Simultaneous biological removal of sulphide and nitrate by autotrophic denitrification in an activated sludge system

2006 ◽  
Vol 53 (12) ◽  
pp. 91-99 ◽  
Author(s):  
I. Manconi ◽  
A. Carucci ◽  
P. Lens ◽  
S. Rossetti
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Electron Donor ◽  
Product Formation ◽  
Fish Analysis ◽  
Autotrophic Denitrification ◽  
Biological Removal ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
Denitrification Process

The feasibility of an autotrophic denitrification process in an activated sludge reactor, using sulphide as the electron donor, was tested for simultaneous denitrification and sulphide removal. The reactor was operated at nitrate (N) to sulphide (S) ratios between 0.5 and 0.9 to evaluate their effect on theN-removal efficiency, the S-removal efficiency and the product formation during anoxic oxidation of sulphide. One hundred per cent removal of both nitrate and sulphide was achieved at a NLR of 7.96 mmol N·L−1·d−1 (111.44 mg NO3−-N·L−1·d−1) and at a N/S ratio of 0.89 with complete oxidation of sulphide to sulphate. The oxygen level in the reactor (10%) was found to influence the N-removal efficiency by inhibiting the denitrification process. Moreover, chemical (or biological) oxidation of sulphide with oxygen occurred, resulting in a loss of the electron donor. FISH analysis was carried out to study the microbial population in the system.

A comparison of NH4/NO3 control strategies for alternating activated sludge processes

1999 ◽  
Vol 39 (4) ◽  
pp. 93-102 ◽  
Author(s):  
L. J. S. Lukasse ◽  
K. J. Keesman ◽  
A. Klapwijk ◽  
G. van Straten
Keyword(s):  
Activated Sludge ◽  
Time Delays ◽  
Control Strategies ◽  
Treatment Plant ◽  
Biological Processes ◽  
Effluent Quality ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
The Difference ◽  
Activated Sludge Processes

Four control strategies for N-removal in alternating activated sludge plants (ASP's) are compared: 1. timer-based, 2. switching the aeration on/off when depletion of nitrate/ammonium is detected, 3. switching the aeration on/off when ammonium crosses an upper/lower-bound, 4. the newly developed adaptive receding horizon optimal controller (ARHOC) as presented in Lukasse et al. (1997). The comparison is made by simulating the controllers' application to an alternating continuously-mixed activated sludge reactor preceded by a small anoxic reactor for predenitrification. The biological processes in the reactors are modelled by the activated sludge model no. 1. Realistic influent patterns, measured at a full-scale wastewater treatment plant, are used. The results show that three totally different controllers (timer-based, NH4-bounds based and ARHOC) can achieve a more or less equal effluent quality, if tuned optimally. The difference mainly occurs in the sensitivity to suboptimal tunings. The timer-based strategy has a higher aeration demand. The sensitivity of the ARHOC controller to sub-optimal tuning, known measurement time delays and changing plant loads is significantly less than that of the other controllers. Also its tuning is more natural and explicit.

Cross effect of temperature, pH and free ammonia on autotrophic denitrification process with sulphide as electron donor

Chemosphere ◽  
2014 ◽  
Vol 97 ◽  
pp. 10-15 ◽  
Author(s):  
Carmen Fajardo ◽  
Mabel Mora ◽  
Isaac Fernández ◽  
Anuska Mosquera-Corral ◽  
José Luis Campos ◽  
...  
Keyword(s):  
Electron Donor ◽  
Free Ammonia ◽  
Effect Of Temperature ◽  
Autotrophic Denitrification ◽  
Cross Effect ◽  
Denitrification Process

Comparison of particulate pyrite autotrophic denitrification (PPAD) and sulfur oxidizing denitrification (SOD) for treatment of nitrified wastewater

