The use of bottle caps as submerged aerated filter medium

2014 ◽  
Vol 69 (7) ◽  
pp. 1518-1525
Author(s):  
Laurence Damasceno de Oliveira ◽  
Amir Mohaghegh Motlagh ◽  
Ramesh Goel ◽  
Beatriz de Souza Missagia ◽  
Benício Alves de Abreu Filho ◽  
...  

In this study, a submerged aerated filter (SAF) using bottle caps as a support medium was evaluated. The system was fed with effluent from an upflow anaerobic sludge blanket system at ETE 2-South wastewater treatment plant, under different volumetric organic load rates (VOLRs). The population of a particular nitrifying microbial community was assessed by fluorescent in situ hybridization with specific oligonucleotide probes. The system showed an average removal of chemical oxygen demand (COD) equal to 76% for VOLRs between 2.6 and 13.6 kg COD m−3_media.day−1. The process of nitrification in conjunction with the removal of organic matter was observed from applying VOLRs lower than 5.5 kg COD m−3_media.day−1 resulting in 78% conversion of NH4+-N. As the applied organic load was reduced, an increase in the nitrifying bacteria population was observed compared with total 4′-6-diamidino-2-phenylindole (DAPI) stained cells. Generally, SAF using bottle caps as a biological aerated filter medium treating wastewater from an anaerobic system showed promising removal of chemical oxygen demand (COD) and conversion of NH4+-N.

2013 ◽  
Vol 67 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Tarek Elmitwalli

Although the upflow anaerobic sludge blanket (UASB) reactor has been widely applied for domestic wastewater treatment in many developing countries, there is no sufficient mathematical model for proper design and operation of the reactor. An empirical model based on non-linear regression was developed to represent the physical and chemical removal of suspended solids (SS) in the reactor. Moreover, a simplified dynamic model based on ADM1 and the empirical model for SS removal was developed for anaerobic digestion of the entrapped SS and dissolved matter in the wastewater. The empirical model showed that effluent suspended chemical oxygen demand (CODss) concentration is directly proportional to the influent CODss concentration and inversely proportional to both the hydraulic retention time (HRT) of the reactor and wastewater temperature. For obtaining sufficient CODss removal, the HRT of the UASB reactor must be higher than 4 h, and higher HRT than 12 h slightly improved CODss removal. The dynamic model results showed that the required time for filling the reactor with sludge mainly depends on influent total chemical oxygen demand (CODt) concentration and HRT. The influent CODt concentration, HRT and temperature play a crucial role on the performance of the reactor. The results indicated that shorter HRT is needed for optimization of CODt removal, as compared with optimization of CODt conversion to methane. Based on the model results, the design HRT of the UASB reactor should be selected based on the optimization of wastewater conversion and minimization of biodegradable SS accumulation in the sludge bed, not only based on COD removal, to guarantee a stable reactor performance.


2021 ◽  
Vol 56 (4) ◽  
pp. 621-629
Author(s):  
Orlando Antonio Duarte Hernandez ◽  
Ana Caroline Paula ◽  
Gustavo Rafael Collere Possetti ◽  
Mauricio Pereira Cantão ◽  
Miguel Mansur Aisse

This study aims to present the time behavior of wastewater flow parameters, organic matter, biogas flow, biogas composition, and its relations, measured through online sensors, in a municipal wastewater treatment plant (WWTP) operating full-scale upflow anaerobic sludge blanket (UASB) reactors, installed in the south of Brazil. WWTP has online measurement devices to evaluate some physicochemical variables of the sewage and the biogas. The COD analyzer (UV– Vis probe), ultrasonic flow meter, biogas flow meter, and biogas composition analyzer were the equipment used. The monitoring occurred for two time periods each of 72 h and one time period for 48 h in the year 2018. Data were checked with descriptive statistics, data independence was checked through the autocorrelation Box– Ljung test, normality behavior was checked with several tests (Shapiro– Wilk, Kolmogorov–Smirnov, Lilliefors, Anderson–Darling, D’Agostino K2, and Chen–Shapiro), and Spearman’s correlation coefficient was used to evaluate the correlations among the parameters. The mean sewage flow was 345 ± 120 L.s-1; removed organic load was, in average, 48%; biogas quality values were 82.32% ± 3.62% v/v (CH4), 2.66% ± 1.19% v/v (CO2), and 3453 ± 1268 ppm (H2S); and the production per capita obtained was 4.51 ± 1.65 NL.hab-1.d-1. It was estimated an electric power generation of 3118.6 kWh.d-1, which is equivalent to an installed power of 130 KW. The behavior of removed organic load and biogas flow (Nm3.h-1), produced in the treatment plant, showed variable, periodic, and nonstationary time behavior.  


