were simultaneously utilized with carbon and sulfide removal efficiencies of 90 and 69% respectively in an anaerobic continuous stirred tank reactor (CSTR) fed at loading rates of 0.29 g C L −1 day −1 of acetate, 0.20 g N L −1 day −1 of nitrate and 0.294 g S L −1 day −1 of sulfide. Chen et al 11 investigated the simultaneous removal of sulfide, nitrate and organic carbon at loading rates of 4.8 g S L −1 day −1 of sulfide, 2.6 g N L −1 day −1 of nitrate and 2.7 g C L −1 day −1 of acetate, generating removal efficiencies of 97, 92 and 95% respectively in an expanded granular sludge bed (EGSB) reactor.…”