scholarly journals Volatile Fatty Acids Recovery In A Reactive Primary Clarifier: A Pilot Case Study

2021 ◽  
Author(s):  
Michele Ponzelli
Keyword(s):  
Flow Rate ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Recirculation Flow ◽  
Process Modification ◽  
Biochemical Reactor ◽  
Downstream Processes ◽  
Solids Removal

Although the aim of primary clarifiers remains to remove particles, the removal of settleable solids affects downstream processes that rely on readily biodegradable oxygen demand (rbCOD) in proportion to nutrient removal demands. However, through some process modification the primary clarifier can be looked at as a physico-biochemical reactor able to accomplish: removal of settleable solids; increase rbCOD concentration in the primary effluent. Pilot-scale experiments were conducted at the 12 m³ water resource recovery facility of Université Laval to determine the effect of different factors on the fermentation process in a primary clarifier. The results showed that providing a sludge retention time larger than one day and a low recirculation flow rate from the bottom of the clarifier of about 15% of the influent flow rate are crucial factors for increased rbCOD concentration. They can lead to a VFAs yield up to 90 mgCH3COOHequivalent/gVSS, along with a 70% solids removal efficiency.

scholarly journals Volatile Fatty Acids Recovery In A Reactive Primary Clarifier: A Pilot Case Study

2021 ◽  
Author(s):  
Michele Ponzelli
Keyword(s):  
Flow Rate ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Recirculation Flow ◽  
Process Modification ◽  
Biochemical Reactor ◽  
Downstream Processes ◽  
Solids Removal

Although the aim of primary clarifiers remains to remove particles, the removal of settleable solids affects downstream processes that rely on readily biodegradable oxygen demand (rbCOD) in proportion to nutrient removal demands. However, through some process modification the primary clarifier can be looked at as a physico-biochemical reactor able to accomplish: removal of settleable solids; increase rbCOD concentration in the primary effluent. Pilot-scale experiments were conducted at the 12 m³ water resource recovery facility of Université Laval to determine the effect of different factors on the fermentation process in a primary clarifier. The results showed that providing a sludge retention time larger than one day and a low recirculation flow rate from the bottom of the clarifier of about 15% of the influent flow rate are crucial factors for increased rbCOD concentration. They can lead to a VFAs yield up to 90 mgCH3COOHequivalent/gVSS, along with a 70% solids removal efficiency.

Novel biofilm reactor for denitrification of municipal wastewater

2018 ◽  
Vol 78 (7) ◽  
pp. 1566-1575 ◽  
Author(s):  
S. S. Rathnaweera ◽  
B. Rusten ◽  
K. Korczyk ◽  
B. Helland ◽  
E. Rismyhr
Keyword(s):  
Carbon Source ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Removal Rates ◽  
Good Filter ◽  
Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

scholarly journals Municipal Wastewater Treatment Using a Packed Bio-tower Approach

2020 ◽  
pp. 42-50
Author(s):  
Klaus Doelle ◽  
Qian Wang
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Continuous Operation ◽  
Growth Media ◽  
Municipal Wastewater Treatment ◽  
Bacteria Growth ◽  
Tower System

The study tested a designed and built pilot scale packed bio-tower system under continuous operation using pre-clarified municipal wastewater. Performance was evaluated by measuring the removal of chemical oxygen demand and nitrogen ammonia. The pilot scale packed bio-tower system had a diameter of 1209 mm (4 ft.) and a height of 3,962 mm (13 ft.) and contained Bentwood CF-1900 bacteria growth media with a surface area of 6,028.80 ft² (560.09 m²). The municipal residential sewage was fed into a 1,481 l (375 gal.) recirculation reservoir at a temperature of 15°C (59.0°F) and a flow rate between 7,571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d) and recirculated through the bio-tower with a fixed recirculation rate of 75.7 l/min (20 gal/min). The influent COD value reduction achieved is between 63.4% and 84.8%, whereas the COD influent value varied between 87 mg/l and 140 mg/l. The influent NH3-N reduction achieved was between 99.8% and 91.8% whereas the influent NH3-N value was between 28.8 mg/l and 18.6 mg/l  at a flow rate between 7571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d).

