Sequenced anaerobic-aerobic treatment of high strength, strong nitrogenous landfill leachates

2004 ◽  
Vol 49 (5-6) ◽  
pp. 301-312 ◽  
Author(s):  
S.V. Kalyuzhnyi ◽  
M.A. Gladchenko
Keyword(s):  
Loading Rate ◽  
High Strength ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Inorganic N ◽  
Landfill Leachates ◽  
Total N ◽  
N Removal ◽  
Biological Nitrogen ◽  
Uasb Reactors

As a first step in treatment of high strength, strong nitrogenous landfill leachates (total COD - 9.66-20.56 g/l, total nitrogen 780-1,080 mg/l), the performance of laboratory UASB reactors has been investigated under sub-mesophilic (19±3°C) and psychrophilic (10±2°C) conditions. Under hydraulic retention time (HRT) of around 1.2 days, when the average organic loading rate (OLR) was around 8.5 g COD/l/day, the total COD removal accounted for 71% (on average) for sub-mesophilic regime. The psychrophilic treatment conducted under the average HRT of 2.44 days and the average OLR of 4.2 g COD/l/day showed an average total COD removal of 58% giving effluents more suitable for subsequent biological nitrogen removal. Both anaerobic regimes were quite efficient for elimination of heavy metals by concomitant precipitation in the form of insoluble sulphides inside the sludge. The subsequent submesophilic aerobic-anoxic treatment of submesophilic anaerobic effluents led to only 75% of total inorganic N removal due to COD deficiency for denitrification created by too efficient anaerobic step. On the contrary, psychrophilic anaerobic effluents (richer in COD compared to the submesophilic ones) were more suitable for subsequent aerobic-anoxic treatment giving the total N removal of 95 and 92% at 19 and 10°C, respectively.

Heavy metal pollution from Russian landfill leachates and its elimination together with other contaminants

2004 ◽  
Vol 50 (5) ◽  
pp. 51-58 ◽  
Author(s):  
S. Kalyuzhnyi ◽  
M. Gladchenko
Keyword(s):  
National Standards ◽  
Treated Wastewater ◽  
Inorganic N ◽  
Landfill Leachates ◽  
Total N ◽  
N Removal ◽  
Removal Processes ◽  
Direct Discharge ◽  
Uasb Reactors ◽  
Final Effluent

Systematic monitoring of raw leachates (RL) from the operating landfill “Khmet'yevo7rdquo; during December, 2001-June, 2002 with regard to heavy metals (HM) revealed that these RL were moderately contaminated with Fe, Zn, Pb and Cd (Cu is present in non-dangerous concentrations). This contamination depends on season - the winter leachates are less polluted compared to the summer ones. For removal of HM together with removal of bulk COD, the UASB reactors were applied where, besides elimination of the major part of organic matter, concomitant precipitation of HM in the form of insoluble sulphides inside the sludge bed occurred due to development of the process of biological sulphate reduction. Both removal processes were quite efficient even during operation under submesophilic and psychrophilic conditions (20-10°C). The subsequent submesophilic aerobic-anoxic treatment of submesophilic anaerobic effluents led to only 75% of total inorganic N removal due to COD deficiency for denitrification created by a too efficient anaerobic step. On the contrary, psychrophilic anaerobic effluents (richer in COD compared to the submesophilic ones) were more suitable for subsequent aerobic-anoxic treatment giving the total N removal of 95 and 92% at 20 and 10°C, respectively. The final effluent is approaching the current national standards for direct discharge of treated wastewater.

Pig Wastewater Treatment in Water Hyacinth Ponds

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2381-2384 ◽  
Author(s):  
C. Polprasert ◽  
S. Kessomboon ◽  
W. Kanjanaprapin
Keyword(s):  
Wastewater Treatment ◽  
Water Hyacinth ◽  
Loading Rate ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Small Scale ◽  
N Removal ◽  
In Series

Small-scale and pilot-scale experiments were conducted on pig wastewater treatment in water hyacinth (Eichhornia crassipesl ponds. The main objectives were to evaluate the treatment performance of the water hyacinth ponds and to determine suitable operating conditions. From the experimental results obtained, the optimum organic loading rate was found to be 200 kg COD/(ha.d), while the hydraulic retention times were proposed to be 10-20 days. The % COD removal in the small-scale water hyacinth ponds were 74-93, while for the pilot-scale ponds the % COD removal were 52-72 because of fluctuations in the influent wastewater characteristics and occasional insect attacks on the water hyacinth leaves and stems. Similar results were obtained for N removal. Although the water hyacinth ponds were found to be feasible for pig wastewater treatment, at least one polishing pond in series should be provided to polish the water hyacinth pond effluents before discharging into the environment.

