Effect of sulfate on anaerobic processes fed with dual substrates

1995 ◽  
Vol 31 (9) ◽  
pp. 101-107 ◽  
Author(s):  
Chongchin Polprasert ◽  
Charles N. Haas
Keyword(s):  
Acetic Acid ◽  
Sulfate Reduction ◽  
Mixed Culture ◽  
Biogas Production ◽  
Cod Removal ◽  
Methane Formation ◽  
Batch Mode ◽  
Sulfate Reducing ◽  
Anaerobic Reactors ◽  
Optimal Feed

Anaerobic reactors were operated in a semi-batch mode and fed with the dual substrates glucose (G) plus acetic acid (Ac) as primary organic sources to study the effect of sulfate on COD oxidation. With glucose, COD removal by methane formation was seriously inhibited, resulting in COD accumulation in the reactor. Although acetic acid can be consumed by some sulfate-reducing species, it was not a major substrate for sulfate reduction, but was largely responsible for methane formation in the anaerobic mixed culture used in this study. With dual substrates, extreme inhibition of methanogenesis did not occur as did with glucose alone. Instead, methanogens were found to work in harmony with acid formers as well as sulfate reducers to oxidise COD. Interestingly, from 12-hour monitoring, increased G/Ac COD ratios decreased COD removal rates as well as biogas production, but resulted in higher sulfate reduction. This suggests that there should be an optimal feed G/Ac COD ratio, for which removal of both organics could be maximised.

scholarly journals Treatment of acidic wastewater from thien ke tin processing factory by sulfate reducing bioreactor: a pilot scale study

2018 ◽  
Vol 14 (4) ◽  
pp. 777-784
Author(s):  
Nguyen Thi Hai ◽  
Dinh Thuy Hang
Keyword(s):  
Sulfate Reduction ◽  
Mixed Culture ◽  
Pilot Scale ◽  
Contaminant Removal ◽  
Batch Mode ◽  
Sulfate Reducing ◽  
High Metal Content ◽  
Hydraulic Load ◽  
Sulfate Reducing Bioreactor ◽  
Acidic Wastewater

A pilot-scale system of a total volume of 6 m3 using sulfate reducing (SR) bioreactor technology was established for the treatment of acidic wastewater from Thien Ke tin processing factory in Tuyen Quang province, Vietnam. In the system, the acidic wastewater with high metal content went first to a collecting tank filled with limestone gravels to increase pH to a value favorable for SRB growth, and at the second step to a SR bioreactor where sulfate reduction occurred to produce sulfide for metal precipitation. To activate the SR bioreactor, a laboratory SRB mixed culture dominated by Desufovibiro, Desulfobulbus and Desulfomicrobium species was added at a cell density of 106 cell/ml so that a full activation was achieved just after a week of incubation. Molasses was added to the SR bioreactor at 0.5 ml/L as substrate for the SRB growth during the operation. The performance of the system was studied under batch and continuous modes. The batch mode showed good results after three day-operation. The pH increased from 2.8 – 3.2 to 7 – 7.2, and a total of 750 mg/L sulfate was reduced to sulfide presumably by the SRB. The produced sulfide efficiently removed metals from the wastewater, such as iron from 143.1 mg/L to 0.3 mg/L, copper from 16.32 mg/L to 0.04 mg/L and manganese from 10.9 mg/L to 0.05 mg/L. The continuous mode with a hydraulic load of 100 l/h and an according retention time of three days showed constitutive contaminant removal. The effluent pH of the system was around 7 within six-day period. The sulfate reduction was active, keeping sulfate concentration in the final effluent as low as  150 mg/L. Accordingly, the three most metal contaminants (iron, copper and manganese) were found at concentrations below the regulated limits. The results showed the possibility of applying SR bioreactor technology for the treatment of AMD is feasible and the use of previously enriched mixed culture of SRB could be a good approach to shorten the activation period of the SR bioreactor.

