Treatment of high sulfate and high strength wastewater in a single stage anaerobic reactor

2004 ◽  
Vol 4 (1) ◽  
pp. 35-45
Author(s):  
J.-C. Huang ◽  
S. Kumar Khanal
Keyword(s):  
Sulfide Oxidation ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Single Stage ◽  
Excess Oxygen ◽  
Oxygen Injection ◽  
Anaerobic Reactor ◽  
Sulfide Toxicity ◽  
Dissolved Sulfide ◽  
High Sulfate

In this study, a preset oxidation-reduction potential (ORP) was employed to regulate oxygen dosing for online sulfide toxicity control during anaerobic treatment of high sulfate wastewater. The experiment was conducted in an upflow anaerobic reactor (UAF), which was operated at a constant influent total organic carbon (TOC) of 6740 mg/L (equivalent to a chemical oxygen demand (COD) of 18000 mg/L) but with different influent sulfates of 1000, 3000 and 6000 mg/L. The reactor was initially run without oxygen injection at a natural ORP of about −290 to −300 mV and then was followed by oxygenation to raise ORP by +25 mV above the natural level for each influent sulfate level. With 1000 and 3000 mg/L influent sulfates, the produced sulfide levels did not impose any appreciable toxicity to methanogens even without oxygen injection. However, with 6000 mg/L influent sulfate without oxygen injections, the dissolved sulfide level quickly went up to over 800 mg/L which imposed a significant suppression on methanogenesis. Upon oxygen injection to raise the ORP by +25 mV, the dissolved sulfide was quickly reduced to 160 mg/L. If more oxygen was injected to raise the ORP by +50 mV, then dissolved sulfide further decreased to 12.2 mg/L with a concomitant improvement in methane yield by 45.9%. With a +25 mV preset ORP increase, it was found that at the 1000 mg/L influent sulfate the supplied oxygen was more than that needed for sulfide oxidation. The excess oxygen could be utilized readily by facultative heterotrophs for organic oxidation, which contributed 13.5% of the total COD removal in the UAF. At the higher sulfate levels of 3000 and 6000 mg/L, the facultative contributions to the total COD removal were only 4.7 and 4.1%, respectively. This study has clearly demonstrated that ORP is a workable and reliable means for regulating oxygen injection to achieve online sulfide toxicity control in a single-stage anaerobic system treating high sulfate wastewater.

Use of ORP (oxidation-reduction potential) to control oxygen dosing for online sulfide oxidation in anaerobic treatment of high sulfate wastewater

2003 ◽  
Vol 47 (12) ◽  
pp. 183-189 ◽  
Author(s):  
S.K. Khanal ◽  
C. Shang ◽  
J.-C. Huang
Keyword(s):  
Reduction Potential ◽  
Sulfide Oxidation ◽  
Anaerobic Treatment ◽  
Oxygen Injection ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Controlling Parameter ◽  
Dissolved Sulfide ◽  
High Sulfate ◽  
Sulfide Control

In this study, oxidation-reduction potential (ORP) was used as a controlling parameter to regulate oxygen dosing to the recycled biogas for online sulfide oxidation in an upflow anaerobic filter (UAF) system. The UAF was operated with a constant influent COD of 18,000 mg/L, but with different influent sulfates of 1000, 3000 and 6000 mg/L. The reactor was initially operated under a natural ORP of -290 mV (without oxygen injection), and was then followed by oxygenation to raise its ORP by 25 mV above the natural level for each influent sulfate condition. At 6,000 mg/L sulfate without oxygen injection, the dissolved sulfide reached 733.8 mg S/L with a corresponding free sulfide of 250.3 mg S/L, thus showing a considerable inhibition to methanogens. Upon oxygenation to raise its ORP to -265 mV (i.e., a 25 mV increase), the dissolved sulfide was reduced by more than 98.5% with a concomitant 45.9% increase of the methane yield. Under lower influent sulfate levels of 1,000 and 3,000 mg/L, the levels of sulfides produced, even under the natural ORP, did not impose any noticeable toxicity to methanogens. Upon oxygenation to raise the ORP by +25 mV, the corresponding methane yields were actually reduced by 15.5% and 6.2%, respectively. However, such reductions were not due to the adverse impact of the elevated ORP; instead, they were due to a diversion of some organic carbon to support the facultative activities inside the reactor as a result of excessive oxygenation. In other words, to achieve satisfactory sulfide oxidation for the lower influent sulfate conditions, it was not necessary to raise the ORP by as much as +25 mV. The ORP increase actually needed depended on both the influent sulfate and also actual wastewater characteristics. This study had proved that the ORP controlled oxygenation was reliable for achieving consistent online sulfide control.

