scholarly journals Anaerobic technology for treatment of concentrated wastewater from estonian food industries

2019 ◽  
pp. 283-291
Author(s):  
H. Mölder ◽  
V. Blonskaya

Anaerobic wastewater treatment technologies are used throughout the world for effective treatment of a wide variety of industrial wastewater, in particular for the wastewater from the food industry. This type of wastewater is rich in easily biodegradable carbohydrates and has a relatively low content in suspended solids. As an example, the anaerobic bio-degradation of organic matter in wastewater (cheese whey ) was studied on a laboratory - scale Upflow Anaerobic Sludge Blanket Reactor (UASB). This wastewater was found characterized by high COD concentration, from 58.000 to 72.000 mg/L. The digester efficiency duringthe treatment process of cheese wastewater at various organic loading rates (0.5 -16 kg COD/m3 • day ) was studied and its performance was assessed by monitoring the p value ( 6.8 -7.3 ) and biogas production ( up to 24 L /day ). The investigation has demonstrated that the process of anaerobic degradation wassufficiently effective for COD removal.

2017 ◽  
Vol 76 (9) ◽  
pp. 2268-2279 ◽  
Author(s):  
Henrique Vieira de Mendonça ◽  
Jean Pierre Henry Balbaud Ometto ◽  
Marcelo Henrique Otenio ◽  
Alberto José Delgado dos Reis ◽  
Isabel Paula Ramos Marques

Abstract New data on biogas production and treatment of cattle wastewater were registered using an upflow anaerobic sludge blanket-anaerobic filter (UASB-AF) hybrid reactor under mesophilic temperature conditions (37 °C). The reactor was operated in semi-continuous mode with hydraulic retention times of 6, 5, 3 and 2 days and organic loading rates of 3.8, 4.6, 7.0 and 10.8 kg CODt m−3 d−1. Biogas volumes of 0.6–0.8 m3 m−3 d−1 (3.8–4.6 kg CODt m−3 d−1) and 1.2–1.4 m3 m−3 d−1 (7.0–10.8 kg CODt m−3 d−1), with methane concentrations between 69 and 75%, were attained. The removal of organic matter with values of 60–81% (CODt) and 51–75% (CODs) allowed methane yields of 0.155–0.183 m3 CH4 kg−1 CODt and 0.401–0.513 m3 CH4 kg−1 CODs to be obtained. Volatile solids were removed in 34 to 69%, with corresponding methane yields of 0.27 to 0.42 m3 CH4 kg−1 VSremoved. The good performance of the novel hybrid reactor was demonstrated by biogas outputs higher than reported previously in the literature, along with the quality of the gas obtained in the various experimental phases. The hybrid reactor investigated in this study presents comparative advantages, particularly in relation to conventional complete mixture units, considering economic factors such as energy consumption, reactor volume and installation area.


2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62


1999 ◽  
Vol 40 (1) ◽  
pp. 77-84 ◽  
Author(s):  
H. H. P. Fang ◽  
D. Wai-Chung Chung

Experiments were conducted in two 2.8 liter UASB (upflow anaerobic sludge blanket) reactors treating proteinaceous wastewaters at 37° and 55°C with 9 hours of hydraulic retention. Results showed that the mesophilic reactor consistently removed 83.5-85.1% of COD (chemical oxygen demand) at loading rates ranging 8-22 g COD l−1 d−1 (corresponding to 3000-8250 mg l−1 of proteinaceous COD in wastewater), whereas the thermophilic reactor removed only 68.5-82.7%. At 32 g COD l−1 d−1 (i.e. 12000 mg COD l−1), the removal efficiencies were lowered to 75.7% in the mesophilic reactor and 65.1% in the thermophilic reactor. At 42 g COD l−1 d−1, severe sludge washout occurred in the mesophilic reactor; at the same loading rate, the thermophilic reactor removed only 53.8% of COD even though sludge washout was under control. The degradation rate in the both reactors was limited by the initial hydrolysis of proteins. However, batch tests showed that thermophilic sludge had slightly higher methanogenic activities than mesophilic sludge in treating proteins and intermediate acids, except propionate. The sludge yields in mesophilic and thermophilic reactors were 0.066 and 0.099 g VSS g COD−1, respectively. Observations by scanning electron microscopy indicated that both types of sludge granules were of irregular shape. There was little noticeable difference between the two granules; both had neither a layered microstructure nor a predominant bacterial species.