scholarly journals Modeling Reduction of Uranium U(VI) under Variable Sulfate Concentrations by Sulfate-Reducing Bacteria

2000 ◽  
Vol 66 (9) ◽  
pp. 3711-3721 ◽  
Author(s):  
John R. Spear ◽  
Linda A. Figueroa ◽  
Bruce D. Honeyman
Keyword(s):  
Sulfate Reduction ◽  
Mixed Culture ◽  
Pure Culture ◽  
Dry Weight ◽  
Sulfate Reducing Bacteria ◽  
Lag Time ◽  
Zero Order ◽  
Uranium Reduction ◽  
Sulfate Reducing ◽  
Reducing Bacteria

ABSTRACT The kinetics for the reduction of sulfate alone and for concurrent uranium [U(VI)] and sulfate reduction, by mixed and pure cultures of sulfate-reducing bacteria (SRB) at 21 � 3�C were studied. The mixed culture contained the SRB Desulfovibrio vulgarisalong with a Clostridium sp. determined via 16S ribosomal DNA analysis. The pure culture was Desulfovibrio desulfuricans (ATCC 7757). A zero-order model best fit the data for the reduction of sulfate from 0.1 to 10 mM. A lag time occurred below cell concentrations of 0.1 mg (dry weight) of cells/ml. For the mixed culture, average values for the maximum specific reaction rate,V max, ranged from 2.4 � 0.2 μmol of sulfate/mg (dry weight) of SRB � h−1) at 0.25 mM sulfate to 5.0 � 1.1 μmol of sulfate/mg (dry weight) of SRB � h−1 at 10 mM sulfate (average cell concentration, 0.52 mg [dry weight]/ml). For the pure culture,V max was 1.6 � 0.2 μmol of sulfate/mg (dry weight) of SRB � h−1 at 1 mM sulfate (0.29 mg [dry weight] of cells/ml). When both electron acceptors were present, sulfate reduction remained zero order for both cultures, while uranium reduction was first order, with rate constants of 0.071 � 0.003 mg (dry weight) of cells/ml � min−1 for the mixed culture and 0.137 � 0.016 mg (dry weight) of cells/ml � min−1 (U0 = 1 mM) for the D. desulfuricans culture. Both cultures exhibited a faster rate of uranium reduction in the presence of sulfate and no lag time until the onset of U reduction in contrast to U alone. This kinetics information can be used to design an SRB-dominated biotreatment scheme for the removal of U(VI) from an aqueous source.

BIOGAS PRODUCTION IN THE CONCENTRATED DISTILLERY WASTEWATER TREATMENT

2018 ◽  
pp. 51-59 ◽  
Author(s):  
N. Golub ◽  
M. Potapova ◽  
M. Shinkarchuk ◽  
O. Kozlovets
Keyword(s):  
Wastewater Treatment ◽  
Dry Matter ◽  
Ph Value ◽  
Biogas Production ◽  
Anaerobic Sludge ◽  
Methane Formation ◽  
Maximum Output ◽  
Processing Technologies ◽  
Spent Wash ◽  
Distillery Spent Wash

