The Cost of Water Treatment by Coagulation, Sedimentation, and Rapid Sand Filtration

To evaluate the appropriateness of using algae as surrogate indices for the removal of Cryptosporidium parvum oocysts in conventional water treatment by rapid sand filtration, investigations on algal removal at eight water treatment plants and laboratory experiments using three species of algae and C. parvum oocysts were conducted. From the 5 years data collected from eight water treatment plants, the algal removal showed 0.63 - 1.83 log in coagulation and 1.66 - 4.17 log in sand filtration including coagulation. In jar tests, zeta potentials of flocs at an ALT ratio of 0.05 were -8.5 mV, -8.5 mV, -7.0 mV and -10.5 mV, and the removal rates at pH 7 were 2.05 log, 1.15 log, 1.51 log and 1.49-log for Microcystis viridis, Microcystis aeruginosa, Selenastrum capricornutum and C. parvum oocysts, respectively. In direct filtration tests, the removal rates of algae and C. parvum oocysts, except for M. aeruginosa, were around 3-log during the filtration time of 15-45 minutes when the best removal occurred. S. capricornutum, out of the three species of algae, showed almost the same coagulation characteristics as C. parvum oocysts and also behaved in a filtration pattern similar to C. parvum. From these results, algae were considered useful surrogate indices for the removal of C. parvum oocysts, and S. capricornutum was thought to be an appropriate one in rapid sand filtration.

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Evaluation of virus removal efficiency of coagulation-sedimentation and rapid sand filtration processes in a drinking water treatment plant in Bangkok, Thailand

Water Research ◽

10.1016/j.watres.2016.05.012 ◽

2016 ◽

Vol 101 ◽

pp. 84-94 ◽

Cited By ~ 32

Author(s):

Tatsuya Asami ◽

Hiroyuki Katayama ◽

Jason Robert Torrey ◽

Chettiyappan Visvanathan ◽

Hiroaki Furumai

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Removal Efficiency ◽

Treatment Plant ◽

Drinking Water Treatment ◽

Water Treatment Plant ◽

Sand Filtration ◽

Virus Removal ◽

Drinking Water Treatment Plant ◽

Rapid Sand Filtration

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Rapid Lava Sand Filtration for Decentralized Produced Water Treatment System in Old Oil Well Wonocolo

Journal of the Civil Engineering Forum ◽

10.22146/jcef.43760 ◽

2019 ◽

Vol 5 (2) ◽

pp. 113

Author(s):

Ekha Yogafanny

Keyword(s):

Water Treatment ◽

Crude Oil ◽

Produced Water ◽

Oil Production ◽

Real Field ◽

Oil Well ◽

Sand Filtration ◽

Turbidity Removal ◽

Produced Water Treatment ◽

Rapid Sand Filtration

The Cepu Block Oil Field has been traditionally extracted since 2008 by the local community in Wonocolo. The oil well-produced gas and fluids consisted of crude oil and produced water. This oil production activity discharges high amounts of produced water. The fluids have been settled down in the sedimentation tank to gain the crude oil optimally. The remaining fluid called produced water has been discharged to the surface towards the river without any further treatment. This activity led to the deterioration of environmental quality. This study aimed to analyze the performance of produced water treatment by rapid sand filtration by measuring the degree of turbidity removal under the specific condition on a laboratory scale using lava sand. The sedimentation was conducted in 3 hours of retention time following the real field condition of the oil production process by community in one sample well. The rapid sand filtration was conducted by a fixed bed column method with 0.2 cm of grain size. The sedimentation process followed by the rapid sand filtration in produced water treatment yielded the high efficiency of turbidity removal reaching 98.65 %. The rapid sand filter also worked excellently in turbidity removal attaining 96.48 % of efficiency. These results confirmed that the sedimentation already done by the community followed by the rapid sand filtration is promising decentralized technology to be applied in a remote area such as Old Oil Wells Wonocolo regarding turbidity removal.

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