scholarly journals Investigation of interaction of particles of pollution and gas bulb in flotation of wastewater waters

2019 ◽  
Vol 135 ◽  
pp. 01032
Author(s):  
Elena Nazimko ◽  
Sergei Malko ◽  
Anna Semenova ◽  
Vladimir Dorovskoy
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Hydrophobic Surface ◽  
Small Scale ◽  
Discrete Elements ◽  
Chemical Factors ◽  
Flotation Method ◽  
Physical And Chemical ◽  
Kinetics Of ◽  
Discrete Elements Method

The interaction of phases is at the basis of many technologies in different industries. Flotation method is used in wastewater treatment plants to capture and remove contaminants from wastewater. In this case, the interaction of air bubbles with particles of pollution with a hydrophobic surface. These interactions are very difficult to investigate because they are dynamic, subject to a large number of physical and chemical factors, and occur on a small scale. The processes mentioned above have traditionally been studied by laboratory experiments. These tests are tedious and time-consuming and show unsatisfactory accuracy. Analytical studies give idealized results. One of the most powerful alternatives for solving this problem is numerical modeling, which combines dynamics, accuracy and consideration of sophisticated details. This model is based on the discrete elements method. In this paper, a computer model for modeling the kinetics of the interaction of phases in wastewater treatment is considered.

Planning Replicable Small Flow Wastewater Treatment Facilities in Developing Nations

1993 ◽  
Vol 28 (10) ◽  
pp. 1-8 ◽  
Author(s):  
A. Gaber ◽  
M. Antill ◽  
W. Kimball ◽  
R. Abdel Wahab
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Local Development ◽  
Treatment Plant ◽  
Development Program ◽  
The United States ◽  
Appropriate Technology ◽  
Funding Agency ◽  
Small Scale ◽  
Technology Choice

The implementation of urban village wastewater treatment plants in developing countries has historically been primarily a function of appropriate technology choice and deciding which of the many needy communities should receive the available funding and priority attention. Usually this process is driven by an outside funding agency who views the planning, design, and construction steps as relatively insignificant milestones in the overall effort required to quickly better a community's sanitary drainage problems. With the exception of very small scale type sanitation projects which have relatively simple replication steps, the development emphasis tends to be on the final treatment plant product with little or no attention specifically focused on community participation and institutionalizing national and local policies and procedures needed for future locally sponsored facilities replication. In contrast to this, the Government of Egypt (GOE) enacted a fresh approach through a Local Development Program with the United States AID program. An overview is presented of the guiding principals of the program which produced the first 24 working wastewater systems including gravity sewers, sewage pumping stations and wastewater treatment plants which were designed and constructed by local entities in Egypt. The wastewater projects cover five different treatment technologies implemented in both delta and desert regions.

scholarly journals Ultrafiltration Process in Disinfection and Advanced Treatment of Tertiary Treated Wastewater

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Microscopic Analysis ◽  
Fecal Coliforms ◽  
Treated Wastewater ◽  
Chemical Parameters ◽  
Virus Particles ◽  
E Coli ◽  
The One ◽  
Physical And Chemical

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).

scholarly journals Long-term investigation of phosphorus removal by iron electrocoagulation in small-scale wastewater treatment plants

2018 ◽  
Vol 78 (6) ◽  
pp. 1304-1311 ◽  
Author(s):  
I. Mishima ◽  
M. Hama ◽  
Y. Tabata ◽  
J. Nakajima
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Phosphorus Release ◽  
Small Scale ◽  
Operational Conditions ◽  
Long Time ◽  
Negative Effect ◽  
Iron Electrolysis

Abstract Small-scale wastewater treatment plants (SWTPs), called Johkasou, are widely used as decentralized and individual wastewater treatment systems in sparsely populated areas in Japan. Even in SWTPs, nutrients should be removed to control eutrophication. An iron electrolysis method is effective to remove phosphorus chemically in SWTPs. However, it is necessary to determine the precise conditions under which phosphorus can be effectively and stably removed in full scale SWTPs for a long period. Therefore, long-term phosphorus removal from SWTPs was investigated and optimum operational conditions for phosphorus removal by iron electrolysis were analyzed in this study. Efficient phosphorus removal can be achieved for a long time by adjusting the amount of iron against the actual population equivalent. The change of the recirculation ratio had no negative effect on overall phosphorus removal. Phosphorus release to the bulk phase was prevented by the accumulated iron, which was supplied by iron electrolysis, resulting in stable phosphorus removal. The effect of environmental load reduction due to phosphorus removal by iron electrolysis was greater than the cost of power consumption for iron electrolysis.

