131I and 99mTc in Effluents from a Nuclear Medicine Facility and Associated Sewage Treatment Unit

2021 ◽  
Vol 232 (4) ◽  
Author(s):  
Alessander Sá do Carmo ◽  
Elizabeth Aparecida Vianello ◽  
Wagner Pereira ◽  
Evangelina Marcia Lima de Macêdo ◽  
Lucas Gomes Padilha Filho ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Sewage Treatment ◽  
Treatment Unit

Effects of hydraulic shock loads on small on-site sewage treatment unit

1997 ◽  
Vol 35 (8) ◽  
pp. 145-152 ◽  
Author(s):  
T. Panswad ◽  
L. Komolmethee
Keyword(s):  
Removal Efficiency ◽  
Sewage Treatment ◽  
Septic Tank ◽  
Hydraulic Shock ◽  
Treatment Unit ◽  
Shock Loads ◽  
Retention Period ◽  
Intermittent Feeding ◽  
Continuous Feed ◽  
Filter Unit

This research was to determine the effects of hydraulic shock loads by intermittent feeding on the removal efficiency of a small prefabricated real-sized septic tank/anaerobic filter unit. Besides the ‘control’ 24-hour continuous runs the other twice a day feeding periods covered 16, 12 and 8 hours per day, with the tank's retention time varying from 22.5 to 90 hours. It was demonstrated that the variation of the hydraulic feeding patterns ranging from 24-hour continuous feed to 8 h per day intermittent feed did not affect the performance of the system much. The percentage of BOD reduction was decreased from 85 to 82 and 81 percent for the feed times of 24, 16 and 8 hours per day, respectively. The tank capacity played a relatively major role in determining the removal efficiency of the process. The efficiency of BOD and SS reduction dwindled from 82.2 to 68.9 and 56.0% with the corresponding reduction in tank sizes from 90 to 45 and 22.5 hours retention, respectively. In any event, the unit could not satisfactorily remove nutrients. A retention period of not less than 48 hours is recommended if the Thai effluent standards are to be met. Equations for predicting the BOD removal capability were also developed.

Feasibility of a pilot-scale UASB/trickling filter system for domestic sewage treatment

2001 ◽  
Vol 44 (4) ◽  
pp. 221-228 ◽  
Author(s):  
C.A.L. Chernicharo ◽  
M.C.P. Nascimento
Keyword(s):  
Sewage Treatment ◽  
Domestic Sewage ◽  
Uasb Reactor ◽  
Trickling Filter ◽  
Treatment Unit ◽  
Promising Alternative ◽  
Operational Conditions ◽  
Belo Horizonte ◽  
Final Effluent ◽  
Bod Removal

This paper presents the results of pilot system comprised of one UASB reactor followed by one trickling filter (TF). The UASB reactor had a volume of 416 litres, being operated at an average hydraulic retention time (HRT) of 4 hours. The trickling filter had a useful volume of 60 litres, being operated at hydraulic and organic loading rates varying from 3.4 to 30.6 m3/m2.d and 0.3 to 3.9 kgBOD/m3.d, respectively. These different operational conditions characterised eight research phases. Both reactors were fed with domestic sewage pumped directly from the main interceptor of Belo Horizonte City, Brazil. After almost 16 months of continuous monitoring, the UASB/TF system produced very good results in terms of COD and BOD removal, and also very low solids concentration in the final effluent. The average results of COD and BOD removal varied from 74 to 88% and from 80 to 94%, respectively, sufficient to maintain the COD concentration in the final effluent in the range of 60 to 120 mg/L and the BOD values systematically below 60 mg/L. The overall averages of SS in the final effluent were kept below 30 mg/L. The UASB/TF system is a very promising alternative for the treatment of domestic sewage in Brazil and other developing countries, since the system can be designed with very short hydraulic retention times, resulting in a very compact and low cost treatment unit. Besides, the energy consumption and the labour costs are minimal.

Design of grit channels controlled by parshall flumes

1996 ◽  
Vol 33 (3) ◽  
pp. 195-210 ◽  
Author(s):  
Gerrit v. R. Marais ◽  
Adrianus C. van Haandel
Keyword(s):  
Liquid Velocity ◽  
Rectangular Cross Section ◽  
Sewage Treatment ◽  
Low Flow ◽  
Treatment Unit ◽  
Flow Rates ◽  
Gravity Settling ◽  
Pre Treatment ◽  
Channel Bottom ◽  
Treatment Step

