Treatment of anaerobically treated domestic wastewater using rotating biological contactor

2002 ◽  
Vol 45 (10) ◽  
pp. 371-376 ◽  
Author(s):  
A. Tawfik ◽  
B. Klapwijk ◽  
F. El-Gohary ◽  
G. Lettinga
Keyword(s):  
Domestic Wastewater ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Uasb Reactor ◽  
Small Scale ◽  
E Coli ◽  
Stage System ◽  
Stage 1 ◽  
Final Effluent ◽  
Post Treatment Process

A small-scale pilot plant consisting of a three-stage RBC has been investigated for the removal of E. coli, COD fractions and ammonia from the effluent of an UASB reactor treating domestic wastewater. The results obtained reveal that a three-stage system operated at a HRT of 3.0 h represents an effective post-treatment process. The remaining COD in the final effluent was only 51 (± 7) mgl−1. Ammonia concentration was reduced by 67 (± 7.6) %. The overall E. coli reduction was 1.39 log10 at an influent count of 6.5 log10 corresponding to an overall removal efficiency of 95.8 (± 4.7) %. However, according to prevailing standards, residual E. coli counts are still high for unrestricted reuse for irrigation purposes. When the system was operated at a HRT of 10 h, overall E. coli removal and ammonia reduction were 99.9 (± 0.05)% and 92 (± 6.5)% respectively. At a HRT of 10 h, recirculation of the 3rd stage effluent to the 1st stage reduced the residual of E. coli in the final effluent from 2 × 103 to 9.8 × 102/100ml. Moreover, the recirculation of nitrified effluent from the 3rd stage to the 1st stage increased ammonia removal in the stage 1 from 23 to 43%. This relatively high ammonia removal likely can be attributed to the supply of nitrifiers from 3rd stage to the 1st one.

Combined biological and physico-chemical treatment of filtered pig manure wastewater: pilot investigations

2002 ◽  
Vol 45 (12) ◽  
pp. 79-87 ◽  
Author(s):  
S. Kalyuzhnyi ◽  
V. Sklyar ◽  
A. Epov ◽  
I. Arkhipchenko ◽  
I. Barboulina ◽  
...  
Keyword(s):  
Chemical Treatment ◽  
Inorganic Nitrogen ◽  
Ammonia Removal ◽  
Uasb Reactor ◽  
Pig Manure ◽  
Fluidised Bed ◽  
Ambient Temperatures ◽  
Effluent Quality ◽  
Physico Chemical ◽  
Final Effluent

Combined biological and physico-chemical treatment of filtered pig manure wastewater has been investigated on the pilot installation operated under ambient temperatures (15-20°C) and included: i) UASB-reactor for elimination of major part of COD from the filtrate; (ii) stripper of CO2 + fluidised bed crystallisator for phosphate (and partially ammonia) removal from the anaerobic effluents in the form of insoluble minerals - struvite (MgNH4PO4) and hydroxyapatite (Ca5(PO4)3OH); (iii) aerobic-anoxic biofilter for polishing the final effluent (elimination of remaining BOD and nutrients). Under overall hydraulic retention time (HRT) for the system of 7.8 days, the total COD, inorganic nitrogen and total phosphorous removals were 88, 65 and 74%, respectively. A decrease of the overall HRT to 4.25 days led to 91, 37 and 82% removals for total COD, inorganic nitrogen and total phosphorus removals, respectively. The approaches for further improvement of effluent quality are discussed.

Treatment of domestic sewage in a combined UASB/RBC system. Process optimization for irrigation purposes

2003 ◽  
Vol 48 (1) ◽  
pp. 131-138 ◽  
Author(s):  
A. Tawfik ◽  
G. Zeeman ◽  
A. Klapwijk ◽  
W. Sanders ◽  
F. El-Gohary ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Domestic Wastewater ◽  
Nitrification Rate ◽  
Combined System ◽  
E Coli ◽  
Operational Temperature ◽  
Residual Values ◽  
Pre Treatment ◽  
Final Effluent ◽  
Very High