Performance of three small-scale wastewater treatment plants. A challenge for possible re use

2015 ◽  
Vol 22 (22) ◽  
pp. 17744-17752 ◽  
Author(s):  
P. Kokkinos ◽  
G. Mandilara ◽  
A. Nikolaidou ◽  
A. Velegraki ◽  
P. Theodoratos ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Small Scale

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 Improvement of phosphorus removal by calcium addition in the iron electrocoagulation process

2017 ◽  
Vol 76 (4) ◽  
pp. 920-927 ◽  
Author(s):  
I. Mishima ◽  
M. Hama ◽  
Y. Tabata ◽  
J. Nakajima
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Chemical State ◽  
Treated Wastewater ◽  
Small Scale ◽  
Calcium Addition ◽  
Ca Addition ◽  
Iron Electrolysis ◽  
Study Laboratory

Small-scale wastewater treatment plants (SWTPs) are widely used as decentralized wastewater treatment systems in sparsely populated areas of Japan. Iron electrolysis, an electrocoagulation technology, is installed in these SWTPs for phosphorus removal. Phosphorus can be removed via the formation of an insoluble compound containing phosphate and iron, such as FePO4; however, it was necessary to determine the conditions under which phosphorus can be effectively and stably removed in actual SWTPs. According to previous studies using iron compounds, improved phosphorus removal was obtained by Ca addition. It is therefore thought that calcium addition may also be effective in improving the phosphorus removal during iron electrolysis in SWTPs. It is also important to determine the chemical state of iron to understand the phosphorus removal mechanism during iron electrolysis. In this study, laboratory-scale batch experiments with the iron electrolysis method were conducted to investigate the effect of phosphorus removal using treated wastewater from actual SWTPs without or with Ca addition. The results indicated that the addition of Ca improved the phosphorus removal performance. Furthermore, phosphorus removal was inhibited in the presence of high dissolved organic carbon (DOC). The X-ray absorption fine structure measurements of the produced particulates in the experiments showed no substantial change in the chemical state of iron without or with Ca addition. The statistical analyses revealed the range of improving or inhibiting effects on phosphorus removal due to the Ca and DOC. Thus, the results of this study provided useful information pertaining to the influence of coexisting substances on phosphorus removal and the chemical state of iron in the produced particulates.

scholarly journals Investigation of the Prevalence of Antibiotic Resistance Genes According to the Wastewater Treatment Scale Using Metagenomic Analysis

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 188
Author(s):  
Keunje Yoo ◽  
Gihan Lee
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Resistance Genes ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Metagenomic Analysis ◽  
Small Scale ◽  
Dominant Bacteria

Although extensive efforts have been made to investigate the dynamics of the occurrence and abundance of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs), understanding the acquisition of antibiotic resistance based on the WWTP scale and the potential effects on WWTPs is of relatively less interest. In this study, metagenomic analysis was carried out to investigate whether the WWTP scale could be affected by the prevalence and persistence of ARGs and mobile genetic elements (MGEs). As a result, 152 ARG subtypes were identified in small-scale WWTP samples, while 234 ARG subtypes were identified in large-scale WWTP samples. Among the detectable ARGs, multidrug, MLS (macrolide–lincosamide–streptogramin), sulfonamide, and tetracycline resistance genes had the highest abundance, and large and small WWTPs had similar composition characteristics of ARGs. In MGE analysis, plasmids and integrons were 1.5–2.0-fold more abundant in large-scale WWTPs than in small-scale WWTPs. The profile of bacteria at the phylum level showed that Proteobacteria and Actinobacteria were the most dominant bacteria, representing approximately 70% across large- and small-scale WWTPs. Overall, the results of this study elucidate the different abundances and dissemination of ARGs between large- and small-scale WWTPs, which facilitates the development of next-generation engineered wastewater treatment systems.

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