Effects of loading, resting period, temperature, porous media, vegetation and aeration on performance of pilot-scale vertical flow constructed wetlands

2012 ◽  
Vol 181-182 ◽  
pp. 416-430 ◽  
Author(s):  
Alexandros I. Stefanakis ◽  
Vassilios A. Tsihrintzis
2015 ◽  
Vol 71 (7) ◽  
pp. 996-1003 ◽  
Author(s):  
Yupan Yun ◽  
Xiaoqin Zhou ◽  
Zifu Li ◽  
Sayed Mohammad Nazim Uddin ◽  
Xiaofeng Bai

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.


2003 ◽  
Vol 48 (5) ◽  
pp. 25-34 ◽  
Author(s):  
G. Langergraber ◽  
R. Haberl ◽  
J. Laber ◽  
A. Pressl

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.


2011 ◽  
Vol 37 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Elissavet Herouvim ◽  
Christos S. Akratos ◽  
Athanasia Tekerlekopoulou ◽  
Dimitrios V. Vayenas

Sign in / Sign up

Export Citation Format

Share Document