scholarly journals Effect of saline drainage water on performance of denitrification bioreactors

2020 ◽  
Author(s):  
Sasan Faramarzmanesh ◽  
Mahmoud Mashal ◽  
Seyyed Ebrahim Hashemi Garmdareh
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Nitrate Removal ◽  
Drainage Water ◽  
The Other ◽  
Salinity Level ◽  
Main Element ◽  
Biological Denitrification ◽  
Removal Process ◽  
Positive Effect

Abstract Excessive use of nitrate fertilizers in agriculture causes harm to humans and the environment. The most suitable nitrate removal process is heterotrophic biological denitrification. The purpose of the present study was to evaluate the performance of three shapes of denitrification bioreactors: triangular, rectangular and semicircular. The main element that was used to remove nitrate was beech woodchips. The concentration of inlet nitrate was 75 mg/l and the salinity of the solution was 1 ds/m and 5 ds/m, for a period of six months. The results showed that the efficiency of the triangular bioreactor with a salinity level of 1 ds/m was 90%, which is more efficient than the rectangular and semicircular bioreactors with performances of 55.8% and 53.8%, respectively. The results also indicated that at a salinity level of 5 ds/m, the semicircular bioreactor with a performance of 50.8% inlet nitrate removal was the best of the three shapes of bioreactors tested, the efficiencies of the triangular and rectangular bioreactors were 49.9% and 48.6% respectively. Also, it was observed that at the salinity level of 1 ds/m, a high hydraulic retention time had a high positive effect on denitrification, on the other hand at the salinity level of 5 ds/m, there was better performance of denitrification if the hydraulic retention time was lower.

Autotrophic denitrification of landfill leachate using elemental sulphur

1996 ◽  
Vol 34 (5-6) ◽  
pp. 469-476 ◽  
Author(s):  
A. Koenig ◽  
L. H. Liu
Keyword(s):  
Particle Size ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Nitrate Removal ◽  
Packed Bed ◽  
Elemental Sulphur ◽  
Limiting Factor ◽  
Autotrophic Denitrification ◽  
Sulphur Particle

One of the most economical means of nitrogen removal from leachate is biological treatment by nitrification, followed by heterotrophic denitrification. An alternative biological denitrification process is autotrophic denitrification using Thiobacillus denitrificans. This autotrophic bacteria oxidizes elemental sulphur to sulphate while reducing nitrate to elemental nitrogen gas, thereby eliminating the need for addition of organic carbon compounds. For this study, pilot-scale elemental sulphur packed bed columns with fixed-film denitrification have been selected as the most suitable treatment process. The effect of hydraulic retention time as well as the effect of concentration and loading rate of nitrate on nitrate removal efficiency as a function of sulphur particle size were determined. The results indicate that (i) autotrophic denitrification can effectively remove nitrate from synthetic and actual nitrified leachate at concentrations much higher than hitherto reported; (ii) the minimum hydraulic retention time necessary for complete denitrification depends on sulphur particle size; (iii) the maximum area loading rate, in g NO3−-N/m2·d, appears to be the process limiting factor and is practically independent of sulphur particle size; and (iv) the observed stoichiometric relationships compare well with those previously reported.

scholarly journals Simultaneous removal of Fe3+ and nitrate in the autotrophic denitrification immobilized systems

2017 ◽  
Vol 18 (5) ◽  
pp. 1625-1634
Author(s):  
Jun feng Su ◽  
Ting ting Lian ◽  
Ting lin Huang ◽  
Dong hui Liang ◽  
Wen dong Wang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Simultaneous Removal ◽  
Autotrophic Denitrification ◽  
Four Levels ◽  
Experimental Group

Abstract In this study, strain CC76, identified as Enterobacter sp., was tested for the reduction of Fe3+ and denitrification using immobilized pellets with strain CC76 as experimental group (IP) and immobilized pellets with strain CC76 and magnetite powder as experimental group (IPM) in the autotrophic denitrification immobilized systems (ADIS). Compared with IP, a higher nitrate removal rate was obtained with IPM by using three levels of influent Fe3+ (0, 5, and 10 mg/L), four levels of pH (5.0, 6.0, 7.0, and 8.0), and three levels of hydraulic retention time (HRT) (12, 14, and 16 h), respectively. Furthermore, response surface methodology (RSM) analysis demonstrated that the optimum removal ratios of nitrate of 87.21% (IP) and 96.27% (IPM) were observed under the following conditions: HRT of 12 h, pH of 7.0 and influent Fe3+ concentration of 5 mg/L (IP) and 1 mg/L (IPM).

