scholarly journals Controlled experiment contradicts the apparent benefits of the Fenton reaction during anaerobic digestion at a municipal wastewater treatment plant

2018 ◽  
Vol 78 (9) ◽  
pp. 1861-1870 ◽  
Author(s):  
Ahmet E. Uman ◽  
Joseph G. Usack ◽  
José L. Lozano ◽  
Largus T. Angenent
Keyword(s):  
Fenton Reaction ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Experimental System ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Sludge Recycling

Abstract A previous study had reported that the Fenton reaction at full scale increased the digestibility of thickened sludge in a digester. The authors of the study had observed a positive effect on biogas productivity, but without a control. Here, we evaluated this result by investigating the anaerobic treatment characteristics of fresh, thickened sludge in an experimental design with a control. To accomplish this, two identical continuously stirred anaerobic digesters (CSADs) were operated in parallel at mesophilic conditions. We also included anaerobic settlers to mimic the full-scale plant and to accomplish sludge recycling. We fed fresh, thickened sludge to both setups once every other day, but performed the Fenton reaction with only the experimental system by adding H2O2 to the recycled biosolids from the anaerobic settler. We observed very large fluctuations in biogas production due to ever-changing characteristics of the thickened sludge both on a daily and seasonal basis. Regardless, the two setups performed almost identically with: 1) chemical oxygen demand removal efficiencies of 63.8 ± 2.9% and 62.1 ± 3.2%; and 2) biogas productivities of 0.280 and 0.279 L CH4·g−1 volatile solids for the experimental (with Fenton) and control (without Fenton) CSADs, respectively. These results indicate that the use of a Fenton reaction did not affect biogas productivities.

A modified anaerobic digestion process with chemical sludge pre-treatment and its modelling

2014 ◽  
Vol 69 (11) ◽  
pp. 2350-2356 ◽  
Author(s):  
N. M. Hai ◽  
S. Sakamoto ◽  
V. C. Le ◽  
H. S. Kim ◽  
R. Goel ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Municipal Wastewater Treatment ◽  
Simulation Accuracy ◽  
Volatile Solids ◽  
Pre Treatment

Activated Sludge Models (ASMs) assume an unbiodegradable organic particulate fraction in the activated sludge, which is derived from the decay of active microorganisms in the sludge and/or introduced from wastewater. In this study, a seasonal change of such activated sludge constituents in a municipal wastewater treatment plant was monitored for 1.5 years. The chemical oxygen demand ratio of the unbiodegradable particulates to the sludge showed a sinusoidal pattern ranging from 40 to 65% along with the change of water temperature in the plant that affected the decay rate. The biogas production in a laboratory-scale anaerobic digestion (AD) process was also affected by the unbiodegradable fraction in the activated sludge fed. Based on the results a chemical pre-treatment using H2O2 was conducted on the digestate to convert the unbiodegradable fraction to a biodegradable one. Once the pre-treated digestate was returned to the digester, the methane conversion increased up to 80% which was about 2.4 times as much as that of the conventional AD process, whilst 96% of volatile solids in the activated sludge was digested. From the experiment, the additional route of the organic conversion processes for the inert fraction at the pre-treatment stage was modelled on the ASM platform with reasonable simulation accuracy.

Full scale experiences with anaerobic pre-treatment of wastewater in the food and beverage industry in Germany

1997 ◽  
Vol 36 (2-3) ◽  
pp. 321-328 ◽  
Author(s):  
Ute Austermann-Haun ◽  
Carl Franz Seyfried ◽  
Karl-Heinz Rosenwinkel
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Ammonium Phosphate ◽  
Solid Material ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Magnesium Ammonium Phosphate

In Germany, there are currently 106 full-scale anaerobic treatment plants treating industrial wastewater. This paper describes the operational experiences of several industries (beet sugar, starch, pectin, brewery, distillery, vegetable) which undertake anaerobic wastewater treatment, with particular emphasis on specific wastewater problems and their solutions. Also presented are experiences of the handling of high nitrate concentrations, with the treatment of mixtures of industrial wastewater from different origins, with the chance to prevent the emergence of lime, magnesium ammonium phosphate (MAP) or aluminium precipitation. This paper deals with the first municipal wastewater treatment plant combined with a separate anaerobic stage to treat a wastewater mixture of several small factories. One particular asset of this plant is the construction of the acidification tank: using the “teapot effect” to enrich the solid material in the centre of the bottom, the solids can be taken from the bottom of the tank and pumped to the municipal sludge digester.