Experimental and Artificial Neural Network Modeling of a Upflow Anaerobic Contactor (UAC) for Biogas Production from Vinasse

2016 ◽  
Vol 14 (6) ◽  
pp. 1241-1254 ◽  
Author(s):  
Ousman R. Dibaba ◽  
Sandip K. Lahiri ◽  
Stephan T’Jonck ◽  
Abhishek Dutta
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Neural Network Modeling ◽  
Artificial Neural

Abstract A pilot scale Upflow Anaerobic Contactor (UAC), based on upflow sludge blanket principle, was designed to treat vinasse waste obtained from beet molasses fermentation. An assessment of the anaerobic digestion of vinasse was carried out for the production of biogas as a source of energy. Average Organic loading rate (OLR) was around 7.5 gCOD/m3/day in steady state, increasing upto 8.1 gCOD/m3/day. The anaerobic digestion was conducted at mesophilic (30–37 °C) temperature and a stable operating condition was achieved after 81 days with average production of 65 % methane which corresponded to a maximum biogas production of 85 l/day. The optimal performance of UAC was obtained at 87 % COD removal, which corresponded to a hydraulic retention time of 16.67 days. The biogas production increased gradually with OLR, corresponding to a maximum 6.54 gCOD/m3/day (7.4 % increase from initial target). A coupled Artificial Neural Network-Differential Evolution (ANN-DE) methodology was formulated to predict chemical oxygen demand (COD), total suspended solids (TSS) and volatile fatty acids (VFA) of the effluent along with the biogas production. The method incorporated a DE approach for the efficient tuning of ANN meta-parameters such as number of nodes in hidden layer, input and output activation function and learning rate. The model prediction indicated that it can learn the nonlinear complex relationship between the parameters and able to predict the output of the contactor with reasonable accuracy. The utilization of the coupled ANN-DE model provided significant improvement to the study and helps to study the parametric effect of influential parameters on the reactor output.

Determination of dairy wastewater treatability by bio-trickling filter packed with lava rocks – case study PEGAH dairy factory

2012 ◽  
Vol 65 (8) ◽  
pp. 1441-1447 ◽  
Author(s):  
N. Mehrdadi ◽  
G. R. Nabi Bidhendi ◽  
M. Shokouhi
Keyword(s):  
Dairy Products ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Dairy Wastewater ◽  
Trickling Filter ◽  
Steady State Condition ◽  
Ph Values ◽  
A Company

This paper investigates the effectiveness of a biological trickling filter for the treatment of wastewaters produced by a company manufacturing dairy products. First a bio-trickling column with a height of 150 cm was packed with lava rocks from north mountain of Tehran. It operates with the recirculation of liquid through the packing. In order to startup the pilot scale, steady state condition was gained by pumping activated sludge and dairy wastewater for 23 days. Afterwards, dairy wastewater was added to liquid tank for treatment. Hydraulic retention time (HRT) of treatment decreases from 5 days to 1 day then at HRT of 12, 8, 7, 6 and 4 h. Results show that the average chemical oxygen demand (COD) decreased from 2,750 to 98 mg/L at HRT of 7 h and efficiency of TKN removal was more than 70%. The microorganisms developed in the bio-trickling filter were able to efficiently remove COD levels up to 2,750 mg/L, under aerobic conditions at pH values between 6.8 and 7.2 under low temperature condition between 10 and 13 °C.

Advanced Monitoring of an Anaerobic Pilot Plant Treating High Strength Wastewaters

1999 ◽  
Vol 40 (8) ◽  
pp. 237-244 ◽  
Author(s):  
A. Puñal ◽  
A. Lorenzo ◽  
E. Roca ◽  
C. Hernández ◽  
J. M. Lema
Keyword(s):  
Pilot Plant ◽  
Gas Flow ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
High Strength ◽  
Pilot Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket

The operation of an industrial pilot scale treating wastewater from a fibreboard-processing factory was monitored by an advanced system. The plant, an anaerobic hybrid UASB-UAF bioreactor (Upflow Anaerobic Sludge Blanket-Upflow Anaerobic Filter), was equipped with the following measurement devices: biogas flow-meter, feed and recycling flow-meters, thermometer Pt-100, biogas analyser (CH4 and CO), Hydrogen analyser and pH-meter. Other parameters such as alkalinity, Chemical Oxygen Demand (COD) and Volatile Fatty Acids (VFA) were determined off-line. All the on-line sensor measurements were monitored, through a PLC (Programmable Logic Controller), which indicated about the plant failures, including the measuring devices (giving messages or alarms to the operator) and provided the set points for the PLC. The pilot plant was started-up at an initial Organic Loading Rate (OLR) of 2 kg COD/m3.d (Hydraulic Retention Time (HRT) 5 days and 10 kg COD/m3), this value increasing up to 10 kg COD/m3.d by decreasing HRT to 1 day. The behaviour of the bioreactor during start-up and steady state operation was studied. After that, an experiment was performed to analyse the response of the bioreactor to an organic overload. From the results, different variables were evaluated as useful control parameters. Monitoring of CO concentration did not permit the prediction of destabilisation of the bioreactor. However, H2 concentration is quite a sensitive variable, which must be analysed together with other parameters such as methane composition or gas flow-rate. Besides, alkalinity is easy to measure and provides immediate information about the state of the plant, as was shown through the off-line measurements.