Enhancement of nitrate removal in synthetic groundwater using wheat rice stone

2012 ◽  
Vol 66 (9) ◽  
pp. 1900-1907 ◽  
Author(s):  
Siqi Hong ◽  
Jianmei Zhang ◽  
Chuanping Feng ◽  
Baogang Zhang ◽  
Puxi Ma
Keyword(s):  
Trace Elements ◽  
Activated Carbon ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Nitrate Removal ◽  
Oxygen Demand ◽  
Nitrite Accumulation ◽  
Synthetic Groundwater ◽  
Biofilm Carriers ◽  
Growth Of Bacteria

To enhance the efficiency of nitrate removal from synthetic groundwater, wheat rice stone (WRS) and granular activated carbon (GAC) were employed as biofilm carriers for denitrification under different HRT (hydraulic retention time) and C/N ratios. Four different ratios of GAC to WRS (0, 0.5, 1.0, and 2.0) were investigated to determine the most appropriate ratio of GAC and WRS. The NO3−-N, NO2−-N, COD levels and pH of the effluent were also investigated under various HRT and C/N ratios. The results showed that the column at a GAC/WRS ratio of 1.0 performed best under a C/N ratio of 0.9 and an HRT of 8 h, with 99% nitrate being removed. In addition, little nitrite accumulation and chemical oxygen demand (COD) were observed in effluent under these conditions. These results demonstrated that, with no addition of phosphor in the influent, the nitrate removal efficiency can be enhanced by WRS because WRS can leach trace elements and phosphor to promote the growth of bacteria.

Condition Analysis of Nitrogen Remove from the Mixture of Municipal Wastewater and Fecal Sewage

2011 ◽  
Vol 418-420 ◽  
pp. 717-720
Author(s):  
Ming Yan Shi ◽  
Dong Hua Mo ◽  
Kang Sheng He ◽  
Jing Peng Li
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Treatment Plant ◽  
Reflux Ratio ◽  
Experimental Conditions ◽  
Test Conditions ◽  
Positive Effect

In order to ensure the stable and standard discharge of mixed nitrogen sewage, Guangzhou Datansha Wastewater Treatment Plant has made a test using an inverted A2/ O process, with the actual Wastewater as entry water. When the ratio of mixed fecal sewage is 0.33%, the results showed that, extending the HRT(Hydraulic Retention Time) can help to enhance the effect of removing nitrogen, and HRT should be ensured at least 8 hours under the test conditions. And the increase of the concentration of dissolved oxygen can promote the effect of removing nitrogen ranging from 1.0 to 1.5 mg/L. And the sludge reflux ratio should be remained at 60%. Besides, the growth of sludge age has positive effect on nitrification, so the sludge age should be controlled in more than 20 days under the experimental conditions.

Effect of sawdust dosage and hydraulic retention time (HRT) on nitrate removal in sawdust/pyrite mixotrophic denitrification (SPMD) systems

2019 ◽  
Vol 5 (2) ◽  
pp. 346-357 ◽  
Author(s):  
Shunlong Jin ◽  
Chuanping Feng ◽  
Shuang Tong ◽  
Nan Chen ◽  
Hengyuan Liu ◽  
...  
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Nitrate Removal ◽  
Contaminated Aquifer ◽  
Aquifer Remediation

Pyrite plays an important role in nitrate-contaminated aquifer remediation.

