Anaerobic Treatment of Wastewater from the Production of Chemi-Thermomechanical Pulp

1985 ◽  
Vol 17 (1) ◽  
pp. 103-111 ◽  
Author(s):  
T Welander ◽  
P.-E Andersson
Keyword(s):  
Waste Water ◽  
Hydrogen Peroxide ◽  
Control Parameter ◽  
Anaerobic Treatment ◽  
Thermomechanical Pulp ◽  
Two Stage ◽  
Loading Rates ◽  
Inhibitory Compounds ◽  
Acidogenic Reactor ◽  
Stage Process

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.

Potato Processing Wastewater Treatment at Relatively High Loading Rates Using a Unified Anaerobic Fermenter-Filter

1982 ◽  
Vol 17 (1) ◽  
pp. 63-74 ◽  
Author(s):  
R.C. Landine ◽  
G.J. Brown ◽  
A.A. Cocci ◽  
T. Viraraghavan
Keyword(s):  
Wastewater Treatment ◽  
Room Temperature ◽  
Anaerobic Treatment ◽  
Basic Design ◽  
Potato Processing ◽  
Two Stage ◽  
Filter System ◽  
Loading Rates ◽  
Laboratory Bench ◽  
Scale Design

Abstract A laboratory bench-scale study using a unified anaerobic fermenter-filter system (referred to as a BVF-HAF system) was conducted at room temperature over an 8 month period on potato processing wastewater for the purpose of verifying a proposed full-scale design concept. In addition to two-stage anaerobic treatment, the first stage anaerobic effluent (BVF effluent) was subjected to aerobic polishing in a simulated facultative aerated lagoon with a retention of 4 days. The basic design conditions entailed treatment of a clarified potato wastewater with a COD of 7600 mg/L and a retention of 4 d in the BVF (loading 1.71 kg/m3.d). After over-coming an upset condition believed due to toxicity of the vacuum filtrate feed, the model performed well achieving 78.9% COD removal in the BVF plus 5 3.4% in the HAF for a combined total of 90.2%. When the BVF effluent was aerated the combined BVF - aerated lagoon removal reached 94.8%.

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
Keyword(s):  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Loading Rates ◽  
Reactor Technology ◽  
Inhibitory Compounds ◽  
Complete Treatment ◽  
Low Costs ◽  
Biological Methods ◽  
Multi Phase ◽  
Near Future

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.

Anaerobic treatment of partly acidified wastewater in a two-stage expanded granular sludge bed (EGSB) system at 8°C

1997 ◽  
Vol 36 (6-7) ◽  
pp. 317-324 ◽  
Author(s):  
Jules B. van Lier ◽  
Salih Rebac ◽  
Piet Lens ◽  
Friso van Bijnen ◽  
Stefanie J. W. H. Oude Elferink ◽  
...  
Keyword(s):  
Specific Activity ◽  
Blot Hybridization ◽  
Effective Diffusion ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Two Stage ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Second Stage ◽  
Sucrose Loading

Psychrophilic (8 °C) anaerobic treatment of partly acidified waste water was investigated using a two stage EGSB system with a total volume of 8.6 dm3. The reactor system was operated at an up-flow velocity of 10 m·h−1 and was fed with a sucrose-VFA mixture of 550–1100 mg COD dm−3. The average CODsol and VFA-COD removal efficiencies were 97 and 90 %, respectively, at total organic loading rates (OLR) ranging between 5.1–6.7 g COD dm−3·day−1, sucrose loading rates up to 1 g COD dm−3 day−1 and a hydraulic retention time (HRT) of 4 h. An increase in the sucrose loading rates resulted in a significant wash-out of biomass from the first stage. The second stage satisfactory served as a scavenger of non-degraded VFA from the first stage. Specific activity assays showed an increase of 15 % in the specific methanogenic activity of the sludge present in the second stage and a decrease of 9 % in the first stage. Apparently, an enrichment of methanogens and acetogens in the anaerobic sludge in the second stage took place at temperatures as low as 8°C. The acidogenic population became much more dominant in the first stage, resulting in a higher acidifying activity and a decreased methanogenic activity. 16S rRNA probe-techniques (dot blot hybridization) showed that the acetate consuming Methanosaeta (formerly Methanothrix) and the hydrogenotrophic Methanobrevibacter species (or relatives) were the most abundant methanogens present in the psychrophilic sludge. The ratio between bacterial and methanobacterial hybridization signal of the first stage was 3 times higher than that of the second stage. By using NMR techniques, a higher effective diffusion coefficient was found for the smaller sized granules in both reactors, which is in congruent with the higher maximum specific acetate degrading activity of the smaller granules.

scholarly journals Characterization and anaerobic digestion of highly concentrated Mexican wine by-products and effluents