2016 ◽  
Vol 75 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Shuang Tong ◽  
Laura C. Rodriguez-Gonzalez ◽  
Chuanping Feng ◽  
Sarina J. Ergas
Keyword(s):  
Packed Bed ◽  
Product Formation ◽  
Electron Donors ◽  
Autotrophic Denitrification ◽  
Reduced Sulfur Compounds ◽  
N Removal ◽  
Sulfur Oxidizing ◽  
Reduced Sulfur ◽  
Carry Over ◽  
Set Up

The use of reduced sulfur compounds as electron donors for biological denitrification has the potential to reduce chemical and sludge disposal costs as well as carry-over of organic carbon to the effluent that often occurs with heterotrophic denitrification. Although a number of prior studies have evaluated sulfur oxidizing denitrification (SOD), no prior studies have evaluated particulate pyrite autotrophic denitrification (PPAD) in continuous flow systems. Bench-scale upflow packed bed reactors (PBRs) were set up to compare denitrification rates, by-product production and alkalinity consumption of PPAD and SOD. At an empty bed contact time of 2.9 h, average NO3−-N removal efficiencies were 39.7% and 99.9% for PPAD and SOD, respectively. Although lower denitrification rates were observed with PPAD than SOD, lower alkalinity consumption and reduced sulfur by-product formation (SO42−, S2− and SO32− plus S2O32−) were observed with PPAD. Furthermore, higher denitrification rates and lower by-product production was observed for SOD than in prior studies, possibly due to the media composition, which included sand and oyster shells. The results show that both pyrite and elemental sulfur can be used as electron donors for wastewater denitrification in PBRs.

Filtration characteristics of immersed coarse pore filters in an activated sludge system for domestic wastewater reclamation

2007 ◽  
Vol 55 (1-2) ◽  
pp. 51-58 ◽  
Author(s):  
G.T. Seo ◽  
B.H. Moon ◽  
Y.M. Park ◽  
S.H. Kim
Keyword(s):  
Activated Sludge ◽  
Domestic Wastewater ◽  
Woven Fabric ◽  
Wastewater Reclamation ◽  
Fabric Filter ◽  
Tubular Type ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
Filtration Area ◽  
Plate Type

The filtration characteristics of two different module configurations with coarse pore filter (non-woven fabric) were investigated for sludge floc separation in an activated sludge reactor for domestic wastewater reclamation. A polypropylene non-woven fabric filter (35 g/m2) was used for the two different module configurations, one flat and one tubular type, each with a filtration area of 0.052 m2. The different module types, submerged in the oxic compartment of A/O (anaerobic/oxic) type reactors, were operated simultaneously. The filtration fluxes were gradually increased from 0.5 to 1.2 and 1.73 m/d. The filtration pressures were more stably maintained for the tubular type module than the plate type. The tubular type module installed horizontally with two-side suction showed less filtration pressures than the tubular type module installed vertically with one-side suction. The solid separation was significantly high showing less than 5 mg/L effluent solids. The organic and T-N removal efficiencies were around 95 and 50%, respectively. The 85% removal of T-P was achieved with 20 mg/L injection of PAC (poly-aluminum chloride).

scholarly journals Nitrate Removal from Actual Wastewater by Coupling Sulfur-Based Autotrophic and Heterotrophic Denitrification under Different Influent Concentrations