Anaerobic hydrolysis of a municipal wastewater in a pilot-scale digester

2003 ◽  
Vol 47 (12) ◽  
pp. 223-230 ◽  
Author(s):  
J.A. Álvarez ◽  
C.A. Zapico ◽  
M. Gómez ◽  
J. Presas ◽  
M. Soto
Keyword(s):  
Volatile Fatty Acids ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Organic Load ◽  
Active Volume ◽  
Santiago De Compostela ◽  
Load Rate ◽  
Pre Treatment

Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a pilot-scale hydrolytic up flow sludge bed (HUSB) digester with an active volume of 25.5 m3. The total influent chemical oxygen demand (COD) ranged from 360 to 470 mg/l, the influent SS varied from 190 to 370 mg/l, and the temperature was between 17° and 20°C. The organic load rate (OLR) applied increased step by step from 1.2 to 3.9 kgCOD/m3.d, while the hydraulic retention time (HRT) decreased from 7.1 h to 2.9 h. A high suspended solids (SS) removal of about 82-85% from the influent was reached, most of which (81 to 88%) was eliminated by hydrolysis, while the rest remained in the purge stream. The total COD removal ranged from 46 to 59%. On the other hand, a high acidification of the COD remaining in the effluent was obtained, so the percent COD in the form of volatile fatty acids (VFACOD) with respect to total effluent COD was about 43% for the highest HRT applied, and about 27% for the lowest HRT. The soluble to total COD ratio (CODs/CODt) increased from 25-32% for the influent to 71-86% for the effluent. The results obtained confirm the viability and interest of direct anaerobic hydrolytic pre-treatment of domestic wastewater.

scholarly journals Chemically Enhanced Primary Sludge as an Anaerobic Co-Digestion Additive for Biogas Production from Food Waste

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 709 ◽  
Author(s):  
Xiaorong Kang ◽  
Yali Liu
Keyword(s):  
Chemical Oxygen Demand ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Mechanism Analysis ◽  
Primary Sludge ◽  
Biogas Yield ◽  
Batch Tests ◽  
Solids Removal

In order to overcome process instability and buffer deficiency in the anaerobic digestion of mono food waste (FW), chemically enhanced primary sludge (CEPS) was selected as a co-substrate for FW treatment. In this study, batch tests were conducted to study the effects of CEPS/FW ratios on anaerobic co-digestion (coAD) performances. Both soluble chemical oxygen demand (SCOD) and protease activity were decreased, with the CEPS/FW mass ratio increasing from 0:5 to 5:0. However, it was also found that the accumulation of volatile fatty acids (VFAs) was eliminated by increasing the CEPS/FW ratio, and that corresponding VFAs concentrations decreased from 13,872.97 to 1789.98 mg chemical oxygen demand per L (mg COD/L). In addition, the maximum value of cumulative biogas yield (446.39 mL per g volatile solids removal (mL/g VSsremoval)) was observed at a CEPS/FW ratio of 4:1, and that the tendency of coenzyme F420 activity was similar to biogas production. The mechanism analysis indicated that Fe-based CEPS relived the VFAs accumulation caused by FW, and Fe(III) induced by Fe-based CEPS enhanced the activity of F420. Therefore, the addition of Fe-based CEPS provided an alternative method for FW treatment.

Anaerobic treatment of food waste in pilot scale

2016 ◽  
Vol 11 (4) ◽  
pp. 774-783 ◽  
Author(s):  
Alexsandro dos Santos Reis ◽  
Savia Gavazza ◽  
Simone Machado Santos
Keyword(s):  
Food Waste ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Ammonia Nitrogen ◽  
Gas Production ◽  
Pollutant Removal ◽  
Organic Loading Rate ◽  
Solids Removal ◽  
Effluent Characteristics

For this work, a pilot scale anaerobic digester was used to assess the treatability of food waste from a canteen. The digester was operated for 720 days, and its efficiency in removing organic matter and suspended solids as well as producing biogas were assessed. At the beginning of operation, the digester failed and alkalinity buffering was required until stabilization. A maximum chemical oxygen demand (COD) and total solids removal efficiency of 71% and 87% were, respectively, found for the organic loading rate of 0.59 kg COD m−3 d−1. The maximum gas production rate and specific gas production were 0.4 m3 m−3 d−1 and 0.76 m3 (kg TVS)−1, respectively, with a methane average of 60% in the biogas composition. Although achieving satisfactory levels of pollutant removal, the effluent characteristics particularly for COD and ammonia nitrogen indicated that recirculation is the best option to use effluent.

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

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