Denitrification of nitrate-contaminated groundwater using a simple immobilized activated sludge bioreactor

2012 ◽  
Vol 66 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Zhengfang Ye ◽  
Feng Wang ◽  
Haitao Bi ◽  
Zhongyou Wang ◽  
Guo-hua Liu
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Nitrite Accumulation ◽  
Activated Sludge System ◽  
N Concentration ◽  
Immobilized Microorganisms ◽  
N Loading ◽  
Anaerobic Biomass

A simple anaerobic-activated sludge system, in which microorganisms are immobilized by a novel functional carrier, was used for removing nitrate in groundwater. The operating conditions, including hydraulic retention time (HRT), C/N ratio, temperature and NO3−-N loading concentration were investigated. The NO3−-N concentration, residual chemical oxygen demand (COD) and nitrite accumulation were used as indicators to assess the water quality of the effluent. The anaerobic biomass loading capacity in the carrier was 12.8 g/L and the denitrifying Pseudomonas sp. and Rhodocyclaceae bacterium were dominant among the immobilized microorganisms in the anaerobic-activated sludge. Under operating conditions of HRT= 1.5 h, C/N= 2–3 and T= 16.8–20 °C, the removal efficiency of NO3−-N exceeded 93%, corresponding to a relatively high denitrification rate of 0.73 kg NO3−-N m−3 d−1, when the NO3−-N loading concentration was 50 mg/L. The NO3−-N concentration of the effluent always met regulatory criteria for drinking water (<10 mg/L) in the main developed and developing countries. The effluent COD was also below 10 mg/L. Although some nitrite accumulated (0–1.77 mg/L) during the operating period, it can be decreased through adjusting the operating pH and HRT. The immobilized activated sludge system may be useful for the removal of nitrate from groundwater.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Relationships between Population Dynamics and Operating Parameters in an Activated Sludge-Plant by Statistical Analysis

1992 ◽  
Vol 25 (4-5) ◽  
pp. 399-400 ◽  
Author(s):  
L. Cingolani ◽  
M. Cossignani ◽  
R. Miliani
Keyword(s):  
Population Dynamics ◽  
Statistical Analysis ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Statistical Analyses ◽  
Operating Parameters ◽  
Aerobic Treatment

Statistical analyses were applied to data from a series of 38 samples collected in an aerobic treatment plant from November 1989 to December 1990. Relationships between microfauna structure and plant operating conditions were found. Amount and quality of microfauna groups and species found in activated sludge proved useful to suggest the possible causes of disfunctions.

PACTTM process for treatment of kraft mill effluent

1997 ◽  
Vol 35 (2-3) ◽  
pp. 283-290 ◽  
Author(s):  
R. M. Narbaitz ◽  
R. L. Droste ◽  
L. Fernandes ◽  
K. J. Kennedy ◽  
D. Ball
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Operating Conditions ◽  
Activated Sludge Process ◽  
Conventional Activated Sludge ◽  
Adsorbable Organic Halides ◽  
Organic Halides ◽  
Solids Retention ◽  
Year 2000

The PACTTM process (powdered activated carbon addition to the activated sludge process) was evaluated for the treatment of Kraft pulp mill wastewater in a series of bench scale experiments. Possibly due to the relatively low strength wastewater, the PACTTM process with carbon doses between 0.5 and 1.0 g/L of influent only performed marginally better than the conventional activated sludge process. Chemical oxygen demand and toxicity, evaluated with the Microtox® assay, were among the parameters monitored. For the operating conditions tested the solids retention time had no impact on performance. The main improvement was increased in adsorbable organic halides (AOX) removal, the magnitude of the improvement was dependent on the wastewater batch and the carbon dose. However conventional activated sludge treatment will meet Ontario's year 2000 AOX regulations. An empirical model from the literature described the data fairly well.

scholarly journals Biofloc production in activated sludge system treating shrimp farming effluent

2018 ◽  
Vol 23 (6) ◽  
pp. 1143-1152 ◽  
Author(s):  
Sandra Tedde Santaella ◽  
Maria do Socorro Vale ◽  
Clara Cabral Almeida ◽  
Willame de Araújo Cavalcante ◽  
Alberto Jorge Pinto Nunes ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Shrimp Farming ◽  
Effluent Treatment ◽  
Nitrogen Compounds ◽  
Suitable Alternative ◽  
Activated Sludge System ◽  
Feed Cost ◽  
Shrimp Feed ◽  
Farming Industry

ABSTRACT The release of wastewater and the shrimp feed cost are the main challenges faced by the shrimp farming industry. An alternative solution to both problems is biofloc production in a unit external to the farm, in an activated sludge system for effluent treatment. The treatment system’s influent was composed of the shrimp farm wastewater supplemented with urea and sugarcane molasses. The results show that the average removal of chemical oxygen demand was 71% and the average biofloc production in the reactor was approximately 1.5g.L-1. Adding molasses to the influent contributed to the increase in the quantity and diversity of existing microorganisms that are beneficial to cultured shrimp. The mass balance of nitrogen compounds confirmed that nitrification occurred in the system. Therefore, the use of the activated sludge system is a viable and environmentally suitable alternative to produce bioflocs and shrimp farming effluent treatment.

