Öz
Arsenik, içme sularında karşılaşılabilen kanserojen ve toksik karakterli önemli bir kirleticidir. En sık karşılaşılan formları ise +3 (As (III)) ve +5 (As(V)) yüklüdür. Günümüzde uygulanan arsenik giderim metotları elektriksel çekim kuvveti yüksek olan As (V)’i başarı ile arıtırken, As (III) giderim verimleri ise daha düşüktür. Bu nedenle bu çalışma kapsamında bir ön arıtma metodu olarak, As (III)’ün As (V)’e 20 kHz ultrasonik frekansta ultrasonik oksidasyonu çalışılmıştır. Deneyler sırasında yardımcı herhangi bir kimyasal madde ilave edilmemiştir. Çalışmada; ışınım süresi, çözelti pH’ı ve ultrasonik gücün, oksidasyon verimine etkisi incelenmiştir. Ultrasonik ışınım süresi ve güçteki artış ile çözeltiye uygulanan toplam ultrasonik enerji arttığı için, ultrasonik oksidasyon verimi de artmıştır. Çözelti pH’ındaki artış; artan OH- iyonlarının OH• radikallerini süpürmesi sonucunda, verimin düşmesine neden olmuştur. Sonuç olarak optimum şartlar; ışınım süresi: 15 dk, çözelti pH’ı: 7 ve ultrasonik güç: 60 W olarak belirlenmiştir. Bu şartlarda, oksidasyon verimi % 28.7 olmuştur. Verimin bu kadar düşük olmasının nedeni, çalışmanın oksitleyici radikal üretiminin düşük olduğu 20 kHz frekansta yapılmış olmasıdır.
Anahtar Kelimeler
Kaynakça
- Mohan D., Pittman C.U., Arsenic removal from water/wastewater using adsorbents: A critical review, Journal of Hazardous Materials, 142, 1 – 53, 2007.
- Niu C.H., Volesky B., Cleiman D., Biosorption of arsenic (V) with acid-washed crab shells, Water Research 41, 2473 – 2478, 2007. http://www.greenfacts.org/en/arsenic/l-3/arsenic-1.htm#2p0.
- Sharma V.K., Sohn M., Aquatic arsenic: toxicity, speciation, transformations, and remediation, Environment Internationa,l 35, 743 – 759, 2009.
- Kundu S., Gupta A.K., Analysis and modeling of fixed bed column operations on As (V) removal by adsorption onto iron oxide-coated cement (IOCC), Colloids and Surfaces A: Physicochemical and Engineering Aspects ,290, 52 – 60, 2005.
- Greenwood N.N., Earnshaw A., Chemistry of Elements, Pergamon Press, Oxford, (Chapter 13) 19 Kundu S., Kavalakatt S.S., Pal A., Ghosh A.K., Mandal M., Pal T., Removal of arsenic using hardened paste of Portland cement: Batch adsorption and column study, Water Research, 38, 3780 – 3790, 2004.
- Johnston R., Heijnen H., Wurzel P., United Nations synthesis report on arsenic in drinking water, Chapter 6: Safe water technology. World Health Organization, Genova, 2001.
- Bilici Başkan M., Pala A., İçme sularında arsenik kirliliği: ülkemiz açısından bir değerlendirme, Pamukkale Üniversitesi, Mühendislik Bilimleri Dergisi, 15, 69 – 79, 2009.
- Fujimoto M., The removal of arsenic from drinking water by carbon adsorption. Master of Science Department of Civil and Environmental Engineering, Michigan State University, 2001. Wang X., Yao Z., Wang J., Guo W., Li G., Degradation of reactive brilliant red in aqueous solution by ultrasonic cavitation, Ultrasonics Sonochemistry 15, 43 – 48, 2008.
- Nakui H., Okitsu K., Maeda Y., Nishimura R., The effect of pH on sonochemical degradation of hydrazine, Ultrasonics Sonochemistry 14, 627 – 632, 2007.
- Şahinkaya S. Ultrasonik ön işlemin anaerobik çamur çürütme reaktörünün verimliliğine etkisi, Selçuk Üniversitesi, 2011.
- Neppolian B., Doronila A., Ashokkumar M., Sonochemical oxidation of arsenic(III) to arsenic(V) using potassium peroxydisulfate as an oxidizing agent. Water Research, 44, 3687 – 3695, 2010.
