Sludge production characteristics of small-scale wastewater treatment facilities using anaerobic/aerobic biofilm reactors

1996 ◽  
Vol 34 (3-4) ◽  
pp. 379-387 ◽  
Author(s):  
Yuhei Inamori ◽  
Tomotake Takai ◽  
Yasuhiro Yamamoto ◽  
Nobuyoshi Katagai ◽  
Toshihiro Sankai ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Plug Flow ◽  
Biofilm Reactor ◽  
Small Scale ◽  
Constant Flow Rate ◽  
Loading Rates ◽  
Circulation Ratio ◽  
Treatment Facilities ◽  
Production Characteristics ◽  
Sludge Production

Sludge production characteristics were investigated in many on-site small-scale wastewater treatment facilities used to treat domestic wastewater of about 1.25m3/day. Two popular types have been used in experiments for several years; one was an anaerobic bed reactor with constant flow-rate control system followed by aerobic bio-filtration reactor CFR type facility), and the other was an aerobic bed reactor with plug-flow stream followed by aerobic biofilm reactor (PFS type facility). Circulation ratio was set at 0 and 4. From the results obtained, lower sludge production rates were observed in CFR type facilities. Furthermore, it was suggested that a promotion of sludge decrease occurred in facilities with high denitrification activity at circulation ratio of 4. The results from experiments with different SS loading rates in laboratory-scale reactors suggested that at higher loading rates, the produced sludge was greater on account of the decrease of nitrification activity even on a circulating operation.

Decentralized wastewater treatment using ‘Pumped Flow Biofilm Reactor’ (PFBR) technology

2016 ◽  
Vol 11 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Shane Fox ◽  
Michael Cahill ◽  
Edmond O'Reilly ◽  
Eoghan Clifford
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
New Technologies ◽  
Phase 1 ◽  
Oxygen Demand ◽  
Biofilm Reactor ◽  
Small Scale ◽  
Mechanical Equipment ◽  
Phase 2 ◽  
Sludge Production

Clean water resources are imperative for sustainable development. Thus, protection and management of waters receiving wastewater discharges have received significant attention from policy and regulatory bodies. The quality of wastewater effluent must meet regional (e.g. Water Framework Directive), national and local discharge standards. In addition, there is now significant pressure on engineers and operators to reduce energy consumption, sludge production and operation/maintenance issues, particularly at small-scale and decentralized wastewater facilities. Therefore, significant interest has risen in new technologies and operational insights which can (i) minimize operating costs; (ii) simplify and reduce the use of mechanical equipment; (iii) result in low sludge production; and (iv) ease operation/maintenance. This study investigated the performance of a small-scale municipal wastewater facility over 5 months from commissioning. The facility uses a new biofilm-based technology – the pumped flow biofilm reactor. Two experimental periods Phase 1 (28 to 36 days) and Phase 2 (Days 100 to 146) were examined. During Phase 2, removal rates averaged 98% for 5-day biochemical oxygen demand (BOD5), 93% for total suspended solids, and 94% ammoniacal-nitrogen (NH4-N). Energy requirements averaged 0.22 kWh.m treated−3 and 1.74 kWh.kg-BOD5 removed−1. Extensive, camera-based studies revealed minimal excess sludge in the reactor tanks and sludge removal was not required during the study period. The use of vertically stacked plastic media to support the biofilm may have limited biofilm sloughing. Sludge yield during steady state operation was estimated at around 0.03 g-SS.g-COD removed−1. The study indicates that given careful design and operation, small-scale wastewater treatment systems can be as efficient as much larger, fully manned plants.

