Advanced anaerobic wastewater treatment in the near future

1997 ◽  
Vol 35 (10) ◽  
pp. 5-12 ◽  
Author(s):  
G. Lettinga ◽  
J. Field ◽  
J. van Lier ◽  
G. Zeeman ◽  
L. W. Hulshoff Pol

New insights into the anaerobic degradation of very different categories of compounds, and into process and reactor technology will lead to very promising new generations of anaerobic treatment system, such as ‘Expanded Granular Sludge Bed’ (EGSB) and ‘Staged Multi-Phase Anaerobic’ (MPSA) reactor systems. These concepts will provide a higher efficiency at higher loading rates, are applicable for extreme environmental conditions (e.g. low and high temperatures) and to inhibitory compounds. Moreover, by integrating the anaerobic process with other biological methods (sulphate reduction, micro-aerophilic organisms) and with physical-chemical methods, a complete treatment of the wastewater can be accomplished at very low costs, while at the same time valuable components can be recovered for reuse.

1999 ◽  
Vol 40 (8) ◽  
pp. 99-106 ◽  
Author(s):  
L. A. Núñez ◽  
B. Martínez

The performance of an Expanded Granular Sludge Bed (EGSB) reactor for treating slaughterhouse wastewater under mesophilic conditions (35°C), was investigated. The reactor was inoculated with granular sludge from an anaerobic reactor of a brewery factory. The averaged COD removal percentages were 67% for total organic loading rates (BV.TCOD) up to 15 kg COD m−3 d−1 and a hydraulic retention time (HRT) of 5 h. Total suspended solids (TSS) were 90% removed for total solids loads of 6 kg TSS m−3 d−1. Fats were 85% removed and no accumulation of fats on the sludge was observed. The specific methanogenic activity of the sludge, after 140 days, was about three times higher than the sludge inoculated into the reactor. The sludge activity did not significantly change after one year of work. These findings indicate that the anaerobic treatment of slaughterhouse wastewater in an EGSB system appears to be a feasible option.


1997 ◽  
Vol 36 (6-7) ◽  
pp. 375-382 ◽  
Author(s):  
Mario T. Kato ◽  
Jim A. Field ◽  
Gatze Lettinga

The application of the UASB and EGSB reactors for the treatment of low strength wastewaters was investigated. The effect of dissolved oxygen on the methanogenic activity of granular sludges, the low substrate levels inside reactors and lower temperatures on the treatment performance were evaluated. The results showed that methanogens located in granular sludge have a high tolerance to oxygen. The concentration to cause 50% inhibition to methanogenic activity was between 7% and 41% oxygen in the head space of flasks, corresponding to 0.05 mg/l and 6 mg/l of DO prevailing in the media, respectively. The feasibility of UASB and EGSB reactors at 30°C was demonstrated. In UASB reactors, COD removal efficiencies exceeded 95% at organic loading rates up to 6.8 g COD/l.d and influent COD concentrations ranging from 422 to 722 mg/l, during the treatment of ethanol substrate. In EGSB reactors, efficiencies were above 80% at OLRs up to 12 g COD/l.d with COD as low as 100 to 200 mg/l. The studies confirmed that in practice DO does not constitute any detrimental effect on the reactor treatment performance. Lowering the temperature down to 15°C in EGSB reactors also showed that the potentials of anaerobic technology can be further explored in the treatment of dilute wastewaters.


1987 ◽  
Vol 19 (1-2) ◽  
pp. 237-247 ◽  
Author(s):  
P. L. Dold ◽  
A. Sam-Soon ◽  
I. H. Palmer ◽  
G v. R. Marais

The new generation of anaerobic digestion systems provide a high level of performance under optimal conditions (~ 37°C). However, in practice many influents will be at lower temperatures - heating of digesters presents problems, particularly in developing countries where technical backup is limited. This paper reports on a study of the treatment of a low/medium strength apple juicing waste in an upflow anaerobic sludge blanket reactor (UASB) at temperatures Less than optimal (25°C and 30°C). Maximum loading rates of approximately 12 and 16 kg COD m−3 d−1 were attained at 25°C and 30°C, respectively, for Influent concentrations in the range 2500 to 5000 rag COD ℓ−1. The comparative treatment capacity is In accord with the reported temperature sensitivity of mesophilic anaerobic processes. Formation of pelletised (granular) sludge enabled high upflow velocities and low hydraulic retention times.


1985 ◽  
Vol 17 (1) ◽  
pp. 103-111 ◽  
Author(s):  
T Welander ◽  
P.-E Andersson

The anaerobic treatment of waste water from the production of peroxide-bleached chemi-thermomechanical pulp was studied. Hydrogen peroxide had to be removed from the waste water before treatment in a methane producing reactor was possible. Peroxide in concentrations up to 200 mg/1 could be removed from the waste water by means of degradation in an acidogenic reactor, the first stage in an anaerobic two-stage process. A system consisting of a prestage and a subsequent acidogenic reactor could successfully remove peroxide in a concentration of 1200 mg/l from the waste water. The prestage was continuously fed with sludge from the acidogenic reactor. The redox potential in the acidogenic stage of a two-stage process proved to be a valuable control parameter when treating waste water containing peroxide. Adaptation of the methanogenic microflora to inhibitory compounds in the waste water was possible. Treatment of the waste water in a pilot plant at low loading rates gave a COD reduction of 50-60% and a methane yield of 0.3 Nm3/kg COD reduced.