- Hamdaoui Q., Naffrechoux E., Sonochemical and photosonochemical degradation of 4chlorophenol in aqueous media, Ultrasonics Sonochemistry 15, 981 – 987, 2008.
Öz
Arsenic is an important pollutant that might be found in drinking water having carcinogenic and toxic characteristics. The most common oxidation states of Arsenic are +3 (As (III)) and +5 (As(V)). While arsenic removal methods successfully applied at the present time efficiently removes As(V) which has high electrical attraction force, removal efficiency for As(III) is very low. For this reason, ultrasonic oxidation of As(III) to As(V) with 20 kHz ultrasonic frequency as a pretreatment method was performed within the scope of this study. During experiments, any chemical material was not added. In the study, the effects of radiation period, solution pH and ultrasonic power on the efficiency of oxidation were examined. Since total ultrasonic energy applied to the solution increases with the increase in ultrasonic radiation period and power, ultrasonic oxidation efficiency also increased. The increase in solution pH caused a decrease in the efficiency as a result of sweeping OH• radicals by increasing OH ions. Consequently, optimum conditions were determined as 15 minutes for radiation period, 7 for solution pH and 60 W for ultrasonic power. Under these conditions, oxidation efficiency was 28.7%. The reason for such a low efficiency was performing the experiment at 20 kHz which is low for oxidizing radical production.
Anahtar Kelimeler
Kaynakça
- Mohan D., Pittman C.U., Arsenic removal from water/wastewater using adsorbents: A critical review, Journal of Hazardous Materials, 142, 1 – 53, 2007.
- Niu C.H., Volesky B., Cleiman D., Biosorption of arsenic (V) with acid-washed crab shells, Water Research 41, 2473 – 2478, 2007. http://www.greenfacts.org/en/arsenic/l-3/arsenic-1.htm#2p0.
- Sharma V.K., Sohn M., Aquatic arsenic: toxicity, speciation, transformations, and remediation, Environment Internationa,l 35, 743 – 759, 2009.
- Kundu S., Gupta A.K., Analysis and modeling of fixed bed column operations on As (V) removal by adsorption onto iron oxide-coated cement (IOCC), Colloids and Surfaces A: Physicochemical and Engineering Aspects ,290, 52 – 60, 2005.
- Greenwood N.N., Earnshaw A., Chemistry of Elements, Pergamon Press, Oxford, (Chapter 13) 19 Kundu S., Kavalakatt S.S., Pal A., Ghosh A.K., Mandal M., Pal T., Removal of arsenic using hardened paste of Portland cement: Batch adsorption and column study, Water Research, 38, 3780 – 3790, 2004.
- Johnston R., Heijnen H., Wurzel P., United Nations synthesis report on arsenic in drinking water, Chapter 6: Safe water technology. World Health Organization, Genova, 2001.
- Bilici Başkan M., Pala A., İçme sularında arsenik kirliliği: ülkemiz açısından bir değerlendirme, Pamukkale Üniversitesi, Mühendislik Bilimleri Dergisi, 15, 69 – 79, 2009.
- Fujimoto M., The removal of arsenic from drinking water by carbon adsorption. Master of Science Department of Civil and Environmental Engineering, Michigan State University, 2001. Wang X., Yao Z., Wang J., Guo W., Li G., Degradation of reactive brilliant red in aqueous solution by ultrasonic cavitation, Ultrasonics Sonochemistry 15, 43 – 48, 2008.
- Nakui H., Okitsu K., Maeda Y., Nishimura R., The effect of pH on sonochemical degradation of hydrazine, Ultrasonics Sonochemistry 14, 627 – 632, 2007.
- Şahinkaya S. Ultrasonik ön işlemin anaerobik çamur çürütme reaktörünün verimliliğine etkisi, Selçuk Üniversitesi, 2011.
- Neppolian B., Doronila A., Ashokkumar M., Sonochemical oxidation of arsenic(III) to arsenic(V) using potassium peroxydisulfate as an oxidizing agent. Water Research, 44, 3687 – 3695, 2010.
- Hamdaoui Q., Naffrechoux E., Sonochemical and photosonochemical degradation of 4chlorophenol in aqueous media, Ultrasonics Sonochemistry 15, 981 – 987, 2008.
Ayrıntılar
| Bölüm | Çevre Mühendisliği |
|---|---|
| Yazarlar | |
| Yayımlanma Tarihi | 20 Haziran 2013 |
| Yayımlandığı Sayı | Yıl 2013 Cilt: 2 Sayı: 1 |