Effects of calcium concentration on up-flow multistage anaerobic reactor performance in treating bagasse spraying wastewater

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4254-4269
Author(s):  
Jinghong Zhou ◽  
Xiaona Shang ◽  
Zhiwei Wang ◽  
Cancan Zhu ◽  
Shuangfei Wang
Keyword(s):  
Anaerobic Digestion ◽  
Loading Rate ◽  
Biogas Production ◽  
Scale Up ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Microbial Community Analysis ◽  
Organic Loading Rate ◽  
Reactor Performance ◽  
Anaerobic Reactor

Bagasse spraying wastewater (BSW) is a source of organic pollutants during bagasse processing. In this study, the feasibility of anaerobic treatment of BSW under different calcium concentrations (60 to 2400 mg/L) was studied. The experiment was performed in a lab-scale up-flow multistage anaerobic reactor (UMAR) inoculated with granular sludge, and operated for 160 days at a constant organic loading rate of 6 kg COD/(m3·d). Treatment of BSW with 60 to 800 mg Ca2+/L resulted in 80.7 to 82.7% of COD removal, 161 to 232.7 mg COD/L of volatile fatty acid (VFA) yield, 0.56 to 0.79 m3/(kgCOD·d) of biogas production rate, and 2.4 to 2.66 m3/(m3·d) of volume loading rate (VLR). The pH remained within the optimal range for anaerobic digestion (adjust to pH = 6.8 to 7.0). The VFAs were composed of 77 to 85% acetic acid, 8.4 to 13.2% butyric acid, and 6.6 to 9.6% propionic acid. At higher influent calcium concentrations (> 800 mg/L), the hydrolysis process appeared to be inhibited, affecting the anaerobic digestion performance of the reactor. In particular, the COD removal efficiency decreased to 55.5%, and the VFA content in the effluent significantly increased due to the lower pH. Microbial community analysis showed that at the end of anaerobic digestion, the Syntrophobacter disappeared, and Clostridium and Anerolineaceae were the main genus and family, respectively. Overall, the results indicated that low calcium (< 300 mg/L) had a positive effect on the UMAR performance.

Treatment characteristics of high strength fermentation wastewater consisting of high sulfate and ammonia by UAHB process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 377-384 ◽  
Author(s):  
Tsuyoshi Imai ◽  
Masao Ukita ◽  
Masahiko Sekine ◽  
Hiroshi Nakanishi ◽  
Masayuki Fukagawa
Keyword(s):  
High Strength ◽  
Methanogenic Bacteria ◽  
Sulfide Concentration ◽  
Sulfide Toxicity ◽  
Treatment Characteristics ◽  
Free Hydrogen ◽  
Dissolved Sulfide ◽  
High Sulfate ◽  
Process Wastewater ◽  
Hybrid Blanket

In this study, the formation process of granules and treatment characteristics were discussed for an Upflow Anaerobic Hybrid Blanket (UAHB) reactor, adding water absorbing polymer particles (WAP) for treating a fermentation process wastewater consisting of high sulfate and ammonia. Sulfide toxicity to methanogenic bacteria and the TOC/SO42− ratio that was usually used as an index of inhibition to methanogenesis were also examined. The results indicated that the granules could be developed in an UAHB process, in which a filter was installed in the upper part of reactor and WAP were also added into inoculum, for treating sulfide- and ammonia-rich wastewater, and inhibition caused by sulfide did not occurred when free hydrogen sulfide concentration was less than 200 mgl−1. Therefore, the UAHB process in the presence of adding WAP was shown to have a better stability for treating the refractory wastewater. The results also showed that total dissolved sulfide concentration had to be considered for inhibition assessment as well as the TOC/SO42− ratio.

