Practical Performance of Nitrogen Removal in Small-Scale Sewage Treatment Plants Operated in Intermittent Aeration Mode

1991 ◽  
Vol 23 (4-6) ◽  
pp. 709-718 ◽  
Author(s):  
Jun Nakajima ◽  
Mitsumi Kaneko
Keyword(s):  
Nitrogen Removal ◽  
High Performance ◽  
Nitrogen Concentration ◽  
Sewage Treatment ◽  
Small Scale ◽  
Aeration Tank ◽  
Intermittent Aeration ◽  
Sewage Treatment Plants ◽  
Chiba Prefecture ◽  
Practical Performance

Research was carried out to clarify the number and the scale of small-scale sewage treatment plants operated in intermittent aeration mode by asking questions to maintenance workers in Chiba Prefecture, Japan. The percentage of the number of plants operated in intermittent aeration mode was 26.5%. This percentage was high in the plants larger than 200 population equivalent (p.e.). The practical performance of nitrogen removal was evaluated in nine existing plants operated in intermittent aeration mode. A high performance of nitrogen removal was noticed in the plants us ing extended aeration process. The performances of nitrogen removal in two plants operated in intermittent aeration mode were compared with those operated in continuous aeration mode. The characteristics of denitrification taking place in the aeration tank in a plant operated in intermittent mode were investigated by measuring the change in nitrogen concentration in the tank during the intermittent period. The seasonal performanee of denitrification was studied by a long term practical experiment for 16 months. By operating the length of intermittent time according to the change of the water temperature in the aeration tank, a high performance of nitrogen removal was obtained throughout the year.

Effect of dissolved oxygen conditions on nitrogen removal in continuously fed intermittent-aeration process with two tanks

2002 ◽  
Vol 45 (12) ◽  
pp. 181-188 ◽  
Author(s):  
T. Hidaka ◽  
H. Yamada ◽  
M. Kawamura ◽  
H. Tsuno
Keyword(s):  
Nitrogen Removal ◽  
Rural Areas ◽  
Aerobic Condition ◽  
Small Scale ◽  
Intermittent Aeration ◽  
Solids Retention ◽  
Oxygen Conditions ◽  
Control Set ◽  
Aeration Process ◽  
Biological Nitrogen

In this study, an intermittent aeration type activated sludge process that is fed continuously is evaluated for nitrogen and organic carbon for facilities in rural areas, which are characterized by small scale, low loading rate and automatic operation. Anoxic and aerobic conditions can be regulated alternatively by intermittent aeration for biological nitrogen removal. It is proved that an intermittent aeration cycle of 90 min, with aeration/anoxic mixing periods of 25~30 min/65~60 min in Tank 1, and 30~45 min/60~45 min in Tank 2, and a DO control set at 0.6~1 mg/L during the aeration period are required for satisfactory treatment performance. Under these conditions, a stable effluent water quality with BOD ≤ 5 mg/L, CODMn ≤ 8 mg/L, Nitrogen ≤ 3 mgN/L, SS ≤ 5 mg/L and transparency ≥ 80 cm can be achieved. The solids retention time in aerobic condition was 10~25 d, which is sufficient for nitrification.

scholarly journals Potential Applications of Biogas Produced in Small-Scale UASB-Based Sewage Treatment Plants in Brazil

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3356 ◽  
Author(s):  
Fabiana Passos ◽  
Thiago Bressani-Ribeiro ◽  
Sonaly Rezende ◽  
Carlos A. L. Chernicharo
Keyword(s):  
Public Health ◽  
Thermal Energy ◽  
Rural Areas ◽  
Sewage Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Small Scale ◽  
Anaerobic Sludge ◽  
Water Heating ◽  
Sewage Treatment Plants ◽  
Majority Population

Rural sanitation is still a challenge in developing countries, such as Brazil, where the majority population live with inadequate services, compromising public health and environmental safety. In this context, this study analyzed the demographic density of these rural agglomerations using secondary data from the Brazilian Institute of Geography and Statistics (IBGE). The goal was to identify the possibilities associated with using small-scale upflow anaerobic sludge blanket (UASB) reactors for sewage treatment, mainly focusing on biogas production and its conversion into energy for cooking, water heating and sludge sanitization. Results showed that most rural agglomerations lacking the appropriate sewage treatment were predominant from 500 to 1500 inhabitants in both northern and southern Brazilian regions. The thermal energy available in the biogas would be enough to sanitize the whole amount of sludge produced in the sewage treatment plants (STPs), producing biosolids for agricultural purposes. Furthermore, the surplus of thermal energy (after sludge sanitization) could be routed for cooking (replacing LPG) and for water heating (replacing electricity) in the northern and southern regions, respectively. This would benefit more than 200,000 families throughout rural areas of the country. Besides the direct social gains derived from the practice of supplying biogas for domestic uses in the vicinity of the STPs, there would be tremendous indirect gains related to the avoidance of greenhouse gas (GHG) emissions. Therefore, an anaerobic-based sewage treatment may improve public health conditions, life quality and generate added value products in Brazilian rural areas.

