Two-stage entrapped mixed microbial cell process for simultaneous removal of organics and nitrogen for rural domestic sewage application

2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Microbial Cell ◽  
Two Stage ◽  
Rate Limiting Step ◽  
Soluble Chemical Oxygen Demand ◽  
Removal Efficiencies ◽  
Entrapped Mixed Microbial Cell

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.

scholarly journals Performance comparison of uninsulated and insulated hybrid anaerobic baffled reactor (HABR) operating at warm temperature

2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan
Keyword(s):  
Removal Efficiency ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Total Suspended Solids ◽  
Performance Comparison ◽  
Warm Temperature ◽  
Anaerobic Baffled Reactor ◽  
Similar Chemical ◽  
Removal Efficiencies

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.

Treatment of low and medium strength sewage in a lab-scale gradual concentric chambers (GCC) reactor

2008 ◽  
Vol 57 (8) ◽  
pp. 1155-1160 ◽  
Author(s):  
L. Mendoza ◽  
M. Carballa ◽  
L. Zhang ◽  
W. Verstraete
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Organic Loading Rate ◽  
Medium Strength ◽  
Low Strength ◽  
And Performance ◽  
Scale Design ◽  
Final Effluent

One of the major challenges of anaerobic technology is its applicability for low strength wastewaters, such as sewage. The lab-scale design and performance of a novel Gradual Concentric Chambers (GCC) reactor treating low (165±24 mg COD/L) and medium strength (550 mg COD/L) domestic wastewaters were studied. Experimental data were collected to evaluate the influence of chemical oxygen demand (COD) concentrations in the influent and the hydraulic retention time (HRT) on the performance of the GCC reactor. Two reactors (R1 and R2), integrating anaerobic and aerobic processes, were studied at ambient (26°C) and mesophilic (35°C) temperature, respectively. The highest COD removal efficiency (94%) was obtained when treating medium strength wastewater at an organic loading rate (OLR) of 1.9 g COD/L·d (HRT = 4 h). The COD levels in the final effluent were around 36 mg/L. For the low strength domestic wastewater, a highest removal efficiency of 85% was observed, producing a final effluent with 22 mg COD/L. Changes in the nutrient concentration levels were followed for both reactors.

scholarly journals Experiences on the implementation of a pilot grey water treatment and reuse based system at a household in the slum of Kyebando-Kisalosalo, Kampala

2014 ◽  
Vol 4 (4) ◽  
pp. 294-307 ◽  
Author(s):  
Charles B. Niwagaba ◽  
Patrick Dinno ◽  
Isaac Wamala ◽  
S. Sahar Dalahmeh ◽  
Cecilia Lalander ◽  
...  
Keyword(s):  
Loading Rate ◽  
Type System ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Organic Loading Rate ◽  
Surface Irrigation ◽  
Limited Effect ◽  
Grey Water ◽  
Multi Media ◽  
Removal Efficiencies

Grey water constitutes the largest fraction of domestic wastewater. It causes environmental sanitation and pollution problems if it is not managed well. If treated, grey water can be a resource for a variety of uses. A pilot system was constructed in February 2013 to treat grey water from a four-member household for sub-surface irrigation of local vegetables. A hydraulic loading rate (HLR) of 60 L m−2d−1 and an organic loading rate (OLR) of 519–1,580 g BOD5m−2d−1 were implemented on a multi-media filter of gravel, charcoal, geotextile and mulch (charcoal being the predominant layer) operated as a batched type-system, with a 36-hour retention time. The system was operated for 3 months, during which it showed remarkable removal efficiencies of 90.8 ± 5.4 and 96.1 ± 3.0% after 36 hours for chemical oxygen demand (COD) and biochemical oxygen demand (BOD), respectively, and 95 ± 3.1% for faecal coliforms (FC). The removal efficiencies at 36 hours, of total nitrogen (TN), total phosphorus (Tot-P), total suspended solids (TSS) and total dissolved solids (TDS) were 39.0, 30.1, 85.2 and 78.6%, respectively. Plant response to sub-surface irrigation with treated grey water was largely masked by rainy season and the effluent had a limited effect on the soil.

Development of a two-stage flexible fibre biofilm reactor for treatment of food processing wastewater

2003 ◽  
Vol 47 (11) ◽  
pp. 189-194 ◽  
Author(s):  
Q.J. Yu ◽  
H. Xu ◽  
D. Yao ◽  
P. Williams
Keyword(s):  
Removal Efficiency ◽  
Food Processing ◽  
Cost Effective ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Two Stage ◽  
Cod Removal Efficiency ◽  
Cost Effective Treatment ◽  
Removal Efficiencies ◽  
Food Processing Wastewater

Biofilm (or attached growth) reactors can be effectively used to treat organic wastewater from various industries such as food processing industry. They have a number of advantages including high organic loading rates (OLRs) and improved operational stability. A flexible fibre biofim reactor (FFBR) has been developed for efficient and cost effective treatment of food processing wastewater. In the process, simple flexible fibre packing with a very high specific surface area is used as support for microorganisms. The COD removal efficiencies for a range of OLRs have been studied. The FFBR can support an increasingly high OLR, but with a corresponding decrease in the COD removal efficiency. Therefore, a two-stage FFBR was developed to increase the treatment efficiency for systems with high OLRs. Experimental results indicated that a high overall COD removal efficiency could be achieved. At an influent COD of about 2700 mg/L and an OLR of 7.7 kgCOD/m3d, COD removal efficiencies of 76% and 82% were achieved in the first and the second stage of the reactor, respectively. The overall COD removal efficiency was 96%. Therefore, even for wastewater samples with high organic strength, high quality treated effluents could be readily achieved by the use of multiple stage FFBRs.

