Toxicity and treatability of leachate: application of UASB reactor for leachate treatment from Okhla landfill, New Delhi

2012 ◽  
Vol 65 (10) ◽  
pp. 1887-1894 ◽  
Author(s):  
V. Singh ◽  
A. K. Mittal
Keyword(s):  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
New Delhi ◽  
Leachate Treatment ◽  
Feed Composition ◽  
Laboratory Scale Reactor ◽  
Anaerobic Sludge Blanket

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.

scholarly journals Black water treatment by an upflow anaerobic sludge blanket (UASB) reactor: a pilot study

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
Keyword(s):  
Removal Efficiency ◽  
Phase 1 ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Phase 3 ◽  
Black Water ◽  
Anaerobic Sludge Blanket

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.

Performance of plastic- and sponge-based trickling filters treating effluents from an UASB reactor

2013 ◽  
Vol 67 (5) ◽  
pp. 1034-1042 ◽  
Author(s):  
P. G. S. Almeida ◽  
A. K. Marcus ◽  
B. E. Rittmann ◽  
C. A. L. Chernicharo
Keyword(s):  
Organic Matter ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Total N ◽  
Trickling Filters ◽  
N Removal ◽  
Anaerobic Sludge Blanket

The paper compares the performance of two trickling filters (TFs) filled with plastic- or sponge-based packing media treating the effluent from an upflow anaerobic sludge blanket (UASB) reactor. The UASB reactor was operated with an organic loading rate (OLR) of 1.2 kgCOD m−3 d−1, and the OLR applied to the TFs was 0.30–0.65 kgCOD m−3 d−1 (COD: chemical oxygen demand). The sponge-based packing medium (Rotosponge) gave substantially better performance for ammonia, total-N, and organic matter removal. The superior TF-Rotosponge performance for NH4+-N removal (80–95%) can be attributed to its longer biomass and hydraulic retention times (SRT and HRT), as well as enhancements in oxygen mass transfer by dispersion and advection inside the sponges. Nitrogen removals were significant (15 mgN L−1) in TF-Rotosponge when the OLRs were close to 0.75 kgCOD m−3 d−1, due to denitrification that was related to solids hydrolysis in the sponge interstices. For biochemical oxygen demand removal, higher HRT and SRT were especially important because the UASB removed most of the readily biodegradable organic matter. The new configuration of the sponge-based packing medium called Rotosponge can enhance the feasibility of scaling-up the UASB/TF treatment, including when retrofitting is necessary.

scholarly journals Performance Comparison of Conventional and Modified Upflow Anaerobic Sludge Blanket (UASB) Reactors Treating High-Strength Cattle Slaughterhouse Wastewater

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 806 ◽  
Author(s):  
Mohammed Ali Musa ◽  
Syazwani Idrus ◽  
Hasfalina Che Man ◽  
Nik Norsyahariati Nik Daud
Keyword(s):  
Oxygen Demand ◽  
High Strength ◽  
Performance Comparison ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Slaughterhouse Wastewater ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Cattle slaughterhouse wastewater (CSWW) with an average chemical oxygen demand (COD) and biochemical oxygen demand of 32,000 mg/L and 17,000 mg/L, respectively, can cause a severe environmental hazard if discharged untreated. Conventional upflow anaerobic sludge blanket (UASB) reactor is used in the treatment of slaughterhouse wastewater to meet the discharge standard limit of wastewater discharge set by the Department of Environment Malaysia (DOE). However, at higher loading rates the conventional systems are characterized by slow-growing microorganism resulting in long startup period, surface scum formation, and sludge washout. In this work, the performance of two laboratory scale (12 L) conventional (R1) and modified (R2) UASB reactors treating CSWW at mesophilic (36 ± 1 °C) condition were investigated. Both reactors were subjected to increasing organic loading rate (OLR) from 1.75 to 32 g L−1 day−1. The average COD, BOD5, and TSS removal efficiencies were ˃90%, at an OLR between 1.75 to 5 g L−1 day−1. The study revealed that R1 drastically reduced to 50, 53, and 43% with increasing OLR until 16 g L−1 day−1, whereas R2 maintained 76, 77, and 88% respectively, under the same OLR. Sign of reactor instability was very much pronounced in R1, showing poorly active Methanosaeta spp., whereas R2 showed a predominantly active Methanosarcina spp.

scholarly journals The Concept of Wastes to Energy Using Sugary Wastes

2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Sugar Mills ◽  
Anaerobic Sludge Blanket

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

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
Keyword(s):  
Loading Rate ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Trickling Filter ◽  
Small Communities ◽  
Capital Costs

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.

Impact of microaeration bioreactor on dissolved sulfide and methane removal from real UASB effluent for sewage treatment

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
Keyword(s):  
Sewage Treatment ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Sulfide Removal ◽  
Dissolved Sulfide ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket

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.

Effect of micro-nutrients in anaerobic degradation of sulfate laden organics

2004 ◽  
Vol 31 (3) ◽  
pp. 420-431 ◽  
Author(s):  
S K Patidar ◽  
Vinod Tare
Keyword(s):  
Anaerobic Degradation ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Sulfide Concentration ◽  
Anaerobic Baffled Reactor ◽  
Sulfide Toxicity ◽  
Anaerobic Sludge Blanket

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.

Mathematical modeling of upflow anaerobic sludge blanket (UASB) reactor treating domestic wastewater

2013 ◽  
Vol 67 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Tarek Elmitwalli
Keyword(s):  
Chemical Oxygen Demand ◽  
Dynamic Model ◽  
Empirical Model ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Model Based ◽  
Anaerobic Sludge Blanket

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.

A downflow hanging sponge (DHS) reactor for faecal coliform removal from an upflow anaerobic sludge blanket (UASB) effluent

2015 ◽  
Vol 72 (11) ◽  
pp. 2034-2044 ◽  
Author(s):  
Rosa Elena Yaya Beas ◽  
Katarzyna Kujawa-Roeleveld ◽  
Jules B. van Lier ◽  
Grietje Zeeman
Keyword(s):  
Oxygen Demand ◽  
Faecal Coliform ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Removal Capacity ◽  
Seed Crops ◽  
Anaerobic Sludge Blanket

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.

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