The Role of PHREEQC Model and Sensor Analysis in Chemical Coagulation Processes Supported by Online Sensors

Yıl 2024, , 45 - 52, 31.03.2024

Meltem Sarp Akarsu , Sevgi Tokgöz Güneş

https://doi.org/10.35229/jaes.1407452

Öz

Population growth and industrial development have led to an increasing demand for water and wastewater treatment in Turkey and around the world. To ensure sustainable treatment, it is necessary to have real-time control and monitor the system. Therefore, this study aims to reveal the removal mechanism and control of the coagulation process using the PHREEQC modeling software, which has a promising potential for simulating the chemical equilibrium and reactions of water. The sensor effectiveness determined by the model was confirmed by experimental tests in the laboratory. This was done to identify the shortcomings and differences of the model, to understand and develop mechanistic structure. To observe the effects of temperature changes in the treatment, PHREEQC software was run for each of the temperatures (T) 1, 9, and 25.3oC, with the addition of FeCl3. The data obtained from pH, conductivity, temperature, and Eh sensors were evaluated. As a result of the study, it was found that different temperatures affect the solubility of the ions, with higher temperatures leading to increased solubility and conductivity. With increasing temperature, the solubility of oxygen in water decreases, while pH, Cl-, and the precipitate Fe(OH)3 are not affected by the temperature change. In general, the modeling results are in line with the analytical results of the samples taken in the laboratory. This highlights the attractiveness of using online sensors for sustainable wastewater treatment. PHREEQC has produced more reliable results by using actual chemical equilibrium constants as it considers equilibrium conditions and includes the effects of ionic bonds and ion pairs.

Anahtar Kelimeler

watewater treatment, sustainability, online sensor, modeling, coagulation

Teşekkür

The authors would like to thank to Cihan GÜNEŞ for modeling support.

Çevrimiçi Sensörler Tarafından Desteklenen Kimyasal Koagülasyon Süreçlerinde PHREEQC Modeli ve Sensör Analizinin Rolü

Öz

Nüfus artışı ve sanayinin gelişmesine bağlı olarak, ülkemizde ve dünyada su ve atıksu arıtımı gün geçtikçe daha önemli bir sorun haline gelmektedir. Bu durumda arıtma sisteminin tam zamanlı kontrol ve izlenebilirliği ile sürdürülebilir arıtma sağlayabilmek için sensör ve yazılımların önemi artmaktadır. Dolayısıyla bu çalışma kapsamında suyun kimyasal dengesini ve reaksiyonlarını simüle etmekte umut vaat eden PHREEQC modelleme yazılımı kullanılarak koagülasyon prosesinin çalışma mekanizması ve kontrol yapısı ortaya koyulmuştur. Bu amaçla pH, iletkenlik, sıcaklık gibi direkt sensörler ve kimyasal analizler kullanılarak. PHREEQC modeli ile belirlenen sensör etkinliği, laboratuvar ortamında alınan örneklere yapılan deneysel testlerden elde edilen verilerle onaylanarak, eksiklikleri ve farklılıkları belirlenmiş ve mekanistik yapının anlaşılması ve geliştirilmesi amaçlanmıştır. Mevsimsel sıcaklık farklılıkları dikkate alınarak arıtmada sıcaklık değişiminin neden olduğu etkilerin gözlemlenmesi amaçlanmış, bunun için, 1, 9 ve 25,3oC sıcaklıklarının (T) her biri için, FeCl3 koagülantı eklenerek PHREEQC yazılımı çalıştırılmış, pH, iletkenlik, sıcaklık, Eh sensörlerinden elde edilen veriler değerlendirilmiştir. Çalışma sonucunda farklı sıcaklıkların iyon çözünürlüğünü etkilediği, daha yüksek sıcaklıklarda iyon çözünürlüğü arttığı ve buna bağlı olarak da iletkenlik arttığı gözlemlenmiştir. Sıcaklık artışı oksijenin sudaki çözünürlüğünü azaltmakta, pH, Cl- ve çökebilen Fe(OH)3 parametreleri sıcaklık değişiminden etkilenmemektedir. Genel olarak modelleme sonuçları, laboratuvar ortamından alınan örneklere ait analiz sonuçları ile paralellik göstermektedir. Bu durum çevrimiçi sensörlerin kullanımının sürdürülebilir atıksu arıtımı için cazip olduğunu vurgulamaktadır. PHREEQC, denge koşullarını göz önünde bulundurması ve iyonik bağ ile iyon çiftlerinin etkilerini dahil etmesi sayesinde güncel kimyasal denge sabitlerini kullanarak daha güvenilir sonuçlar ortaya koymuştur.

Anahtar Kelimeler

atıksu arıtımı, sürdürülebilirlik, çevrimiçi sensör, modelleme, koagülasyon

Kaynakça

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