Anaerobic Degradation of PCP and Phenol in Fixed-Film Reactors: The Influence of an Additional Substrate

1991 ◽  
Vol 24 (3-4) ◽  
pp. 431-436 ◽  
Author(s):  
H. V. Hendriksen ◽  
S. Larsen ◽  
B. K. Ahring
Keyword(s):  
Sewage Sludge ◽  
Carbon Source ◽  
Anaerobic Degradation ◽  
Degradation Products ◽  
Phenol Degradation ◽  
Treatment Plant ◽  
Continuous Operation ◽  
Mineral Medium ◽  
Fixed Film ◽  
Digested Sewage Sludge

The anaerobic degradation of pentachlorophenol (PCP) and phenol was examined in two lab-scale fixed-film reactors. Anaerobic digested sewage sludge from a municipal treatment plant was used as inoculum. The reactors were fed a mineral medium containing PCP (1-2 mg/l) and phenol (4-6 mg/l). In addition one of the reactors received 1 g/l glucose as an easily degradable carbon source. After 6 months of continuous operation, the removal of PCP in the reactor with no glucose added was approximately 60%, whereas the removal in the reactor with glucose reached 98%. Tetrachlorophenol (TeCP) and trichloro-phenol (TCP) were found as degradation products and the removal of these compounds was also significantly enhanced by the presence of glucose. Phenol degradation was approximately 70% with glucose added and 95% without glucose.

Aeration of anaerobically digested sewage sludge for COD and nitrogen removal: optimization at large-scale

2008 ◽  
Vol 57 (2) ◽  
pp. 257-264 ◽  
Author(s):  
V. Parravicini ◽  
K. Svardal ◽  
R. Hornek ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Process Conditions ◽  
Nitrite Accumulation ◽  
Digested Sludge ◽  
Digested Sewage Sludge

The paper will report about the experiences at an Austrian large wastewater treatment plant of 720,000 population equivalents, where anaerobically digested sewage sludge is further stabilised under aerobic conditions. Enhanced stabilisation of the anaerobically digested sludge was required at the plant in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment (SRT ∼ 6d; 36 °C) after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations on site showed that during digested sludge post-aeration anoxic phases for denitrification are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, inhibition of the biological process due to nitrite accumulation can be avoided. By optimising the aeration/pause ratio ∼ 45% of total nitrogen in digested sludge can be removed. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. NH4-removal occurs mainly through nitritation and denitritation with an efficiency of 98%. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Result of molecular biological analyses (DGGE) indicate that all four ammonium-oxidizing bacteria species present in activated sludge can survive anaerobic digestion, but only two of them can adapt in the digested sludge post-aeration tanks. Additionally, in the post-aerated digested sludge a further ammonium-oxidizing bacteria species was identified.

scholarly journals Influence of Valorization of Sewage Sludge on Energy Consumption in the Drying Process

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4511
Author(s):  
Ewa Siedlecka ◽  
Jarosław Siedlecki
Keyword(s):  
Energy Consumption ◽  
Sewage Sludge ◽  
Moisture Content ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Calorific Value ◽  
High Energy ◽  
Dry Matter Content ◽  
Drying Process ◽  
Digested Sewage Sludge

Valorization of digested sewage sludge generated in a medium-sized sewage treatment plant and the effect of valorization on energy consumption during sludge drying used for energy recovery are presented. Anaerobic digestion of sewage sludge reduces dry matter content compared to raw sludge. This lowers its calorific value leading to the lower interest of consumers in using it as fuel. The aim of the study was to valorize digested sewage sludge prior to drying with high-energy waste with low moisture content. The procedure led to the reduction in moisture content by about 50% in the substrate supplied for solidification and drying. The calorific value of digested sewage sludge increased by 50%–80%, and the energy consumption of the drying process decreased by about 50%. Physical and chemical properties of sewage sludge and moisture content of substrates and mixtures after valorization were determined. The heat of combustion of valorized sewage sludge mixtures, their elemental composition, and ash content is investigated. Their calorific value in the analytical and working states of 10% H2O was calculated. The highest calorific value was obtained for the mixture of sewage sludge valorized with waste plastics or combined with wood dust, averaging 23 MJ/kg. A mathematical approximation of sewage sludge valorization is presented.

Post-aeration of anaerobically digested sewage sludge for advanced COD and nitrogen removal: results and cost-benefit analysis at large-scale

2008 ◽  
Vol 57 (7) ◽  
pp. 1087-1094 ◽  
Author(s):  
V. Parravicini ◽  
K. Svardal ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Process Conditions ◽  
Nitrite Accumulation ◽  
Benefit Analysis ◽  
Digested Sludge ◽  
Digested Sewage Sludge

At a large Austrian municipal wastewater treatment plant enhanced stabilisation of anaerobically digested sewage sludge was required in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations at this plant showed that during digested sludge post-aeration anoxic phases are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, under the process conditions applied nitrite accumulation would inhibit the stabilisation process if denitrification is not adequately applied. By optimising the aeration/pause ratio ∼45% of total nitrogen in digested sludge can be removed. NH4-removal occurs through nitritation and denitritation with an efficiency of 98%. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Specific costs for nitrogen removal (0.32 Euro/kgN) are comparable with other biological processes for N-removal in reject water.

