Performance Evaluation of Rotating Biological Contactor Process

1987 ◽  
Vol 19 (3-4) ◽  
pp. 483-494 ◽  
Author(s):  
K. Tanaka ◽  
A. Oshima ◽  
B. E. Rittmann
Keyword(s):  
Field Study ◽  
Energy Demand ◽  
Fine Particles ◽  
Secondary Treatment ◽  
Liquid Separation ◽  
Small Communities ◽  
Acceptable Quality ◽  
Study Results ◽  
Rotating Biological Contactors ◽  
Final Effluent

Rotating Biological Contactors (RBC) have only recently been introduced in Japan as a means of providing secondary treatment to domestic wastewaters. The use of RBCs appears to be particularly attractive for small communities because of their low energy demand and reduced O-M requirements. To evaluate and demonstrate the feasibility of the process as an alternative to conventional secondary treatment, a field study was performed at three municipal facilities in Japan. A single, fundamental model of biofilm kinetics was shown to be capable of accurately predicting soluble BOD5 removals throughout the RBC. Model and field study results indicated that effluent soluble BOD5 should be 3 to 7 mg/l for conventional loads. Approximately 30 percent of the RBC effluent solids were found to be fine particles having a settling velocity of less than 10 to 15 m/day and which exerted 60 to 70 percent of the final effluent total BOD5. Therefore, special attention must he given to solids-liquid separation of the RBC effluent to ensure that the final effluent is of acceptable quality. Several solids-liquid separation methods, including direct screening of RBC effluent, were shown to be feasible in upgrading the effluent quality.

Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1457-1466 ◽  
Author(s):  
Kazuhiro Tanaka ◽  
Minoru Tada ◽  
Mitsuo Ito ◽  
Noritugu Shimizu
Keyword(s):  
Suspended Solids ◽  
Fine Particles ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Particle Fraction ◽  
Effluent Quality ◽  
Rotating Biological Contactors ◽  
Activated Sludge Processes ◽  
Fraction Method ◽  
Final Effluent

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.

Obtaining Secondary Treatment with RBC/Underflow Clarifiers

1982 ◽  
Vol 14 (6-7) ◽  
pp. 429-442
Author(s):  
I L Bogert
Keyword(s):  
Treatment Process ◽  
High Rate ◽  
Experimental Program ◽  
Secondary Treatment ◽  
Lower Zone ◽  
Treatment Efficiency ◽  
Winter Conditions ◽  
Rotating Biological Contactors ◽  
One Year ◽  
The U.S

A one-year experimental program conducted at Edgewater, New Jersey, U.S.A. evaluated the concept of providing secondary treatment by the installation of rotating biological contactors (RBC's) in modified primary sedimentation tanks. A primary tank was divided horizontally into two zones separated by an intermediate floor. Four RBC's were placed in the upper zone. The lower zone provided secondary sedimentation. High rate primary sedimentation was provided to remove grit and trash without removing substantial portions of BOD and SS. The experimental program funded by the U.S. EPA and the Borough of Edgewater was conducted over a full year at different loads. The system proved to be an effective secondary treatment process with little difference in treatment efficiency between summer and winter conditions.

scholarly journals Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Electric Vehicles ◽  
Energy Demand ◽  
Lithium Ion ◽  
Life Cycles ◽  
Future Research ◽  
Research Areas ◽  
Study Results ◽  
The Impact

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

scholarly journals The metropolitan acid aerosol characterization study: results from the summer 1994 Washington, D.C. field study.

1997 ◽  
Vol 105 (8) ◽  
pp. 826-834 ◽  
Author(s):  
H H Suh ◽  
Y Nishioka ◽  
G A Allen ◽  
P Koutrakis ◽  
R M Burton
Keyword(s):  
Field Study ◽  
Characterization Study ◽  
Study Results ◽  
Aerosol Characterization

scholarly journals Estimation of Reduced Air Emissions as a Result of the Implementation of the Measure to Reduce Burned Sugarcane in Thailand

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 366 ◽  
Author(s):  
Agapol Junpen ◽  
Jirataya Pansuk ◽  
Savitri Garivait
Keyword(s):  
Particulate Matter ◽  
Financial Support ◽  
Fine Particles ◽  
Air Emissions ◽  
First Year ◽  
Study Results ◽  
Reduction Measure ◽  
Human Labor ◽  
The Government ◽  
Pm2.5 Emissions

In the middle of 2019, Thailand introduced an urgent measure to solve the haze and fine particles problem caused by preharvest sugarcane. The measure is to eradicate the burning of sugarcane before harvesting within the next four years. This study focuses on estimation of future reduced air emissions from the implementation of this measure. The study results showed that without the implementation of the measure in the production season 2022/23, the amount of burned sugarcane will be as high as 102.4 ± 1.0 Mt/yr, resulting in the release of small particulate matter of 2.5 microns or less in diameter (PM2.5) emissions into the atmosphere at 30.6 ± 8.6 kt/yr, which is about a 21% increase in emissions from the 2018/19 season. However, with the government’s enforcement of the measure to reduce burned sugarcane, the amount of air emissions will immediately be reduced in the first year. In order to effectively implement the sugarcane burning reduction measure, in which the harvesting methods will change from cutting burned sugarcane to cutting fresh sugarcane with human labor and with machinery, the government must provide financial support, to farmers, of approximately 3.3 USD per ton of fresh sugarcane for the use of human labor and 2.9 USD per ton of fresh sugarcane for the use of machinery. The costs of investment to reduce PM2.5 emissions can be calculated in the range of 9.7−11.0 million USD per kiloton of PM2.5.

