Analysis of organic removal rates in the aerated submerged fixed film process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Hydraulic Loading ◽  
Organic Removal ◽  
Wide Range ◽  
Fixed Film ◽  
Cod Removal Rate ◽  
And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

Simultaneous organic stabilization and nitrogen removal in multi-stage biodrum system

2004 ◽  
Vol 50 (6) ◽  
pp. 95-101
Author(s):  
C. Chiemchaisri ◽  
C. Liamsangoun
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Rotational Speed ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Domestic Wastewater ◽  
Organic Removal ◽  
Multi Stage ◽  
Domestic Wastewater Treatment ◽  
Removal Efficiencies

This paper presents the performance of a multi-stage biodrum system applied to domestic wastewater treatment. The organic stabilization and nitrogen removal efficiency in the system was investigated at different hydraulic retention times (HRT) of 12, 6 and 3 hours. The rotational speed of the biodrum was examined at 2,4 and 8 rpm. Average organic removal efficiencies in the system at different HRTs of 12, 6 and 3 hours were 96.3, 94.4 and 90.9%. Simultaneously, average nitrogen removal efficiencies were 91.5, 90.6 and 81.0%. The effect of rotational speed on nitrogen removal efficiencies in the system was clearly observed at a low HRT of 3 hours. The experimental results suggested that optimum HRT in the system was 6 hours. Moreover, they revealed that nitrogen removal efficiencies in the reactors operated at different rotational speed were in the same degree when considering the effluent nitrogen concentration. However, the reactors operated at lower rotational speed needed to employ higher numbers of biodrums (4 stages) than the others with higher rotational speed (3 and 2 stages at 4 and 8 rpm.) in order to achieve similar effluent qualities. At a rotational speed of 2 rpm, maximum nitrogen removal rate was found to be 0.2 kg/m3/d.

An Experimental Study on Compatible Solute Ectoine Dosing of High Salinity Wastewater

2014 ◽  
Vol 955-959 ◽  
pp. 1907-1910
Author(s):  
Su Chen ◽  
Lei Chao ◽  
Ning Chen ◽  
Lin Shan Wang ◽  
Xue Shao ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Waste Treatment ◽  
High Salinity ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Ammonium Nitrogen ◽  
Treatment Efficiency ◽  
Removal Rates ◽  
Cod Removal Rate ◽  
Salinity Wastewater

When the reactor is added with ectoine of concentrations of 0, 0.1, 1 and 10 mmol/L, the impacts on brine waste treatment efficiency are investigated. The results show that the outflow COD and ammonia nitrogen removal rates are the highest, when the ectoine concentration is 0.1 mmol/L. The brine waste treatment efficiency under addition of ectoine of 1 and 10 mmol/L is even worse than that without ectoine addition. It can be preliminarily determined that the best ectoine dosage is in between 0.1-1.0 mmol/L. When ectoine concentrations added in reactors are 0.2, 0.5, 0.8 and 1.0 mmol/L, the results show that the average reactor outflow COD and ammonia nitrogen removal rates are increased compared with those of reactor without adding ectoine. But when ectoine of 1.0 mmol/L is added, the outflow COD and ammonia nitrogen removal rates decrease. When ectoine dosage is 0.5 mmol/L, the reactor outflow COD and ammonia nitrogen values are the lowest, the removal rates are the highest, the average COD removal rate is 74.46%, and the average ammonium nitrogen removal rate is 54.97%. Compared with reactor without adding ectoine, COD and ammonium nitrogen removal rates are increased by 13.16% and 26.81%. Therefore, the best dosage of ectoine is 0.5 mmol/L.

Dissolved oxygen as a factor influencing nitrogen removal rates in a one-stage system with partial nitritation and Anammox process

2011 ◽  
Vol 64 (5) ◽  
pp. 1009-1015 ◽  
Author(s):  
G. Cema ◽  
E. Płaza ◽  
J. Trela ◽  
J. Surmacz-Górska
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Removal Rate ◽  
Waste Water Treatment Plant ◽  
Removal Rates ◽  
Partial Nitritation ◽  
Do Concentration ◽  
Anammox Process

