Application of light-weight filtration media in an anoxic biofilter for nitrate removal from micro-polluted surface water

2016 ◽  
Vol 74 (4) ◽  
pp. 1016-1024 ◽  
Author(s):  
Zheng Wang ◽  
Xiang Fei ◽  
Shengbing He ◽  
Jungchen Huang ◽  
Weili Zhou
Keyword(s):  
Surface Water ◽  
Removal Efficiency ◽  
Sodium Acetate ◽  
Consumption Rate ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Light Weight ◽  
Stage Process

The research investigated nitrate removal from micro-polluted surface water by the single-stage process of anoxic biofilter using light-weight polystyrene beads as filtration media. In this study, sodium acetate was used as an external carbon source and the nitrate removal efficiency under different regimes of hydraulic loading rate (HLR), water temperature, and C/N ratio was studied. In addition, the effect of backwash on denitrification efficiency was investigated. The results show that the biofilter achieved a high nitrate removal efficiency in 2 weeks at water temperatures ranging between 22 and 25 °C at a C/N ratio (COD:NO3−-N) of 6:1. Besides, the average removal efficiency of nitrate at HLRs of 5.66, 7.07 and 8.49 m3 m−2 h−1 were 87.5, 87.3 and 87.1%, respectively. The average removal efficiency of nitrate nitrogen was 13.9% at a HLR of 5.66 m3 m−2 h−1 at water temperatures of 12–14 °C, then it increased to 93.7% when the C/N ratio increased to 10. It suggests that the optimal hydraulic retention time is at water temperatures of 8–10 °C. The water consumption rate of backwash was about 0.2–0.3%, and denitrification efficiency returned to the normal level in 12 h after backwash.

Formation of Biofilms in a Biofilm Air-Lift Suspension Reactor

1992 ◽  
Vol 26 (3-4) ◽  
pp. 647-654 ◽  
Author(s):  
J. J. Heijnen ◽  
M. C. M. van Loosdrecht ◽  
A. Mulder ◽  
L. Tijhuis
Keyword(s):  
Biofilm Formation ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Single Cells ◽  
Particle Interactions ◽  
Particle Characteristics ◽  
Biofilm Detachment ◽  
Stage Process ◽  
Volumetric Loading ◽  
Air Lift

Biofilm Air-lift Suspension reactors can be used to treat waste water at a high volumetric loading rate combined with a low sludge loading. The biofilms are formed on small suspended particles (r = 0.1 mm). We have studied the effect of particle characteristics and hydraulic retention time on the biofilm formation. It is shown that small, rough particles show the best biofilm formation. Low hydraulic retention times benefit the formation of biofilms. This results from the fact that suspension growth is minimal under these conditions. The effect of biofilm detachment became distinct from the observation that most of the bacterial growth in the biofilm is transferred to the liquid. The biofilm formation process is concluded to be a three stage process: (i) the outgrowth of single cells to micro-colonies, this process is positively influenced by the carrier surface roughness; (ii) the outgrowth of micro-colonies to small biofilms, this process is negatively influenced by the concentration of carrier material; (iii) the outgrowth of biofilms, this occurs when the majority of particles are covered with a biofilm. At that time the influence of shear due to particle-particle interactions diminishes.

Bio-anaerobic treatability study for PCBs-contaminated oil

2006 ◽  
Vol 53 (6) ◽  
pp. 161-167 ◽  
Author(s):  
S.Y. Ahn ◽  
S.J. Kim ◽  
P.Y. Yang
Keyword(s):  
Removal Efficiency ◽  
Sequencing Batch Reactor ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Batch Reactor ◽  
Organic Loading Rate ◽  
Operational Parameters ◽  
Loading Rates ◽  
Anaerobic Sequencing Batch Reactor ◽  
Us Epa

