scholarly journals Removal and Survival of Fecal Indicators in a Constructed Wetland after UASB Pre-Treatment

2021 ◽  
Vol 13 (16) ◽  
pp. 9302
Author(s):  
Fabio Conti ◽  
Elena Cristina Rada ◽  
Paolo Viotti ◽  
Massimo Raboni
Keyword(s):  
Removal Efficiency ◽  
Fecal Coliforms ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Experimental Plant ◽  
Fecal Indicators ◽  
Increased Risk ◽  
North Brazil ◽  
Pre Treatment

The experimentation plant, based on a sub-surface horizontal flow phytodepuration (SSHFP) unit with a pre-treatment by an upflow anaerobic sludge blanket (UASB) reactor, proved valuable in treating the sewage of a small rural community located in north Brazil. During a six-month trial, the plant achieved an average removal efficiency of 98.2% (1.74 log removal) for fecal coliforms (FC) and 96.0% (1.40 log removal) for Enterococci (EN), as well as 95.6% for BOD5, 91.0% for COD,00 and 95.4% for suspended solids (SS). The contribution of the UASB reactor to this overall performance was very significant as, alone, it achieved a yield of 62.7% for FC and 60% for EN, in addition to 65.2% for BOD5 and 65.0% for SS. EN was chosen, in addition to FC, because of its higher specificity and strong environmental persistence, leading to an increased risk to human health. In fact, the experimental results confirmed its lower removal efficiency compared to FC. The mechanical and biological mechanisms that led to such a removal efficiency of the two fecal indicators (FIs) are outlined in the article. The same mechanisms led to a good level of equivalence between the removal efficiency of the two FIs with the removal efficiency of SS and BOD5, for both the whole plant and the UASB reactor alone. The research demonstrated the close correlation between the concentrations of EN and FC for the plant effluent. This correlation can be explained by the following mathematical expression of the regression line Log EN = 0.2571 Log FC + 3.5301, with a coefficient of determination R2 = 0.912. This implies that the concentration of the more specific indicator EN could be calculated, with acceptable approximation, from the simple analysis of FC and vice versa. The experimental plant brought important health benefits to the local population. In particular, there were no significant odor emissions; moreover, the risk of fecal pathogenic diseases was drastically reduced; finally, there was no proliferation of insects and other disease vectors, due to the absence of stagnant or semi-stagnant water exposed to the atmosphere.

Degradation of xenobiotic substances using sulfate-reducing bacteria in a UASB reactor

2004 ◽  
Vol 48 (11-12) ◽  
pp. 227-234 ◽  
Author(s):  
S. Tsuneda ◽  
T. Shiono ◽  
K. Nakamura ◽  
T. Dogan ◽  
A. Hirata
Keyword(s):  
Removal Efficiency ◽  
Yeast Extract ◽  
Sulfate Reducing Bacteria ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Ozone Treatment ◽  
Anaerobic Sludge ◽  
Equivalent Diameter ◽  
Sulfate Reducing ◽  
Reducing Bacteria

An upflow anaerobic sludge blanket (UASB) reactor was successfully applied to continuous degradation of ferric ethylene diamine tetraacetate (Fe-EDTA) as a typical xenobiotic substance contained in photo-processing wastewater. The sludge in the UASB reactor had an abundance of sulfate-reducing bacteria (SRB), which had been anaerobically cultivated in a sulfate-rich culture medium including Fe-EDTA and yeast-extract as the carbon sources. Since the prominent reductions of Fe-EDTA and sulfate ion were observed, the contribution of SRB to Fe-EDTA degradation in the UASB reactor was confirmed. The aggregated sludge in the UASB reactor became gradually large reaching steady state with an equivalent diameter of 60-90 μm after 124 days operation. An increase of the amount of yeast extract addition to feed solution improved the Fe-EDTA removal efficiency up to 90%. Moreover, the combination of ozone treatment with SRB treatment further improved removal efficiency of total organic carbon (TOC) in an actual photo-processing wastewater composed of fixing and developing wastes.

scholarly journals Black water treatment by an upflow anaerobic sludge blanket (UASB) reactor: a pilot study

2019 ◽  
Vol 80 (8) ◽  
pp. 1505-1511 ◽  
Author(s):  
Nathalie Dyane Miranda Slompo ◽  
Larissa Quartaroli ◽  
Grietje Zeeman ◽  
Gustavo Henrique Ribeiro da Silva ◽  
Luiz Antonio Daniel
Keyword(s):  
Removal Efficiency ◽  
Phase 1 ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Phase 3 ◽  
Black Water ◽  
Anaerobic Sludge Blanket