Reduction of chemical oxygen demand in a conventional activated sludge system treating coke oven wastewater

2020 ◽  
Vol 273 ◽  
pp. 122482 ◽  
Author(s):  
Viktória Pitás ◽  
Viola Somogyi ◽  
Árpád Kárpáti ◽  
Péter Thury ◽  
Tamás Fráter
Keyword(s):  
Activated Sludge ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Coke Oven ◽  
Conventional Activated Sludge ◽  
Activated Sludge System

scholarly journals Performance of Novel Contact Stabilization Activated Sludge System on Domestic Wastewater Treatment

2015 ◽  
Vol 19 (2) ◽  
pp. 7
Author(s):  
Andrés Felipe Torres Franco ◽  
Nancy Vásquez Sarria ◽  
Jenny Rodriguez Victoria
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Growth Zone ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Activated Sludge System ◽  
Suspended Growth ◽  
Removal Efficiencies ◽  
Final Effluent

A pilot-scale study was conducted to evaluate a traditional contact stabilization activated sludge system (CSASC) and a modified CSAS (CSASM) treating domestic wastewater. The CSASC system was comprised of a contact reactor (CR), a stabilization reactor (SR) and a secondary settler (SS); the CSASM included a second CR, a second SS (CR2 and SS2), and a modified SR (SRM) divided into four zones: an attached-suspended growth zone which allowed the system to reach an average sludge retention time close to 36 d and favored the occurrence of nitrification; an anoxic zone for denitrification occurrence; an aerated suspended growth zone with a high presence of organic carbon; and an additional aerated suspended growth zone with a high ammonia concentrations environment. The CSASC’s removal efficiencies of chemical oxygen demand (COD) and total ammonia nitrogen (TAN) were respectively 94±4 % and 53±12%; whereas CSASM’s efficiencies were 88±7% for COD and 92±7% for TAN. Concentrations of TAN and NO3 --N in the CSASC’s final effluent were 14.3±5.2 and 5.0±2.9 mg×L-1; and 4.8±4.4 and 9.1±5.8 mg×L-1 in the CSASM’s final effluent. Results demonstrated that the proposed configuration obtained higher nitrogen removal efficiencies than traditional CSAS.</p>

Adaptation of microbial communities in activated sludge to 1-decyl-3-methylimidazolium bromide

2016 ◽  
Vol 74 (5) ◽  
pp. 1227-1234 ◽  
Author(s):  
Dorota Gendaszewska ◽  
Ewa Liwarska-Bizukojc
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Biotic Index ◽  
Activated Sludge Process ◽  
Control Test ◽  
Chemical Oxygen Demand Removal ◽  
Microbial Composition ◽  
Mean Values ◽  
Activated Sludge System ◽  
High Level

The effects of 1-decyl-3-methylimidazolium bromide on activated sludge process and microbial composition were investigated. Ionic liquid (IL) was dosed continuously to the laboratory activated sludge system at an influent concentration from 1 to 20 mg l−1 for about 1 month. As compared to the control test, mean values of degree of chemical oxygen demand removal and degree of biochemical oxygen demand removal were almost remaining constant at a high level, equaling 92.6% and 98.1%, respectively. In addition, no influence of IL on size and shape of flocs was observed. The values of the sludge biotic index indicate that sludge exposed on IL was stable and very well colonized with good biological activity. Increases in Proteobacteria (mainly Variovorax sp., Vogesella sp., Hydrogenophaga sp.), Bacteroidetes (mainly Lewinella sp., Haliscomenobacter sp., Runella sp.) and Nitrospirae were detected in sludge adapted to IL compared to the control system. The results showed that activated sludge can adapt to IL present in wastewater.

scholarly journals A Practical Methodology for Forecasting the Impact of Changes in Influent Loads and Discharge Consents on Average Energy Consumption and Sludge Production by Activated Sludge Wastewater Treatment