Sludge thickening performance of mesh filtration process

2004 ◽  
Vol 50 (8) ◽  
pp. 125-133 ◽  
Author(s):  
M.-S. Park ◽  
Y. Kiso ◽  
Y.-J. Jung ◽  
M. Simase ◽  
W.H. Wang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Level ◽  
Domestic Wastewater ◽  
Small Scale ◽  
Mechanical Equipment ◽  
Hydraulic Pressure ◽  
Sludge Treatment ◽  
Filtration System ◽  
Treatment Facilities ◽  
Sludge Thickening

Small-scale wastewater treatment facilities play an important role in improving the aquatic environment in many countries. Although sludge treatment is essential for overall wastewater treatment, it is difficult for small-scale facilities to use mechanical equipment or other facilities. As the first step of the sludge treatment, it is important to develop a convenient sludge thickening process for small-scale facilities. In this work, we examined the sludge thickening performance of a mesh filtration system: the mesh opening sizes of 100-500 μm, and the sludge (3,000-9,000 mg-SS/L) was obtained from a domestic wastewater treatment facility. The filtration was carried out only under the hydraulic pressure between the water level and the effluent port connected to the mesh filter module. The sludge reduction rates were in the range of 85-95% for 6-7 h; the initial filtration rate was very high, but the rate decreased with a decrease in hydraulic pressure due to the reduction of the water level in the vessel. In addition, the effluents (passed through the mesh) contained very low SS and could be directly discharged into the environment.

scholarly journals RATIONAL CONSTRUCTION AND TECHNOLOGICAL PARAMETERS OF WATER TREATMENT FACILITIES IN RURAL AREAS

2019 ◽  
pp. 74-81
Author(s):  
Y. B. Mosiichuk ◽  
V. P. Khoruzhy
Keyword(s):  
Wastewater Treatment ◽  
Rural Areas ◽  
Water Filtration ◽  
Small Scale ◽  
Rural Settlements ◽  
Technological Parameters ◽  
Active Sludge ◽  
Industrial Enterprises ◽  
High Efficient ◽  
Treatment Facilities

In view of the development of cottage construction and enterprises of agricultural products processing, located mainly in rural areas, the development of high-efficient, reliable and easy-to-use treatment plants for the purification of domestic wastewater of low quality is very relevant. The objective of the research is to ensure the high quality purified water and minimize capital and operating costs. To solve this problem, the methods of physical and mathematical modeling were used, as well as numerical and analytical methods for determination and analysis of the parameters of treatment facilities operation. To use the latest advances in science and technology in the area of small-scale wastewater treatment facilities, which are typical for rural settlements and agro-industrial enterprises, in these conditions it is proposed to use bioreactors and contact clarifying filters. As the research has shown, water quality indicators of purified water change during the time of water filtration Tf and depend on the velocity of water filtration Vf and a specific cleanings capacity of the filter: at the beginning their values decrease as a result of accumulation of active sludge in the subfilter space, and then they begin to rise due to the increase of hydraulic resistance to water motion and removing this residual matter into filtered water. The article also presents the results of investigations on changes in the content of organic compounds in filtered water during the filtration cycle Тf by the biochemical oxygen consumption value (BOCV) depending on a water filtration rate Vf, m/h, and the amount of active sludge (specific dirt content of the filter G, kg/m2), as well as the changes in the content of suspended matter Сf.i. due to the same parameters. The recommendations on the effective operation of wastewater treatment facilities of the proposed design that which ensure their reliable and high-performance operation, were developed.  

Feasibility of contact aeration method for small-scale domestic wastewater treatment system in rural China

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
T. Kuyama ◽  
M. Mizuochi ◽  
H. Koyanagi ◽  
T. Wako
Keyword(s):  
Wastewater Treatment ◽  
Rural Areas ◽  
Wastewater Treatment Plants ◽  
Rural China ◽  
Domestic Wastewater ◽  
Treated Wastewater ◽  
Small Scale ◽  
Billing System ◽  
Domestic Wastewater Treatment ◽  
Treatment Facilities

This study examines the feasibility of the contact aeration method for utilisation in small-scale domestic wastewater treatment facilities in various rural areas of China, where the national government starts to address the water pollution issue. Three pilot facilities using the contact aeration method with different capacities were constructed, operated and monitored in Chongqing city and Jiangsu province. In order to evaluate the feasibility of the constructed facilities, the quality of treated wastewater and the operational cost were monitored. Results obtained from the monitoring showed that BOD and COD effluent concentrations achieved quality targets in all facilities. As for the other pollutants, quality targets were met for most of the period. Operational costs of facilities bettered those set for the facility in the town of Baiyang and new village of Zhaojia, but exceeded them for the facility in the village of Dongbei. The main reasons for the differences were the electricity billing system and operational system for each facility. In order to promote small-scale aeration-based domestic wastewater treatment plants in rural China in the future, the issue of what constitutes efficient facility maintenance first needs to be addressed.