1997 ◽  
Vol 36 (2-3) ◽  
pp. 279-285 ◽  
Author(s):  
J. A. Rintala ◽  
S. S. Lepistö

Thermophilic anaerobic treatment of food industry wastewaters was studied using a 0.65 m3 upflow anaerobic sludge bed (UASB) reactor. The reactor was operated at 55°C and placed on the premises of a factory manufacturing deep-frozen goods from vegetables. The hot (>80-90°C) and concentrated (COD 14-79 g/l) wastewater streams, deriving from steam peeling and blanching of carrot and potato were used. The UASB reactor was inoculated with a small amount of granular sludge from a full-scale mesophilic UASB reactor. Prior to inoculation, the inoculum was acclimated to 55°C for 2 days. The reactor was fed with a mixture of wastewaters diluted to the desired COD. The reactor was started with loading rates of about 1.2 kgCOD/m3d. After the initial acidification of the process, apparently due to insufficient buffer capacity, the COD removal started to improve and reached 60% within 35 days of inoculation. At the end of the 70 days run, more than 80% COD removal was achieved with loading rates of about 4 kgCOD/m3d. The pilot-study run was limited due to the end of the seasonal production in the target factory. The results of the pilot study together with the results from the intensive laboratory studies suggest the feasibility of thermophilic anaerobic treatment for the studied wastewaters.


1985 ◽  
Vol 17 (1) ◽  
pp. 223-230 ◽  
Author(s):  
P K Latola

A wastewater from an integrated paper mill with a COD of 1200 mg/dm3 was anaerobically treated in a multi-stage reactor. The BOD7 removal efficiencies of 60-75 % were achieved at maximal loading rates of 5-6 kg COD/m3d and HRT of 4-6 hours due to the granular sludge. Industrial sulphite evaporator condensates from Ca- and Na-processes were treated in anaerobic filters containing light gravel, plastic foam and power plant slag as filter media. The BOD7 removals of 78 % on average were achieved at loading rates of 1.8-3.3 kg COD/m3d with Ca-process evaporator condensates and 80 % BOD7 removals were achieved with Na-process condensates at loading rates of 3.5-4.1 kg COD/m3d.


1999 ◽  
Vol 40 (11-12) ◽  
pp. 67-75 ◽  
Author(s):  
Sigrun J. Jahren ◽  
Jukka A. Rintala ◽  
Hallvard Ødegaard

Thermomechanical pulping (TMP) whitewater was treated in thermophilic (55°C) anaerobic laboratory-scale reactors using three different reactor configurations. In all reactors up to 70% COD removals were achieved. The anaerobic hybrid reactor, composed of an upflow anaerobic sludge blanket (UASB) and a filter, gave degradation rates up to 10 kg COD/m3d at loading rates of 15 kg COD/m3d and hydraulic retention time (HRT) of 3.1 hours. The anaerobic multi-stage reactor, consisting of three compartments, each packed with granular sludge and carrier elements, gave degradation rates up to 9 kg COD/m3d at loading rates of 15-16 kg COD/m3d, and HRT down to 2.6 hours. Clogging and short circuiting eventually became a problem in the multi-stage reactor, probably caused by too high packing of the carriers. The anaerobic moving bed biofilm reactor performed similar to the other reactors at loading rates below 1.4 kg COD/m3d, which was the highest loading rate applied. The use of carriers in the anaerobic reactors allowed short HRT with good treatment efficiencies for TMP whitewater.


2018 ◽  
Vol 2018 (13) ◽  
pp. 2295-2298
Author(s):  
A. di Biase ◽  
S.F Corsino ◽  
T.R Devlin ◽  
M Torregrossa ◽  
G Munz ◽  
...  

2013 ◽  
Vol 14 (2) ◽  
pp. 149-156 ◽  

This work focused on glycerol exploitation for biogas and hydrogen production. Anaerobic digestion of pure glycerol was studied in a continuous stirred tank reactor (CSTR), operated under mesophilic conditions (35oC) at various organic loading rates. The overall operation of the reactor showed that it could not withstand organic loading rates above 0.25 g COD L-1 d-1, where the maximum biogas (0.42 ± 0.05 L (g COD)-1) and methane (0.30 ± 0.04 L (g COD)-1) production were achieved. Fermentative hydrogen production was carried out in batch reactors under mesophilic conditions (35oC), using heat-pretreated anaerobic microbial culture as inoculum. The effects of initial concentration of glycerol and initial pH value on hydrogen production were studied. The highest yield obtained was 22.14 ± 0.46 mL H2 (g COD added)-1 for an initial pH of 6.5 and an initial glycerol concentration of 8.3 g COD L-1. The main metabolic product was 1.3 propanediol (PDO), while butyric and acetic acids as well as ethanol, at lower concentrations, were also determined.


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