Pond Treatment of Rettery Wastewaters

1987 ◽  
Vol 19 (12) ◽  
pp. 79-83
Author(s):  
K. Bartoszewski ◽  
A. Bilyk
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
New Technology ◽  
Treatment Plant ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Experimental Results ◽  
Aerobic Conditions ◽  
Aerobic Stabilization ◽  
In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina
Keyword(s):  
Polyethylene Terephthalate ◽  
Loading Rate ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Foam Formation ◽  
Organic Loading ◽  
Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

The anaerobic treatment of a ligno-cellulosic substrate offering little natural pH buffering capacity

1998 ◽  
Vol 38 (4-5) ◽  
pp. 29-35 ◽  
Author(s):  
C. J. Banks ◽  
P. N. Humphreys
Keyword(s):  
Ph Control ◽  
Anaerobic Treatment ◽  
Buffering Capacity ◽  
Single Stage ◽  
Stable Operation ◽  
Reactor Performance ◽  
Two Stage ◽  
Ph Buffering ◽  
Stage System ◽  
The Stability

The stability and operational performance of single stage digestion with and without liquor recycle and two stage digestion were assessed using a mixture of paper and wood as the digestion substrate. Attempts to maintain stable digestion in both single stage reactors were unsuccessful due to the inherently low natural buffering capacity exhibited; this resulted in a rapid souring of the reactor due to unbuffered volatile fatty acid (VFA) accumulation. The use of lime to control pH was unsatisfactory due to interference with the carbonate/bicarbonate equilibrium resulting in wide oscillations in the control parameter. The two stage system overcame the pH stability problems allowing stable operation for a period of 200 days without any requirement for pH control; this was attributed to the rapid flushing of VFA from the first stage reactor into the second stage, where efficient conversion to methane was established. Reactor performance was judged to be satisfactory with the breakdown of 53% of influent volatile solids. It was concluded that the reactor configuration of the two stage system offers the potential for the treatment of cellulosic wastes with a sub-optimal carbon to nitrogen ratio for conventional digestion.

Final products and kinetics of biochemical and chemical sulfide oxidation under microaerobic conditions

2018 ◽  
Vol 78 (9) ◽  
pp. 1916-1924 ◽  
Author(s):  
Lucie Pokorna-Krayzelova ◽  
Dana Vejmelková ◽  
Lara Selan ◽  
Pavel Jenicek ◽  
Eveline I. P. Volcke ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxidation Rate ◽  
Elemental Sulfur ◽  
Sulfide Oxidation ◽  
Cost Effective ◽  
Anaerobic Treatment ◽  
Batch Experiments ◽  
Cost Effective Method ◽  
Microaerobic Conditions ◽  
Kinetics Of

Abstract Hydrogen sulfide is a toxic and usually undesirable by-product of the anaerobic treatment of sulfate-containing wastewater. It can be removed through microaeration, a simple and cost-effective method involving the application of oxygen-limiting conditions (i.e., dissolved oxygen below 0.1 mg L−1). However, the exact transformation pathways of sulfide under microaerobic conditions are still unclear. In this paper, batch experiments were performed to study biochemical and chemical sulfide oxidation under microaerobic conditions. The biochemical experiments were conducted using a strain of Sulfuricurvum kujiense. Under microaerobic conditions, the biochemical sulfide oxidation rate (in mg S L−1 d−1) was approximately 2.5 times faster than the chemical sulfide oxidation rate. Elemental sulfur was the major end-product of both biochemical and chemical sulfide oxidation. During biochemical sulfide oxidation elemental sulfur was in the form of white flakes, while during chemical sulfide oxidation elemental sulfur created a white suspension. Moreover, a mathematical model describing biochemical and chemical sulfide oxidation was developed and calibrated by the experimental results.

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