scholarly journals Upgrading and evaluation of a simple pond system for small communities with simple interventions to reduce land requirements and increase performance

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.

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.


2004 ◽  
Vol 49 (11-12) ◽  
pp. 69-76 ◽  
Author(s):  
J.E. Schmidt ◽  
D.J. Batstone ◽  
I. Angelidaki

Upflow anaerobic sludge blanket reactors may offer a number of advantages over conventional mixed-tank, SBR, and biofilm reactors, including high space-loading, low footprint, and resistance to shocks and toxins. In this study, we assessed the use of upflow anaerobic sludge blanket (UASB) reactor technology as applied to anaerobic ammonia removal, or Anammox. Four 200 ml UASB reactors were inoculated with 50% (by volume) anaerobic granular sludge and 50% flocular sludge from different sources (all with the potential for containing Anammox organisms). Tools used to assess the reactors included basic analyses, fluorescent in-situ hybridisation, and mathematical modelling, with statistical non-linear parameter estimation. Two of the reactors showed statistically identical Anammox activity (i.e., identical kinetic parameters), with good ammonia and nitrite removal (0.14 kgNHx m-3 reactor day-1, with 99% ammonia removal). The third reactor also demonstrated significant Anammox activity, but with poor identifiability of parameters. The fourth reactor had no statistical Anammox activity. Modelling indicated that poor identifiability and performance in the third and fourth reactors were related to an excess of reduced carbon, probably originating in the inoculum. Accumulation of Anammox organisms was confirmed both by a volume loading much lower than the growth rate, and response to a probe specific for organisms previously reported to mediate Anammox processes. Overall, the UASB reactors were effective as Anammox systems, and identifiability of the systems was good, and repeatable (even compared to a previous study in a rotating biological contactor). This indicates that operation, design, and analysis of Anammox UASB reactors specifically, and Anammox systems in general, are reliable and portable, and that UASB systems are an appropriate technology for this process.


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.


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.


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.


1996 ◽  
Vol 34 (5-6) ◽  
pp. 445-452 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau

Performances during startup of three 2.8-litre UASB (upflow anaerobic sludge blanket) reactors operated under thermophilic condition were investigated. All reactors were seeded with mesophilic sludges: one with flocculent digester sludge (Reactor-F), another with UASB granules (Reactor-G), and the third with disintegrated granules (Reactor-D). The reactors were operated in parallel at 55°C and 24 hours of retention time, using sucrose and milk as substrate at COD (chemical oxygen demand) loadings up to 10 g-COD/l·day. Immediately after temperature was step-increased from 37°C to 55°C, all reactors encountered sludge washout and deterioration of COD removal efficiency; however, the impact of temperature increase was more severe on Reactor-F. Sludge granulation took place in all reactors; first granules became noticeable after 45 days in Reactor-D, and after 90 days in Reactor-F. Reactor-G and Reactor-D were capable of removing 95% of soluble COD after 75 days, while Reactor-F after 110 days. Throughout this study, there was little difference in performance between Reactors G and D. The thermophilic granule were estimated to have a yield of 0.099 g-VSS/g-COD, and a methanogenic activity of 0.71-1.55 g-methane-COD/g-VSS·day, comparable to that of mesophilic granules.


2019 ◽  
Vol 35 (4) ◽  
pp. 1352-1359
Author(s):  
Nimeshchandra Vasanji Vashi ◽  
Navinchandra Champaklal Shah ◽  
Kishor Ratilal Desai

Upflow Anaerobic Sludge Blanket (UASB) process is a popular process for treatment of sewage in India due to its low power requirement. However, UASB system has many limitations in terms of removal of carbon, nutrients and pathogens. This requires post treatment after UASB to meet the treated water quality standards. Current treatment processes adopted for the post-treatment of anaerobically treated sewage, especially the full-scale UASB reactors in Surat, India are presented. Two full scale treatment plants with different UASB post treatment processes viz., Extended Aeration and Moving Bed Biological Reactor (MBBR) are selected for studies. A pilot study was carried out in a full scale Sewage Treatment Plant (STP) to study the performance of Sequential Batch Reactor (SBR) for treatment of UASB treated sewage and the results are reported for period of Three months. Inlet and outlet parameters such as Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), etc. for post UASB biological process are presented. The performance of the SBR process was observed to be better among all the processes studied.


2013 ◽  
Vol 33 (2) ◽  
pp. 367-378 ◽  
Author(s):  
Estevão Urbinati ◽  
Rose M. Duda ◽  
Roberto A. de Oliveira

In this study it was evaluated the effects of hydraulic retention time (HRT) and Organic Loading Rate (OLR) on the performance of UASB (Upflow Anaerobic Sludge Blanket) reactors in two stages treating residual waters of swine farming. The system consisted of two UASB reactors in pilot scale, installed in series, with volumes of 908 and 188 L, for the first and second stages (R1 and R2), respectively. The HRT applied in the system of anaerobic treatment in two stages (R1 + R2) was of 19.3, 29.0 and 57.9 h. The OLR applied in the R1 ranged from 5.5 to 40.1 kg CODtotal (m³ d)-1. The average removal efficiencies of chemical oxygen demand (COD) and total suspended solids (TSS) ranged, respectively, from 66.3 to 88.2% and 62.5 to 89.3% in the R1, and from 85.5 to 95.5% and 76.4 to 96.1% in the system (R1 + R2). The volumetric production of methane in the system (R1 + R2) ranged from 0.295 to 0.721 m³CH4 (m³ reactor d)-1. It was found that the OLR applied were not limiting to obtain high efficiencies of CODtotal and TSS removal and methane production. The inclusion of the UASB reactor in the second stage contributed to increase the efficiencies of CODtotal and TSS removal, especially, when the treatment system was submitted to the lowest HRT and the highest OLR.


2015 ◽  
Vol 71 (9) ◽  
pp. 1333-1339 ◽  
Author(s):  
A. Morvannou ◽  
N. Forquet ◽  
S. Michel ◽  
S. Troesch ◽  
P. Molle

Approximately 3,500 constructed wetlands (CWs) provide raw wastewater treatment in France for small communities (<5,000 people equivalent). Built during the past 30 years, most consist of two vertical flow constructed wetlands (VFCWs) in series (stages). Many configurations exist, with systems associated with horizontal flow filters or waste stabilization ponds, vertical flow with recirculation, partially saturated systems, etc. A database analyzed 10 years earlier on the classical French system summarized the global performances data. This paper provides a similar analysis of performance data from 415 full-scale two-stage VFCWs from an improved database expanded by monitoring data available from Irstea and the French technical department. Trends presented in the first study are confirmed, exhibiting high chemical oxygen demand (COD), total suspended solids (TSS) and total Kjeldahl nitrogen (TKN) removal rates (87%, 93% and 84%, respectively). Typical concentrations at the second-stage outlet are 74 mgCOD L−1, 17 mgTSS L−1 and 11 mgTKN L−1. Pollutant removal performances are summarized in relation to the loads applied at the first treatment stage. While COD and TSS removal rates remain stable over the range of applied loads, the spreading of TKN removal rates increases as applied loads increase.


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