Hydrodynamic effect on biofouling of milli-labyrinth channel and bacterial communities in drip irrigation systems fed with reclaimed wastewater

AbstractDripper clogging reduces the performance and service life of a drip irrigation system. The impact of chlorination (1.5 ppm of free chlorine during 1 h application) and pressure flushing (0.18 MPa) on the biofouling of non-pressure-compensating drippers fed by real reclaimed wastewater was studied at lab scale using Optical Coherence Tomography. The effect of these treatments on microbial composition (bacteria and eukaryotes) was also investigated by High-throughput DNA sequencing. Biofouling was mainly observed in inlet, outlet and return areas of the drippers. Chlorination limited biofilm development mainly in the mainstream of the milli-labyrinth channel. It was more efficient when combined with pressure flushing. Moreover, chlorination was more efficient in maintaining the water distribution uniformity. It reduced the bacterial concentration and the diversity of the dripper biofilms compared to the pressure flushing method. This method strongly modified the microbial communities, promoting chlorine-resistant bacteria such as Comamonadaceae or Azospira. Inversely, several bacterial groups were identified as sensitive to chlorination such as Chloroflexi and Planctomycetes. Nevertheless, one month after stopping the treatments the bacterial diversity re-increased and the chlorine-sensitive bacteria such as Chloroflexi phylum and the Saprospiraceae, Spirochaetaceae, Christensenellaceae and Hydrogenophilaceae families re-emerged with the growth of biofouling, highlighting the resilience of the bacteria from drippers. Based on PCoA analyses, the structure of the communities still clustered separately from never-chlorinated drippers, showing that the effect of chlorination was still present one month after stopping the treatment.HighlightsThe fouling of drippers is a bottleneck for drip irrigation using reclaimed wastewaterBiofouling was lowest when chlorination was combined with pressure flushingThe β-Proteobacteria and Firmicutes contain chlorine resistant bacteriaThe decrease of Chloroflexi by chlorination was transitoryThe bacterial community was resilient after the interruption of cleaning events

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The Clogging Capacity of Reclaimed Wastewater: A New Quality Criterion for Drip Irrigation

Water Science & Technology ◽

10.2166/wst.1991.0242 ◽

1991 ◽

Vol 24 (9) ◽

pp. 123-131 ◽

Cited By ~ 6

Author(s):

B. Teltsch ◽

M. Juanico ◽

Y. Azov ◽

I. Ben Harim ◽

G. Shelef

Keyword(s):

Water Quality ◽

Water Potential ◽

Irrigation Water ◽

Drip Irrigation ◽

Quality Criterion ◽

Additional Parameter ◽

Reclaimed Wastewater ◽

Irrigation Systems ◽

Particle Content ◽

Water Quality Criterion

The paper proposes a new water quality criterion for the evaluation of the water potential to clog screen filters which protect drip irrigation systems. This additional parameter is required by the increasing use of reclaimed wastewater for drip irrigation. A filtrability test which simulates actual clogging processes is used to analyze reservoirs receiving different portions of reclaimed wastewater (0 to 100 %) and the use of fish to reduce the particle content of water. The study demonstrates the suitability of the filtrability test to measure and analyze the clogging capacity of irrigation water, and the possibility to reduce clogging problems by proper reservoir management.

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Identification and Management of Clustered Pellitory (Parietaria praetermissa) in Citrus Groves

EDIS ◽

10.32473/edis-hs1341-2019 ◽

2019 ◽

Vol 2019 (5) ◽

pp. 3

Author(s):

Ramdas Kanissery ◽

Biwek Gairhe ◽

Brent Sellers ◽

Steve Futch

Keyword(s):

Drip Irrigation ◽

Early Summer ◽

Irrigation Systems ◽

Spray Pattern ◽

Citrus Groves ◽

Low Volume ◽

Florida Citrus ◽

Heavy Infestation

In Florida, clustered pellitory is becoming a troublesome weed for citrus, especially from the winter through early summer. Inadequate management of this weed can result in its heavy infestation in tree rows and can interrupt the spray pattern of low-volume drip irrigation systems. This new 3-page publication of the UF/IFAS Horticultural Sciences Department will assist Florida citrus growers with proper identification of clustered pellitory and with adoption of adequate and timely strategies to manage this weed in their groves. Written by Ramdas Kanissery, Biwek Gairhe, Brent Sellers, and Steve Futch. https://edis.ifas.ufl.edu/hs1341

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The experience of designing and building of drip irrigation systems in the Krasnodar territory

Prirodoobustrojstvo ◽

10.26897/1997-6011/2018-4-85-88 ◽

2018 ◽

pp. 85-88

Author(s):

A.K. Semerdjian ◽

◽

А.V. Ben ◽

◽

Keyword(s):

Drip Irrigation ◽

Irrigation Systems

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Behaviour of the fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation

Water Science & Technology ◽

10.2166/wst.2000.0294 ◽

2000 ◽

Vol 42 (1-2) ◽

pp. 75-79 ◽

Cited By ~ 7

Author(s):

C. Campos ◽

G. Oron ◽

M. Salgot ◽

L. Gillerman

Keyword(s):

Organic Matter ◽

Drip Irrigation ◽

Organic Matter Content ◽

Fecal Pollution ◽

Fecal Coliforms ◽

Subsurface Drip Irrigation ◽

Treated Wastewater ◽

Reclaimed Wastewater ◽

Pollution Indicators ◽

Subsurface Drip

A critical objective for any wastewater reuse programme is to minimise health and environmental hazard. When applying wastewater to soil–plant systems, it is to be noted that the passage of water through the soil considerably reduces the number of microorganisms carried by the reclaimed wastewater. Factors that affect survival include number and type of microorganisms, soil organic matter content, temperature, moisture, pH, rainfall, sunlight, protection provided by foliage and antagonism by soil microflora. The purpose of this work was to examine the behaviour of fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation. The experiment was conducted in a vineyard located at a commercial farm near the City of Arad (Israel). Wastewater and soil samples were monitored during the irrigation period and examined for fecal coliforms, somatic and F+ coliphages and helminth eggs. Physico-chemical parameters were controlled in order to determine their relationship with removal of microorganisms. The results showed high reduction of the concentration of microorganisms when wastewater moves through the soil; and a good correlation between the reduction of fecal pollution indicators and moisture content, organic matter concentration and pH. The application of secondary treated domestic wastewater in this specific soil and under these irrigation systems affect the survival of microorganisms, thus reducing the health and environmental risk.

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