Grit removal is a necessary pre treatment step in sewage treatment. Grit can be separated from the liquid phase by gravity settling in a channel. For an adequate performance of the pre treatment unit, it is necessary that the liquid velocity in the channel is kept approximately constant, even when the flow rate varies. This can be accomplished by coupling a channel with a rectangular cross section to a Parshall flume, provided the channel bottom level is placed at a higher level than the flume base. The height of the step between the two devices depends on the magnitude and variation of the sewage flow. At low flow rates the step will start to act as a weir and can take over the function of the Parshall flume as the liquid velocity controlling device, thereby extending significantly the range of flow rates that can be degritted in the pre treatment unit.

scholarly journals LOCAL SEWAGE TREATMENT UNIT ENGINEERING

2019 ◽  
pp. 174-185
Author(s):  
E. I. Vyalkova ◽  
E. S. Glushchenko ◽  
A. V. Shalabodov ◽  
A. V. Shalabodov ◽  
E. Yu. Osipova
Keyword(s):  
Industrial Wastewater ◽  
Suspended Solids ◽  
Sewage Treatment ◽  
Dairy Production ◽  
Organic Substances ◽  
Treatment Technology ◽  
Treatment Unit ◽  
Large Fluctuations ◽  
Wastewater Quality ◽  
Treatment And Disposal

Problems of treatment and disposal of industrial wastewater from dairy enterprises exist in Russia and abroad. Industrial wastewater from dairy cannot be discharged even into the do-mestic sewage system. The local sewage treatment units of such enterprises require in detail studying the wastewater quality and supply modes. This article presents such parameters of the wastewater composition as environmental aggressiveness, organic matter, suspended solids, fats, nitrogen, phosphate, and others. It is shown that changes in the qualitative composition of effluents depend on the dairy production processes. A serious problem when choosing a treatment technology is the significant content of organic substances, fats, ammonium, ni-trates and phosphates in the resulting effluent. In addition, effluents are characterized by large fluctuations in quality when dumped in a sewage treatment unit or reagent solutions generated by the equipment flushing. A production process flowchart is proposed for the dairy water dis-posal with the appropriate water treatment for discharge into sewage treatment units.  

Design and Implementation of Chemical Wastewater pH Control System

2014 ◽  
Vol 700 ◽  
pp. 447-450
Author(s):  
Yun Qian ◽  
Tao Wu ◽  
Meng Fan Zhang
Keyword(s):  
Organic Matter ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Processing Unit ◽  
Biochemical Treatment ◽  
Treatment Unit ◽  
Organic Degradation ◽  
Hydrolysis Acidification ◽  
Ph Range

pH parameter is one of the main factors influencing organic degradation in the sewage treatment, and the degradation of organic matter in biochemical treatment unit is the largest, the hydrolysis acidification processing unit is the second largest. When the water pH range of biochemical treatment unit is [6.8 7.2], organic degradation is in the largest degree. The pH range of neutralization unit must be based on a subsequent hydrolysis acidification treatment unit, in order to adjust the pH range dynamically. Finally we make wastewater treated by biochemical unit meet the pH standard, and make the organic matter degrade in the largest degree. We designed chemical wastewater pH intelligent control device based on MSP430F149 MCU. The application of this device shows that the method has high control accuracy, less drug consumption and has large organic matter degradation in the sewage treatment plant, etc.

Combination of a UASB reactor and a curtain type DHS (downflow hanging sponge) reactor as a cost-effective sewage treatment system for developing countries

2000 ◽  
Vol 42 (3-4) ◽  
pp. 83-88 ◽  
Author(s):  
I. Machdar ◽  
Y. Sekiguchi ◽  
H. Sumino ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
Sewage Treatment ◽  
Cost Effective ◽  
Ammonia Nitrogen ◽  
Treatment System ◽  
Uasb Reactor ◽  
Municipal Sewage ◽  
Combined System ◽  
Treatment Unit ◽  
Pre Treatment ◽  
Sewage Treatment System

The second generation of our originally proposed sewage treatment system, which consists of a UASB reactor as an anaerobic pre-treatment unit and curtain-type DHS (downflow hanging sponge) reactor as an aerobic post-treatment unit, was installed at a municipal sewage treatment site. A 550-day continuous experiment demonstrated that the whole combined system successfully achieved 94–97% of unfiltered-BOD removal, 81–84% of unfiltered-COD removal, and 63–79% of SS removal, at an overall HRT of 8 h (6 h for UASB and 2 h for DHS units). The combined system performed an excellent organic removal as well as a fairly efficient nitrification, i.e. 52–61% of ammonia-nitrogen removal. Our proposed combined system possesses prominent advantages: requiring neither external aeration input nor excess sludge withdrawal.