A biofilm system with Kaldnes biofilm carrier was used in these studies to cultivate bacteria responsible for both partial nitritation and Anammox processes. Due to co-existence of oxygen and oxygen-free zones within the biofilm depth, both processes can occur in a single reactor. Oxygen that inhibits the Anammox process is consumed in the outer layer of the biofilm and in this way Anammox bacteria are protected from oxygen. The impact of oxygen concentration on nitrogen removal rates was investigated in the pilot plant (2.1 m3), supplied with reject water from the Himmerfjärden Waste Water Treatment Plant. The results of batch tests showed that the highest nitrogen removal rates were obtained for a dissolved oxygen (DO) concentration around 3 g O2 m−3. At a DO concentration of 4 g O2 m−3, an increase of nitrite and nitrate nitrogen concentrations in the batch reactor were observed. The average nitrogen removal rate in the pilot plant during a whole operating period oscillated around 1.3 g N m−2d−1 (0.3 ± 0.1 kg N m−3d−1) at the average dissolved oxygen concentration of 2.3 g O2 m−3. The maximum value of a nitrogen removal rate amounted to 1.9 g N m−2d−1 (0.47 kg N m−3d−1) and was observed for a DO concentration equal to 2.5 g O2 m−3. It was observed that increase of biofilm thickness during the operational period, had no influence on nitrogen removal rates in the pilot plant.

Study on Rural Sanitary Sewage Treatment in Compound Purifying Tank

2013 ◽  
Vol 726-731 ◽  
pp. 2599-2603
Author(s):  
Gong Di Xu ◽  
Jin Zhao Hu ◽  
Zhao Hui Huang ◽  
Da Dong Zhan ◽  
Chong Li ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Cod Removal ◽  
Removal Rates ◽  
Start Up ◽  
Potential Alternative ◽  
Cod Removal Rate

In the present work, a novel compound purifying tank was adopted in the rural sanitary sewage treatment. The cultivation and acclimation of biological film could be completed in a short start-up by aerobic precoating. According to the running results,the average COD removal rate reached 59.62%,and the removal efficiency of TP was 33.4%.For the denitrogenation,the removal rates were not remarkable (21.7 to NH4+-N,21.9 to TN),but the large removal quantity of NH4+-N and TN were abtained as 8.58mg/L and 9.12mg/L,respectively. The study suggests that the compound purifying tank is a potential alternative for rural sanitary sewage treatment.

COD and NH4-N Removal in Two-Stage Batch-Flow Constructed Wetland

2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Two Stage ◽  
Removal Rates ◽  
N Removal ◽  
Domestic Wastewater Treatment

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.

Efficiency of removal of nitrogen, phosphorus, and zinc from domestic wastewater by a constructed wetland system in rural areas: a case study

2008 ◽  
Vol 58 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Kaoru Abe ◽  
Michio Komada ◽  
Akihito Ookuma
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Rural Areas ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Total N ◽  
Household Wastewater ◽  
Percentage Removal ◽  
Total P

The effluent from the combined household wastewater treatment facilities used in unsewered areas of Japan is generally high in nitrogen (N) and phosphorus (P). In Japan, environmental quality standards for zinc (Zn) pollution were enacted recently because of the toxicity of Zn to aquatic ecosystems. In 2004 a fallow paddy field at the Koibuchi College of Agriculture and Nutrition was converted into a surface-water-flow constructed wetland (500 m2) to clean the effluent from the combined household wastewater treatment facility of a dormitory (100 residents) before discharge to a pond. We evaluated N and P removal efficiencies and the fate of soluble Zn in the wetland from April 2006 to March 2007. Wetland influent contained an average of 18.3 mg L−1 total N and 1.86 mg L−1 total P. In the effluent from the wetland, average total N concentration was 10.3 mg L−1 and average total P was 0.90 mg L−1. Average removal rates were 0.37 g m−2 d−1 for total N and 0.050 g m−2 d−1 for total P (percentage removal rates of 40% and 48%, respectively). Soluble Zn concentration decreased from 0.041 in the influent to 0.023 mg L−1 after passing through the wetland. The average Zn removal rate during the year was 0.0007 g m−2 d−1 (percentage removal rate 37%).