scholarly journals High-strength ethylene glycol wastewater treatment in anaerobic polyvinyl alcohol gel beads based biofilm reactor

2015 ◽  
Vol 18 (1) ◽  
pp. 47-55
Keyword(s):  
Ethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Settling Velocity ◽  
Loading Rate ◽  
High Strength ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Gel Beads ◽  
Pva Gel

<div> <p>In this paper, ethylene glycol wastewater (EGW) treatment was studied by using one anaerobic polyvinyl alcohol (PVA) gel beads based biofilm reactor. Enhanced by PVA-gel beads based biofilm, organic loading rate (OLR) about 11 g COD l<sup>-1</sup> d<sup>-1</sup> was achieved at the end of this study. Black PVA-gel beads with an average settling velocity 322 m h<sup>-1</sup> (9 cm s<sup>-1</sup>) and 0.24g VSS g<sup>-1</sup> PVA gel mainly composed of <em>Methanosarcina spp</em>. were got, while no natural granules were found in this experiment. The COD removal efficiency in this study could reach a high value about 95%. Most COD removal was contributed by the PVA-gel beads based biofilm. It could be concluded that the PVA-gel beads based biofilm reactor is appropriate for EGW treatment.</p> </div> <p>&nbsp;</p>

Combined anaerobic-aerobic treatment of landfill leachates under mesophilic, submesophilic and psychrophilic conditions

2003 ◽  
Vol 48 (6) ◽  
pp. 311-318 ◽  
Author(s):  
S. Kalyuzhnyi ◽  
M. Gladchenko ◽  
A. Epov
Keyword(s):  
Cod Removal ◽  
Treated Wastewater ◽  
Organic Loading ◽  
Landfill Leachates ◽  
Leachate Treatment ◽  
Loading Rates ◽  
Anaerobic Biodegradability ◽  
Biological Nitrogen ◽  
Direct Discharge ◽  
Uasb Reactors

As a first step of treatment of landfill leachates (total COD - 1,430-3,810 mg/l, total nitrogen 90-162 mg/l), a performance of laboratory UASB reactors has been investigated under mesophilic (30°C), sub-mesophilic (20°C) and psychrophilic (10°C) conditions. Under hydraulic retention times (HRT) of around 7 h, when the average organic loading rates (OLR) were around 5 g COD/l/day, the total COD removal accounted for 81% (on the average) with the effluent concentrations close to anaerobic biodegradability limit (0.25 g COD/l) for mesophilic and sub-mesophilic regimes. The psychrophilic treatment conducted under the average HRT of 8 h and the average OLR of 4.22 g COD/l/day showed a total COD removal of 47% producing the effluents (0.75 g COD/l) more suitable for subsequent biological nitrogen removal. All three anaerobic regimes used for leachate treatment were quite efficient for elimination of heavy metals (Fe, Zn, Cu, Pb, Cd) by concomitant precipitation in the form of insoluble sulphides inside the sludge bed. The application of aerobic/anoxic biofilter as a sole polishing step for psychrophilic anaerobic effluents was acceptable for elimination of biodegradable COD and nitrogen approaching the current standards for direct discharge of treated wastewater.

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.

Nitrite reduction and methanogenesis in a single-stage UASB reactor

2015 ◽  
Vol 72 (12) ◽  
pp. 2236-2242 ◽  
Author(s):  
L. I. Borges ◽  
C. M. López-Vazquez ◽  
H. García ◽  
J. B. van Lier
Keyword(s):  
Domestic Wastewater ◽  
High Strength ◽  
Single Stage ◽  
Nitrite Reduction ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
N Removal

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO2−-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO2−-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO2−-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO2− reduction to N2. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

Anaerobic treatment of landfill leachate by sulfate reduction

2000 ◽  
Vol 41 (3) ◽  
pp. 239-246 ◽  
Author(s):  
J.G. Henry ◽  
D. Prasad
Keyword(s):  
Landfill Leachate ◽  
High Surface ◽  
High Strength ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Sulphate Reduction ◽  
High Rate ◽  
Organic Loading Rate ◽  
Filter Performance ◽  
Low Strength