2004 ◽  
Vol 31 (3) ◽  
pp. 420-431 ◽  
Author(s):  
S K Patidar ◽  
Vinod Tare

The effect of micro-nutrients, such as Fe, Ni, Zn, Co, and Mo, on anaerobic degradation of sulfate laden organics was investigated using bench-scale models of upflow anaerobic sludge blanket (UASB) reactor, anaerobic baffled reactor (ABR), and hybrid anaerobic baffled reactor (HABR), operating in varying conditions in ten phases (organic loading of 1.9–5.75 kg COD/(m3·d), sulfate loading of 0.54–1.88 kg SO42–/(m3·d), chemical oxygen demand (COD):SO42–ratio of 2.0–8.6). In the initial phase, no nutrient limitation was observed with COD removal of more than 94% in all three systems. Subsequently, increase in sulfate loading resulted in Ni and Co limitation and their supplementation restored COD removal in UASB system. However, baffled systems did not recover because of severe inhibition by sulfide. Results indicate that precipitation of nutrients could seriously deteriorate process performance, leading to failure even before sulfide concentration attains toxic level. The limitation of Fe coupled with high sulfate loading (1.88 kg SO42–/(m3·d)) resulted in growth of low-density, fragile, hollow, and granular biomass in UASB that washed out and caused process instability. Supplementation of Fe with other nutrients stabilized UASB process and also improved COD removal.Key words: anaerobic degradation, nutrients, UASB, ABR, HABR, sulfide toxicity, sulfate laden organics.


2001 ◽  
Vol 44 (4) ◽  
pp. 79-82 ◽  
Author(s):  
L. F. Lopes ◽  
P. R. Koetz ◽  
M. S. Santos

Parboiled rice industry is one of main food industries in the south of Brazil. The main parts of the processing are the humidification and gelatinization of the grain. This procedure increases the productivity and nutritive and cooking values of the product. Some of these industries in the region utilize upflow anaerobic sludge blanket (UASB) reactors as a biological treatment for carbon removal. For nitrogen removal, the proposed system aims to eliminate an extra denitrification reactor, making this step in the top of the UASB, an anoxic zone of the reactor. Nitrification was performed in aerated mixed reactor of 3,6 L. A fraction of the NR was recycled in the top of UASB reactor above the sludge blanket. Recycled ratio varied from 0; 1:0.5; 1:1.0; to 1:1.5. The maximum removal efficiency of NTK was 80%. The results confirm the viability of the proposed system for denitrification.


2015 ◽  
Vol 72 (11) ◽  
pp. 2034-2044 ◽  
Author(s):  
Rosa Elena Yaya Beas ◽  
Katarzyna Kujawa-Roeleveld ◽  
Jules B. van Lier ◽  
Grietje Zeeman

This research was conducted to study the faecal coliforms removal capacity of downflow hanging sponge (DHS) reactors as a post-treatment for an upflow anaerobic sludge blanket (UASB) reactor. Three long-term continuous laboratory-scale DHS reactors, i.e. a reactor with cube type sponges without recirculation, a similar one with recirculation and a reactor with curtain type sponges, were studied. The porosities of the applied medium were 91%, 87% and 47% respectively. The organic loading rates were 0.86 kgCOD m−3 d−1, 0.53 kgCOD m−3 d−1 and 0.24 kgCOD m−3 d−1 correspondingly at hydraulic loading rates of 1.92 m3 m−2 d−1, 2.97 m3 m−2 d−1 and 1.32 m3 m−2 d−1, respectively (COD: chemical oxygen demand). The corresponding averages for faecal coliform removal were 99.997%, 99.919% and 92.121% respectively. The 1989 WHO guidelines standards, in terms of faecal coliform content for unrestricted irrigation (category A), was achieved with the effluent of the cube type DHS (G1) without recirculation. Restricted irrigation, category B and C, is assigned to the effluent of the cube type with recirculation and the curtain type, respectively. Particularly for organic compounds, the effluent of evaluated DHS reactors complies with USEPA standards for irrigation of so called non-food crops like pasture for milking animals, fodder, fibre, and seed crops.