Denitrification in trickling filters

1994 ◽  
Vol 30 (6) ◽  
pp. 181-184 ◽  
Author(s):  
Bernd Dorias ◽  
Peter Baumann
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Capital Expenditure ◽  
Sewage Treatment ◽  
Innovative Technology ◽  
Activated Sludge Process ◽  
Trickling Filter ◽  
Sewage Treatment Plants ◽  
Trickling Filters ◽  
Test Operation

National and international regulations require a minimum nitrogen removal efficiency of 70% in most public sewage treatment plants. Unlike in activated sludge plants, selective denitrification in trickling filters was not possible until now. Therefore the aim was to employ trickling filter plants for selective denitrification, using innovative technology that involved minimum capital expenditure. For selective denitrification, it is necessary to prevent as much as possible the transfer of oxygen into the trickling filter while feeding the nitrate to be removed, a process similar to upstream denitrification in the activated sludge process. In a test operation conducted in several sewage treatment plants for over a year, the new process with selective denitrification in a covered trickling filter has given successful results. The denitrification efficiency of this system is comparable to that of upstream denitrification in the activated sludge process. Thus, selective denitrification in the trickling filter is a practical alternative to other nitrogen removal processes, while maintaining the established advantages offered by the trickling filter process.

Development of a routine analytical procedure for nonylphenol polyethyoxylates and their biodegradation products in sludge from sewage treatment plants

2001 ◽  
Vol 44 (10) ◽  
pp. 101-106 ◽  
Author(s):  
M. Tateda ◽  
N.V. Hung ◽  
H. Kaku ◽  
M. Asano ◽  
M. Ike ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Sewage Sludge ◽  
High Performance ◽  
Analytical Procedure ◽  
Sewage Treatment ◽  
Soxhlet Extraction ◽  
Average Concentration ◽  
Recovery Efficiency ◽  
Sewage Treatment Plants ◽  
Freeze Dried

A method of quantitative analysis of nonylphenol polyethoxylates (NPnEOs) and their biodegration products (NPE-BDPs) in sewage sludge, which is effective, economical, and applicable to a high performance liquid chromatography was developed and actual sludge samples collected from Japanese sewage treatment plants (STPs) were analyzed using the method to confirm its effectiveness. Soxhlet extraction showed better recovery in a spike and recovery test than shaking extraction. Among the four pretreatments for Soxhlet extraction tested, the condition in which samples were freeze-dried, ultrasonicated, and extracted with methanol showed the best recovery efficiency. Quantitative analysis of NPE-BDPs in STP sludge resulted in 6.1 μg/g, 4.3 μg/g, and 8. μg/g in average concentration for NPnEOs (n=1-3), NPnEOs (n=4-18), and nonylphenol ethoxycarboxylates (NPnECs (n=1-3)), respectively, and the values of concentration were 100-1000 times higher than those in effluent at Japan's STPs. The results implied importance of quantitation of NPE-BDPs in sewage sludge to assess the risk to the environment.

Extension of the Sewage Treatment Plants in Stockholm: Some Technical and Economical Aspects

1993 ◽  
Vol 27 (5-6) ◽  
pp. 357-367 ◽  
Author(s):  
J. Hultgren ◽  
L. G. Reinius
Keyword(s):  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Good Chance ◽  
Sewage Treatment Plants ◽  
Treated Sewage ◽  
The Future ◽  
Future Extension ◽  
The City

The requirements for the sewage treatment plants in Sweden will be more stringent in the future. The three plants in Stockholm, Henriksdal, Bromma and Loudden have to be extended to meet requirements for nitrogen removal and increased phosphorus removal. Since 1989 the plants have the same recipient for the treated sewage and to save money during the future extension the city would like to regard the three effluents as one common. The authorities have not yet decided to admit this but there is a good chance for it. The paper describes the strategy for extension and how the plants have been designed.