Effectiveness of flow stabilization in small-scale wastewater treatment facilities

2005 ◽  
Vol 51 (11) ◽  
pp. 167-174
Author(s):  
J. Nakajima ◽  
R. Tanaka
Keyword(s):  
Wastewater Treatment ◽  
Flow Velocity ◽  
Water Level ◽  
Flow Rate ◽  
Maximum Flow ◽  
Small Scale ◽  
Household Type ◽  
Flow Stabilization ◽  
Treatment Facilities ◽  
Anaerobic Chamber

Household type Johkasous which have a flow stabilization function were surveyed on their performance. The water level, flow velocity and SS were measured after the maximum flow entering the anaerobic filter chamber with or without flow stabilization operation. In operation without the flow stabilization, the flow peak directly reached the biofiltration chamber and the flow rate kept at 1 cm/sec during 3–4 min in the connection baffle between the two anaerobic chambers. This suggested the possibility of sludge transfer from the first anaerobic chamber. Moreover the increase of SS in the second anaerobic chamber indicated sludge transfer from the second anaerobic chamber to the biofiltration chamber. In contrast, in operation with flow stabilization the relaxation of the water flow in the second anaerobic chamber and the biofilm chamber was verified. By the increase of the water level in the first anaerobic chamber, the flow stabilization performance was satisfactorily obtained. A model describing the change of the water level was developed and the calculated values and the measured value agreed well. The model will be useful in the design of the flow stabilization function.

Qualitative evaluation of small scale municipal Wastewater Treatment Plants (WWTPs) in South India

2015 ◽  
Vol 10 (4) ◽  
pp. 711-719 ◽  
Author(s):  
S. Suneethi ◽  
G. Keerthiga ◽  
R. Soundhar ◽  
M. Kanmani ◽  
T. Boobalan ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
South India ◽  
Municipal Wastewater ◽  
Energy Requirement ◽  
Biofilm Reactor ◽  
Plant Performance ◽  
Small Scale ◽  
Treatment Technology ◽  
Natural Treatment ◽  
Treatment Technologies

Decentralized wastewater treatment system (DEWATS) are widely used for the treatment of wastewater originating from residences, institutes and municipalities, specifically in South India. Most of these STPs are denounced owing to failures on several fronts including design, operation and maintenance, installation and monitoring. A comprehensive review and evaluation of STPs was timely, in order to derive sound conclusions and recommendations for future wastewater management strategies. The objective of the present study was to conduct an independent evaluation of already existing decentralized STPs in South India. The technologies assessed were Aerated lagoon (AL), Extended aeration (EA), Anaerobic filter/Vortex put forward by Centre for Scientific Research (CSR VORTEX), Constructed Wetland (DEWATS others), Membrane bioreactor (MBR) and Moving bed Biofilm reactor (MBBR). Among the various technologies evaluated, MBR exhibited the highest total COD, BOD and solids removal efficiency. Pathogen count was lowest in MBR, followed by MBBR and AL. Nutrient removal in terms of ammoniacal nitrogen and nitrate nitrogen was highest in DEWATS. Effective hours of continuous operation enabled improved plant performance. In case of natural treatment technology such as DEWATS, energy requirement is quite low, whereas conventional treatment technologies such as EA necessitate considerably high demand of energy, requiring few personnel to operate the system. Innovative high cell density systems such as MBBR and MBR entail significant power consumption and elaborate maintenance, requiring large number of skilled professionals. The major reasons for failure of STPs were related to mechanical, electrical and labour problems. Regular monitoring and maintenance is required with due diligence in all the treatment technologies for proper functioning.

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