2019 ◽  
Vol 14 (2) ◽  
pp. 249-258
Author(s):  
S. R. Amaral ◽  
L. V. dos Santos ◽  
L. M. Lima ◽  
D. V. Vich ◽  
L. M. Queiroz

Abstract The aim of this paper was to evaluate the performance of two modified upflow anaerobic reactor (RAns) as a decentralized technology for the treatment of high-strength domestic wastewater. Two full-scale anaerobic reactors (Ran1 and Ran2) with the same configuration and total volume of 14.6 m³, total height of 2.57 m, and constructed from fibreglass reinforced plastics were operated with a 16-hour hydraulic retention time and submitted to a volumetric organic load less than 2.7 kg chemical oxygen demand (COD)·m−3·d−1. The RAns were monitored for 10 consecutive months and showed the capability to support the fluctuations of organic loading and volumetric rates. The compact anaerobic reactors proved to be effective in removing organic matter (biological oxygen demand removal efficiencies greater than 70% and the average soluble COD removal efficiencies greater than 57.4%). The solids profile in the reactor ranged from very dense particles with good settleability close to the bottom (sludge bed) to a more dispersed and light sludge close to the top of the reactor (sludge blanket), similar to conventional UASB reactors.


2017 ◽  
Vol 76 (8) ◽  
pp. 2003-2014 ◽  
Author(s):  
Pollyane Diniz Saliba ◽  
Marcos von Sperling

The objective of this study was to evaluate the behaviour of a system comprising an upflow anaerobic sludge blanket reactor followed by activated sludge to treat domestic sewage. The Betim Central sewage treatment plant, Brazil, was designed to treat a mean influent flow of 514 L/s. The study consisted of statistical treatment of monitoring data from the treatment plant covering a period of 4 years. This work presents the concentrations and removal efficiencies of the main constituents in each stage of the treatment process, and a mass balance of chemical oxygen demand (COD) and nitrogen. The results highlight the good overall performance of the system, with high mean removal efficiencies: BOD (biochemical oxygen demand) (94%), COD (91%), ammonia (72%) and total suspended solids (92%). As expected, this system was not effective for the removal of nutrients, since it was not designed for this purpose. The removal of Escherichia coli (99.83%) was higher than expected. There was no apparent influence of operational and design parameters on the effluent quality in terms of organic matter removal, with the exceptions of the BOD load upstream of the aeration tank and the sludge age in the unit. Results suggest that this system is well suited for the treatment of domestic sewage.


2020 ◽  
Vol 81 (9) ◽  
pp. 1951-1960 ◽  
Author(s):  
C. S. Cabral ◽  
A. L. Sanson ◽  
R. J. C. F. Afonso ◽  
C. A. L. Chernicharo ◽  
J. C. Araújo

Abstract Two bioreactors were investigated as an alternative for the post-treatment of effluent from an upflow anaerobic sludge blanket (UASB) reactor treating domestic sewage, aiming at dissolved sulfide and methane removal. The bioreactors (R-control and R-air) were operated at different hydraulic retention times (HRT; 6 and 3 h) with or without aeration. Large sulfide and methane removal efficiencies were achieved by the microaerated reactor at HRT of 6 h. At this HRT, sulfide removal efficiencies were equal to 61% and 79%, and methane removal efficiencies were 31% and 55% for R-control and R-air, respectively. At an HRT of 3 h, sulfide removal efficiencies were 22% (R-control) and 33% (R-air) and methane removal did not occur. The complete oxidation of sulfide, with sulfate formation, prevailed in both phases and bioreactors. However, elemental sulfur formation was more predominant at an HRT of 6 h than at an HRT of 3 h. Taken together, the results show that post-treatment improved the anaerobic effluent quality in terms of chemical oxygen demand and solids removal. However, ammoniacal nitrogen was not removed due to either the low concentration of air provided or the absence of microorganisms involved in the nitrogen cycle.


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.


Sign in / Sign up

Export Citation Format

Share Document