A Rotating Biological Contactor (RBC) was fed with raw domestic wastewater or anaerobic effluents. The experiments were conducted at increasing operational temperatures viz. 11, 20 and 30°C to assess the potential increase in removal efficiencies for the different COD fractions (CODtotal, CODsuspended, CODcolloidal and CODsoluble), E. coli and in the nitrification rate. The results clearly show that, the RBC at HRT of 2.5 h and OLR of 47 gCOD/m2.d provided a very high residual CODtotal value of 228 mg/l when treating domestic wastewater. This was not the case as compared to the results obtained for the system when operated at the same HRT but at lower OLR's of 27, 20 and 14.5 g COD/m2.d with a UASB effluent at operational temperatures of 11, 20 and 30°C respectively. The residual CODtotal values amounted to 100, 85 and 72 mg/l in the final effluents. Moreover, a high removal of ammonia and low residual values of E. coli was found for the RBC when treating a UASB effluent at operational temperature of 30°C as compared to the situation for treatment of domestic wastewater and UASB effluent at lower temperatures of 11 and 20°C. It can be concluded that an efficient pre-treatment of sewage implies a substantial reduction of OLR applied to the RBC and consequently improves the residual of CODtotal, ammonia and E. coli in the final effluent. Therefore, this study supports using a combined system UASB/RBC for treatment of domestic wastewater for reuse in irrigation.

Ammonia removal by magnesium ammonium phosphate precipitation in industrial wastewaters

1997 ◽  
Vol 36 (2-3) ◽  
pp. 225-228 ◽  
Author(s):  
Olcay Tünay ◽  
Isik Kabdasli ◽  
Derin Orhon ◽  
Saadettin Kolçak
Keyword(s):  
Ammonium Phosphate ◽  
Domestic Wastewater ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Magnesium Ammonium Phosphate ◽  
The Public ◽  
Effluent Quality ◽  
Leather Tanning ◽  
Segregated Flow ◽  
Magnesium Ammonium

In this study, the theoretical basis and limitations of magnesium ammonium phosphate (MAP) precipitation are investigated and experimentally tested for leather tanning industry. The MAP precipitation is applied to leather tanning wastewaters for both segregated flows containing high ammonia concentrations and combined flows. Segregated flow treatment on smaller volumes of wastewater provided an ammonia concentration of down to 150 mg l−1 NH3-N. The resulting ammonia concentration of MAP precipitation on combined wastewater is at the level of domestic wastewater which eliminates the need of further nitrogen removal in the biological treatment and provides an effluent quality acceptable for the public sewer.

Optimization of the performance of an integrated anaerobic–aerobic system for domestic wastewater treatment

2008 ◽  
Vol 58 (1) ◽  
pp. 185-194 ◽  
Author(s):  
A. Tawfik ◽  
F. El-Gohary ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
Removal Efficiency ◽  
Suspended Solids ◽  
Substantial Reduction ◽  
Domestic Wastewater ◽  
Ammonia Concentration ◽  
Faecal Coliform ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Combined System ◽  
Anaerobic Sludge Blanket

A promising system consisting of Up-flow Anaerobic Sludge Blanket (UASB) and Down-Flow Hanging Sponge (DHS) system was investigated for removal of COD, BOD5 fractions, ammonia and faecal coliform from domestic wastewater. The combined system was operated at different HRTs of 16, 11 and 8 h. The results indicate that increasing the total HRT from 8 to 16 h significantly (p < 0.05) improves the CODtotal and BOD5 total removal mainly as a result of a higher removal of CODsoluble, BODsoluble, CODparticulate and BODparticulate. The main part of coarse suspended solids was removed in the UASB reactor (76.4±18%) and the remaining portion was adsorbed and/or enmeshed and degraded in the biomass of the DHS system. The combined system achieved a substantial reduction of total suspended solids (TSS) resulting in an average overall percentage removal of 94±6% (HRT = 16 h) and 89.5±7.8% (HRT = 8 h). Faecal coliform reduction was significantly improved when increasing the total HRT from 8 to 16 h. Residual counts of faecal coliform were 3.1 × 103/100 ml at a total HRT of 16 h, and 2.8 × 104/100 ml at total HRT of 8 h, corresponding to overall removal efficiency of 99.97±0.03 and 99.6±0.3% respectively. Despite the increase of ammonia concentration as a result of protein hydrolysis in the UASB reactor, a substantial removal of ammonia was achieved in the DHS system. The results obtained show that decreasing the OLR imposed to DHS system from 2.6 to 1.6 kg COD/m3·d significantly (p < 0.05) improves the removal efficiency of ammonia by a value of 29%. However, the removal efficiency of ammonia is not further increased when decreasing the OLR from 1.6 to 1.3 kg COD/m3·d. The discharged sludge from UASB + DHS system exerts a good settling property and partially stabilized. DHS profile results have shown that the major part of COD, BOD5, and TSS was removed in the upper part of the system, consequently, the nitrification process was occurring in the lower part of the DHS system.