Biotechnological Sulphide Removal from Effluents

1991 ◽  
Vol 24 (3-4) ◽  
pp. 347-356 ◽  
Author(s):  
C. J. N. Buisman ◽  
G. Lettinga ◽  
C. W. M. Paasschens ◽  
L. H. A. Habets
Keyword(s):  
Fatty Acids ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Elemental Sulphur ◽  
Carrier Material ◽  
Removal Process ◽  
Carrier Materials ◽  
Sulphur Bacteria ◽  
Removal Efficiencies ◽  
New System

A new system for sulphide removal is reported in which sulphide is converted to elemental sulphur using colourless sulphur bacteria. A 4 m3 biorotor reactor has been tested using sulphide-containing anaerobically treated papermill wastewater. Sulphide removal efficiencies well above 90% were achieved at a hydraulic retention time of 19 minutes, using Pall rings of 2.5 cm or Bio-Net 200 as carrier materials. It was also found that reticulated polyurethane is not suitable as carrier material for the sulphide removal process in the presence of fatty acids.

scholarly journals Potential of biogas production from swine manure supplemented with glycerine waste

2014 ◽  
Vol 34 (5) ◽  
pp. 844-853 ◽  
Author(s):  
Odorico Konrad ◽  
Fabio F. Koch ◽  
Marluce Lumi ◽  
Jaqueline F. Tonetto ◽  
Alberto Bezama
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Swine Manure ◽  
The Other ◽  
Automated System ◽  
Batch System ◽  
Very High ◽  
Mesophilic Conditions

In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

Biological Phosphorus Removal in Fixed Films Reactors

1992 ◽  
Vol 25 (12) ◽  
pp. 165-174 ◽  
Author(s):  
R. Franci Gonçalves ◽  
F. Rogalla
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Hydraulic Retention Time ◽  
Phosphorus Release ◽  
Organic Substrate ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Fixed Film ◽  
Film Reactor ◽  
Biological Phosphorus

Possible procedures to achieve biological phosphorus removal in a fixed film reactor are discussed and the feasibility of phosphorus removal process in a fixed film reactor under continous flow is demonstrated. The behaviour of an upflow aerated filter operating under continuous feed and alternate aerobic/anaerobic conditions is analyzed. The influence of the duration of anaerobic and aerobic contact periods and of organic substrate loadings on the phosphorus removal process is verified. During the anaerobic state, the longer the duration, or the higher the substrate load, the better the phosphorus release and consequently the higher the uptake in the aerobic phase. The excess of accumulated phosphorus in the aerobic phase over released phosphorus in the anaerobic phase approaches 33 %. For each mg of phosphorus released, 5 mg filtered COD are consumed. Continuous phosphorus removal on two biofilters in series was performed by alternating aeration conditions, always introducing the influent to the anaerobic reactor.The tests carried out on laboratory scale showed that this system carrys out complete nitrification and removal of 80% of the phosphorus with a maximum hydraulic retention time of 5 hours. The hydraulic retention time and the residence time of the biomass in the reactor are independent and, therefore, the time the bacteria are exposed to alternate A/O conditions can be optimized. The very low concentrations of suspended solids in the effluent of the biofilter enable residual levels below 1 mg PO4-P/l to be obtained. Further investigations are carried out on full scale and to introduce denitrification in the same reactor.

Nitrogen Removal Optimization in a Biofilm Reactor from Groundwater

2012 ◽  
Vol 518-523 ◽  
pp. 2604-2607
Author(s):  
Chang Hang Wu ◽  
Yun Xiao Jin
Keyword(s):  
Nitrogen Removal ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Nitrate Removal ◽  
Biofilm Reactor

In the present study a lab-scale biofilm reactor was monitored for approximately 6 months to evaluate the use of ratios of carbon to nitrogen (C/N), pH and hydraulic retention time(HRT) levels as monitoring parameters in order to optimize nitrate removal from groundwater. The results indicated it was possible to operate the biofilm system at high denitrification rates and relatively low HRT of 8 hours.

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