scholarly journals A full-scale hybrid vertical anaerobic and aerobic biofilm wastewater treatment system: case study

2018 ◽  
Vol 14 (1) ◽  
pp. 189-197 ◽  
Author(s):  
Shuai Wang ◽  
Ilya Savva ◽  
Rune Bakke
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Full Scale ◽  
Organic Loading Rate ◽  
Municipal Wastewater Treatment ◽  
Holistic Treatment ◽  
Set Up

Abstract The first full-scale Hybrid Vertical Anaerobic Aerobic Biofilm (HyVAB) reactor has been set up for treating wastewater from a vegetable processing industry in Grimstad, Norway. The novel HyVAB reactor integrates a bottom expanded granular sludge bed with a top aerobic biofilm stage, resulting in a small footprint and high treatment efficiency. The full scale holistic treatment plant consists of a pretreatment system of a sand trap and an equalization tank, a HyVAB reactor and an effluent sludge settlement tank. The HyVAB system has been operated continuously for 219 days with flow and chemical oxygen demand (COD) fluctuations corresponding to different product seasons. The reactor hydraulic retention time ranges from 32 to 10 hours, with the anaerobic organic loading rate (OLR) reaching a maximum 16 kg-COD/m3·d. The HyVAB removed on average of 90% of the total feed COD, at an operational temperature of 25 °C. Sludge production was low at 0.11 kg-volatile suspended solids/kg-COD removed. Odorless effluent from HyVAB can be discharged directly to a local municipal wastewater treatment plant without sludge handling. Over 82% of feed COD was converted to methane, leaving high methane content (84 ± 2%) biogas out of the reactor. Energy consumption of HyVAB was 0.5 kwh/ton wastewater. The cost of wastewater treatment is 1.5 NOK/kg COD removed (based on rates in Norway).

scholarly journals Control of hydrogen sulphide in full-scale anaerobic digesters using iron (III) chloride: performance, origin and effects

Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
D Erdirencelebi ◽  
M Kucukhemek
Keyword(s):  
Large Scale ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Full Scale ◽  
Solid Loading ◽  
Municipal Wastewater Treatment ◽  
Noticeable Effect ◽  
Anaerobic Digesters ◽  
H2s Production

The study presents the results of sulphide control using iron (III) chloride in full-scale anaerobic digesters (ADs) at a large-scale municipal wastewater treatment plant (WWTP). Iron (III) (‘ferric’) chloride was applied at a range of 24–105 mg FeCl3/L with and without alkali solution using different strategies. Introduction points were implemented at the feeding line and the sludge thickener unit. Response of the ADs in terms of biogas H2S reduction over time, solid loading rates (SLR), feed sludge flow rate and pH level were investigated. Reduction of H2S in the biogas reached 4 035 μg/L in directly-dosed AD versus a 1 345 μg/L drop in non-dosed ADs, as a result of internal recirculation among the digesters, where actual values were possibly higher as volatile solid (VS) degradation increased in all ADs during the dosing period. No noticeable effect on biogas production and pH was observed. The degree of H2S production was found to be correlated to the volatile SLR, where primary sludge solids contributed mostly to the organic and proteinaceous content of the thickened sludge and presented a high variation and a strong relationship with H2S production. Correlation analysis based on data for the 17-month period that followed supported the significant role of primary SLR in H2S production.

