摘要:

ABSTRACT:
The City of Los Angeles' Hyperion Treatment Plant is a 16.6 m3/s (380 mgd) municipal wastewater treatment plant with 8.8 m3/s (200 mgd) secondary treatment capacity. Digested sludge, mechanically dewatered by centrifuge, is stored as 20% solids wet cake in large storage bins. Previous studies identified the primary odorous constituents as dimethyl disulfide, dimethyl sulfide, and methyl mercaptan. Earlier pilot tests conducted at the plant indicated that activated carbon and dual‐media adsorption were not cost‐effective technologies for controlling the emission of odors, regulated volatile organic compounds (VOCs), and reactive organic gases (ROGs). An additional pilot test was therefore conducted to test multistage packed towers and various combinations of treatment chemicals. Scrubbing solutions tested included water, effluent, water with surfactants, sodium hypochlorite, sodium hydroxide, sulfuric acid, hydrogen peroxide, proprietary chemicals, and, as a polishing step, activated carbon.
Chemical combinations were screened for effectiveness in a preliminary test phase using hand‐held instruments, gas chromatography, and dynamic olfactometry. Based on the results of these trials, more extensive testing was conducted. Analyses included gas chromatography–flame photometric detection (GC–FPD) for reduced sulfur compounds, and gas chromatography–mass spectrometry (GC–MS) for volatile organics. Two methods were used for reactive organics analyses. Total combustion analysis–flame‐ionization detection (TCA–FID), specified by the local regulatory agency was used, as well as nonmethane hydrocarbon approximations using GC.
Results were encouraging for controlling wet cake storage odors with wet scrubbing. Removal efficiencies of up to 97% were encountered using a caustic/bleach scrubbing solution. The greatest ROG removal achieved was 89% using acid/bleach and peroxide. VOC removal, however, was poor for most combinations. VOC removal efficiencies ranging from 68 to 81% were recorded when carbon was used as a polishing step. The majority of removal occurred within the carbon stage, however, and not within the packed towers.
It is expected that odors and ROGs can be controlled to acceptable levels using this multistage wet scrubbing approach. Additional studies are required to determine whether ROGs are oxidized or simply dissolved in the scrubbing liquid. Removal of VOCs was not encouraging and optimization of VOC removal needs to be investigated further.

ISSN:1061-4303    

DOI:10.2175/WER.65.1.9

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

摘要:

ABSTRACT:
AJanthinobacteriumsp. and aRhodococcussp., both capable of mineralizing 2,4–dinitrophenol (DNP), were used as inoculum for activated sludge in bench‐scale sequencing batch reactors (SBRs). Degradation of 10 mg/L of DNP in these SBRs was enhanced to varying degrees by the addition of glucose at concentrations of 50, 100, and 500 mg/L. Addition of 10 mg of glucose/L had no effect, while 1000 mg of glucose/L inhibited DNP degradation. Maximal degradation, based on the rate of DNP degradation per unit of glucose added, was obtained at a glucose concentration of 100 mg/L. A Michaelis‐Menten type saturation rate model was successfully used to model DNP degradation kinetics in the SBRs; comparison of model parameters then allowed us to determine the effect of glucose addition. Also, it was found that the added glucose was associated with an increase in the standing biomass of DNP‐degrading bacteria, probably because of greater retention of this population in the activated sludge. This research demonstrates the usefulness of supplemental carbon substrates for enhancing the degradation of toxic chemicals in bioreactors containing heterogeneous microbial communities.

ISSN:1061-4303    

DOI:10.2175/WER.65.1.10

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.11

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.12

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.13

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.14

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.15

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.16

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY

ISSN:1061-4303    

DOI:10.2175/WER.65.1.19

出版商:Water Environment Research Foundation (WERF)    

年代:1993

数据来源: WILEY