scholarly journals Effect of container geometry on colloids removal from water in oscillation-based flocculation

2019 ◽  
Vol 20 (1) ◽  
pp. 328-334
Author(s):  
Eran Halfi ◽  
Asher Brenner ◽  
David Katoshevski

Abstract Colloid removal in water treatment plants is commonly done by a sequence of processes that includes coagulation, flocculation, sedimentation, and filtration. The current study presents an innovative technique, termed grouping, for the removal of these suspended particles based on physical flow manipulation, which causes the particles to aggregate. Previous results showed that gentle oscillation in a cylindrical container facilitates simultaneous flocculation and sedimentation in the same reactor over shorter periods of time than are possible using the conventional treatment approach. This finding may confer marked improvements on the processes used today by enabling the use of both smaller reactors and less energy. Based on the findings with the cylindrical vessel, here the grouping technique is further examined in a rectangular container and over a range of different initial turbidities. The results indicate that the removal efficiency is higher in the rectangular container under the different initial turbidities tested. In addition, the removal efficiency was shown to remain robust with the decreases in initial turbidity and alum concentrations that occur during treatment. The positive results of our previous study taken together with this finding hint at the strong potential of the grouping technique to improve common flocculation processes.

2017 ◽  
Vol 12 (3) ◽  
pp. 576-588 ◽  
Author(s):  
Seyed Ahmad Mirbagheri ◽  
Sima Malekmohamadi ◽  
Sheida Sohrabi Nasrabadi

Clarifying is one of the most crucial stages in water treatment at water treatment plants. Determining the type of the clarifier in water treatment plants and using it efficiently is necessary. In this study, a pilot is designed and constructed in which the pulsator, the superpulsator and the accelerator are simulated. For each system, turbidity removal efficiency for different influent turbidities and flow rates were studied and the optimum condition was obtained. The results showed that the superpulsator has a superior performance compared to the pulsator, and the pulsator has a superior performance compared to the accelerator and these differences are more sensible at higher flow rates. Also, the best condition for achieving the highest efficiency for the pulsator and the superpulsator is determined to be at flow rate 3 lit/min for an initial turbidity of 2,500 NTU with alum as the coagulant and the highest efficiency for the accelerator is determined to be at flow rate 3 lit/min for an initial turbidity of 2,500 NTU with ferric chloride as the coagulant. Comparing the turbidity removal efficiency shows that for 67% of the cases, ferric chloride has a better performance as the coagulant compared to alum and increasing the influent turbidity leads to an increase in the removal efficiency. Furthermore, three water treatment plants located in Tehran were studied and their characteristics were compared and suggestions were made to enhance their qualities.


2012 ◽  
Vol 12 ◽  
pp. 201-210 ◽  
Author(s):  
Janardan Lamichhane ◽  
Bimal B Upadhyaya ◽  
Nishant Chalise ◽  
Sudeep Makaju

Sewage including liquids from household waste to industry and commerce effluent along with storm water runoff carries various contaminants including soil particles, heavy metals, organic compounds, animals waste, oils and grease which are required to be treated before they are discharged directly to the water into waterways. Various waste water treatment plants established in different part of Nepal include small to large scale treatment of waste discharge. The evaluation of all those plants by scientific mean was carried out for the recommend of standard of treatment plant suitable to the country. Among the plants under study, removal efficiency of TSS, TDS and TS was found highest in KU reed bed systems with 97.5, 74.3 and 95.6% respectively. Similarly, removal efficiency of chemical compounds such as NH3, N2, NO3 2-, Cl-, PO3 2- and COD were found highest in KU and DH reed bed system ranging from 98 to 33.3 % whereas BOD was found highest, 93.1 and 82.1% in HIDWTP and BASP respectively. pH and conductivity measurement and comparison indicates the requirement of continuous use and maintenance of the plant. This could be one of the major ways to inform the government about the maintenance, sustainability and importance of ongoing operation of waste water treatment plants of Nepal in cost effective manner.DOI: http://dx.doi.org/10.3126/njst.v12i0.6500 Nepal Journal of Science and Technology 12 (2011) 201-210


2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Adriana Muniz De Almeida Albuquerque

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.


2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Taty Hernaningsih

Waste water treatment by industry usually uses chemicals that may lead to additional environmental pollution load. On the other hand, water demand increases and environmental regulations regarding waste water disposal requirements that apply more stringent. It is necessary for waste treatment technique that accommodate this requirement. Electrocoagulation process is a technique of wastewater treatment that has been chosen because the technique is environmentally friendly. This paper will review some of the research or application electrocoagulation process which is conducted on industrial waste water. Types of industrial waste water that is to be reviewed include: industries batik, sarongs, textiles, palm oil, slaughterhouses, food, leather tanning, laundry, pulp and paper. Overview reviewed in this research include the waste water treatment process in several processing variations such as: change in time, electricity and kind of electrodes. The results of the research with electrocoagulation process in the industry are the removal efficiency of TSS, COD, BOD5, Chrome, phosphate, surfactants, color turbidity influenced by several factors including time, strong current, voltage, distance and type of electrode and pH. The results of the study with electrocoagulation process in the industry is the removal efficiency of TSS, COD, BOD5, chromium, phosphate, surfactant, turbidity color that are influenced by several factors including time, strong current, voltage, distance and type of electrode and pH. It is hoped the information presented in this article can be a reference for similar research for the improvement of research on the process ektrokoagulasi.Key words: elektrocoagulation, removal eficiency, environmental friendly


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