A novel and cost-effective sewage treatment system consisting of UASB pre-treatment and aerobic post-treatment units for developing countries

1997 ◽  
Vol 36 (12) ◽  
pp. 189-197 ◽  
Author(s):  
Izarul Machdar ◽  
Hideki Harada ◽  
Akiyoshi Ohashi ◽  
Yuji Sekiguchi ◽  
Hiroyuki Okui ◽  
...  
Keyword(s):  
Developing Countries ◽  
Low Cost ◽  
Sewage Treatment ◽  
Cost Effective ◽  
Post Treatment ◽  
Cod Removal ◽  
Treatment System ◽  
Treatment Unit ◽  
Pre Treatment ◽  
Sewage Treatment System

A novel sewage treatment system was proposed, which consists of a UASB anaerobic pre-treatment unit and the following DHS (downflow hanging sponge-cubes) aerobic post-treatment unit, as a low-cost and easy-maintenance process for developing countries. Over six months experiment by feeding sewage our proposed system achieved 94% of total-COD removal, 81% of soluble-COD removal, and nearly perfect SS removal and total-BOD removal at the overall HRT of 8.3 hr (7 hr in UASB and 1.3 hr in DHS unit). Moreover, the DHS reactor was capable of performing high (73–78%) nitrification. Our whole system requires neither external aeration input nor withdrawal of excess sludge.

scholarly journals Enhancing Microplastics Removal from Wastewater Using Electro-Coagulation and Granule-Activated Carbon with Thermal Regeneration

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 617
Author(s):  
Keug Tae Kim ◽  
Sanghwa Park
Keyword(s):  
Activated Carbon ◽  
Sewage Treatment ◽  
Tertiary Treatment ◽  
Regeneration System ◽  
Thermal Regeneration ◽  
Treatment Unit ◽  
Sewage Treatment Plants ◽  
Important Barrier ◽  
Significant Pathway ◽  
Electro Coagulation

Discharge from sewage treatment plants (STPs) is a significant pathway of entry for microplastics (MPs) to the environment. Therefore, STPs should be considered as an important barrier to the distribution and circulation of MPs in the aquatic environment. In this study, the fate and material-specific properties of MPs were investigated in an STP-equipped and granule-activated carbon (GAC) tower with a thermal regeneration system. This system functioned with a tertiary treatment unit. The GAC with thermal regeneration removed 92.8% of MPs and was useful for removing MPs with a specific gravity less than that of water and with a size of 20–50 µm, which had negligible removal in the conventional STP process. In addition, a lab-scale electric-coagulation experiment was conducted to examine its potential utility as a pretreatment process for further enhancing the removal efficiency of MPs by GAC. After 30 min of electro-coagulation using aluminum electrodes, 90% of MPs were converted into separable flocs by centrifugation. These flocs may be effectively removed by GAC or other tertiary treatment steps. This study demonstrates that GAC with thermal regeneration is a tertiary process that can efficiently prohibit the release of MPs from STPs and circulation of MPs in the natural environment.

scholarly journals Adaptation of domestic effluent for agricultural reuse by biological, physical treatment and disinfection by ultraviolet radiation

2019 ◽  
Vol 14 (2) ◽  
pp. 1
Author(s):  
Andressa De Almeida Soares Oliveira ◽  
Reinaldo Gaspar Bastos ◽  
Claudinei Fonseca Souza
Keyword(s):  
Ultraviolet Radiation ◽  
Removal Efficiency ◽  
Sewage Treatment ◽  
Treated Wastewater ◽  
Septic Tank ◽  
Irrigated Agriculture ◽  
Physical Treatment ◽  
Treatment Unit ◽  
E Coli ◽  
Domestic Effluent

Domestic effluent reuse is an alternative for irrigated agriculture in situations of reduced water availability. However, as there is the presence of pathogens in wastewater, the disinfection process is necessary before use. This research evaluated the sanitary and agricultural viability of treated wastewater at a pilot-scale station composed of a septic tank, Wetlands and an ultraviolet radiation (UV) disinfection system. The Sewage Treatment Station (STS) is installed in the Agricultural Sciences Center, UFSCar, in Araras city, SP, and receives 2000 L of sewage daily, which was monitored in terms of pH, turbidity, electrical conductivity (EC), dissolved oxygen (DO), sodium (Na), potassium (K), calcium (Ca), total nitrogen (TN), total phosphorus (TP), magnesium (Mg), total organic carbon (TOC), total coliforms (TC), Escherichia coli (E. coli) and Sodium Adsorption Ratio (SAR).The removal efficiency of the parameters was calculated based on the input and output means of each treatment unit. Results indicated removal efficiency for K (68.2%), TN (54.1%) and TP (36.1%). The levels of Na (26.7%) and Ca (22.9%) demonstrated the contribution of these salts to the wastewater; however, SAR did not present any risks for soil sodification. Microbiologically, the STS presented removal efficiency of 4 and 5 log-cycles for TC and E. coli, respectively. Therefore, results of monitoring indicate that the treated wastewater presents sanitary and agricultural viability, and conforms with the current legislation.

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