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2913
Author(s):  
Feng Liu ◽  
Suqin Wang ◽  
Xuezhi Zhang ◽  
Feiyue Qian ◽  
Yaobing Wang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrate Removal ◽  
Operating Conditions ◽  
Coupled Systems ◽  
Polluted Water ◽  
Sequencing Analysis ◽  
Autotrophic Denitrification ◽  
Actual Wastewater ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Contamination of wastewater with organic-limited nitrates has become an urgent problem in wastewater treatment. The cooperating heterotrophic with sulfur autotrophic denitrification is an alternative process and the efficiency has been assessed in many studies treating simulated wastewater under different operating conditions. However, due to the complex and diverse nature of actual wastewater, more studies treating actual wastewater are still needed to evaluate the feasibility of collaborative denitrification. In this study, lab-scale experiments were performed with actual nitrate polluted water of two different concentrations, with glucose and sodium thiosulfate introduced as mixed electron donors in the coupling sulfur-based autotrophic and heterotrophic denitrification. Results showed that the optimum denitrification performance was exhibited when the influent substrate mass ratio of C/N/S was 1.3/1/1.9, with a maximum denitrification rate of 3.52 kg NO3−-N/(m3 day) and nitrate removal efficiency of 93% in the coupled systems. Illumina high-throughput sequencing analysis revealed that autotrophic, facultative, and heterotrophic bacteria jointly contributed to high nitrogen removal efficiency. The autotrophic denitrification maintained as the predominant process, while the second most prevalent denitrification process gradually changed from heterotrophic to facultative with the increase of influent concentration at optimum C/N/S ratio conditions. Furthermore, the initiation of dissimilatory nitrate reduction to ammonium (DNRA) was very pivotal in promoting the entire denitrification process. These results suggested that sulfur-based autotrophic coupled with heterotrophic denitrifying process is an alternative and promising method to treat nitrate containing wastewater.

Petro® concept: a tentative approach to biological phosphorus removal incorporating waste stabilisation ponds

2000 ◽  
Vol 42 (10-11) ◽  
pp. 223-229 ◽  
Author(s):  
O. V. Shipin ◽  
P. G. Meiring ◽  
J. R. Hoffmann
Keyword(s):  
Activated Sludge ◽  
High Rate ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Waste Stabilisation Ponds ◽  
Biological Removal ◽  
Activated Sludge Reactor ◽  
Calcium Magnesium ◽  
Additional Process ◽  
Biological Phosphorus

Ponding which is usually considered a low tech process can be successfully integrated with downstream Biological Nutrient Removal (BNR) facility. The PETRO system incorporating ponds and downstream trickling filter (TF) or activated sludge process (ASP) is a technology which offers simplicity of O and M combined with biological removal of P and N. It is feasible to produce in a primary facultative pond with a deep fermentation pit quantities of readily biodegradable substrates sufficient to meet the requirements of phosphate accumulating organisms (PAO) in a downstream BNR facility. Malodorous conditions are dealt with by high rate recirculation. This novel low tech approach is a step towards a more straightforward BNR process. PETRO concept features phenomenon of algae-assisted chemical P-removal in activated sludge reactor. The process results in precipitation of inorganic phosphates apparently in a form of calcium/magnesium salts. Possible mechanism of this additional process which removes up to several milligrams per litre of inorganic P is discussed.

scholarly journals Effect of current on biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) for nitrate removal from wastewater

2021 ◽  
Vol 267 ◽  
pp. 02021
Author(s):  
Hengyuan Liu ◽  
Chenhe Zhang
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Nitrate Removal ◽  
Great Influence ◽  
Current Intensity ◽  
Autotrophic Denitrification ◽  
Nitrite Production ◽  
Coupled Process ◽  
Denitrification Process

The biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) was used to remove nitrate in groundwater, and the effect of current intensity on the denitrification characteristics of the coupled process was explored. Current intensity had a great influence on the denitrification effect of the coupled process, the maximum nitrate removal efficiency of 99.9% and lowest nitrite production were gained under the optimum current density of 100 mA. Moreover, the accumulation concentration of SO42- increased gradually with the increase of current intensity. With the increase of current intensity, the proportion of hydrogen autotrophic denitrification decreased, while the proportion of sulfur autotrophic denitrification increased.