2011 ◽  
Vol 71-78 ◽  
pp. 2103-2106
Author(s):  
Ming Yue Zheng ◽  
Ming Xia Zheng ◽  
Kai Jun Wang ◽  
Hai Yan

The performance of upflow anaerobic sludge blanket (UASB) fed with three metabolic intermediate (acetate, ethanol, and propionate) respectively was studied. The degradation of metabolic intermediate were investigated to discuss the reason for propionate inhibition problem in anaerobic treatment. The hydraulic retention time (HRT) in the reactors started with 8.0h.The yield rate of biogas were 237ml/gCOD, 242ml/gCOD, 218ml/gCOD for acetate, ethanol and propionate, respectively when finishing start-up under OLR of 5.0 kgCOD/(m3·d) (HRT=9.6h).The HRT remained constant 9.6h,and the substrate concentration was gradually increased from 1,000 to 16,000mg/L as COD,and the organic loading rates(OLR) was from 3.0 to 40.0 kgCOD/(m3·d).The maximum propionate concentration was 41.6 gHPr-COD/L at the organic loading rate of 43.9 kgCOD/(m3·d) (HRT, 9.6h) as well as acetate and ethanol.


Author(s):  
Anwar Ahmad ◽  
Rumana Ghufran ◽  
Zularisam Abd. Wahid

Palm oil Mill Effluent (POME) with concentrated butyrate was treated in a 4.5 l upflow anaerobic sludge blanket reactor (UASBR), run over a range of influent concentrations (16.5–46.0 g-COD l−1), chemical oxygen demand (COD) loading rates (1.5–11.5 g-CODl−1d−1) and 11–4 days hydraulic retention time (HRT) at 37 °C by maintaining pH between 6.5–7.5. The process consistently removed 97–99% of COD at loading rates up to 1.5–4.8 g-COD l−1d−1 by varying HRT (11–7.2 days). Butyrate is an important intermediate in the anaerobic degradation of organic matter. In sulphate-depleted environment, butyrate in POME (BOD/COD ratio of 0.5) is β-oxidised to acetate and hydrogen, by obligate proton reducers in syntrophic association with hydrogen utilizing methanogens. The conversion of acetate to methane appeared to be rate limiting step. Maximum biogas (20.17 ll−1d−1) and methane production (16.2 ll−1d−1) were obtained at COD loading rate of 4.80 gl−1d−1and HRT of 7.2 days. The biogas and methane production were higher in the presence of butyrate compared to control. The methane content of the biogas was in the range of 70–80% throughout the study while in control it was 60–65%. Finding of this study clearly indicates the successful treatment of POME with butyrate in UASBR. Santrauka Palmių aliejaus gamybinės nuotekos (POME) su koncentruotu butiratu buvo apdorotos 4,5 l talpos aukštyn tekančio aerobinio dumblo plokšteliniame reaktoriuje (UASBR). Nuotekos tekėjo įvairių koncentracijų (16,5–46,0 g – ChDS 1−1), cheminio deguonies suvartojimo (ChDS) normos (1,5–11,5 g – ChDS 1−1d.−1). Hidraulinio sulaikymo trukmė (HRT) nuo 11 iki 4 dienų, kai temperatūra 37 °C, pH palaikant 6,5–7,5. Vykstant procesui nuolat buvo pašalinama 97–99% ChD, kai tiekimo ir pakrovimo sparta 1,5–4,8 g – ChDS 1−1d.−1 kintant HRT(11–7,2 d.). Butiratas yra svarbus tarpininkas organinių medžiagų anaerobinio skilimo procese. Sulfatas iš aplinkos, butiratas iš POME (BDS/ChDS santykis 0,5) yra acetato ir vandenilio β oksidatoriai, priverčiantys protonų reducentus sintrofinės sąveikos su vandeniliu metu utilizuoti metanogenus. Acetato virtimas metanu pasirodė esąs greitį ribojantis veiksnys. Daugiausia biodujų (20,17 l 1−1 d.−1) ir metano (16,2 l 1−1 d.−1) susidarė tada, kai suvartojamo ChD tiekimo greitis buvo 4,80 g 1−1d.−1, o HRT – 7,2 dienos. Daugiau biodujų ir metano susidarė dalyvaujant butiratui, palyginti su kontroliniu pavyzdžiu. Biodujose metano kiekis tyrimo metu svyravo 70–80%, o kontroliniame buvo 60–65%. Šis tyrimas aiškiai parodė, kad POME su butiratu UASBreaktoriuje apdorojamas sėkmingai.


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