Treatment of high organic content wastewater from food-processing industry with the French vertical flow constructed wetland system

2015 ◽  
Vol 72 (1) ◽  
pp. 70-76 ◽  
Author(s):  
J. Paing ◽  
V. Serdobbel ◽  
M. Welschbillig ◽  
M. Calvez ◽  
V. Gagnon ◽  
...  

Abstract This study aimed at determining the treatment performances of a full-scale vertical flow constructed wetlands designed to treat wastewater from a food-processing industry (cookie factory), and to study the influence of the organic loading rate. The full-scale treatment plant was designed with a first vertical stage of 630 m², a second vertical stage of 473 m² equipped with a recirculation system and followed by a final horizontal stage of 440 m². The plant was commissioned in 2011, and was operated at different loading rates during 16 months for the purpose of this study. Treatment performances were determined by 24 hour composite samples. The mean concentration of the raw effluent was 8,548 mg.L−1 chemical oxygen demand (COD), 4,334 mg.L−1 biochemical oxygen demand (BOD5), and 2,069 mg.L−1 suspended solids (SS). Despite low nutrients content with a BOD5/N/P ratio of 100/1.8/0.5, lower than optimum for biological degradation (known as 100/5/1), mean removal performances were very high with 98% for COD, 99% for BOD5 and SS for the two vertical stages. The increasing of the organic load from 50 g.m−2.d−1 COD to 237 g.m−2.d−1 COD (on the first stage) did not affect removal performances. The mean quality of effluent reached French standards (COD < 125 mg.L−1, BOD5 < 25 mg.L−1, SS < 35 mg.L−1).

2002 ◽  
Vol 46 (6-7) ◽  
pp. 347-354 ◽  
Author(s):  
E. Choi ◽  
Y. Eum

This study was conducted with an influent containing about 20% solids, obtainable from scraper type separation resulting in about 40 g/L TCOD and 5.5 g/L TKN, to find an optimum operating condition for nitrogen removal. Both laboratory scale reactors and a full scale treatment plant removed 80 to 90% nitrogen by biological means up to 35°C with 10% by ammonia stripping. The full scale plant however was operated at 35 to 45°C, and at 45°C, 30% nitrogen was removed by biological means, 50% by ammonia stripping, 14% by chemical coagulation and 6% by activated carbon adsorption, respectively. Struvite formation could not be observed at 30°C or higher. Nitrite nitrification and denitrification could save about 35% in tank volume and 50% in carbon requirements at 25°C, respectively. For a complete denitrification with a proper temperature, the influent TCOD/TKN ratio must exceed 6 with oxic/total reactor volume ratio of 0.5. The influent TCOD level or organic load should be lower so as not to increase the reactor temperature above 35°C and avoid nitrification inhibition. The estimated optimum nitrogen loading rates were 0.15 for summer and 0.23 kgTKN/m3/d for winter, respectively. With a cooling facility, the nitrogen loads could be increased to 0.35 kgTKN/m3/d equivalent to an organic loading rate of 2.5 kgCOD/m3/d.


2017 ◽  
Vol 63 (No. 9) ◽  
pp. 411-420
Author(s):  
Rudinskaya Tamara

In the paper, the observed heterogeneity and technical efficiency of Czech food processing companies are investigated. Recent studies proved that food processing firms’ heterogeneity can influence the result of the efficiency estimation. For the empirical study, the panel data set from the years 2005–2012 containing 2854 observations of 607 food processing companies was used. Variables representing heterogeneity factors were incorporated in the mean of inefficiency term distribution of the Battese and Coelli model (1995). The models were estimated in the form of translogarithmic production function using the Stochastic Frontier Approach. The results indicate the presence of significant heterogeneity among the firms in the analysed branches and among different branches of the food processing industry.


2018 ◽  
Vol 14 (1) ◽  
pp. 189-197 ◽  
Author(s):  
Shuai Wang ◽  
Ilya Savva ◽  
Rune Bakke

Abstract The first full-scale Hybrid Vertical Anaerobic Aerobic Biofilm (HyVAB) reactor has been set up for treating wastewater from a vegetable processing industry in Grimstad, Norway. The novel HyVAB reactor integrates a bottom expanded granular sludge bed with a top aerobic biofilm stage, resulting in a small footprint and high treatment efficiency. The full scale holistic treatment plant consists of a pretreatment system of a sand trap and an equalization tank, a HyVAB reactor and an effluent sludge settlement tank. The HyVAB system has been operated continuously for 219 days with flow and chemical oxygen demand (COD) fluctuations corresponding to different product seasons. The reactor hydraulic retention time ranges from 32 to 10 hours, with the anaerobic organic loading rate (OLR) reaching a maximum 16 kg-COD/m3·d. The HyVAB removed on average of 90% of the total feed COD, at an operational temperature of 25 °C. Sludge production was low at 0.11 kg-volatile suspended solids/kg-COD removed. Odorless effluent from HyVAB can be discharged directly to a local municipal wastewater treatment plant without sludge handling. Over 82% of feed COD was converted to methane, leaving high methane content (84 ± 2%) biogas out of the reactor. Energy consumption of HyVAB was 0.5 kwh/ton wastewater. The cost of wastewater treatment is 1.5 NOK/kg COD removed (based on rates in Norway).


2011 ◽  
Vol 3 (3) ◽  
pp. 80-81 ◽  
Author(s):  
S. Saravanan S. Saravanan ◽  
◽  
Dr. V. Mohanasundaram Dr. V. Mohanasundaram

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.


Sign in / Sign up

Export Citation Format

Share Document