Abstract Decentralized sanitary wastewater treatment has become a viable and sustainable alternative, especially for developing countries and small communities. Besides, effluents may present variations in chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total nitrogen values. This study describes the feasibility of using a pilot upflow anaerobic sludge blanket (UASB) reactor to treat wastewater with different organic loads (COD), using black water (BW) and sanitary wastewater, in addition to its potential for preserving nutrients for later recovery and/or reuse. The UASB reactor was operated continuously for 95 weeks, with a hydraulic retention time of 3 days. In Phase 1, the reactor treated simulated BW and achieved 77% CODtotal removal. In Phase 2, treating only sanitary wastewater, the CODtotal removal efficiency was 60%. Phase 3 treated simulated BW again, and CODtotal removal efficiency was somewhat higher than in Phase 1, reaching 81%. In Phase 3, the removal of pathogens was also evaluated: the efficiency was 1.96 log for Escherichia coli and 2.13 log for total coliforms. The UASB reactor was able to withstand large variations in the organic loading rate (0.09–1.49 kg COD m−3 d−1), in continuous operation mode, maintaining a stable organic matter removal.

Thermophilic Anaerobic Treatment of Sulfate-Rich Pulp and Paper Integrate Process Water

1991 ◽  
Vol 24 (3-4) ◽  
pp. 149-160 ◽  
Author(s):  
J. Rintala ◽  
J. L. Sanz Martin ◽  
G. Lettinga
Keyword(s):  
Sulfate Reduction ◽  
Removal Efficiency ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Process Water ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Uasb Reactors

Anaerobic treatment of sulfate - rich (COD/SO4 ratio 1.4-2.1) clarified Whitewater from a thermomechanical pulping (TMP) process was studied in three laboratory-scale upflow anaerobic sludge blanket (UASB) reactors at 55°C and in batch digesters at 55° and 65°C. Different seed materials were used in the UASB reactors. The highest COD removal efficiency (effluent sulfide stripped) achieved was approximately 65 % in the UASB reactors. About 55 % COD removal efficiency was obtained at a loading rate of about 41 kgCODm−3d−1 in the UASB reactor seeded with thermophilic sludge cultivated with volatile fatty acids (VFAs). The total sulfide present in the liquid phase after anaerobic treatment accounted for approximately 65-78 % and 15-61 % of the removed COD in the batch digesters and the UASB reactors, respectively. Sulfate reduction was almost complete in the batch digesters, whereas about 24-64 % of sulfate was reduced in the UASB reactors. Acetate utilization for sulfate reduction was apparent in the batch digesters, whereas that could not be demonstrated in the UASB reactors. Sulfate reduction in the UASB reactors was obviously substrate limited. In conclusion, thermophilic anaerobic treatment is an alternative for the treatment of warm sulfate rich TMP process water.

Impact of ozone pre-treatment on the performance of upflow anaerobic sludge blanket treating pre-treated grain distillery wastewater

2014 ◽  
Vol 70 (10) ◽  
pp. 1702-1708 ◽  
Author(s):  
L. Robertson ◽  
T. J. Britz ◽  
G. O. Sigge
Keyword(s):  
Unsaturated Fatty Acids ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reactor Performance ◽  
Distillery Wastewater ◽  
Pre Treatment ◽  
Anaerobic Sludge Blanket ◽  
Performance Results

Two 2 L laboratory-scale upflow anaerobic sludge blanket (UASB) reactors were operated for 277 days. The substrate of the control reactor (Rc) contained grain distillery wastewater (GDWW) that had undergone coagulant pre-treatment, and the substrate of the second UASB reactor consisted of GDWW that had undergone coagulant pre-treatment and ozone pre-treatment (Ro). Both reactors treated pre-treated GDWW successfully at ca. 9 kgCOD m−3 d−1. Chemical oxygen demand (COD) reductions of ca. 96% for Rc and 93% for Ro were achieved. Fats, oils and grease (FOG) reductions (%) showed variations throughout the study, and reductions of ca. 88 and 92% were achieved for Rc and Ro, respectively. Rc produced more biogas, and the methane percentage was similar in both reactors. UASB granule washout in Rc suggested possible toxicity of unsaturated fatty acids present in non-ozonated substrate. The feasibility of FOG removal was demonstrated as both reactors successfully treated pre-treated GDWW. Better results were obtained for Ro effluent during post-ozonation. The ozone pre-treatment possibly led to easier degradable wastewater, and better results could potentially be obtained when other post-treatment steps are applied. Ozone pre-treatment did not, however, show an added benefit in the reactor performance results.