Biological wastewater treatment for removal of polymeric resins in UASB reactor: influence of oxygen

2008 ◽  
Vol 57 (7) ◽  
pp. 1047-1052 ◽  
Author(s):  
U. Durán ◽  
O. Monroy ◽  
J. Gómez ◽  
F. Ramírez
Keyword(s):  
Acrylic Acid ◽  
Vinyl Acetate ◽  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Cod Removal Efficiency ◽  
Consumption Rates ◽  
Polymeric Resins

The biological elimination of polymeric resins compounds (PRC) such as acrylic acid and their esters, vinyl acetate and styrene under methanogenic and oxygen-limited methanogenesis conditions was evaluated. Two UASB reactors (A and B) were used and the removal of the organic matter was studied in four stages. Reactor A was used as methanogenic control during the study. Initially both reactors were operated under methanogenic conditions. From the second stage reactor B was fed with 0.6 and 1 mg/L·d of oxygen (O2). Reactor A had diminution in chemical oxygen demand (COD) removal efficiency from 75±4% to 37±5%, by the increase of PRC loading rate from 750 to 1125 mg COD/L·d. In this reactor there was no styrene elimination. In reactor B the COD removal efficiency was between 73±5% and 80±2%, even with the addition of O2 and increase of the PRC loading rate, owing to oxygen being used in the partial oxidation of these compounds. In this reactor the yields were modified from 0.56 to 0.40 for CH4 and from 0.31 to 0.60 for CO2. The O2 in low concentrations increased 40.7% the consumption rates of acrylic acid, methyl acrylate and vinyl acetate, allowing styrene consumption with a rate of 0.103 g/L·d. Batch cultures demonstrated that under methanogenic and oxygen-limited methanogenesis conditions, the glucose was not used as an electron acceptor in the elimination of PRC.

A pilot bioretention system with commercial activated carbon and river sediment-derived biochar for enhanced nutrient removal from stormwater

2019 ◽  
Vol 80 (4) ◽  
pp. 707-716 ◽  
Author(s):  
Min Sang ◽  
Miansong Huang ◽  
Wei Zhang ◽  
Wu Che ◽  
Huichao Sun
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Nutrient Removal ◽  
River Sediment ◽  
Oxygen Demand ◽  
Column Experiment ◽  
Average Mass ◽  
Mass Removal ◽  
The Media ◽  
Removal Efficiencies

Abstract Bioretention is an effective technology for urban stormwater management, but the nutrient removal in conventional bioretention systems is highly variable. Thus, a pilot bioretention column experiment was performed to evaluate the nutrient control of systems with commercial activated carbon and river sediment-derived biochar. Significant chemical oxygen demand (COD) and total phosphorus (TP) leaching were found with the addition of activated carbon and biochar, but total nitrogen (TN) leaching was significantly improved when activated carbon was used as the medium. During a semi-synthetic runoff experiment, the bioretention systems containing two types of fluvial biochar showed relatively better COD and TN control (average mass removal efficiencies and cumulative removal efficiencies) than commercial activated carbon. However, the average TP mass removal efficiency with commercial activated carbon (95% ± 3%) was significantly higher than biochar (48% ± 20% and 56 ± 14%). The addition of biochar in the media increased the nitrogen removal efficiency, and the addition of activated carbon significantly increased the phosphorous removal efficiency. Therefore, both biochar and activated carbon are effective materials for bioretention, and fluvial biochar provides an alternative approach to comprehensively utilize river sediment.

Performance evaluation of subsurface wastewater infiltration system in treating domestic sewage

2012 ◽  
Vol 65 (4) ◽  
pp. 713-720 ◽  
Author(s):  
Ying-Hua Li ◽  
Hai-Bo Li ◽  
Jing Pan ◽  
Xin Wang ◽  
Tie-Heng Sun
Keyword(s):  
Operation Mode ◽  
Oxygen Demand ◽  
Surface Water Quality ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
The Mean ◽  
Removal Efficiencies ◽  
One Year ◽  
Physical And Chemical ◽  
Over Time

This study was to investigate domestic treatment efficiency of a subsurface wastewater infiltration (SWI) system over time. The performances of a young SWI system (in Shenyang University, China, fully operated for one year) and a mature SWI system (in Shenyang Normal University, China, fully operated for seven years) under the same operation mode were contrasted through field-scale experiments for one year. The performance assessment for these systems is based on physical and chemical parameters collected. The removal efficiencies within the young system were relatively high if compared with the mature one: for biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), ammonia nitrogen (NH3-N) and total phosphorus (TP) were 95.0, 89.1, 98.1, 87.6 and 98.4%, respectively. However, the removal efficiencies decreased over time. The mean removal efficiencies for the mature SWI system were as follows: BOD (89.6%), COD (87.2%), SS (82.6%), NH3-N (69.1%) and TP (74.4%). The results indicate that the mature SWI system successfully removed traditional pollutants such as BOD from domestic wastewater. However, the nutrient reduction efficiencies (including NH3-N and TP) decreased after seven years of operation of the mature SWI system. Meanwhile, the SWI system did not decrease the receiving surface water quality.