2021 ◽  
Vol 13 (21) ◽  
pp. 12293
Author(s):  
Catarina Silva ◽  
Maria João Rosa
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Activated Sludge ◽  
Average Energy ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Limit Values ◽  
Oxygen Requirements ◽  
The Impact ◽  
Sludge Production

This paper proposes a simple and easy-to-use methodology for forecasting the impact of changes in influent chemical oxygen demand (COD) and in the emission limit values (ELVs) of COD and total nitrogen on average energy requirements for aeration and sludge production by activated sludge wastewater treatment plants (WWTPs). The methodology is based on mass balances of sludge production and oxygen requirements for carbonaceous material biodegradation and/or nitrification, oxygen transfer and aeration equipment efficiency. Using average values of historical data of regular monitoring (water quality and operating conditions) WWTP-specific equations of oxygen requirements, energy consumption and sludge production are derived as a function of influent COD and influent N-total, which may be used to quantify the impact of influent and ELV changes. The methodology was tested in five extended aeration WWTPs for three scenarios established by the utility. The results show that increasing influent COD, from 900 to 1300 mg/L, for example, significantly increases the energy consumption by 49% and sludge production by 53%. For influent 54–68 mg/L N-total, imposing 15 mgN/L ELV results in a 9–26% increase in energy consumption. The COD ELV change studied (season-specific, from 150 mg/L 12 months/year to 125 mg/L 8 months/year to 100 mg/L 4 months/year) increases the energy consumption by 1.8–2.6% and the sludge production by 4.3–5.4%.

Effects of high sodium chloride concentrations on activated sludge treatment

1995 ◽  
Vol 31 (9) ◽  
pp. 61-72 ◽  
Author(s):  
M. F. Hamoda ◽  
I. M. S. Al-Attar
Keyword(s):  
Activated Sludge ◽  
Biomass Concentration ◽  
Experimental Conditions ◽  
High Sodium ◽  
Effluent Quality ◽  
Toc Removal ◽  
Activated Sludge System ◽  
Biological Solids ◽  
Solids Retention

The performance and kinetics of the activated sludge process treating wastewaters of freshwater and salinewater (10 g/l NaCl and 30 g/l NaCl) origin were investigated using bench-scale, completely mixed reactors operated at different biological solids retention times (BSRT's) in the range of 3 to 20 d and organic loadings in the range of 0.5 to 2.0 kg COD/kg VSS.d. It has been found that the organic (COD or TOC) removal efficiency and the effluent quality of the activated sludge system were not deteriorated as a result of constant application of NaCl to acclimated biomass. However, the salinity of the effluent increased. The salt did not inhibit biomass growth under the experimental conditions studied but rather increased the biomass concentration in the reactors due to selection of salt tolerant microbial species. It has been demonstrated that kinetic models developed for the freshwater activated sludge system can be used successfully for the salinewater system. Biokinetic coefficients were determined which can be used for process design.

Biotic and abiotic bisphenol-A removal from wastewater by activated sludge: effects of temperature, biomass, and bisphenol-A concentrations

2015 ◽  
Vol 73 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Olcayto Keskinkan ◽  
Behzat Balci
Keyword(s):  
Bisphenol A ◽  
Activated Sludge ◽  
High Performance ◽  
Oxygen Demand ◽  
Kinetic Studies ◽  
Control Groups ◽  
Reaction Rate Constants ◽  
Activated Sludge System ◽  
Bpa Removal ◽  
And Control

In this study, bisphenol-A (BPA) removal from synthetic wastewaters using a laboratory-scale activated sludge system was achieved. Activated (biotic) sludge was used for BPA elimination, whereas inactivated (abiotic) sludge was used during the adsorption study. In each step, six different BPA concentrations (5, 10, 20, 30, 40, and 50 mg L−1) were tested, and temperatures were set to 10, 20, and 30 °C in the shakers. Four different activated sludge concentrations (1,000, 2,000, 3,000, and 4,000 mgTSS L−1) were applied in the biotic study, and only 2,000 mgTSS L−1 was used in the abiotic study. After settlement of the sludge in the shakers, supernatants and control groups were filtered and analyzed for BPA using high performance liquid chromatography. In the biotic study, BPA and chemical oxygen demand (COD) concentrations were reduced at 100% and 99% levels, respectively. However, the BPA concentrations during the abiotic study changed slightly at varying temperatures, whereas there was no change of BPA concentration observed in the control groups. Results indicate that the main factor of BPA removal in an activated sludge system is biological. Kinetic studies were also conducted. BPA removal was best fit to zero- and first-order reaction kinetics, and the reaction rate constants are provided in this paper.

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