Treatment of hazardous landfill leachate using Fenton process followed by a combined (UASB/DHS) system

2015 ◽  
Vol 73 (7) ◽  
pp. 1700-1708 ◽  
Author(s):  
Sherif Ismail ◽  
Ahmed Tawfik
Keyword(s):  
Catalytic Oxidation ◽  
Removal Efficiency ◽  
Landfill Leachate ◽  
Oxidation Process ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Combined Processes ◽  
Fenton Process ◽  
Removal Efficiencies ◽  
Pre Treatment

Fenton process for pre-treatment of hazardous landfill leachate (HLL) was investigated. Total, particulate and soluble chemical oxygen demand (CODt, CODp and CODs) removal efficiency amounted to 67%, 47% and 64%, respectively, at pH value of 3.5, molar ratio (H2O2/Fe2+) of 5, H2O2 dosage of 25 ml/L and contact time of 15 min. Various treatment scenarios were attempted and focused on studying the effect of pre-catalytic oxidation process on the performance of up-flow anaerobic sludge blanket (UASB), UASB/down-flow hanging sponge (DHS) and DHS system. The results obtained indicated that pre-catalytic oxidation process improved the CODt removal efficiency in the UASB reactor by a value of 51.4%. Overall removal efficiencies of CODt, CODs and CODp were 80 ± 6%, 80 ± 7% and 78 ± 16% for UASB/DHS treating pre-catalytic oxidation effluent, respectively. The removal efficiencies of CODt, CODs and CODp were, respectively, decreased to 54 ± 2%, 49 ± 2% and 71 ± 16% for UASB/DHS system without pre-treatment. However, the results for the combined process (UASB/DHS) system is almost similar to those obtained for UASB reactor treating pre-catalytic oxidation effluent. The DHS system achieved average removal efficiencies of 52 ± 4% for CODt, 51 ± 4% for CODs and 52 ± 15% for CODp. A higher COD fractions removal was obtained when HLL was pre-treated by Fenton reagent. The combined processes provided a removal efficiency of 85 ± 1% for CODt, 85 ± 1% for CODs and 83 ± 8% for CODp. The DHS system is not only effective for organics degradation but also for ammonia oxidation. Almost complete ammonia (NH4-N) removal (92 ± 3.6%) was occurred and the nitrate production amounted to 37 ± 6 mg/L in the treated effluent. This study strongly recommends applying Fenton process followed by DHS system for treatment of HLL.

Removal of indigenous coliphages and fecal coliforms by a novel sewage treatment system consisting of UASB and DHS units

2002 ◽  
Vol 46 (11-12) ◽  
pp. 303-309 ◽  
Author(s):  
S. Uemura ◽  
K. Takahashi ◽  
A. Takaishi ◽  
I. Machdar ◽  
A. Ohashi ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Sewage Treatment ◽  
Treatment System ◽  
Fecal Coliforms ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Combined System ◽  
Treatment Unit ◽  
Indicator Microorganisms ◽  
Sewage Treatment System

A novel sewage treatment system, which consists of an upflow anaerobic sludge blanket (UASB) pre-treatment unit and the following downflow hanging sponge (DHS) unit for polishing up the UASB effluent, was developed as a cost-effective and easy-maintenance sewage treatment system for developing countries. A long-term experiment with actual sewage was conducted in order to evaluate its treatment efficiency of organic substances, nutrients, and pathogen indicator microorganisms such as total coliphages, F+-specific RNA coliphages (RNA coliphages), and fecal coliforms. The main objective of this paper is to investigate the removal efficiency of those indicator microorganisms by the UASB-DHS combined system. The results obtained from the continuous flow experiment indicated a fairly promising removal of the indicator microorganisms, i.e., the log10 reductions of total coliphages, RNA coliphages, and fecal coliforms (based on sewage and DHS effluent) achieved were 2.01 log, 2.02 log, and 2.57 log, respectively. The UASB-DHS combined system was superior to the conventional activated sludge process in the reduction of fecal coliforms, but in the reductions of total and RNA coliphages, the system showed somewhat less removal efficiency. The vertical reducing patterns of the indicator microorganisms along the DHS reactor were also discussed.

Inhibition of methanogenic activity of starch-degrading granules by aromatic pollutants

1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung
Keyword(s):  
Chemical Industry ◽  
Functional Group ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Aromatic Pollutants ◽  
Methanogenic Activity ◽  
Phenolic Pollutants ◽  
Ic50 Values

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

scholarly journals Microbial Removal of Pb(II) Using an Upflow Anaerobic Sludge Blanket (UASB) Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 512
Author(s):  
Jeremiah Chimhundi ◽  
Carla Hörstmann ◽  
Evans M. N. Chirwa ◽  
Hendrik G. Brink
Keyword(s):  
Treatment Process ◽  
Removal Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Anaerobic Sludge Blanket ◽  
Microbial Removal ◽  
Maximum Removal

The main objective of this study was to achieve the continuous biorecovery and bioreduction of Pb(II) using an industrially obtained consortia as a biocatalyst. An upflow anaerobic sludge blanket reactor was used in the treatment process. The bioremediation technique that was applied made use of a yeast extract as the microbial substrate and Pb(NO3)2 as the source of Pb(II). The UASB reactor exhibited removal efficiencies of between 90 and 100% for the inlet Pb concentrations from 80 to 2000 ppm and a maximum removal rate of 1948.4 mg/(L·d) was measured. XRD and XPS analyses of the precipitate revealed the presence of Pb0, PbO, PbS and PbSO4. Supporting experimental work carried out included growth measurements, pH, oxidation–reduction potentials and nitrate levels.

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