This study investigated the bio-treatability of PCB contaminated oil for the development of design and operational parameters for the bioreactor. Input of external carbon and nutrient source in the aqueous phase was found to be required for the treatment of polychlorinated biphenyls (PCBs)-contaminated oil. Addition of surfactant was investigated for the emulsification of oil to reduce interference of contact with microorganisms and PCBs. The ratio of surfactant to oil was empirically optimized to 1 : 1. The higher PCB removal efficiency was obtained at 30 days of hydraulic retention time (HRT) in the semi-batch reactor study without cell recycle. The removal efficiency measured in mixed liquor was maintained at over 85% on average at 32±2 °C and 30% at 22±2 °C. More than 0.2 g/l/d of the organic loading rate was suggested to be maintained for various PCB loading rates (0.02–0.6 mg-PCB/l/d). For high biomass retaining and easy collection of treated oil, an Anaerobic Sequencing Batch Reactor (ASBR) was investigated. The removal of Aroclor was observed as more than 50% in the oil phase with 3 days reaction time and about 40% in overall phases, i.e. oil, liquid, biomass phases at 22±2 °C. US EPA verification results on the process performance are included in this presentation.

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.

Investigation of furfural biodegradation in a continuous inflow cyclic biological reactor

2015 ◽  
Vol 73 (2) ◽  
pp. 292-301 ◽  
Author(s):  
Gholamreza Moussavi ◽  
Mostafa Leili ◽  
Kazem Nadafi
Keyword(s):  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Filling Ratio ◽  
Operating Parameters ◽  
High Concentrations ◽  
Moving Media ◽  
Main Operating ◽  
Bioreactor Performance

The performance of a continuous inflow cyclic biological reactor (CBR) containing moving media was investigated for the degradation of high concentrations of furfural. The effects of hydraulic retention time (HRT) and furfural initial concentrations (loading rate), as main operating parameters, on the bioreactor performance were studied. The results indicated that the CBR could remove over 98% of furfural and 71% of its chemical oxygen demand (COD) at inlet furfural concentrations up to 1,200 mg L−1 (2.38 g L−1 d−1), a 6-h cycle time and HRT of 12.1 h. The removal efficiency decreased slightly from 98 to 94% when HRT decreased from 12.1 to 10.5 h. The average removal efficiency of furfural and COD during the 345-day operational period under steady-state conditions were 97.7% and 82.1%, respectively. The efficiency also increased approximately 17.2% after addition of synthetic polyurethane cubes as moving media at a filling ratio of 10%.

Evaluation of microbial fuel cell coupled with aeration chamber and bio-cathode for organic matter and nitrogen removal from synthetic domestic wastewater

2009 ◽  
Vol 60 (6) ◽  
pp. 1409-1418 ◽  
Author(s):  
J. Cha ◽  
C. Kim ◽  
S. Choi ◽  
G. Lee ◽  
G. Chen ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Nitrogen Removal ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Domestic Wastewater ◽  
Carbon And Nitrogen

For simultaneous carbon and nitrogen removal via single stream, a microbial fuel cell (MFC) coupled with an aeration chamber and a bio-cathode was investigated. Without catalysts and any additional buffer, the MFC produced electricity continuously and the power density reached 1.3 W/m3 at a loading rate of 1.6 kg COD/m3 d. Simultaneously, the COD and the nitrate removal rate were 1.4 kg COD/m3 d and 67 g NO3-N/m3 d, respectively. When the hydraulic retention time was changed from 6 to 0.75 hours, the power density significantly increased from 0.2 to 10.8 W/m3 due to an increase of cathodic potential. When the aeration chamber was removed and the nitrate was injected into the cathode, the power density increased to 3.7 W/m3. At a high recirculation rate of 10 ml/min, the power density and the nitrate removal rate greatly increased to 34 W/m3 and 294 g NO3−-N/m3 d, respectively.

