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IERI Procedia 9 ( 2014 ) 8 – 12

2014 International Conference on Environment Systems Science and Engineering Evaluation of and Color Removal in Treatment of Containing Resistant with Ozonation

Amir Hajialia*, Gevorg P. Pirumyanb

aPh.D Graduate;No.7, Parvin Alley, Shahid Miri St., Dorahi Qolhak, Tehran,1949913761, Iran bChair of Ecological Chemistry,Head;Yerevan State University, 40 b-6, Tigran Mets Ave., Yerevan, 0005, Armenia

Abstract

In this research a comparison in turbidity and color removal between biological treatment of industrial wastewater and a combination of that with ozonation is studied. Wastewater arising from pulp factories has toxic and resistant pollutants which cause some serious environmental problems and its color and turbidity must be considered to meet the standards (Metcalf et al. 2004). Because of high molecular weight of these toxic compounds the treatment is performed in a sequential process in order to make these compounds smaller and change them to dissolvable substances in the environment. Although with bio--bio treatment the value of consumed ozone is considerably increased, but through this way the quality of treatment and the value of dissolvable substances which can be returned to the environment are increased. A very remarkable reduction of color and turbidity in this treatment system in comparison with the most common biological treatment systems in pulp factories is achieved.

© 20142014 The Amir Authors. Hajiali Published and Gevorgby Elsevier P. B.V. Pirumyan. This is an Publishopen accessed articleby Elsevier under the B.V. CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and and peer peer review review under responsibilityunder responsibility of Information of EngineeringInformation Research Engineering Institute Research Institute

Keywords: Color, Ozonation, Resistant Pollutants, Turbidity,

1. Mani Text

Wastewater of pulp factories which are by-products of cellulose causes a hazardous vapour that is

* Corresponding author. Tel.: +982122631054; Mobile: +989101868601. E-mail address: [email protected].

2212-6678 © 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer review under responsibility of Information Engineering Research Institute doi: 10.1016/j.ieri.2014.09.033 Amir Hajiali and Gevorg P. Pirumyan / IERI Procedia 9 ( 2014 ) 8 – 12 9 dangerous because of containing different combinations of chlorophenol (Kaballo HP et al., 1995). This is known as a factor in the environment which is even not possible to be solved by treating wastewater in traditional ways. The most hazardous part of these substances is monomers of chlorophenolic combinations (Prat.C et al., 1989). These monomers and especially monomers with high molecular weights are seen in such wastewater treatment systems. Therefore decreasing or removing the value of turbidity and colour will be more difficult by using the biological methods of treatment. The Ozonated wastewater provides necessary substances for bio-treatment in both aerobic and anaerobic stages (R, Parag et al., 2003). And as a result a very remarkable improvement in removing turbidity and colour will be achieved.For providing the essential substances for final biological treatment, sufficient solution which is ozonated wastewater is produced in some groups. Because of that which is high number of groups and the number of adding ozone, calculation of final value and real value of added ozone to the solution is very difficult.

1.1.Materials and Methods

Two main methods of bio-ozone-bio treatment and professional biological treatment were done continuously. In continuous treatment at first wastewater producer source should be considered biologically. The main purpose of this research is a comparison of biological treatment with a combination of ozonation and biological treatment for treating such a wastewater. First the wastewater enters the BFB system with a water vapour which has been formed by biological dissolvable substances and then it enters a gas reservoir tank which includes ozone gas, and extra air. The environment`s PH is kept about 7 in the whole reaction time. The concentration of ozone in the BFB system cycle is measured and controlled. This kind of system can be designed for pulp factories` wastewater treatment for about 10 years. The treatment process begins by removing salts and other harmful combinations, and increasing the concentration of dissolvable substances, and it continues by extracting 200ml of Di-ethyl from the acidified sample. The standard begins in 700C for 2 minutes, and reaches to 2400C, and the final temperature of 2400C continues for 3 minutes. The concentration of the phase is also measured. After measuring different parameters, ozonation was performed and all the parameters were measured again. Ozone is produced in an ozone generator. The feed gas can be either air or pure oxygen. A high voltage is applied to two electrodes and the high voltage causes the O2 to be converted into O3. Ozone is very unstable and reverts back into O2 in minutes. That is why ozone must be generated on-site and cannot be shipped to the plant. So it was produced on site according to the mentioned method.