The paper deals with the waste disposal problem of the alcohol industry caused by the widespread use of alcohol as biofuels. In the technology for the production of alcohol from cereal crops, a distillery spent wash (DSW) is formed (per 1 dm3 of alcohol – 10–20 dm3 DSW), which refers to highly concentrated wastewater, the COD value reaches 40 g O2/dm3. Since the existing physical and chemical methods of its processing are not cost-effective, the researchers develop the processing technologies for its utilization, for example, an anaerobic digestion. Apart from the purification of highly concentrated wastewater, the advantage of this method is the production of biogas and highquality fertilizer. The problems of biotechnology for biogas production from the distillery spent wash are its high acidity–pH 3.7–5.0 (the optimum pH value for the methanogenesis process is 6.8–7.4) and low nitrogen content, the lack of which inhibits the development of the association of microorganisms. In order to solve these problems, additional raw materials of various origins (chemical compounds, spent anaerobic sludge, waste from livestock farms, etc.) are used. The purpose of this work is to determine the appropriate ratio of the fermentable mixture components: cosubstrate, distillery spent wash and wastewater of the plant for co-fermentation to produce an energy carrier (biogas) and effective wastewater treatment of the distillery. In order to ensure the optimal pH for methanogenesis, poultry manure has been used as a co-substrate. The co-fermentation process of DSW with manure has been carried out at dry matter ratios of 1:1, 1:3, 1:5, 1:7 respectively. It is found that when the concentration of manure in the mixture is insufficient (DSW/manure – 1:1, 1:3), the pH value decreases during fermentation which negatively affects methane formation; when the concentration of manure in the mixture is increased (DSW/manure – 1:5, 1:7), the process is characterized by a high yield of biogas and methane content. The maximum output of biogas with a methane concentration of 70 ± 2% is observed at the ratio of components on a dry matter “wastewater: DSW: manure” – 0,2:1:7 respectively. The COD reduction reaches a 70% when using co-fermentation with the combination of components “wastewater: DSW: manure” (0,3:1:5) respectively.

Trialing wetlands to treat coal mining wastewaters in a low rainfall, high evaporation environment

1997 ◽  
Vol 35 (5) ◽  
pp. 293-299 ◽  
Author(s):  
Wendy R. Tyrrell ◽  
David R. Mulligan ◽  
Lindsay I. Sly ◽  
L. Clive Bell
Keyword(s):  
Sulfate Reduction ◽  
Coal Mining ◽  
Pilot Scale ◽  
Cattle Manure ◽  
Annual Rainfall ◽  
Sulfate Reducing ◽  
Black Precipitate ◽  
Final Treatment ◽  
Reducing Bacteria ◽  
Initial Results

The large number of wetlands treating mining wastewaters around the world have mostly been constructed in temperate environments. Wetlands have yet to be proven in low rainfall, high evaporation environments and such conditions are common in many parts of Australia. BHP Australia Coal is researching whether wetlands have potential in central Queensland to treat coal mining wastewaters. In this region, mean annual rainfall is < 650 mm and evaporation > 2 000 mm. A pilot-scale wetland system has been constructed at an open-cut coal mine. The system comprises six treatment cells, each 125 m long and 10 m wide. The system is described in the paper and some initial results presented. Results over the first fourteen months of operation have shown that although pH has not increased enough to enable reuse or release of the water, sulfate reduction has been observed in parts of the system, as shown by the characteristic black precipitate and smell of hydrogen sulfide emanating from the wetlands. These encouraging signs have led to experiments aimed at identifying the factors limiting sulfate reduction. The first experiment, described herein, included four treatments where straw was overlain by soil and the water level varied, being either at the top of the straw, at the top of the soil, or about 5 cm above the soil. The effect of inoculating with sulfate-reducing bacteria was investigated. Two controls were included, one covered and one open, to enable the effect of evaporation to be determined. The final treatment consisted of combined straw/cattle manure overlain with soil. Results showed that sulfate reduction did occur, as demonstrated by pH increases and lowering of sulfate levels. Mean pH of the water was significantly higher after 19 days; in the controls, pH was < 3.3, whereas in the treatments, pH ranged from 5.4 to 6.7. The best improvement in sulfate levels occurred in the straw/cattle manure treatment.

scholarly journals Pseudodesulfovibrio cashew sp. Nov., a Novel Deep-Sea Sulfate-Reducing Bacterium, Linking Heavy Metal Resistance and Sulfur Cycle

2021 ◽  
Vol 9 (2) ◽  
pp. 429
Author(s):  
Rikuan Zheng ◽  
Shimei Wu ◽  
Chaomin Sun
Keyword(s):  
Heavy Metal ◽  
Sulfate Reduction ◽  
Marine Sediments ◽  
Deep Sea ◽  
Sulfur Cycle ◽  
Metal Sulfides ◽  
Phenotypic Traits ◽  
Dissimilatory Sulfate Reduction ◽  
Metabolic Potential ◽  
Sulfate Reducing

