Biological nitrate removal in a laboratory-scale slow sand filter

In this paper, a study on using fixed-film biological denitrification to remove nitrates from water supplies is reported. Fixed-film biological systems have not been used in water supply systems in the U.S. although they are proven to be efficient and economical for removing nitrates with the reason being the possibility of imparting residual organics, suspended solids and bacteria to the treated water. In this research, fixed-film upflow biodenitrification columns were operated under carbon-starved conditions and the effluent was treated with a granular activated carbon (GAC) and sand filter system (combined in one unit) to remove residual organics and suspended matter. The system resulted in an average effluent turbidity of 0.8 NTU, and COD and total suspended solids (TSS) concentrations of 5.7 and 0.6 mg/L, respectively.

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Verification of filter efficiency of horizontal roughing filter by Weglin's design criteria and Artificial Neural Network

Drinking Water Engineering and Science ◽

10.5194/dwes-2-21-2009 ◽

2009 ◽

Vol 2 (1) ◽

pp. 21-27 ◽

Cited By ~ 1

Author(s):

◽

Keyword(s):

Genetic Model ◽

Neural Model ◽

Model Verification ◽

Design Criteria ◽

Experimental Setup ◽

Mean Square ◽

Raw Water ◽

Neural Models ◽

Sand Filter ◽

Slow Sand Filter

Abstract. The general objective of this study is to estimate the performance of the Horizontal Roughing Filter (HRF) by using Weglin's design criteria based on 1/3–2/3 filter theory. The main objective of the present study is to validate HRF developed in the laboratory with Slow Sand Filter (SSF) as a pretreatment unit with the help of Weglin's design criteria for HRF with respect to raw water condition and neuro-genetic model developed based on the filter dataset. The results achieved from the three different models were compared to find whether the performance of the experimental HRF with SSF output conforms to the other two models which will verify the validity of the former. According to the results, the experimental setup was coherent with the neural model but incoherent with the results from Weglin's formula as lowest mean square error was observed in case of the neuro-genetic model while comparing with the values found from the experimental SSF-HRF unit. As neural models are known to learn a problem with utmost efficiency, the model verification result was taken as positive.

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Comparison of denitrification performances using PLA/starch with different mass ratios as carbon source

Water Science & Technology ◽

10.2166/wst.2015.048 ◽

2015 ◽

Vol 71 (7) ◽

pp. 1019-1025 ◽

Cited By ~ 12

Author(s):

Chuanfu Wu ◽

Danqi Tang ◽

Qunhui Wang ◽

Juan Wang ◽

Jianguo Liu ◽

...

Keyword(s):

Carbon Source ◽

Groundwater Remediation ◽

Nitrate Concentration ◽

Starch Content ◽

Nitrate Removal ◽

Carbon Sources ◽

National Standard ◽

Biofilm Carrier ◽

Carbon Release ◽

Biological Nitrate Removal

A suitable carbon source is significant for biological nitrate removal from groundwater. In this study, slow-release carbon sources containing polylactic acid (PLA) and starch at 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7 ratios were prepared using a blending and fusing technique. The PLA/starch blend was then used as a solid carbon source for biological nitrate removal. The carbon release rate of PLA/starch was found to increase with increased starch content in leaching experiments. PLA/starch at 5:5 mass ratio was found to have the highest denitrification performance and organic carbon consumption efficiency in semi-continuous denitrification experiments, and was also revealed to support complete denitrification at 50 mg-N/L influent nitrate concentration in continuous experiments. The effluent nitrate concentration was <2 mg NO3–-N/L, which met the national standard (GB 14848-93) for groundwater. Scanning electron microscopy results further showed that the surface roughness of PLA/starch increased with prolonged experimental time, which may be conducive to microorganism attachment. Therefore, PLA/starch was a suitable carbon source and biofilm carrier for groundwater remediation.

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A23 Seasonal abundance of chironomid larvae in slow sand filter bed

Medical Entomology and Zoology ◽

10.7601/mez.53.41_1 ◽

2002 ◽

Vol 53 (Supplement) ◽

pp. 41

Author(s):

K. Hirabayashi ◽

N. Nakamoto ◽

S. Tanizaki

Keyword(s):

Seasonal Abundance ◽

Sand Filter ◽

Chironomid Larvae ◽

Slow Sand Filter ◽

Filter Bed

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Bacterial Community and Biological Nitrate Removal: Comparisons of Autotrophic and Heterotrophic Reactors for Denitrification with Raw Sewage

Journal of Microbiology and Biotechnology ◽

10.4014/jmb.0800.276 ◽

2008 ◽

pp. 1826-1835 ◽

Cited By ~ 9

Author(s):

Han Woong Lee

Keyword(s):

Bacterial Community ◽

Nitrate Removal ◽

Biological Nitrate Removal

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Influence of slow sand filter cleaning process type on filter media biomass: backwashing versus scraping

Water Research ◽

10.1016/j.watres.2020.116581 ◽

2021 ◽

Vol 189 ◽

pp. 116581 ◽

Cited By ~ 1

Author(s):

F.H. de Souza ◽

P.B. Roecker ◽

D.D. Silveira ◽

M.L. Sens ◽

L.C. Campos

Keyword(s):

Cleaning Process ◽

Filter Media ◽

Sand Filter ◽

Slow Sand Filter

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Streptophyta and Acetic Acid Bacteria Succession Promoted by Brass in Slow Sand Filter System Schmutzdeckes

Scientific Reports ◽

10.1038/s41598-019-43489-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Ma. Carmen E. Delgado-Gardea ◽

Patricia Tamez-Guerra ◽

Ricardo Gomez-Flores ◽

Mariela Garfio-Aguirre ◽

Beatriz A. Rocha-Gutiérrez ◽

...

Keyword(s):

Acetic Acid ◽

Acetic Acid Bacteria ◽

Sand Filter ◽

Filter System ◽

Slow Sand Filter

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Occurrence of Phytophthora Species in Commercial Nursery Production

Plant Health Progress ◽

10.1094/php-rs-15-0045 ◽

2016 ◽

Vol 17 (2) ◽

pp. 64-75 ◽

Cited By ~ 8

Author(s):

Corina Junker ◽

Patrick Goff ◽

Stefan Wagner ◽

Sabine Werres

Keyword(s):

Phytophthora Species ◽

Phytophthora Ramorum ◽

Water Recycling ◽

Infection Rates ◽

Sand Filter ◽

Detection Rates ◽

Water And Sediment ◽

Nursery Production ◽

Slow Sand Filter ◽

Soil Substrates

Two commercial woody ornamental nurseries were sampled for the presence of Phytophthora species over a period of three years between 2011 and 2014. The samples were taken every two months at different propagation (greenhouses, plastic tunnels) and cultivation (container stands) areas as well as from nearby pathways and from a water recycling system with a slow sand filter. Furthermore, different materials like soil, substrates, residues, wind-carried leaves, water and sediment were sampled. In total, 12 known Phytophthora species could be detected. Further, three isolates did not match any of the known species. Phytophthora ramorum, P. gonapodyides, and P. plurivora were the species with the highest detection rates. Phytophthora ramorum could be detected during all seasons of the year. In total, the puddles on the pathways had the highest percentage of positive detections. Residues, wind-carried leaves and water and sediment from the water runoffs were also good places for Phytophthora survival. In both nurseries, the plant samples showed very low infection rates. Ideas for surveys and management are discussed. Accepted for publication 14 March 2016. Published 11 April 2016.

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