Removal of fluoride and arsenic by pilot vertical-flow constructed wetlands using soil and coal cinder as substrate

2014 ◽  
Vol 70 (4) ◽  
pp. 620-626 ◽  
Author(s):  
Juan Li ◽  
Xinchun Liu ◽  
Zhisheng Yu ◽  
Xin Yi ◽  
Yiwen Ju ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Constructed Wetlands ◽  
Pilot Scale ◽  
Vertical Flow ◽  
Arsenic Adsorption ◽  
Artificial Wetlands ◽  
Arsenic Accumulation ◽  
Vertical Flow Constructed Wetlands ◽  
High Fluoride ◽  
Set Up

This study evaluated the performance of soil and coal cinder used as substrate in vertical-flow constructed wetlands for removal of fluoride and arsenic. Two duplicate pilot-scale artificial wetlands were set up, planted respectively with cannas, calamus and no plant as blank, fed with a synthetic sewage solution. Laboratory (batch) incubation experiments were also carried out separately to ascertain the fluoride and arsenic adsorption capacity of the two materials (i.e. soil and coal cinder). The results showed that both soil and coal cinder had quite high fluoride and arsenic adsorption capacity. The wetlands were operated for two months. The concentrations of fluoride and arsenic in the effluent of the blank wetlands were obviously higher than in the other wetlands planted with cannas and calamus. Fluoride and arsenic accumulation in the wetlands body at the end of the operation period was in range of 14.07–37.24% and 32.43–90.04%, respectively, as compared with the unused media.

Comparative research on phosphorus removal by pilot-scale vertical flow constructed wetlands using steel slag and modified steel slag as substrates

2015 ◽  
Vol 71 (7) ◽  
pp. 996-1003 ◽  
Author(s):  
Yupan Yun ◽  
Xiaoqin Zhou ◽  
Zifu Li ◽  
Sayed Mohammad Nazim Uddin ◽  
Xiaofeng Bai
Keyword(s):  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Steel Slag ◽  
Pilot Scale ◽  
Phosphorus Concentration ◽  
Vertical Flow ◽  
Phosphorus Adsorption ◽  
Vertical Flow Constructed Wetlands ◽  
Low Phosphorus ◽  
Set Up

This research mainly focused on the phosphorus removal performance of pilot-scale vertical flow constructed wetlands with steel slag (SS) and modified steel slag (MSS). First, bench-scale experiments were conducted to evaluate the phosphorus adsorption capacity. Results showed that the Langmuir model could better describe the adsorption characteristics of the two materials; the maximum adsorption of MSS reached 12.7 mg/g, increasing by 34% compared to SS (9.5 mg/g). Moreover, pilot-scale constructed wetlands with SS and MSS were set up outdoors. Then, the influence of hydraulic retention time (HRT) and phosphorus concentration in phosphorus removal for two wetlands were investigated. Results revealed that better performance of the two systems could be achieved with an HRT of 2 d and phosphorus concentration in the range of 3–4.5 mg/L; the system with MSS had a better removal efficiency than the one with SS in the same control operation. Finally, the study implied that MSS could be used as a promising substrate for wetlands to treat wastewater with a high phosphorus concentration. However, considering energy consumption, SS could be regarded as a better alternative for substrate when treating sewage with a low phosphorus concentration.

Evaluation of substrate clogging processes in vertical flow constructed wetlands

2003 ◽  
Vol 48 (5) ◽  
pp. 25-34 ◽  
Author(s):  
G. Langergraber ◽  
R. Haberl ◽  
J. Laber ◽  
A. Pressl
Keyword(s):  
Constructed Wetlands ◽  
Substrate Surface ◽  
Infiltration Rate ◽  
Chemical Precipitation ◽  
Pilot Scale ◽  
Vertical Flow ◽  
Infiltration Capacity ◽  
Vertical Flow Constructed Wetlands ◽  
Operational Problem ◽  
Water And Wastewater

Substrate clogging is by far the biggest operational problem of vertical flow constructed wetlands. The term “substrate clogging” summarises several processes which lead to reduction of the infiltration capacity at the substrate surface. The lower infiltration rate causes a reduced oxygen supply and further leads to a rapid failure of the treatment performance. Reasons for substrate clogging include accumulation of suspended solids, surplus sludge production, chemical precipitation and deposition in the pores, growth of plant-rhizomes and roots, generation of gas and compaction of the clogging layer. However, it is not clear how much each process contributes to the clogging process. Detailed investigations were carried out at pilot-scale constructed wetlands (PSCWs) using a variety of methods: e.g. soil physical investigations, microbial methods, and various analysis methods of drinking water and wastewater. The paper shows the results of these investigations and presents an equation to calculate the theoretical clogging time.

Treatment of olive mill wastewater in pilot-scale vertical flow constructed wetlands

2011 ◽  
Vol 37 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Elissavet Herouvim ◽  
Christos S. Akratos ◽  
Athanasia Tekerlekopoulou ◽  
Dimitrios V. Vayenas
Keyword(s):  
Constructed Wetlands ◽  
Pilot Scale ◽  
Olive Mill Wastewater ◽  
Vertical Flow ◽  
Vertical Flow Constructed Wetlands ◽  
Olive Mill
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