Effects of Ultrasonic Treatment on the Waste Activated Sludge

Öz

Many of the organic compounds make up much of the sludge mass in particulate form and thus require hydrolysis, which is a rather slow process. In order to improve the hydrolysis, some other physical and chemical pretechniques such as thermal hydrolysis, mechanical disintegration, ultrasonic irradiation (ultrasonication), ozone treatment, acidification, and alkaline supplement are applied. Two of these techniques, those are ozone treatment and ultrasonication are generally regarded as environmentally non-hazardous. This preference of ultrasonication is based on the view that this method, as a speed fixing instrument, reduces the time limit of hydrolysis from 20 to 8 days; improves the quality and quantity of the biogas as an end-product; helps microbiological cells break into intracellular entities. The current studies have proved a lengthy ultrasonication period, a low-frequency ultrasonic wave and a high ultrasonic intensity are highly effective for the sludge disintegration. The aim of this work was to review the current studies on the issue mentioned above and presented a brief summary of the results. 

Anahtar Kelimeler

• Cavitation
• disintegration
• sludge treatment
• ultrasound
• wastewater treatment

Ultrasonik Arıtmanın Atık Aktif Çamur Üzerine Etkileri

Öz

Aktif çamur içerisindeki birçok organik bileşik partiküler formda bulunmakta olup, yavaş bir süreç olan hidroliz işlemiyle ayrışmaktadır. Bu süreci hızlandırmak için ısıl hidroliz, mekanik bozunma, ultrasonik radyasyon (ultrasonikasyon), ozonla arıtımı ile ortama ilave asit ve alkali kimyasalların eklenmesi gibi fiziksel ve kimyasal ön işlemler uygulanabilmektedir. Bahsedilen yöntemler içerisinden ozonla arıtım ve ultrasonikasyon işlemleri çevresel açıdan zararsız olmaları dolayısıyla tercih edilmektedir. Bu bakımdan ultrasonikasyon işlemi, gerekli ekipmanın hızlı kurulumu ile hidroliz süresini 20 günden 8 güne kadar indirebilmesi, biyogaz kalite ve miktarını artırıcı etki göstermesi ve mikrobiyal bozunmadaki etkinliği gibi nedenlerden ötürü dikkat çekici bulunmuştur. Günümüzdeki çalışmalar uzun süreli ve düşük frekanslı ultrasonik uygulamaların çamur bozundurmasında oldukça etkili olduğunu göstermektedir. Bu çalışmanın amacı, yukarıda belirtilen konulara ait yapılmış çalışmaları inceleyerek, sonuçlarını özet olarak sunmaktır.  

Anahtar Kelimeler

• −Kavitasyon
• bozunma
• çamur arıtımı
• ultrason
• atıksu arıtımı

Kaynakça

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