Biological leaching of heavy metals from anaerobically digested sewage sludge using indigenous sulfur-oxidizing bacteria and sulfur waste in a closed system

2001 ◽  
Vol 43 (2) ◽  
pp. 59-65 ◽  
Author(s):  
K. Kitada ◽  
A. Ito ◽  
K. Yamada ◽  
J. Aizawa ◽  
T. Umita
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Closed System ◽  
Elemental Sulfur ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sulfur Oxidizing ◽  
Digested Sewage Sludge ◽  
Sulfur Oxidizing Bacteria

The utilization of indigenous sulfur-oxidizing bacteria and sulfur waste was investigated in order to remove heavy metals from anaerobically digested sewage sludge economically. Indigenous sulfur-oxidizing bacteria existing in anaerobically digested sewage sludge were activated by adding elemental sulfur to the sludge and then the bacteria were isolated. It was found that indigenous sulfur-oxidizing bacteria could utilize sulfur waste generated by desulfurization of digestion gas as a substrate. Then, biological leaching of heavy metals from anaerobically digested sewage sludge was carried out using indigenous sulfur-oxidizing bacteria and sulfur waste. By adding sulfur waste to sewage sludge, sulfuric acid was produced by the bacteria and the sludge pH decreased. Heavy metals in sewage sludge were effectively removed owing to the decrease of pH. The optimum amount of sulfur waste added to decrease the pH sufficiently was 5g/L when the sludge concentration was 2%. It was presented that the biological leaching of heavy metals from sewage sludge can be carried out in a closed system, where all required materials are obtained in a sewage treatment plant.

EVALUATION OF BIOMETHANE YIELDS FROM HIGH-ENERGY ORGANIC WASTE AND SEWAGE SLUDGE: A PILOT STUDY FOR A WASTEWATER TREATMENT PLANT

2019 ◽  
Vol 18 (9) ◽  
pp. 2023-2034 ◽  
Author(s):  
Agnieszka A. Pilarska ◽  
Krzysztof Pilarski ◽  
Boguslawa Waliszewska ◽  
Magdalena Zborowska ◽  
Kamil Witaszek ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Pilot Study ◽  
Sewage Sludge ◽  
Wastewater Treatment Plant ◽  
Organic Waste ◽  
Treatment Plant ◽  
High Energy

Production of fuels on the basis of sewage sludge through conditioning using high calorific value fractions

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Karl-Georg Schmelz ◽  
Anja Reipa ◽  
Hartmut Meyer
Keyword(s):  
Sewage Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Calorific Value ◽  
Fluidised Bed ◽  
Sludge Treatment ◽  
Heating Value ◽  
Fine Coal ◽  
Used Cars ◽  
Plastic Components

Emschergenossenschaft and Lippeverband operate 59 wastewater treatment plants which produce approx. 100,000 Mg TS of sewage sludge each year. Using sludge pressure pipelines, about 60 % of this sludge are transported to the central sludge treatment plant in Bottrop. The digested sludges are conditioned using fine coal and polymers and are dewatered using membrane filters. By adding coal, the heating value of the sludge is raised which enables autothermal combustion of the dewatered sludges in fluidised bed furnaces at the central sludge treatment plant. In order to replace coal, a fossil fuel, as conditioning agent, experiments were conducted using alternative materials with high heating values. The addition of shredder fluff agglomerates proved to be particularly successful. Shredder fluff agglomerates are a residue from the recycling of used cars and are generated in a multistage process (e.g. Volkswagen-SiCon Process) by separating the light shredder fraction (plastic components etc.) from the total shredder fluff. The fibrous material is outstandingly suitable for improving the dewaterability and for sufficiently raising the heating value of the dewatered sludge in order to enable autothermal combustion. Since first experiments showed very positive results, a full-scale long-term test-run will take place in 2007.

Sludge minimization by disintegration at different wastewater treatment plants

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Degradation ◽  
Ongoing Research ◽  
Sludge Minimization

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).

Packed-Cage RBC with Combined Cultivation of Suspended and Fixed-Film Biomass

1990 ◽  
Vol 22 (1-2) ◽  
pp. 101-111 ◽  
Author(s):  
J. Wanner ◽  
M. Sýkora ◽  
M. Kos ◽  
J. Miklenda ◽  
P. Grau
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Random Medium ◽  
Treatment Plant ◽  
Mixing Effect ◽  
Scale Unit ◽  
Fixed Film ◽  
Rotating Biological Contactors ◽  
Bod Removal

The situation in the treatment of wastewaters from small sources in Czechoslovakia has been discussed and two types of manufactured rotating biological contactors have been described. The evaluation of RBCs' operation showed the main disadvantages of the contactors with conventional discs, viz. the low 0C and low mixing effect. In a newly designed RBC, the discs or packets of discs were replaced by a cage packed with a random medium. The cage was equipped with tubular aeration and mixing elements. The long-term tests with a pilot-plant and a full-scale unit using synthetic as well as municipal wastewaters proved the ability of the packed-cage RBC to achieve a low effluent BOD with such organic loadings when the effluent from the conventional RBCs already deteriorated. Besides the BOD removal the 0C of the packed-cage RBCs was tested to verify the possibility of the combined cultivation of suspended and fixed-film biomass. On the basis of results presented here, a new package wastewater treatment plant for about 500 PE will be designed.

Sign in / Sign up

Export Citation Format

Share Document