Effects of pre-ozonation and chemical coagulation on the removal of turbidity, color, TOC, and chlorophyll a from drinking water

Abstract

Background: Ozone can be used as a single technology or in combination with other processes to improve the coagulation- flocculation or biodegradability in order to remove pollutants in natural water treatment. Methods: In this study, the effects of pre-ozonation with coagulant substances on the quality parameters of drinking water were investigated using humic acid, kaolin, clay, and green algae in a pilot scale. This study was conducted under laboratory conditions (at both acidic and alkaline pH in different dosages of ozone and coagulant at ozone contact time with simulated water sample (5-20 minutes) in different scenarios). Results: The highest removal efficiency of parameters in the state of pre-ozonation alone and preozonation with a coagulant was observed at contact time of 20 minutes, ozone dosage of 5 g/h, coagulant dosage of 25 mg/L, at alkaline pH along with a decrease in temperature. So that, the average removal rate of turbidity, total organic carbon (TOC), color, and chlorophyll a in contact time of 20 minutes was 76.9%, 52.8%, 66.6%, and 85%, respectively. However, compared to ozonation under similar conditions, the reduction in turbidity, TOC, color, and chlorophyll a was 36.13%, 24.4%, 32.13%, and 79.6%, respectively. Also, it was revealed that pre-ozonation with coagulant could effectively improve the removal of parameters. Conclusion: However, since pre-ozonation can be effectively used to improve the coagulation efficacy in the drinking water treatment, the pre-ozonation combined with coagulation is proposed as an alternative to conventional coagulation to improve the process of drinking water treatment plant.

Evaluation of the efficiency of electrocoagulation process in removing cyanide, nitrate, turbidity, and chemical oxygen demand from landfill leachate

“…As a result of these mechanisms, the amount of turbidity was also significantly reduced. The released ions (Al 3+ , H + , and OH -) based on electric charge neutralization mechanism neutralized the electric charge of the particles and thus coagulation process was formed (35). The removal efficiency of any pollutant directly depends on the concentration of ions presented in the solution and reaction time.…”

Preozonasi Sebagai Pretreatment Air Baku: Studi Kasus Instalasi Pengolahan Air Minum (IPAM) Ngagel I Kota Surabaya

“…Berdasarkan hasil penelitian Yan & Wu (2014) menambahkan bahwa adanya kemungkinan dari saturasi air terhadap ozon (sehingga tidak menghasilkan cukup radikal hidroksil) yang menginduksi senyawa organik terlarut dan meningkatkan warna. Di sisi lain, jika suhu >35℃ dapat menyebabkan ozon cenderung sulit terlarut dan kurang efektif menyisihkan warna (Masoomi et al, 2019). Dapat disederhanakan bahwa penyisihan warna dengan ozonasi bergantung pada radikal hidroksil yang tercipta (Bismo, 2010).…”

“…Dapat dikatakan bahwa penyisihan warna paling optimal mampu dicapai saat dosis ozon rendah. Nilai tersebut sedikit lebih besar dari hasil penelitian Masoomi et al (2019) yang hanya mampu menyisihkan warna 32,13% dengan konsentrasi ozon 5g/jam setelah 20 menit.…”