Experimental Studies of Water Purification: IV. Observations on the Effects of Certain Modifications in Coagulation-Sedimentation on the Bacterial Efficiency of Preliminary Water Treatment in Connection with Rapid Sand Filtration: A. Observed Effect of Variations in the Period of Sedimentation
0
Citation
0
Reference
10
Related Paper
Keywords:
Sedimentation
Filtration (mathematics)
Cite
Filtration (mathematics)
Potable water
Asbestos fibers
Cite
Citations (16)
A set of Millipore Filtration(MF) equipment(5 000 m~3·d~(-1)) was used for the treatment of water in WUSHA Water Treatment Plant,which applies Al_2(SO_4)_3as the coagulation agent because of the heavy turbidity of this kind of water.In this paper,we reported the investigation on coagulation treatment of water with PAC and Al_2(SO_4)_3,respectively.The results showed that PAC was more effective than Al_2(SO_4)_3 and the amount of PAC was 43% of Al_2(SO_4)_3.The optimal addition of PAC was 10 mg ·L~(-1).
Turbidity
Filtration (mathematics)
Cite
Citations (0)
Sedimentation
Filtration (mathematics)
Cite
Citations (0)
The pilot treatment effects between coagulation- dissolved air flocculation process( DAF) and coagulation- sedimentation process for the low temperature and turbidity water of Queshan reservoir are compared. The polyaluminium chloride iron( PAFC) coagulant is used. The dosing quantity of PAFC of DAF process is 5 mg / L,17% lower than that in coagulation- sedimentation process. The continuous test shows that for the low temperature and turbidity reservoir water the DAF process is superior to coagulation- sedimentation process. The removal rates of turbidity,particle counts,CODMn,UV254 and DOC by DAF are 7. 7%,12. 8%,3. 9%,5. 1% and 8. 5% respectively higher than those by sedimentation process.
Turbidity
Sedimentation
Cite
Citations (0)
Sedimentation
Titanium Dioxide
Cite
Citations (4)
Application of physical theory of coagulation to processes that take place in chemical water treatment gives satisfactory explanation of phenomena observed in water treatment using hydrolyzing coagulants; theory of coagulation presented overcomes difficulty encountered in Langelier and Ludwig theory, and does not contradict available experimental data on chemical water treatment; study confined to basic mechanism of coagulation.
Sanitary engineering
Cite
Citations (21)
Taking secondary effluent from urban sewage treatment plant as the research object,the effects of different preoxidants of ordinary coagulation sedimentation process and preoxidation-coagulation sedimentation process on reclaimed water treatment were compared.The results showed that,when using KMnO4 as preoxidant,the best treatment effect could be obtained under the follow condition: the KMnO4 dosage was 1.8 mg/L,the pH value of the raw water was 7-8.To reach the same turbidity removal efficiency,the flocculation and sedimen-tation time were 12 and 15 min shorter respectively,and the PAC dosage was decreased by 8 mg/L by the preoxidation-coagulation and sedimentation process in contrast with that by the ordinary coagulation sedimenta-tion process.Furthermore,the removal rate of turbidity could be increased by 15% with KMnO4 preoxidation under the optimal condition.It could be seen that,preoxidation could obviously accelerate the formation and sedimentation of flocs,increase the density of flocs,which showed a significant coagulation aid effect for the coagulation and sedimentation technology in reclaimed water treatment.
Sedimentation
Turbidity
Raw water
Cite
Citations (0)
Microplastics detected in potable water sources and tap water have led to concerns about the efficacy of current drinking water treatment processes to remove these contaminants. It is hypothesized that drinking water resources contain nanoplastics (NPs), but the detection of NPs is challenging. We, therefore, used palladium (Pd)-labeled NPs to investigate the behavior and removal of NPs during conventional drinking water treatment processes including ozonation, sand and activated carbon filtration. Ozone doses typically applied in drinking water treatment plants (DWTPs) hardly affect the NPs transport in the subsequent filtration systems. Amongst the different filtration media, NPs particles were most efficiently retained when aged (i.e. biofilm coated) sand was used with good agreements between laboratory and pilot scale systems. The removal of NPs through multiple filtration steps in a municipal full-scale DWTP was simulated using the MNMs software code. Removal efficiencies exceeding 3-log units were modeled for a combination of three consecutive filtration steps (rapid sand filtration, activated carbon filtration and slow sand filtration with 0.4-, 0.2- and 3.0-log-removal, respectively). According to the results from the model, the removal of NPs during slow sand filtration dominated the overall NPs removal which is also supported by the laboratory-scale and pilot-scale data. The results from this study can be used to estimate the NPs removal efficiency of typical DWTPs with similar water treatment chains.
Filtration (mathematics)
Tap water
Portable water purification
Slow sand filter
Trihalomethane
Cite
Citations (53)
This report presents current knowledge of the physics of coagulation (rapid mixing and flocculation) and addresses the chemistry of coagulants—particularly aluminum coagulants—and methods for determining optimum coagulant dosages. Coagulation as a process for removing organic contaminants is examined. The selection of water treatment schemes for removing particles is considered with respect to raw water quality and coagulant types. Research needs are presented.
Raw water
Cite
Citations (25)