Waste stabilisation ponds upgrading at Blenheim and Seddon, New Zealand - case studies

2003 ◽  
Vol 48 (2) ◽  
pp. 17-23
Author(s):  
H.E. Archer ◽  
S.A. Donaldson
Keyword(s):  
Wastewater Treatment ◽  
New Zealand ◽  
Lower Cost ◽  
Small Communities ◽  
Large Cities ◽  
Effluent Quality ◽  
Waste Stabilisation Ponds ◽  
Bank Protection ◽  
In Series ◽  
Final Effluent

Waste stabilisation ponds (WSP) have been a popular form of wastewater treatment in New Zealand both for large cities and small communities. Most WSP were constructed from 1960 to 1985 and were single ponds or a primary and secondary pond in series of similar size. Since 1995, improvements comprising primary and maturation ponds, with four to six cells in series have been constructed or retrofitted to original two cell ponds. The Seddon and Blenheim ponds include in-bank rock filters between maturation cells as a lower cost way of providing this feature for reduction of solids. Operating results show reduced variability in final effluent quality for BOD and SS. In addition, very good reductions of faecal coliform and enterococci have been achieved along with good reductions of ammonia and total nitrogen for most of the year except the middle of winter. Extensive use of rock as rip-rap bank protection and in the rock filters, appears to have provided sufficient extra surface area for a nitrifying biofilm to develop.

Iron-Coated Sponge as Effective Media to Remove Arsenic from Drinking Water

2006 ◽  
Vol 41 (2) ◽  
pp. 164-170 ◽  
Author(s):  
Tien Vinh Nguyen ◽  
Saravanamuthu Vigneswaran ◽  
Huu Hao Ngo ◽  
Damodar Pokhrel ◽  
Thiruvenkatachari Viraraghavan
Keyword(s):  
Drinking Water ◽  
Filtration Rate ◽  
High Capacity ◽  
Small Communities ◽  
Effluent Quality ◽  
Effective Media ◽  
Acceptable Quality ◽  
The World ◽  
New Material ◽  
Dynamic Filter

Abstract Arsenic (As) contamination in drinking water is a serious problem in a number of countries in the world, especially in small communities and developing countries. Arsenic is related to many health diseases. Several technologies such as coagulation, adsorption, ion exchange and membrane processes, etc., are used in removing arsenic from water. In this study, a new material, namely iron-coated sponge (IOCSp), was developed and used to remove As, and it was found that IOCSp has a high capacity for removing both As(V) and As(III). Each gram of IOCSp adsorbed about 160 µg of As upon a 9-h contact of IOCSp with As solution. A dynamic filter column conducted showed that even a small quantity of IOCSp (8 g) could reduce As from 156 µg/L to a concentration of less than 50 µg/L while treating 75 L of groundwater contaminated with arsenic. Both the filtration rate and the size of the sponge had an effect on effluent quality, and the amount of water treated to the acceptable quality.

Flixweed (Descurainia sophia) Shade Tolerance and Possibilities for Flixweed Management Using Rapeseed Seeding Rate

2017 ◽  
Vol 31 (3) ◽  
pp. 477-486
Author(s):  
Christopher A. Landau ◽  
Brian J. Schutte ◽  
Abdel O. Mesbah ◽  
Sangamesh V. Angadi
Keyword(s):  
Field Study ◽  
Light Transmission ◽  
Light Transmittance ◽  
Seeding Rate ◽  
Seed Oil Content ◽  
Greenhouse Study ◽  
Study Results ◽  
Rate Effects ◽  
Shade Tolerant Species ◽  
Photosynthetic Responses

Brassicaceae weeds can be problematic in canola varieties that have not been modified to resist specific broad-spectrum herbicides. The overall objective of this study was to evaluate the potential for increased rapeseed seeding rate as a management strategy for flixweed. To accomplish this objective, a field study was conducted to determine crop seeding rate effects on canopy light transmission and rapeseed yield characteristics, as well as a greenhouse study to determine morphological and photosynthetic responses of flixweed to decreasing irradiance levels. Results from the field study indicated that light transmittance through the canopy decreased linearly as crop seeding rate increased from 1.8 to 9.0 kg ha-1. Increasing crop seeding rate did not influence rapeseed aboveground biomass, seed yield, and harvest index, but negatively affected rapeseed seed oil content in one of two site-years. Greenhouse study results indicated that declining irradiance levels caused reductions in flixweed biomass, root allocation, and photosynthetic light compensation point. Flixweed leaf allocation, foliage area ratio, and specific foliage area increased in response to decreasing irradiance levels. Combined results of field and greenhouse studies suggest that increasing rapeseed seeding rate can suppress flixweed growth while not causing yield penalties from increased intraspecific competition. However, increased rapeseed seeding rate might not be an adequate control strategy on its own because flixweed displays characteristics of a shade-tolerant species.

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