1.2. Results and Discussion

Two of the most important factors in this method are ozone dosage, and time. Since economic aspects are considered very important in wastewater treatment systems, and producing ozone because of its electrical costs seems to be important, its low dosage and the limited time of ozonation that was spent in the treatment process proved the remarkable efficiency of this method of treatment. First studying on ozonation among pulp factories` wastewater and their biological treatment is considered, and then how to remove the combinations derived by ozonation is mentioned (Sozanska Z. et al., 1989). Ozonation performance is by a Bio film in liquid reactors system (BF). In this system are passed through the treatment system sequentially in specific periods of time, and oznation and oxidation are done intermittently. It means that in each liquid passing through the system only a little amount of ozone is added. And it is expected that the combinations exist in liquids react with ozone acceptably and are treated well. The productions of this process and the combinations which have not been combined with ozone should be returned to BF system rapidly and be changed to absorbable substances in the environment by oxidation there (Shun Dar Lin et al., 2007). This 10 Amir Hajiali and Gevorg P. Pirumyan / IERI Procedia 9 ( 2014 ) 8 – 12

study was done for combinations which have low molecular weights only.



Fig. 1. Efficiency of wastewater treatment with ozonation in colour removal in comparison with treatment without ozonation

As it is shown in fig.1 a very considerable decreasing in the value of colour begins from step 5 and keeping this removal trend to the end of the experiments is also remarkable, but the most important matter is the colour value after ozonation which is obvious that this parameter was almost below the standard level for the moment depletion which is 100 (mg/l Pl-Co) except the beginning of ozonation. Considering the biological treatment shows that the recorded data in most steps are above the standard level. It should be mentioned that the standard value of colour for , for leaching pits, and also agricultural use is 75 (mg/l Pl-Co). As it is shown in fig.2 even with biological treatment can be suitable for meeting the standard level of turbidity in this wastewater, but as it was recorded and revealed in the figure below turbidity of the wastewater with ozonation treatment causes a very remarkable decrease from step 9 by 20 (NTU) while it was recorded 30 (NTU) at the same step and 50 (NTU) in almost all previous steps. It is obvious that this parameter not only is below the standard level for the moment effluent depletion which is 50 (NTU), but also the removal trend to end of the Bio-ozone-bio treatment remains well. It should be mentioned that the standard value of turbidity for effluent depletion to surface water and leaching pits is 50 (NTU). Amir Hajiali and Gevorg P. Pirumyan / IERI Procedia 9 ( 2014 ) 8 – 12 11



Fig. 2. Efficiency of wastewater treatment with ozonation in turbidity removal in comparison with treatment without ozonation

2. Conclusion

In this research and according to the calculation and estimation of bio-ozone- bio treatment very significant reduction in colour and turbidity is seen that leads to using the treated water out of pulp factories wastewater for surface water, leaching pit and for agricultural or irrigational consumption. And it shows that ozonation permits such a wastewater to be treated easily with better efficiencies. Two main reasons can be mentioned for the above achievement; reduction of the chloration activity, and existence of oxidation reaction in bio- ozone- bio treatment system.

References

[1] Metcalf and Eddy, Wastewater Engineering, Treatment and Reuse, fourth edition, 12, 1287-1290, (2004) [2] Kaballo HP, Zhao Y, Wilderer PA, Elimination of chlorophenol in biofilm reactors –a comparative study of continuous flow and sequenced batch operation . Water Sci Technol; 31(1):51-60, (1995) [3] Prat .C; Vicente, M.; Esplugas, S.Ozonization of bleaching of the paper industry. Water Res., 23, 12 Amir Hajiali and Gevorg P. Pirumyan / IERI Procedia 9 ( 2014 ) 8 – 12

51-55, (1989) [4] R, Parag, B, Aniruddha, A review of imperative technologies for wastewater treatment II: hybrid methods, Advances in Environ.Res., (2003) [5] Sozanska , Z.; Sozanski , M.M.Eficiency of Ozonation as a unit process in the treatment of secondary from pulp and paper industry; Ozone Association: Vienna, VA; Vol.2, 203-220; (1989) [6] Shun Dar Lin, Water and Wastewater calculations manual, 2nd edition, 6,755, (2007)