Application of ultrasound and air stripping for the removal of aromatic hydrocarbons from spent sulfidic caustic for use in autotrophic denitrification as an electron donor

2013 ◽  
Vol 67 (7) ◽  
pp. 1497-1502 ◽  
Author(s):  
Jae-Ho Lee ◽  
Jeung-Jin Park ◽  
Gi-Choong Choi ◽  
Im-Gyu Byun ◽  
Tae-Joo Park ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Electron Donor ◽  
Aromatic Hydrocarbons ◽  
Ultrasound Irradiation ◽  
Phenol Removal ◽  
Autotrophic Denitrification ◽  
Air Stripping ◽  
Spent Sulfidic Caustic ◽  
Study Laboratory ◽  
Sulfidic Caustic

Spent sulfidic caustic (SSC) produced from petroleum industry can be reused to denitrify nitrate-nitrogen via a biological nitrogen removal process as an electron donor for sulfur-based autotrophic denitrification, because it has a large amount of dissolved sulfur. However, SSC has to be refined because it also contains some aromatic hydrocarbons, typically benzene, toluene, ethylbenzene, xylene (BTEX) and phenol that are recalcitrant organic compounds. In this study, laboratory-scale ultrasound irradiation and air stripping treatment were applied in order to remove these aromatic hydrocarbons. In the ultrasound system, both BTEX and phenol were exponentially removed by ultrasound irradiation during 60 min of reaction time to give the greatest removal efficiency of about 80%. Whereas, about 95% removal efficiency of BTEX was achieved, but not any significant phenol removal, within 30 min in the air stripping system, indicating that air stripping was a more efficient method than ultrasound irradiation. However, since air stripping did not remove any significant phenol, an additional process for degrading phenol was required. Accordingly, we applied a combined ultrasound and air stripping process. In these experiments, the removal efficiencies of BTEX and phenol were improved compared to the application of ultrasound and air stripping alone. Thus, the combined ultrasound and air stripping treatment is appropriate for refining SSC.

Evaluation of Sequencing Batch Biofilm Reactor for Biological Nutrient Removal from Simulated Domestic Wastewater

2012 ◽  
Vol 209-211 ◽  
pp. 2049-2052
Author(s):  
Chang Hang Wu ◽  
Wei Jun Zhang
Keyword(s):  
Removal Efficiency ◽  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Biofilm Reactor ◽  
Biological Nutrient Removal ◽  
Sequencing Batch Biofilm Reactor ◽  
N Removal ◽  
Nitrification Process ◽  
Nitrification And Denitrification ◽  
Denitrification Process

A lab-scale sequencing batch biofilm reactor (SBBR) was developed to treat domestic wastewater. After one year’s operation, the results were obtained as follows: when the reaction carried out in 3 h, COD removal efficiency approached or reached the maximal value, up to 90%. The nitrification process of NH3-N needed 4 h, and NH3-N removal efficiency reached the maximal value. Moreover, according to the variation of TN , NO3--N and NO2--N concentration in the nitrification and denitrification process, when NH3-N degraded to zero or the minimal value, just two cycles ending, it means that the SBBR system completed the nitrification and denitrification process.

Treatment of bleaching effluent in sequential activated sludge and nitrification systems

1999 ◽  
Vol 40 (1) ◽  
pp. 269-274
Author(s):  
U. Altınbaş ◽  
V. Eroǧlu ◽  
İ. Öztürk
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Degradation Mechanisms ◽  
Organic Loading ◽  
Loading Rates ◽  
Toc Removal ◽  
Activated Sludge Reactor ◽  
Removal Efficiencies

Dechlorination and degradation mechanisms of bleaching effluent were studied in a sequential activated sludge and nitrification reactor. Effect of bleaching effluent on dechlorination performances was examined at various organic loading rates in the system. Released inorganic chlorine (ICl) was increased from 4.5 to 8.5 mg/l in the first stage activated sludge reactor while it was decreased from 10 to 2.5 mg/l in the subsequent nitrification reactor. Removal efficiencies of AOX were found as 15-33% and 5-25% in the activated sludge and the nitrification reactor respectively. TOC removal efficiencies achieved were 67-85% in the activated sludge reactor. The removal efficiency of NH4 achieved 94-98% in the nitrification reactor.

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