Influence of earthworm presence and hydraulic loading rate on the performance of vertical flow constructed wetlands

Abstract The technology of vertical flow constructed wetlands – French system for treating raw wastewater depends on several hydraulic factors, one of them being the duration of the pulse feeding and the resulting instantaneous hydraulic loading rate. This paper analyses two scenarios in the same system, the first of a faster feeding by pump and the second of a slower feeding by siphon, both with instantaneous hydraulic loading rate values lower than the literature recommendations. The system treated raw wastewater from a population equivalent of 100 p.e. in Brazil, and was comprised by only the first stage and two units in parallel. The shorter duration of feeding time and higher instantaneous hydraulic loading rate were associated with significantly higher chemical oxygen demand and total Kjeldahl nitrogen removal efficiencies, but with no significant differences in terms of biochemical oxygen demand (BOD) and suspended solids (SS). Oxygen concentrations and redox potential in the effluent were evaluated, together with the effluent flow rate profiles. The removal efficiencies were associated with the accumulation of solids in the upper part of the filter resulting from seven years of operation and to the operating hydraulic conditions, which are important elements in the performance of the system.

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Influence of hydraulic loading rate on antibiotics removal and antibiotic resistance expression in soil layer of constructed wetlands

Chemosphere ◽

10.1016/j.chemosphere.2020.129100 ◽

2021 ◽

Vol 265 ◽

pp. 129100

Author(s):

Lin Liu ◽

Shuangrong Chen ◽

Kaiqin Xu ◽

Xu Huang ◽

Chaoxiang Liu

Keyword(s):

Antibiotic Resistance ◽

Constructed Wetlands ◽

Loading Rate ◽

Soil Layer ◽

Hydraulic Loading Rate ◽

Hydraulic Loading ◽

Resistance Expression

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Purification Effect of Vertical-Flow Constructed Wetlands with Multi-Size Combined Filter Medium

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.1720 ◽

2013 ◽

Vol 726-731 ◽

pp. 1720-1723 ◽

Cited By ~ 1

Author(s):

Xiang Ling Zhang ◽

Lu Xu ◽

Jun Jie Chen ◽

Liang Hu

Keyword(s):

Constructed Wetlands ◽

Loading Rate ◽

Great Influence ◽

Filter Medium ◽

Vertical Flow ◽

Vertical Flow Constructed Wetlands ◽

Vertical Flow Constructed Wetland ◽

Removal Efficiencies ◽

Single Medium ◽

Made In

Three columns filled with multi-size combined medium were utilized in the simulative vertical-flow constructed wetland systems to treat wastewater at hydraulic loading rate of 2000-3000 mm/d, that the same kind of media including biological ceramsite, anthracite and zeolite in each column. Comparative analyses were made in treatment performances between multi-size medium and single medium. The results showed that compared with the treatment performances of single medium, the purifying effect had great influence by the multi-size combined medium which were made up of same kind and different size of filter medium. Contrast with the corresponding single medium, the average removal efficiencies of CODCr, Total Nitrogen (TN), and Total Phosphorus (TP) were increased obviously which were purified by the multi-size combined medium. Good performances were achieved in terms of removal of BOD5 and CODCr in the column of multi-size combined biological ceramsite medium. The average removal efficiencies of TN were great in the column of multi-size combined zeolite medium. Good performances were also achieved in terms of removal of TP in the column of multi-size combined anthracite medium.

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Effect of hydraulic loading rate on the efficiency of effluent treatment in a recirculating puffer aquaculture system coupled with constructed wetlands

Journal of Ocean University of China ◽

10.1007/s11802-014-2000-3 ◽

2013 ◽

Vol 13 (1) ◽

pp. 146-152 ◽

Cited By ~ 10

Author(s):

Jiabo Xu ◽

Yonghai Shi ◽

Genyu Zhang ◽

Jianzhong Liu ◽

Yazhu Zhu

Keyword(s):

Constructed Wetlands ◽

Loading Rate ◽

Effluent Treatment ◽

Hydraulic Loading Rate ◽

Hydraulic Loading ◽

Aquaculture System

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Performance of vertical flow constructed wetlands for faecal sludge drying bed leachate: Effect of hydraulic loading

Ecological Engineering ◽

10.1016/j.ecoleng.2014.07.041 ◽

2014 ◽

Vol 71 ◽

pp. 384-393 ◽

Cited By ~ 12

Author(s):

Ebenezer Soh Kengne ◽

Ives Magloire Kengne ◽

Wilfried Arsene Letah Nzouebet ◽

Amougou Akoa ◽

Hung Nguyeng Viet ◽

...

Keyword(s):

Constructed Wetlands ◽

Vertical Flow ◽

Hydraulic Loading ◽

Vertical Flow Constructed Wetlands ◽

Sludge Drying ◽

Faecal Sludge

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Study on Biofortification in Vertical Flow Constructed Wetland

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.2570 ◽

2014 ◽

Vol 955-959 ◽

pp. 2570-2573

Author(s):

Ji Ku Zhang ◽

Hui Ting Shao ◽

Yue Ming ◽

Hui Ye Wang

Keyword(s):

Constructed Wetlands ◽

Constructed Wetland ◽

Loading Rate ◽

Removal Rate ◽

Nitrifying Bacteria ◽

Vertical Flow ◽

Microbial Inoculants ◽

Vertical Flow Constructed Wetlands ◽

Technology And Economy ◽

Number Of Bacteria

The methods of dosing composite microbial inoculants are used in vertical flow constructed wetlands for biofortification. The removal of the main pollution indicators by substrate microorganisms was studied. The results show that compared with the blank system, the number of bacteria and nitrifying bacteria was higher in the substrate of constructed wetland by biofortification. At the hydraulic loading rate (HLR) of about 0.8 m3/(m2·d), relationship between total number of bacteria and the removal rate of COD was significant in Device A and Device B. Relationship with TP removal rate is not evident. Correlation between the number of nitrifying bacteria and TN removal rate was obvious. The biofortification is feasible on technology and economy.

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