Open trickling filter: an innovative, cheap and simple form of post-treatment of sanitary effluents from anaerobic reactors in small communities

2012 ◽  
Vol 2 (2) ◽  
pp. 59-67 ◽  
Author(s):  
P. C. Vieira ◽  
M. von Sperling

We aimed to evaluate the performance and cost savings of an innovative design of a trickling filter (TF) for small population sizes, developed at the Federal University of Minas Gerais, Brazil referred to as an open trickling filter (OTF). The OTF had no side walls and no perforated bottom slab, and was applied for the post-treatment of sanitary sewage from an upflow anaerobic sludge blanket (UASB) reactor. The OTF had crushed-stone packing (3.5 m high) and was operated with an average surface hydraulic loading rate of 4.1 m3 m−2 d−1 and an average volumetric organic loading rate of 0.10 kg BOD m−3 d−1 (biochemical oxygen demand). The average concentrations obtained at the OTF effluent were 48 mg TSS L−1 (total suspended solids), 132 mg COD L−1 (chemical oxygen demand), 51 mg BOD L−1, 19 mg TKN L−1 (total Kjeldahl nitrogen), 16 mg NH4+-N L−1 and 10 mg NO3−-N L−1, complying with local discharge standards. Analysis of the construction costs indicated savings of 74% compared to conventional TF. Based on the performance, compactness, simplicity and reduced capital costs, it is believed that the proposed OTF is a good alternative for small communities, especially in developing countries.

2013 ◽  
Vol 67 (12) ◽  
pp. 2746-2752 ◽  
Author(s):  
P. C. Vieira ◽  
M. von Sperling ◽  
L. C. M. Nogueira ◽  
B. F. S. Assis

The objective of the work is to evaluate the performance of an innovative design of a trickling filter for small population sizes, which has been implemented for the post-treatment of sanitary effluent from a UASB (upflow anaerobic sludge blanket) reactor. The unit, named open trickling filter (OTF), operates with no side walls, no perforated bottom slab and no secondary settler. The OTF packing was 3.5 m high, composed of crushed stone, with a fixed distribution system made of channels with V-notch weirs. The OTF was operated with mean surface hydraulic loading rates of 4.1 and 9.3 m3 m−2 d−1, corresponding to population equivalents of approximately 250 and 550 inhabitants, respectively. For the surface hydraulic loading rate of 4.1 m3 m−2 d−1, the median removal efficiencies obtained by the OTF and overall system (UASB + OTF) were, respectively, 24 and 83% for total suspended solids (TSS), 44 and 79% for chemical oxygen demand (COD), 42 and 82% for biochemical oxygen demand (BOD), 40 and 40% for N-ammonia. For the surface hydraulic loading rate of 9.3 m3 m−2 d−1, the median removal efficiencies obtained by the OTF and global system (UASB + OTF) were 14 and 76% for TSS, 28 and 76% for COD, 25 and 86% for BOD, 15 and 15% for N-ammonia. Considering the great simplicity, no mechanization and small footprint of the system, these results can be considered satisfactory, suggesting that the OTF is suitable for small communities, especially in developing countries.


2013 ◽  
Vol 68 (3) ◽  
pp. 650-657 ◽  
Author(s):  
E. F. A. Mac Conell ◽  
P. G. S. Almeida ◽  
A. M. Zerbini ◽  
E. M. F. Brandt ◽  
J. C. Araújo ◽  
...  

