Algae as surrogate indices for the removal of Cryptosporidium oocysts by direct filtration

2002 ◽  
Vol 2 (3) ◽  
pp. 73-80 ◽  
Author(s):  
M. Akiba ◽  
S. Kunikane ◽  
H.-S. Kim ◽  
H. Kitazawa
Keyword(s):  
Water Treatment ◽  
Selenastrum Capricornutum ◽  
Sand Filtration ◽  
Removal Rates ◽  
Filtration Time ◽  
Direct Filtration ◽  
Zeta Potentials ◽  
Water Treatment Plants ◽  
Cryptosporidium Parvum Oocysts ◽  
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.

scholarly journals Study of Head Loss in Rapid Filtration with four River Sands

2021 ◽  
Vol 7 (4) ◽  
pp. 690-700
Author(s):  
Komitse Edoh Agbo ◽  
Yawovi M. X. Dany Ayité ◽  
Irina Pachoukova
Keyword(s):  
Water Treatment ◽  
Full Text ◽  
Filtration Rate ◽  
Head Loss ◽  
Filtration Time ◽  
Water Treatment Plants ◽  
The One

In this work, we studied the filtration behavior, with regard to the head loss, of four calibrated Togo Rivers sands compared to that of a reference filter sand imported from Europe. The objective is to determine the suitability of local rivers sands as filter sands for water treatment plants. The sands were successively loaded into a filtration pilot and subjected, during at least 20 hours, to the filtration of water whose turbidity was maintained at around 20 NTU. The results show that the average deviations of the head loss profiles as a function of depth, calculated in relation to the head loss recorded on the reference sand, at the same filtration time t=20h, are small and vary from 2 cm to 8 cm.  In the same way, the curves of the head loss as a function of time are quite close to the one observed for the reference sand. Examination of the clogging front after 20 hours of filtration reveals that the progression is either the same or greater and reached 20 cm in depth at the same time. This study can be extended to other rivers sand samples and by varying the turbidity and the filtration rate. Doi: 10.28991/cej-2021-03091682 Full Text: PDF

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

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.

The characterisation of natural organic matter (NOM) in South African waters

2012 ◽  
Vol 12 (5) ◽  
pp. 648-657
Author(s):  
T. I. Nkambule ◽  
R. W. M. Krause ◽  
J. Haarhoff ◽  
B. B. Mamba
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
South African ◽  
Natural Organic Matter ◽  
Water Samples ◽  
Sand Filtration ◽  
Water Treatment Plants

The removal of natural organic matter (NOM) from water is becoming increasingly important in order to prevent the formation of carcinogenic disinfection by-products (DBPs). The inadequate removal of NOM has a bearing on the capacity of other treatment processes to remove organic micro-pollutants or inorganic species that may be present in water. In order to effectively study the nature of South African water sources in terms of their NOM composition, water samples were collected from drinking water treatment plants in the five geographic water regions of South Africa. A raw water sample, an intermediate sample taken before sand filtration and a final sample after sand filtration were collected three times from these water treatment plants at two-month intervals and over three different seasons. Fluorescence excitation-emission matrices (FEEM), biodegradable dissolved organic carbon (BDOC), ultraviolet (UV) characterisation (200–900 nm) and dissolved organic carbon (DOC) analyses were used to characterise the NOM in the water samples. The FEEM and UV results revealed that the samples were composed mainly of non-humic substances with low UV-254 absorbance, while some samples had high humic substances with high UV-254 values. The samples' DOC results were within the range of 3.25–21.44 mg/L carbon, which was indicative of the varying nature of the NOM composition in the regions where samples were collected. The BDOC fraction of the NOM, on the other hand, ranged from 20 to 65%, depending on the geographical location of the sampling site.

Applicability of statistical analysis for performance and reliability evaluation of large-scale water treatment plants with direct filtration systems

2021 ◽  
Author(s):  
Lívia Duarte Ventura Melo ◽  
Gabriela Rodrigues Barroso ◽  
Raíssa Santos Figueiredo ◽  
Elizângela Pinheiro Costa ◽  
Sílvia Corrêa Oliveira
Keyword(s):  
Statistical Analysis ◽  
Water Treatment ◽  
Large Scale ◽  
Reliability Evaluation ◽  
Direct Filtration ◽  
Water Treatment Plants
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