The present study was conducted to investigate the effectiveness of the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The effects of several COD/SO4 ratios (keeping COD constant) and loadings on anaerobic filter performance were studied and compared with the results from anaerobic filters which followed the methanogenic pathway. Results indicated that the treatability of leachate by sulphate reducing bacteria (SRB) was dependent upon the leachate strength. With high strength leachate (COD=15000 mg/L) from the Keele Valley Landfill, it was found that at lower COD/SO4 ratios (≤1.6) toxic conditions developed in the system that were more inhibitory to the SRB than to the methane producing bacteria (MPB). As the COD/SO4 ratio increased, methanogenesis predominated. No predominance of SRB occurred at any COD/SO4 ratio with high strength leachate. The highest COD removal achieved was about 70% of which 20% was accomplished by the SRB at a COD/SO4 ratio of 1.6 and an organic loading rate (OLR) of 4 kg COD/m3.d. With low strength leachate (COD=1500-3300 mg/L) from the Brock West Landfill, and a COD/SO4 ratio &lt;1, SRB became predominant. In these anaerobic filters in which SRB were predominant, the SRB reduced the COD as well as the MPB could. Sulphide inhibition did not take place at any loading in units treating low strength leachate. Consequently, both SRB and MPB should function at COD/SO4 ratios between 1 and 3. About 60% COD removal was achieved at a loading of 2.8 kg COD/m3.d and a COD/SO4 ratio of 1.0. However at a loading of 6 kg COD/m3.d only 27% COD removal was achieved, all of it through the sulphate-reduction pathway. These OLR values are comparable to those applied in systems where methanogenesis was dominant. It was also observed that once the methanogens were established in the units, it was not possible to displace them completely. However, where methanogenesis had not been previously established, it was found that sulphate-reduction could be the sole pathway for COD removal. From this study, it can be concluded that there is no advantage to the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The other options for increasing the loadings, i.e. the use of high surface/volume filter media (to achieve higher biomass concentrations) or high rate systems are likely to be more successful.

Start-up and steady-state results of a full-scale UASB reactor treating malting wastewater

2006 ◽  
Vol 54 (2) ◽  
pp. 261-267 ◽  
Author(s):  
L. Borzacconi ◽  
I. López ◽  
M. Passeggi
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Yield Coefficient ◽  
Reactor Operation ◽  
Operation Temperature ◽  
Start Up ◽  
Anaerobic Lagoon

An Imhoff tank was reconstructed into a 250 m3 UASB reactor in order to treat a malting plant wastewater. The UASB was inoculated with sludge from an anaerobic lagoon used for slaughterhouse wastewater treatment. After two months of operation the reactor achieved full load with an HRT of 17 h, a COD removal higher than 80% and a biogas production of 300 m3/day (77% average methane content), with an organic loading rate of 3.6 kgCOD/m3.d (0.24 kgCOD/kgVSS.d). A yield coefficient of 0.09 gVSS/gCODrem was found from a mass balance. The fat present in the inoculated sludge (48 mg/gSSV) did not affect the start up performance. Sludge from the inoculum with high content of fat (270 mg/gSSV), was separated by flotation in the first week of operation. The COD removal efficiency was scarcely influenced by the reactor operation temperature (17–25 °C).

scholarly journals Performance of AnMBR in Treatment of Post-consumer Food Waste: Effect of Hydraulic Retention Time and Organic Loading Rate on Biogas Production and Membrane Fouling

2021 ◽  
Vol 8 ◽  
Author(s):  
Javkhlan Ariunbaatar ◽  
Robert Bair ◽  
Onur Ozcan ◽  
Harish Ravishankar ◽  
Giovanni Esposito ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Food Waste ◽  
Membrane Fouling ◽  
Loading Rate ◽  
Biogas Production ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Side Stream ◽  
Removal Efficiencies

Anaerobic digestion of food waste (FW) is typically limited to large reactors due to high hydraulic retention times (HRTs). Technologies such as anaerobic membrane reactors (AnMBRs) can perform anaerobic digestion at lower HRTs while maintaining high chemical oxygen demand (COD) removal efficiencies. This study evaluated the effect of HRT and organic loading rate (OLR) on the stability and performance of a side-stream AnMBR in treating diluted fresh food waste (FW). The reactor was fed with synthetic FW at an influent concentration of 8.24 (± 0.12) g COD/L. The OLR was increased by reducing the HRT from 20 to 1 d. The AnMBR obtained an overall removal efficiency of &gt;97 and &gt;98% of the influent COD and total suspended solids (TSS), respectively, throughout the course of operation. The biological process was able to convert 76% of the influent COD into biogas with 70% methane content, while the cake layer formed on the membrane gave an additional COD removal of 7%. Total ammoniacal nitrogen (TAN) and total nitrogen (TN) concentrations were found to be higher in the bioreactor than in the influent, and average overall removal efficiencies of 17.3 (± 5) and 61.5 (± 3)% of TAN and TN, respectively, were observed with respect to the bioreactor concentrations after 2 weeks. Total phosphorus (TP) had an average removal efficiency of 40.39 (± 5)% with respect to the influent. Membrane fouling was observed when the HRT was decreased from 7 to 5 d and was alleviated through backwashing. This study suggests that the side-stream AnMBR can be used to successfully reduce the typical HRT of wet anaerobic food waste (solids content 7%) digesters from 20 days to 1 day, while maintaining a high COD removal efficiency and biogas production.

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