Kimyasal şartlandırılmış çamur ile dondurma/çözme ile şartlandırılmış çamurun su verme özelliklerinin karşılaştırılması

Öz

Bu çalışmanın amacı kimyasal olarak şartlandırılmış çamur ve dondurulup çözdürülmüş çamurun su verme özelliklerinin özgül filtre direnci (ÖFD), çamur keki katı madde içeriği (KM) ve kapiler emme süresi (KES) parametre değerlerinin belirlenmesi ile karşılaştırılmasıdır. Deneysel çalışmada, İzmir (Türkiye)’de bulunan bir kentsel atıksu arıtma tesisi çamurları kullanılmıştır. Kimyasal şartlandırma deneylerinde çamurlar farklı dozlardaki polimer ile klasik jar testi metodu kullanılarak şartlandırılmıştır. Dondurma/çözme yöntemi ile şartlandırma çalışmalarında ise çamur örnekleri -16.5 °C’de farklı donma hızlarında dondurulmuş ve sonra 21±1 °C’de çözme süresinin su alma performansına etkisini belirlemek amacıyla farklı çözme sürelerinde çözdürülmüştür. 25 mg/L polimer dozu ve 2.71 mm/sa. donma hızı çamur şartlandırma için en uygun koşul olarak belirlenmiştir. 8.13 mm/sa.’ten daha hızlı dondurma işlemi çamurun şartlandırılması için yeterli olmamıştır. Yanı sıra, çözme süresinin çamur şartlandırma performansı üzerinde önemli bir etkisi olmadığı belirlenmiştir. Çalışmanın bir sonucu olarak, kimyasal şartlandırılmış çamur ile dondurma/çözme ile şartlandırılan çamurların su verme özellikleri birbirine oldukça yakın olduğu belirlenmiştir. 25 mg/L polimer uygulamasında KES ve ÖFD değerlerindeki azalma sırasıyla %76 ve %75 iken ve 2.71 mm/sa. dondurma hızı uygulaması sırasıyla  %79 ve %76 KES ve ÖFD azalmasına sebep olmuştur. Çalışmanın diğer bir sonucu ise dondurma/çözme ile şartlandırılmış çamurların kimyasal şartlandırılmış çamurlara oranla vakum filtrasyonu sonrasında daha yüksek katı madde içeriklerine ulaşmasıdır.

Anahtar Kelimeler

• Çamur,Susuzlaştırma,Kimyasal şartlandırma,Polimer,Dondurma/Çözme

Comparison of dewatering characteristics of chemically conditioned sludge and freeze/thawed sludge

Abstract

The objective of this study was to compare dewatering properties of chemically conditioned sludge and freeze/thawed sludge as determined by mainly specific resistance to filtration (SRF), dry solids content of sludge cake (DS), and capillary suction time (CST) parameters. The experimental studies were carried out with mixed sludge samples taken from a municipal wastewater treatment plant in Turkey. In chemical conditioning experiments, sludge samples were conditioned with different dosages of polymer using classical jar test method. In freeze/thaw conditioning experiments, samples were frozen at -16.5 °C at different freezing rates and then thawed at 21±1 °C at different times in order to determine the effect of thawing time on dewatering performance. 25 mg/L polymer dose and 2.71 mm/h freezing rate were found to be optimum in terms of sludge conditioning. Rapid freezing that is higher than 8.13 mm/h could not sufficiently condition the sludge and there was no significant effect of thawing time on conditioning performance. Dewatering properties of chemically conditioned sludge and freeze/thawed sludge was determined as very close to each other. While CST and SRF reductions were calculated as 76% and 75%, respectively at 25 mg/L polymer dosage, 2.71 mm/h freezing rate application caused 79% and 76% reduction in CST and SRF, respectively.

Keywords

• Sludge,Dewatering,Chemical conditioning,Polymers,Freeze/Thaw

Kaynakça

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