Sulfur cycling is primarily driven by sulfate reduction mediated by sulfate-reducing bacteria (SRB) in marine sediments. The dissimilatory sulfate reduction drives the production of enormous quantities of reduced sulfide and thereby the formation of highly insoluble metal sulfides in marine sediments. Here, a novel sulfate-reducing bacterium designated Pseudodesulfovibrio cashew SRB007 was isolated and purified from the deep-sea cold seep and proposed to represent a novel species in the genus of Pseudodesulfovibrio. A detailed description of the phenotypic traits, phylogenetic status and central metabolisms of strain SRB007 allowed the reconstruction of the metabolic potential and lifestyle of a novel member of deep-sea SRB. Notably, P. cashew SRB007 showed a strong ability to resist and remove different heavy metal ions including Co2+, Ni2+, Cd2+ and Hg2+. The dissimilatory sulfate reduction was demonstrated to contribute to the prominent removal capability of P. cashew SRB007 against different heavy metals via the formation of insoluble metal sulfides.

scholarly journals Influence of the Heating Method on the Efficiency of Biomethane Production from Expired Food Products

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Joanna Kazimierowicz ◽  
Marcin Zieliński ◽  
Marcin Dębowski
Keyword(s):  
Biogas Production ◽  
Food Products ◽  
Organic Load ◽  
Organic Substrates ◽  
Methane Fermentation ◽  
Anaerobic Reactors ◽  
Convection Heating ◽  
Load Rate ◽  
Biomethane Production ◽  
Positive Effect

The aim of the study was to determine the effect of heating with microwave electromagnetic radiation (EMR) on the efficiency of the methane fermentation (MF) of expired food products (EFP). The research was inspired by the positive effect of EMR on the production of biogas and methane from different organic substrates. The experiment was carried out on a laboratory scale in fully mixed, semi-continuous anaerobic reactors. The technological conditions were as follows: temperature, 35 ± 1 °C; organic load rate (OLR), 2.0 kgVS·m−3∙d−1; and hydraulic retention time (HRT), 40 days. The source of the EMR was a magnetron (electric power, 300 W). There was no statistically significant influence of the use of EMR on the achieved technological effects of MF. The efficiency of biogas production was 710 ± 35 dm3·kgVS−1 in the variant with EMR and 679 ± 26 dm3·kgVS−1 in the variant with convection heating (CH). The methane contents were 63.5 ± 2.4% (EMR) and 62.4 ± 4.0% (CH), and the cumulative methane production after 40 days was 271.2 and 288.6 dm3CH4, respectively.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

Precipitation of heavy metals from coal ash leachate using biogenic hydrogen sulfide generated from FGD gypsum

2013 ◽  
Vol 67 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Madawala Liyanage Duminda Jayaranjan ◽  
Ajit P. Annachhatre
Keyword(s):  
Heavy Metals ◽  
Hydrogen Sulfide ◽  
Sulfate Reduction ◽  
Bottom Ash ◽  
Coal Ash ◽  
Reduction Process ◽  
Fgd Gypsum ◽  
Sulfate Reducing ◽  
Sulfate Reduction Process ◽  
Biological Sulfate Reduction

Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H2S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation.

Microbial ecology of sulfate-reducing bacteria in wastewater biofilms analyzed by microelectrodes and fish (fluorescent in situ hybridization) technique

1999 ◽  
Vol 39 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Satoshi Okabe ◽  
Hisashi Satoh ◽  
Tsukasa Itoh ◽  
Yoshimasa Watanabe
Keyword(s):  
In Situ Hybridization ◽  
Sulfate Reduction ◽  
Sulfate Reducing Bacteria ◽  
Hybridization Technique ◽  
Concentration Profiles ◽  
Reduction Zone ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Culture Dependent

The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in all states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 μm below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm. The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.

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