Kimyasal çöktürme yöntemiyle sulardan amonyum giderimi
Yükleniyor...
Dosyalar
Tarih
2011
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Aksaray Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Canlıların yaşaması ve üremesi için gerekli besi maddelerinden birisi olan azot; sularda amonyum (NH4+) formunda bulunabilir. Düşük konsantrasyonda bile su canlılarına toksik etki yapan amonyum; çeşitli süreçler sonucunda alglerin faydalanabileceği formlara dönüşerek ötrofikasyona zemin oluşturabilir. Dolayısıyla alıcı ortamlara belli bir değerin üzerinde amonyum girişinin engellenmesi gerekir. Sulardan kimyasal çöktürme yöntemiyle amonyum giderimi; işlem sonucu elde edilen ürünlerin (MAP: Magnezyum Amonyum Fosfat) ekonomik getirisi de dikkate alındığında tercih edilen bir yöntemdir. Bu çalışmada MAP çöktürmesinde etkin olan kimyasal ve fiziksel parametreler incelenmiştir. Biyokatalitik Kalsifikasyon Reaktöründe (BCR) ürenin hidrolizi sonucu yüksek miktarda oluşan amonyumun (Cort=348 mg NH4+/L ±38,1 ; n=25) MAP şeklinde çöktürülerek giderimi gerçekleştirilmiştir. Çöktürme için gerekli olan magnezyum ve fosfat; MgCl2.6H2Okatı ve H3PO4sıvı’ den sağlanmıştır. Optimum Mg:NH4:PO4 molar oranı 1,25:1:1 olarak belirlenmiştir. Bu oranlarla farklı pH değer aralığında (7-10) yapılan çalışmalarda; 9,36 pH değerinde yaklaşık %96 amonyum giderimine ulaşılmıştır. 30s’ lik hızlı karıştırma (200 rpm) ve 2dk’ lık yavaş karıştırma (30 rpm) sürelerinin MAP çöktürmesinde yeterli olduğu görülmüştür. Çöktürme sonrası elde edilen struvit gübre olarak kullanılmış ve bitki gelişimini desteklediği gözlemlenmiştir
One of the essential nutrients for living and growth of organisms is nitrogen, which presents in aquatic environment as ammonium (NH4+) form. Ammonium, which is toxic effect on aquatic organisms even at low concentrations, could lead to eutrophication, transformed into forms that algae can benefit as a result of various processes. Therefore, ammonium input at certain levels in receiving environment should be prevented. Ammonium removal from waters using chemical precipitation is the preferred method when taking into consideration economic return of products obtained (MAP; Magnesium Ammonium Phosphate; Struvite) after removal process. In this study, physical and chemical parameters, which are effective in MAP precipitation, were investigated. Removal of ammonium at high concentrations (Cmean=348 mg NH4+/L ± 38,1; n=25) taking place as a result of urea hydrolysis in the Biocatalytic Calcification Reactor (BCR) was carried out in the form of MAP precipitation. Magnesium and phosphate required for precipitation were provided from MgCl2.6H2O as solid form and H3PO4 as liquid form, respectively. Optimum molar ratio of Mg:NH4:PO4 was determined as 1,25:1:1. Different pH ranges (7?10) studies with used that molar ratio, ammonium removal of approximately 96% reached at pH value of 9,36. It was seen that rapid mixing (200 rpm) of 30 s. and slow mixing (30 rpm) of 2 min. periods were sufficient for MAP precipitation. Struvite obtained after precipitation was used as fertilizer and it was observed that struvite supported to development of plant
One of the essential nutrients for living and growth of organisms is nitrogen, which presents in aquatic environment as ammonium (NH4+) form. Ammonium, which is toxic effect on aquatic organisms even at low concentrations, could lead to eutrophication, transformed into forms that algae can benefit as a result of various processes. Therefore, ammonium input at certain levels in receiving environment should be prevented. Ammonium removal from waters using chemical precipitation is the preferred method when taking into consideration economic return of products obtained (MAP; Magnesium Ammonium Phosphate; Struvite) after removal process. In this study, physical and chemical parameters, which are effective in MAP precipitation, were investigated. Removal of ammonium at high concentrations (Cmean=348 mg NH4+/L ± 38,1; n=25) taking place as a result of urea hydrolysis in the Biocatalytic Calcification Reactor (BCR) was carried out in the form of MAP precipitation. Magnesium and phosphate required for precipitation were provided from MgCl2.6H2O as solid form and H3PO4 as liquid form, respectively. Optimum molar ratio of Mg:NH4:PO4 was determined as 1,25:1:1. Different pH ranges (7?10) studies with used that molar ratio, ammonium removal of approximately 96% reached at pH value of 9,36. It was seen that rapid mixing (200 rpm) of 30 s. and slow mixing (30 rpm) of 2 min. periods were sufficient for MAP precipitation. Struvite obtained after precipitation was used as fertilizer and it was observed that struvite supported to development of plant
Açıklama
Anahtar Kelimeler
Amonyum, MAP, Struvit, Kimyasal Çöktürme, Ammonium, Struvite, Chemical Precipitation