On the Issue of Monitoring Odor-Generating Volatile Pollutants during Sewage Treatment Plant Operation

2020 ◽  
pp. 52-55
Author(s):  
EV Zaritskaya ◽  
PA Ganichev ◽  
AYu Mikheeva ◽  
OL Markova ◽  
GB Yeremin ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
High Performance ◽  
Local Population ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Analytical Techniques ◽  
Ambient Air ◽  
Sewage Treatment Plants ◽  
Study Results

Summary. Introduction: The problem of strong offensive odor produced by operation of sewage treatment plants is known to be quite pressing and common. It is now related to the fact that urban development made these plants, once built on the outskirts, appear within city boundaries, near summerhouses and cottage villages. Malodor is perceived by local population as a sign of poor ambient air quality that evokes negative emotions and unfavorable reflex responses and makes most people feel unwell. Materials and methods: We analyzed sewage sludge from wastewater treatment plants for the whole range of chemicals that can migrate into ambient air and identified priority odor-generating pollutants. Sewage sludge testing was carried out in simulated conditions using advanced high-precision analytical techniques such as mass-spectrometry, spectrophotometry, fluorimetry, gas chromatography, and high performance liquid chromatography. Conclusions: Based on study results, we developed a list of chemicals subject to laboratory monitoring and substantiated the expediency of their detection in the presence of public complaints of offensive odors coming from sewage treatment plants.

Upgrading for Biological Nitrogen Removal – Some Full-Scale Experiences from Sweden

1990 ◽  
Vol 22 (7-8) ◽  
pp. 93-104 ◽  
Author(s):  
Bengt Andersson ◽  
Björn Rosén
Keyword(s):  
Nitrogen Removal ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Development Program ◽  
Organic Content ◽  
Full Scale ◽  
Municipal Sewage ◽  
Biological Nitrogen Removal ◽  
Sewage Treatment Plants ◽  
Biological Nitrogen

Nitrogen removal is now required by the Swedish parliament. The new requirements will be valid before 1995 and in some cases before 1992. A comprehensive development program, mostly in full scale at about 35 municipal sewage treatment plants, has been started to meet the new demands. In order to co-ordinate all activities, a National Nitrogen Project with representatives from authorities and municipalities has been formed. The general ambition is to meet the demand by process development, using existing volumes rather than to invest in civil works. A Swedish concept has appeared, which in most cases has served as a guideline for the development program. The basic principles are to decrease the load on the biological process by pre-precipitation, to utilize the remaining organic content in the wastewater in a pre-denitrification system, to increase the active biomass in the biological system and to use a two-sludge system with post-denitrification. In this paper, some experiences from the activities in Sweden are discussed and exemplified with results mainly from Falkenberg, Malmö and Norrköping. The treatment plant in Falkenberg was the first to introduce biological nitrogen removal in Sweden. A pre-denitrification system has been in operation since May 1983 with good results. Comprehensive full-scale and pilot tests are in operation at the Sjölunda and Klagshamn sewage treatment plants in Malmö. Special interests have been paid to studies on different applications of fixed film technology. The plant in Norrköping is operated with pre-precipitation followed by combined pre- and post-denitrification.

Performance evaluation of on-site treatment facilities for wastewater from Households, Hotels and Restaurants

1999 ◽  
Vol 39 (8) ◽  
pp. 85-92 ◽  
Author(s):  
Jun Nakajima ◽  
Yoko Fujimura ◽  
Yuhei Inamori
Keyword(s):  
Nitrogen Removal ◽  
Treated Wastewater ◽  
Small Scale ◽  
Environment Protection ◽  
Intermittent Aeration ◽  
Household Wastewater ◽  
Hexane Extracts ◽  
Individual Household ◽  
Treatment Facilities ◽  
Low Performance

In order to evaluate performance of on-site treatment facilities which can be provided for environment protection in coastal areas, effluent qualities and removal efficiencies were surveyed in actual treatment facilities for wastewater from households, hotels and restaurants. On-site treatment facilities in Japan are fundamentally built according to the structural standards. They have a pretreatment process (sedimentation separation tank, anaerobic filter or equalization tank with screens) followed by an aerobic process (contact aeration, activated sludge, etc.). Small-scale facilities for individual household wastewater showed good performance of BOD removal with their effluent BOD below 20mg 1−1. They also exhibited nitrogen removal efficiency when they were operated in mixed liquor recycle mode. The facilities applied to wastewater from hotels, restaurants and stores showed good performance when the influent oil (hexane extracts) concentration had been decreased below 30mg 1−1 by using pretreatment. Nitrogen removal performance was high in the facilities which treated wastewater from a residential area or a condominium when they were operated in intermittent aeration mode. But resort condominiums of which influent BOD load was extremely low showed low performance of nitrogen removal even though they were operated in intermittent aeration mode because of the low BOD/N ratio in the influent. An equation was proposed to estimate the amount of methanol to be added in facilities in which the influent BOD/N ratio is low.

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