Nitrate removal by nitrate-dependent Fe(II) oxidation in an upflow denitrifying biofilm reactor

2015 ◽  
Vol 72 (3) ◽  
pp. 377-383 ◽  
Author(s):  
Jun Zhou ◽  
Hongyu Wang ◽  
Kai Yang ◽  
Yuchong Sun ◽  
Jun Tian
Keyword(s):  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Biofilm Reactor ◽  
Nitrite Accumulation ◽  
Pseudomonas Sp ◽  
Reaction Parameters ◽  
Optimum Reaction ◽  
Maximum Removal

A continuous upflow biofilm reactor packed with ceramsite was constructed for nitrate removal under an anaerobic atmosphere without an organic carbon source. Denitrifying bacteria, Pseudomonas sp. W1, Pseudomonas sp. W2 and Microbacterium sp. W5, were added to the bioreactor as inocula. Nitrate concentration, nitrite accumulation and nitrogen removal efficiency in the effluent were investigated under various conditions set by several parameters including pH, hydraulic retention time (HRT), ratios of carbon to nitrogen (C/N) and temperature. The results illustrated that the maximum removal efficiency of nitrogen was 85.39%, under optimum reaction parameters, approximately pH 6.5–7, HRT = 48 hours and C/N = 13.1:1 at temperature of 30 °C, which were determined by experiment.

scholarly journals Effects of Methanol on the Treatability of Black Liquor using UASB Reactor

1970 ◽  
Vol 6 ◽  
pp. 42-46
Author(s):  
Arshad Ali ◽  
Hasim Nisar Hashmi ◽  
Intikhab A. Q.
Keyword(s):  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Black Liquor ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Anaerobic Sludge Blanket ◽  
Gas Conversion

This study was conducted on a laboratory scale UASB (upfow anaerobic sludge blanket) reactor, treating an actual pulping effluent at an organic loading rate and hydraulic retention time of 2.1 kg-COD/m3d and 44 hours, respectively. To investigate the impacts of methanol, it was subjected to the reactor with the feeding solution (substrate) in concentration ranging from 100 mgTOC/l to 700mgTOC/l. It was observed that the overall TOC and COD removal efficiency of the reactor was improved gradually from 36% and 34% to 57% and 55%, respectively, by increasing the concentration of methanol up to 600 mgTOC/l, but very little effects of methanol on the removal efficiency of lignin were observed. The lignin removal efficiency of the reactor slightly changed from 25% to 31%. The gas conversion rate was found to be improved slightly from 0.31[L-CH4/g-CODrem.day] to 0.34 [L-CH4/g-CODrem.day], with an average methane composition of 61%. Hence, addition of methanol to the reactor can improve the black liquor degradation up to certain extent.Key words: Black liquor; Methanol; UASB; Lignin; TOCDOI: 10.3126/hn.v6i0.4193Hydro Nepal Vol. 6, January 2010Page: 42-46Uploaded Date: 24 January, 2011

scholarly journals Optimization of Biogas Production from Dairy Wastewater using Upflow Anaerobic Filter (UAF) Reactor

2020 ◽  
Vol 9 (4) ◽  
pp. 1469-1472
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Cod Removal ◽  
Dairy Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Filter ◽  
Cod Removal Efficiency

The present study explores the feasibility of biogas production from dairy wastewater in the UAF reactor with simultaneous wastewater treatment. The study was carried out at different hydraulic retention times (8h, 12h, 16h, 24h). Two different media such as pebble stone media and aggregate media were used as the packed media. The maximum COD removal efficiency of 91.55 % is achieved at the hydraulic retention time of 24 Hours with an organic loading rate of 1.35 kg/m3 /d for aggregate media, whereas for pebble stone media a maximum COD removal efficiency of 76.32 % is achieved. Before the start of the experiments, the COD/BOD ratio is fixed to 1.4 with initial COD and BOD of 1350 mg/L and 960 mg/L. So, from the results it is concluded that the Upflow Anaerobic Filter (UAF) Reactor can be used as a one of the best treatment methods for the diary wastewater treatment.

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

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