Changes in ammonia-oxidizing bacterial (AOB) population dynamics were examined in a new sponge-based trickling filter (TF) post-upflow anaerobic sludge blanket (UASB) reactor by denaturating gradient gel electrophoresis (DGGE), and these changes were linked to relevant components influencing nitrification (chemical oxygen demand (COD), nitrogen (N)). The sponge-based packing media caused strong concentration gradients along the TF, providing an ecological selection of AOB within the system. The organic loading rate (OLR) affected the population dynamics, and under higher OLR or low ammonium-nitrogen (NH4+-N) concentrations some AOB bands disappeared, but maintaining the overall community function for NH4+-N removal. The dominant bands present in the upper portions of the TF were closely related to Nitrosomonas europaea and distantly affiliated to Nitrosomonas eutropha, and thus were adapted to higher NH4+-N and organic matter concentrations. In the lower portions of the TF, the dominant bands were related to Nitrosomonas oligotropha, commonly found in environments with low levels of NH4+-N. From a technology point of view, changes in AOB structure at OLR around 0.40–0.60 kgCOD m−3 d−1 did not affect TF performance for NH4+-N removal, but AOB diversity may have been correlated with the noticeable stability of the sponge-based TF for NH4+-N removal at low OLR. This study is relevant because molecular biology was used to observe important features of a bioreactor, considering realistic operational conditions applied to UASB/sponge-based TF systems.


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


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.


2012 ◽  
Vol 65 (10) ◽  
pp. 1887-1894 ◽  
Author(s):  
V. Singh ◽  
A. K. Mittal

This study reports applicability of upflow anaerobic sludge blanket (UASB) process to treat the leachate from a municipal landfill located in Delhi. A laboratory scale reactor was operated at an organic loading rate of 3.00 kg chemical oxygen demand (COD)/m3 d corresponding to a hydraulic retention time (HRT) of 12 h for over 8 months. The effect of toxicity of leachate, and feed composition on the treatability of leachate was evaluated. Average COD of the leachate, during the study period varied between 8,880 and 66,420 mg/l. Toxicity of the leachate used during a period of 8 months varied from LC50 1.22 to 12.35 for 96 h. The removal efficiency of soluble COD ranged between 91 and 67% for fresh leachate and decreased drastically from 90 to 35% for old leachate having high toxicity. The efficiency varied from 81 to 65%. The reactor performed more efficiently for the treatment of fresh leachate (less toxic, LC50 11.64, 12.35, and 12.15 for 96 h) as compared with old leachate (more toxic, LC50 1.22 for 96 h). Toxicity of the leachate affected its treatment potential by the UASB.


2010 ◽  
Vol 113-116 ◽  
pp. 1031-1035 ◽  
Author(s):  
Yi Sun ◽  
Zi Rui Guo ◽  
Xiao Ye Liu ◽  
Yong Feng Li

In order to disscuss the ability of H2-production and wastewater treatment, a up-flow anaerobic sludge bed (UASB) using a synthesize substrate with brown sugar wastewater was conducted to investigate the hydrogen yield, hydrogen producing rate, fermentation type of biohydrogen production, and the chemical oxygen demand (COD) removal rate, respectively. In this paper, UASB reactor was seeded with sludge from the Harbin Wenchang Sewage treatment plant dewatered sludge. Successful start-up of the reactor was achieved within 40 days at 35±1°C.The concentration of chemical oxygen demand (COD) in influent is increased from 1100mg/L . When it reached maximum, the loading rate was adjusted in a small way and indicators such as VFA, pH and COD in effluent as well as gas production are observed. The most relevant parameters were calibrated with lab-scale experimental data. These experimental results clearly showed that, the most proper corresponding organic loading rate (OLR) and hydraulic retention time (HRT) were 6 kg/ (m3.d)(COD=6000mg/L)and 24 h respectively. Up to 85% of COD was removed and the CH4 production rate of 3.2 m3 / (m3 .d) was obtained. The produced biogas contained 72% of CH4. In the mean time, anaerobic sludge multiplies more faster and exiguous particles appeared. Granules with diameter 1-3mm.