Analysis of Degradation by Aerobic Recharge for Concentrated Leachate

2014 ◽  
Vol 675-677 ◽  
pp. 483-488
Author(s):  
Jian Zhang ◽  
Ping Xian ◽  
Long Hui Yang ◽  
Long Hui Zhan ◽  
Guang Hui Bu
Keyword(s):  
Membrane Separation ◽  
Ph Value ◽  
Early Stage ◽  
Removal Rate ◽  
Hydraulic Loading ◽  
Strong Trend ◽  
N Removal ◽  
Cod Removal Rate ◽  
The Impact ◽  
Mean Time

Concentrated leachate obtained from landfill leachate by membrane separation was treated using technique of aerobic recharge. Variation of effluent COD, NH3-N and pH in concentrated leachate during aerobic recharge was studied. The impact of hydraulic loading on the removal rate of COD and NH3-N was investigated. The results indicate that, after passing through the three stages of rapid declining, smooth declining and stabilization, the variation of effluent COD of the concentrated leachate versus time maintains in the range of 900~2000 mg/L, and the corresponding removal rate is 88%~92%. The variation of effluent NH3-N versus time indicates a trend that it climbs up initially and then declines. The effluent NH3-N starts from 700 mg/L. After 35 days, it declines down to 18 mg/L and maintains in the range of 93%~99% with a corresponding removal rate up to 98%. Aerobic recharge reduces the build up of organic acids in the early stage. After 10 days, the pH value of the leachate maintains in the range between 7.5 and 9.0. The COD removal rate decreases from 94.39% down to 75.75% when the hydraulic loading increases from 12.5 mL / (L·d) to 75mL / (L·d), indicating a strong trend. In the mean time, the NH3-N removal rate decreases from 98.14% down to 90.11%, indicating a weak tread.

Nitrogen removal rates at a technical-scale pilot plant with the one-stage partial nitritation/Anammox process

2006 ◽  
Vol 54 (8) ◽  
pp. 209-217 ◽  
Author(s):  
G. Cema ◽  
B. Szatkowska ◽  
E. Plaza ◽  
J. Trela ◽  
J. Surmacz-Górska
Keyword(s):  
Nitrogen Removal ◽  
Pilot Plant ◽  
Removal Rate ◽  
New Technology ◽  
Anaerobic Bacteria ◽  
Ammonium Nitrogen ◽  
Anammox Bacteria ◽  
Removal Rates ◽  
Partial Nitritation ◽  
Batch Tests

Traditional nitrification/denitrification is not suitable for nitrogen removal when wastewater contains high concentrations of ammonium nitrogen and low concentrations of biodegradable carbon. Recently, a deammonification process was developed and proposed as a new technology for treatment of such streams. This process relies on a stable interaction between aerobic bacteria Nitrosomonas, that accomplish partial nitritation and anaerobic bacteria Planctomycetales, which conduct the Anammox reaction. Simultaneous performance of these two processes can lead to a complete autotrophic nitrogen removal in one single reactor. The experiments where nitrogen was removed in one reactor were performed at a technical-scale moving-bed pilot plant, filled with Kaldnes rings and supplied with supernatant after dewatering of digested sludge. It was found that a nitrogen removal rate obtained at the pilot plant was 1.9 g m−2d−1. Parallel to the pilot plant run, a series of batch tests were carried out under anoxic and aerobic conditions. Within the batch tests, where the pilot plant's conditions were simulated, removal rates reached up to 3 g N m−2d−1. Moreover, the batch tests with inhibition of Nitrosomonas showed that only the Anammox bacteria (not anoxic removal by Nitrosomonas) are responsible for nitrogen removal.

Induced change in heart metabolism as a primary determinant of heart performance

1965 ◽  
Vol 209 (3) ◽  
pp. 519-531 ◽  
Author(s):  
Marvin B. Bacaner ◽  
Franco Lioy ◽  
Maurice B. Visscher
Keyword(s):  
Work Performance ◽  
Removal Rate ◽  
Work Capacity ◽  
Left Ventricular ◽  
Heart Metabolism ◽  
Heart Performance ◽  
Wide Range ◽  
Primary Determinant ◽  
And Performance ◽  
Isotonic Shortening

In 65 isolated dog hearts, left ventricular isometric developed tension (LVDT) or isotonic shortening (LVS) were measured at various levels of coronary blood flow (CBF) and heart load. It was found that imposed changes in CBF (over a wide range) 1) caused directionally similar changes in LVDT (or LVS) and O2 consumption at any given heart load (metabolic effect); 2) governed the magnitude of change in LVDT or LVS in response to an altered load (Starling effect). In some hearts autoregulation of CBF occurred which obscured but did not obliterate the effect. Autoregulation of CBF could be diminished or abolished by lowering arterial O2 saturation and restored by resaturation. It is suggested that CBF rate may be an important normal determinant of cardiac work capacity and performance by regulating the delivery rate of O2 and substrate as well as removal rate of CO2 and other metabolites in various parts of the myocardium. Possible defects in experiments reported by others failing to show a dependence of work performance on CBF rate are mentioned.

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