scholarly journals Biomass granulation in an upflow anaerobic sludge blanket reactor treating 500 m3/day low-strength sewage and post treatment in high-rate algal pond

2017 ◽  
Vol 76 (5) ◽  
pp. 1234-1242
Author(s):  
Pritha Chatterjee ◽  
M. M. Ghangrekar
Keyword(s):  
Ammonia Removal ◽  
Phosphate Removal ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Probable Number ◽  
Moving Bed ◽  
Anaerobic Sludge Blanket ◽  
Final Effluent

A pilot-scale upflow anaerobic sludge blanket-moving bed biofilm (UASB-MBB) reactor followed by a high-rate algal pond (HRAP) was designed and operated to remove organic matter, nutrients and pathogens from sewage and to facilitate reuse. For an influent chemical oxygen demand (COD) concentration of 233 ± 20 mg/L, final effluent COD was 50 ± 6 mg/L. Successful biomass granulation was observed in the sludge bed of the upflow anaerobic sludge blanket (UASB) reactor after 5 months of operation. Ammonia removal in HRAP was 85.1 ± 2.4% with average influent and effluent ammonia nitrogen concentrations of 20 ± 3 mg/L and 3 ± 1 mg/L, respectively. Phosphate removal after treatment in the HRAP was 91 ± 1%. There was a 2–3 log scale pathogen removal after treatment in HRAP with most probable number (MPN) of the final effluent being 600–800 per 100 mL, which is within acceptable standards for surface irrigation. The blackwater after treatment in UASB-MBBR-HRAP is being reused for gardening and landscaping. This proper hydro-dynamically designed UASB reactor demonstrated successful granulation and moving bed media improved sludge retention in UASB reactor. This combination of UASB-MBB reactor followed by HRAP demonstrated successful sewage treatment for a year covering all seasons.

Pathogen removal efficiency from UASB + BF effluent using conventional and UV post-treatment systems

2004 ◽  
Vol 50 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Keller ◽  
R.F. Passamani-Franca ◽  
F. Passamani ◽  
L. Vaz ◽  
S.T. Cassini ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Uv Irradiation ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Uasb Reactor ◽  
Salmonella Spp ◽  
E Coli ◽  
Helminth Eggs ◽  
Uv Reactor ◽  
Thermotolerant Coliforms

The aim of this study was to verify the efficiency of removal of microorganisms in effluents of a Wastewater Treatment Plant (WWTP) comprising an association of a UASB reactor followed by three submerged aerated biofilters (BAF) and one tertiary filter. The WWTP designed to treat domestic wastewater from a population of 1,000 inhabitants showed high removal efficiency for organic matter and suspended solids. Helminth eggs were also efficiently removed from the tertiary effluent and were found in the sludge from the UASB reactor; however, removal of bacteria in this system was very low. To enhance the efficiency of the system, the effluent from tertiary filters was submitted to UV disinfection in a real scale reactor. Our results showed that UV irradiation was very effective at lowering the concentrations of E. coli, thermotolerant coliforms and coliphages to acceptable levels for agricultural reuse. Salmonella spp. and helminth eggs were seeded into the tertiary effluent before passing through the UV reactor. Salmonella was not found in the final effluent, but helminth eggs were not completely inactivated by UV irradiation and viable eggs were detected after 28 d of incubation.

Performance evaluation of a simple wastewater treatment system comprised by UASB reactor, shallow polishing ponds and coarse rock filter

2008 ◽  
Vol 58 (6) ◽  
pp. 1313-1319 ◽  
Author(s):  
Marcos von Sperling ◽  
Carolina Moreira Oliveira ◽  
Juliana G. B. Andrada ◽  
Valéria M. Godinho ◽  
Fernando A. L. Assunção ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Ammonia Removal ◽  
Treatment System ◽  
Uasb Reactor ◽  
E Coli ◽  
Wastewater Treatment System ◽  
Treatment Processes ◽  
Natural Treatment ◽  
In Series ◽  
Overall Performance

The work investigates a small full-scale wastewater treatment system comprised by the following units in series: UASB reactor, three polishing ponds and one coarse rock filter. The overall performance of the system is analyzed based on three years of monitoring using physical-chemical and biological parameters. Good organic matter, suspended solids and ammonia removal is achieved, together with excellent coliform removal (5.70 log units). Mean effluent concentrations of the main parameters are: BOD: 39 mg/L; COD: 109 mg/L; SS = 41 mg/L; ammonia: 10 mg/L; E. coli: 540 MPN/100 mL, indicating compliance with many regulations for effluent discharge and reuse. Main algal classes found in the ponds and final effluent were chlorophyta and euglenophyta. The system is completely unmechanized and has a relatively small total hydraulic retention time (less than 13 days), compared with most natural treatment processes. No sludge removal from the ponds and filter has been necessary so far.

Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1457-1466 ◽  
Author(s):  
Kazuhiro Tanaka ◽  
Minoru Tada ◽  
Mitsuo Ito ◽  
Noritugu Shimizu
Keyword(s):  
Suspended Solids ◽  
Fine Particles ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Particle Fraction ◽  
Effluent Quality ◽  
Rotating Biological Contactors ◽  
Activated Sludge Processes ◽  
Fraction Method ◽  
Final Effluent

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.

Basic Studies on Phosphorus Removal by the Contact Aeration Process Using Iron Contactors

1991 ◽  
Vol 23 (4-6) ◽  
pp. 641-650 ◽  
Author(s):  
S. Haruta ◽  
T. Takahashi ◽  
T. Nishiguchi
Keyword(s):  
Corrosion Rate ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Small Scale ◽  
Combined Method ◽  
Sulfate Reducing ◽  
Biological Sludge ◽  
Aeration Process ◽  
Basic Studies ◽  
Volumetric Loading

The authors have developed what we call the submerged iron contactor process as a simple and inexpensive phosphorus removal method for small-scale plants disposing of domestic wastewater and household wastewater treatment tanks. In this method iron contactors are submerged in biological treatment tanks, where phosphate anions in wastewater are combined with iron cations produced through corrosion of the contactors, and the compound thus produced is precipitated and removed together with biological sludge. In these studies, laboratory experiments were made on the contact aeration process combined with the above-mentioned method, and the following findings were obtained. (1) It is desirable to treat wastewater by making use of corrosion by sulfate-reducing bacteria instead of corrosion by oxygen dissolved in wastewater, to conduct a stable phosphorus removal by this combined method. (2) The corrosion rate of iron contactors is affected by the volumetric loading of BOD in the tanks where they are submerged. (3) Assuming that an iron contactor continues to suffer corrosion evenly all over the surface when our combined method is applied, it is estimated that the corrosion rate is about 1mm or less in 30 years.

Microbiological performance and salmonella dynamics in a wastewater depuration pond system of southeastern spain

1995 ◽  
Vol 31 (12) ◽  
pp. 239-248 ◽  
Author(s):  
Ana Emparanza-Knörr ◽  
Francisco Torrella
Keyword(s):  
Fecal Coliform ◽  
No Reduction ◽  
Agar Medium ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Fecal Coliforms ◽  
Selective Media ◽  
E Coli ◽  
The Village ◽  
Final Effluent

The Salmonella presence and the microbiological quality indicators, total and fecal coliforms and coliphages of E. coli C, have been studied in a overloaded wastewater lagoon system treating urban wastewatrers of the village of Guardamar del Segura (Alicante, Spain). Classical microbiological technology to detect salmonellae was used, including pre-enrichment, enrichment, selective media plating and biochemical and serological confirmation. Water was physicochemically characterized according to COD, SS, temperature, pH and dissolved oxygen. The selective migration step through Rappaport-Vassiliadis semisolid agar medium was essential for the consistent detection of Salmonella in the different lagoon effluents. Total and fecal coliform levels of up to 105-106 MPN/100 ml were detected in the final effluent. High coliphage concentrations of 103-104 pfu/ml were also found in the effluent waters. Salmonella was always detected in 100 ml samples and eventually reached an order of value of 103 MPN/100 ml. Total coliform reduction was higher in the anaerobic ponds whereas fecal coliforms were more efficiently eliminated in the facultative (mostly “anoxic”) lagoons. Coliphage reduction was higher in the facultative lagoons when compared to the anaerobic ponds. On many occasions, no reduction or eventual increment of the concentration of salmonellae was detected in the effluents from the anaerobic ponds compared to concentrations of the patohogen in the influent raw wasterwaters. The possibility exists for a capacity of Salmonella to multiply in the anoxic phase of the wastewater treatment, but the presence of microorganisms in raw sewage waters which could maskSalmonella detection with the enrichment methodology employed cannot be ruled out.

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