2013 ◽  
Vol 68 (7) ◽  
pp. 1495-1502 ◽  
Author(s):  
Jocilene Ferreira da Costa ◽  
André Cordeiro de Paoli ◽  
Martin Seidl ◽  
Marcos von Sperling

A system composed of two horizontal subsurface flow constructed wetlands operating in parallel was evaluated for the post-treatment of UASB (upflow anaerobic sludge blanket) reactor effluent, for a population equivalent of 50 inhabitants per unit. One unit was planted with cattail (Typha latifolia) and the other was unplanted. The study was undertaken over a period of 4 years, comprising monitoring of influent and effluent constituents together with a full characterization of the behaviour of the units (tracer studies, mathematical modelling of chemical oxygen demand (COD) decay, characterization of solids in the filter medium). The mean value of the surface hydraulic load was 0.11 m3m−2d−1, and the theoretical hydraulic retention time was 1.1 d in each unit. Using tracer tests with 82Br, dispersion number (d) values of 0.084 and 0.079 for the planted and unplanted units were obtained, indicating low to moderate dispersion. The final effluent had excellent quality in terms of organic matter and suspended solids, but the system showed low capacity for nitrogen removal. Four-year mean effluent concentration values from the planted and unplanted units were, respectively: biochemical oxygen demand (BOD5): 25 and 23 mg L−1; COD: 50 and 55 mg L−1; total suspended solids (TSS): 9 and 9 mg L−1; N-ammonia: 27 and 28 mg L−1. The COD decay coefficient K for the traditional plug-flow model was 0.81 and 0.84 d−1 for the planted and unplanted units. Around 80% of the total solids present in the filter medium were inorganic, and most of them were present in the interstices rather than attached to the support medium. As an overall conclusion, horizontal subsurface flow wetlands can be a very suitable post-treatment method for municipal effluents from anaerobic reactors.


2019 ◽  
Vol 80 (8) ◽  
pp. 1505-1511 ◽  
Author(s):  
Nathalie Dyane Miranda Slompo ◽  
Larissa Quartaroli ◽  
Grietje Zeeman ◽  
Gustavo Henrique Ribeiro da Silva ◽  
Luiz Antonio Daniel

Abstract Decentralized sanitary wastewater treatment has become a viable and sustainable alternative, especially for developing countries and small communities. Besides, effluents may present variations in chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total nitrogen values. This study describes the feasibility of using a pilot upflow anaerobic sludge blanket (UASB) reactor to treat wastewater with different organic loads (COD), using black water (BW) and sanitary wastewater, in addition to its potential for preserving nutrients for later recovery and/or reuse. The UASB reactor was operated continuously for 95 weeks, with a hydraulic retention time of 3 days. In Phase 1, the reactor treated simulated BW and achieved 77% CODtotal removal. In Phase 2, treating only sanitary wastewater, the CODtotal removal efficiency was 60%. Phase 3 treated simulated BW again, and CODtotal removal efficiency was somewhat higher than in Phase 1, reaching 81%. In Phase 3, the removal of pathogens was also evaluated: the efficiency was 1.96 log for Escherichia coli and 2.13 log for total coliforms. The UASB reactor was able to withstand large variations in the organic loading rate (0.09–1.49 kg COD m−3 d−1), in continuous operation mode, maintaining a stable organic matter removal.


2017 ◽  
Vol 12 (1) ◽  
pp. 1-11 ◽  
Author(s):  
D. F. C. Dias ◽  
M. P. de Matos ◽  
R. G. Passos ◽  
V. A. J. Rodrigues ◽  
M. von Sperling

The study covers different investigations related to the upgrading of a post-treatment system for the effluent from a upflow anaerobic sludge blanket reactor. The original post-treatment scheme comprised three ponds in series and a small coarse rock filter inserted in the last pond. Upgrading involved reducing the pond depths, applying baffles in the second pond and converting all of the third pond into a rock filter (three decreasing grain sizes). The system was conceived for 250 population equivalents, occupied an area of only 1.5 m2/inhabitant and aimed at very good removals of all major wastewater constituents. Overall final effluent concentrations for Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS) were very good, and lower than those from the previous treatment line. Hydraulic flow patterns in both ponds showed daily thermal stratification and destratification periods. The conversion of the third pond into a rock filter increased the removal capacity of TSS (algae), but could potentially result in clogging, a phenomenon that was evaluated by a geophysical method called Georadar. The influence of accumulated sludge on treatment performance was tested before starting the operation of the upgraded system by operating the two ponds in parallel (one with sludge accumulated after 11 years of operation and the other without sludge). In this test, ammonia removal was virtually the same in both ponds.


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