Degradation of Nonylphenol Polyethoxylates and its Microflora Structure in an Anoxic-Oxic Activated Sludge Process

2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han
Keyword(s):  
In Situ Hybridization ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Gel Electrophoresis ◽  
Loading Rate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Oxygen Demand ◽  
Activated Sludge Process ◽  
Gradient Gel Electrophoresis

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).

Treatment of synthetic wastewater and hog waste with reduced sludge generation by the multi-environment BioCAST technology

2013 ◽  
Vol 67 (3) ◽  
pp. 587-593 ◽  
Author(s):  
L. Yerushalmi ◽  
M. Alimahmoodi ◽  
C. N. Mulligan
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Nitrogen And Phosphorus ◽  
Treatment Technology ◽  
Minimal Impact ◽  
Biological Sludge ◽  
Removal Efficiencies ◽  
Cod Removal Rate

Simultaneous removal of carbon, nitrogen and phosphorus was examined along with reduced generation of biological sludge during the treatment of synthetic wastewater and hog waste by the BioCAST technology. This new multi-environment wastewater treatment technology contains both suspended and immobilized microorganisms, and benefits from the presence of aerobic, microaerophilic, anoxic and anaerobic conditions for the biological treatment of wastewater. The influent concentrations during the treatment of synthetic wastewater were 1,300–4,000 mg chemical oxygen demand (COD)/L, 42–115 mg total nitrogen (TN)/L, and 19–40 mg total phosphorus (TP)/L. The removal efficiencies reached 98.9, 98.3 and 94.1%, respectively, for carbon, TN and TP during 225 days of operation. The removal efficiencies of carbon and nitrogen showed a minimal dependence on the nitrogen-to-phosphorus (N/P) ratio, while the phosphorus removal efficiency showed a remarkable dependence on this parameter, increasing from 45 to 94.1% upon the increase of N/P ratio from 3 to 4.5. The increase of TN loading rate had a minimal impact on COD removal rate which remained around 1.7 kg/m3 d, while it contributed to increased TP removal efficiency. The treatment of hog waste with influent COD, TN and TP concentrations of 960–2,400, 143–235 and 25–57 mg/L, respectively, produced removal efficiencies up to 89.2, 69.2 and 47.6% for the three contaminants, despite the inhibitory effects of this waste towards biological activity. The treatment system produced low biomass yields with average values of 3.7 and 8.2% during the treatment of synthetic wastewater and hog waste, respectively.

Treatment of anaerobically digested dairy manure in a two-stage biofiltration system

2012 ◽  
Vol 65 (11) ◽  
pp. 1975-1981 ◽  
Author(s):  
Mengjing Xia ◽  
Wendong Tao ◽  
Ziyuan Wang ◽  
Yuansheng Pei
Keyword(s):  
Chemical Oxygen Demand ◽  
Nitrogen Removal ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Dairy Manure ◽  
Ammonium Oxidation ◽  
Two Stage ◽  
Sand Filters ◽  
Soluble Chemical Oxygen Demand ◽  
Anaerobically Digested Dairy Manure

High concentrations of ammonium and phosphate present a challenge to cost-effective treatment of anaerobically digested dairy manure. This study investigated the efficacy of a two-stage biofiltration system for passive treatment of digested dairy manure. The first stage pebble filters were batch loaded. When the slurry-like digested dairy manure was retained on pebble beds, soluble contaminants were removed before liquid infiltrated over 8–17 days. The pebble filters removed 70% of soluble chemical oxygen demand, 71% of soluble biochemical oxygen demand, 75% of ammonium, and 68% of orthophosphate. Nitrogen removal was attributed to the conventional nitrification – denitrification process and novel nitritation – anammox process. Aerobic ammonium oxidizing and anammox bacteria accounted for 25 and 23% of all bacteria, respectively, in the filtrate of the pebble filters. The longer it took for filtration, the greater the removal efficiency of soluble contaminants. The second stage sand filters had removal efficiencies of 17% for soluble chemical oxygen demand, 45% for soluble biochemical oxygen demand, 43% for ammonium, and 16% for orthophosphate during batch operations at a hydraulic retention time of 7 days. Aerobic ammonium oxidation and anammox were primarily responsible for nitrogen removal in the sand filters. Vegetation made an insignificant difference in treatment performance of the sand filters.

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