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.

scholarly journals A Mini-Review of Urban Wastewater Treatment in Greece: History, Development and Future Challenges

2020 ◽  
Vol 12 (15) ◽  
pp. 6133
Author(s):  
Charikleia Prochaska ◽  
Anastasios Zouboulis
Keyword(s):  
Wastewater Treatment ◽  
Environmental Sustainability ◽  
Rural Areas ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Septic Tank ◽  
Urban Wastewater ◽  
Tourism Sector ◽  
Future Challenges ◽  
Urban Wastewater Treatment

Although Greece has accomplished wastewater infrastructure construction to a large extent, as 91% of the country’s population is already connected to urban wastewater treatment plants (WWTPs), many problems still need to be faced. These include the limited reuse of treated wastewater and of the surplus sludge (biosolids) produced, the relative higher energy consumption in the existing rather aged WWTPs infrastructure, and the proper management of failing or inadequately designed septic tank/soil absorption systems, still in use in several (mostly rural) areas, lacking sewerage systems. Moreover, the wastewater treatment sector should be examined in the general framework of sustainable environmental development; therefore, Greece’s future challenges in this sector ought to be reconsidered. Thus, the review of Greece’s urban wastewater history, even from the ancient times, up to current developments and trends, will be shortly addressed. This study also notes that the remaining challenges should be analyzed in respect to the country’s specific needs (e.g., interaction with the extensive tourism sector), as well as to the European Union’s relevant framework policies and to the respective international technological trends, aiming to consider the WWTPs not only as sites for the treatment/removal of pollutants to prevent environmental pollution, but also as industrial places where energy is efficiently used (or even produced), resources’ content can be potentially recovered and reused (e.g., nutrients, treated water, biosolids), and environmental sustainability is being practiced overall.

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.  

scholarly journals The biomass, survival, reproductive and biomarker responses of Helix pomatia to soil contaminated with treated and untreated wastewater.

2021 ◽  
Author(s):  
Semase Matseleng ◽  
Ozekeke Ogbeide ◽  
Patricks' Otomo Voua
Keyword(s):  
Wastewater Treatment ◽  
Egg Production ◽  
Wastewater Treatment Plants ◽  
Helix Pomatia ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Invertebrate Fauna ◽  
Untreated Wastewater ◽  
Industrial Town ◽  
Treatment Facilities

Abstract Wastewater treatment facilities in developing countries like South Africa are major sources of contaminants via effluent into the environment, which could portend high toxicity risks for non-target flora and fauna. To this end, a study was conducted to determine the ecotoxicological responses of selected organism to treated and untreated wastewater from the wastewater treatment plants in an industrial town. The snail Helix pomatia was exposed to OECD artificial soil spiked with untreated or treated wastewater at the following concentrations: 0, 25, 50, 75, 100%. The ecotoxicological responses of Helix pomatia to wastewater were determined by assessing the biomass, survival, reproduction and biomarker responses (Catalase ‒ CAT and Acetylcholinesterase ‒ AChE activities). The overall results showed significant effects on the survival, reproduction and biomass of H. pomatia. Similar results were observed for juvenile emergence. An EC50 of 5.751% for egg production and an EC50 of 6.233% for juvenile emergence were determined in the untreated wastewater. Such indices could not be computed for the treated wastewater, indicating a decreased in toxicity between the untreated and the treated samples. For both the AChE and CAT activities, there was no statistical difference between treated and untreated wastewater treatments. The results from this study highlight the toxic effects of untreated wastewater and indicate that treated wastewater (effluent) released from the wastewater treatment plant in Phuthaditjhaba remains suitable for invertebrate fauna such as H. pomatia.

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