2020 ◽  
Vol 81 (1) ◽  
pp. 190-198 ◽  
Author(s):  
M. Vital-Jacome ◽  
M. Cazares-Granillo ◽  
J. Carrillo-Reyes ◽  
G. Buitron
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Single Stage ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Two Stage ◽  
Wine Production ◽  
Stage Process ◽  
By Products

Abstract Wine production has increased in recent years, especially in developing countries such as Mexico. This increase is followed by an increase of winery effluents that must be treated to avoid environmental risks. However, little information is available about the characteristics of these effluents and the possible treatments. This paper aimed to characterize the effluents and by-products generated by the Mexican winery industry and to evaluate the performance and stability of the anaerobic treatment using a single-stage and a two-stage process. Results showed that the winery effluents had a high content of biodegradable organic matter, with chemical oxygen demand (COD) values ranging from 221 to 436 g COD/L. The single-stage anaerobic process was able to treat an organic loading rate of 9.6 kg COD/(m3 d); however, it was unstable and highly dependent on the addition of bicarbonate alkalinity (0.31 g NaHCO3/g COD removed). The two-stage process was more stable working at a higher organic load (12.1 kg COD/(m3 d)) and was less dependent on the addition of bicarbonate (0.17 g NaHCO3/g COD removed). The results highlight the potential of the winery effluents to produce methane through anaerobic digestion in a two-stage process, making wine production more sustainable.

Pilot-scale two-stage process: a combination of acidogenic hydrogenesis and methanogenesis

2005 ◽  
Vol 52 (1-2) ◽  
pp. 131-138 ◽  
Author(s):  
S.-K. Han ◽  
S.-H. Kim ◽  
H.-W. Kim ◽  
H.-S. Shin
Keyword(s):  
Food Waste ◽  
Environmental Conditions ◽  
Loading Rate ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Maximum Efficiency ◽  
Two Stage ◽  
Loading Rates ◽  
High Loading Rate ◽  
Stage Process

This study was performed to optimize both acidogenic hydrogenesis and methanogenesis, and then to develop a pilot-scale two-stage process producing not only CH4 but also H2. Firstly, acidogenic hydrogenesis of food waste was examined in pilot-scale leaching-bed reactors using dilution rate (D) as a tool to improve the environmental conditions. The maximum efficiency of 71.4% was obtained by adjusting D from 4.5 to 2.5 d−1 depending on the state of degradation. Secondly, the wastewater from acidogenic hydrogenesis was converted to CH4 in a pilot-scale UASB reactor. The COD removal efficiency exceeded 95% up to the loading rates of 13.1 g COD/L/d, which corresponded to HRT of 0.25 d (6 h). Lastly, a pilot-scale two-stage process was devised based on a combination of acidogenic hydrogenesis and methanogenesis. Over 120 days, the pilot-scale process resulted in large VS reduction of 70.9% at the high loading rate of 12.5 kg VS/m3/d in a short SRT of 8 days.

New method for enhanced reactivation of anaerobic plants

2016 ◽  
pp. 36-39
Author(s):  
Hans-Joachim Jördening ◽  
Ralph-Matthias Schoth ◽  
Charlotte Pipper ◽  
Runi Egholm
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Control Problem ◽  
Waste Water Treatment ◽  
New Method ◽  
Treatment Results ◽  
Loading Rates ◽  
Drastic Increase ◽  
Expected Increase

A major problem in anaerobic waste-water treatment results from difficulties with the mixing of sludge, when it has settled after periods of standstill. A new method for reactivating those plants is discussed in this paper. In a technical anaerobic plant (volume 9600 m3) a control problem led to a breakdown of the process, connected with a drastic increase of the reactor COD. The load to the reactor was temporarily stopped to remove the inhibiting conditions. Restart with low loading rates and addition of new sludge did not lead to the expected increase in performance. The main problem was to suspend the sludge layer, which was settled on the bottom of the reactor. For activating the sludge layer feed “shots” were added up to three times per day. These shots consisted of volume streams of high loaded waste-water, up to five times bigger than the normal stream at that time and lasting for 1 h. The shots provided the sludge layer much better with substrate and caused biogas formation which itself led to a suspension of bacterial flocs. The same strategy was applied again successfully for reactivating a second anaerobic 10,000 m3 reactor.

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.

scholarly journals Two-Stage Biodiesel Synthesis from Used Cooking Oil with a High Acid Value via an Ultrasound-Assisted Method

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Acid Value ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Two Stage ◽  
Cooking Oil ◽  
High Acid ◽  
Used Cooking Oil ◽  
Biodiesel Synthesis ◽  
Stage Process ◽  
Ultrasound Assisted

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.

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