Full scale experiences with anaerobic/aerobic treatment plants in the food and beverage industry

1999 ◽  
Vol 40 (1) ◽  
pp. 305-312 ◽  
Author(s):  
U. Austermann-Haun ◽  
H. Meyer ◽  
C. F. Seyfried ◽  
K.-H. Rosenwinkel
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Ammonium Phosphate ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Potato Processing ◽  
Magnesium Ammonium Phosphate

In Germany, there are currently 125 full-scale anaerobic treatment plants treating industrial wastewater. This paper describes the operational experiences of several industries (beet sugar, starch, pectin brewery, distillery, vegetable, potato processing) which undertake anaerobic wastewater treatment, with particular emphasis on specific wastewater problems and their solutions. Also presented are experiences with the handling of high nitrate concentrations, with the treatment of mixtures of industrial wastewater from different origins, with the chance to prevent the emergence of lime, magnesium ammonium phosphate (MAP) or aluminium precipitation. This paper deals as well with the first EGSB reactor (Expanded Granular Sludge Bed) at a German potato processing factory as well as the first municipal wastewater treatment plant combined with a separate anaerobic stage to treat a wastewater mixture from several small factories.

An optimal solution to achieve the energy neutral Waste Water Treatment Plant

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
Christophe Amiel ◽  
Delphine Nawawi-Lansade ◽  
Kim Sorensen
Keyword(s):  
Energy Consumption ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Waste Water Treatment ◽  
Carbon Sources ◽  
Treatment Plant ◽  
Co2 Reduction ◽  
Optimal Solution ◽  
Waste Water Treatment Plant ◽  
Municipal Wastewater Treatment

Many recent studies have shown processes or models to minimize the energy consumption on a municipal wastewater treatment plant (WWTP) in operation. Today the main drivers are the energy and CO2 reduction. On existing plants, the potential success of achieving the Energy neutral WWTP depends on the effluent guarantees demanded and the eventual additional carbon sources on the digesters. Veolia has now developed a tool to estimate the energy consumption and the CO2 impact to select the appropriate treatment lines (water and sludge) up front at the project stage. The real challenge is to cover the needs of the plant without external carbon sources added to the digester. At the project stage, before the bid of the WWTP, due to time constraints only few comparisons can be performed to predict the energy consumption and CO2 impact and provide the best solution to reach to the energy neutral plant as electricity wise. One conclusion of the study is that, the raw water characteristics and the effluent guarantee has a great impact on the possibilities to reach the target. Furthermore, working on reducing the power consumption and on increasing the biogas production for example by a continuous Thermal hydrolysis is a good way to go towards self sufficiency.

Nitrogen removal from digester supernatant via nitrite - SBR or SHARON?

2003 ◽  
Vol 48 (8) ◽  
pp. 9-18 ◽  
Author(s):  
C. Fux ◽  
K. Lange ◽  
A. Faessler ◽  
P. Huber ◽  
B. Grueniger ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Flow Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidation ◽  
High Concentrations ◽  
Nitrite Nitrate ◽  
Sharon Process

Separate biological elimination of nitrogen from the digester supernatant of a municipal wastewater treatment plant (WWTP) was investigated in pilot and full-scale plants. Denitrification mainly via nitrite was achieved in a sequencing batch reactor (SBR) and a continuous flow reactor (CSTR or SHARON). Suppression of nitrite oxidation in the SBR was feasible at short aerobic/anaerobic intervals allowing for immediate denitrification of the produced nitrite. Nitrate production could also be stopped by exposing the biomass to anaerobic conditions for 11 days. Temporarily high concentrations (up to 80 gNH3-Nm-3) of free ammonia could not be considered as the major reason for inhibiting nitrite oxidation. In a full-scale SBR plant 90% of the nitrogen load was denitrified in a total hydraulic retention time (HRT) of 1.6 days and with a sludge age between 15 and 20 days. Ethanol and methanol were used for denitrification. The specific average substrate consumption was 2.2 gCODdosedg-1Nremoved with an effective biomass yield of 0.2 gCODbiomassg-1CODdosed. No dosing with base was required. In the SHARON process full nitrogen elimination was achieved only with a total HRT greater than 4 days at 29°C. The overall costs were estimated at €1.4 kg-1Nremoved for the SBR and €1.63 kg-1Nremoved in SHARON mode, respectively. The SHARON process is simple in operation (CSTR) but the tank volume has to be significantly greater than in SBR.

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