Unveiling the role of sediments in phosphorus removal in pilot-scale constructed wetlands for swine wastewater treatment

2021 ◽  
pp. 150684
Author(s):  
Juan Zhou ◽  
Pei Luo ◽  
Feng Liu ◽  
Dianlin Gong ◽  
Baozhen Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Pilot Scale ◽  
Swine Wastewater

Study of oyster shell as a potential substrate for constructed wetlands

2013 ◽  
Vol 13 (4) ◽  
pp. 1007-1015 ◽  
Author(s):  
Zhen Wang ◽  
Jian Dong ◽  
Lin Liu ◽  
Gefu Zhu ◽  
Chaoxiang Liu
Keyword(s):  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Oyster Shell ◽  
Swine Wastewater ◽  
Vertical Flow ◽  
Flow State ◽  
Phosphorus Adsorption ◽  
Study Results ◽  
Predominant Form ◽  
Potential Substrate

We tested the suitability of oyster shell (OS) as a substrate for phosphorus removal in constructed wetlands (CWs) treating swine wastewater. OS is proven to have a significant phosphorus adsorption capacity; significant phosphorus removal was achieved in vertical subsurface flow constructed wetlands (VSSFs) that were filled with OS and used to treat swine wastewater. In the VSSF system, OS adsorption and precipitation played the greatest role in phosphorus removal, and the phosphorus distribution in the substrate layers was attributed to the vertical flow state of wastewater in the system. Ca–P was the predominant form of phosphorus in the system. Overall, the study results showed that OS could be used for phosphorus removal in CWs. OS also allowed for reuse of a waste substance, making the overall system more environmentally friendly.

scholarly journals Role of different plants on nitrogen and phosphorus removal at low temperature in lab-scale constructed wetlands

2019 ◽  
Vol 118 ◽  
pp. 01023 ◽  
Author(s):  
Liwei Xiao ◽  
Hong Jiang ◽  
Chao Shen ◽  
Ke Li ◽  
Lei Hu
Keyword(s):  
Constructed Wetlands ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Sichuan Basin ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Relative Growth ◽  
Stems And Leaves ◽  
Removal Efficiencies

In this study, plant growth and nitrogen and phosphorus removal efficiency in lab-scale CWs by five plants (H. vulgaris, N. peltatum, N. tetragona, N. pumilum, S. trifolia) in winter in Sichuan basin was evaluated. H. vulgaris and N. tetragona would well adapt to the winter wetland environment, and the relative growth at the end of the experiment was 89.83% and 66.85%, respectively. In winter, H. vulgaris kept growing with accumulated stems and leaves, while growth of N. tetragona was mainly caused by the growth of roots and stems underwater. In addition, during the winter, removal efficiencies were 66.29%, 57.47%, 54.78%, 55.47%, 41.66% of TN and 62.40%, 69.75%, 69.97%, 65.65%, 76.55% of TP for each planted CWs respectively. The results indicated that the removal of nitrogen and phosphorus from CWs was mainly achieved by substrate, while a small portion was attributed by plant. However, plants like H. vulgaris and N. tetragona, in the CWs in winter can play the role of landscaping. Thus, H. vulgaris could be considered as a suitable and effective nutrient removal plant for treatment of nitrogen and phosphorus water in winter wetlands in Sichuan basin.

Bench Scale and Pilot Scale Experiments on Biological Phosphorus Removal

1985 ◽  
Vol 17 (11-12) ◽  
pp. 287-288 ◽  
Author(s):  
R. Ramadori ◽  
V. Tandoi ◽  
A. Misiti
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Phosphorus Removal ◽  
Pilot Plant ◽  
Inorganic Phosphate ◽  
Pilot Scale ◽  
Anaerobic Reactor ◽  
Bench Scale ◽  
Anaerobic Reactors ◽  
Biological Removal

In connection with studies aimed at developing low-energy wastewater treatment processes considerable interest has been shown in the possibility of removal of phosphorus biologically rather than chemically. The results over one year from bench and pilot scale tests conducted with synthetic and settled domestic wastewaters respectively are reported. The pilot plant was installed in one of the Rome urban wastewater treatment works and consisted of a two stage (anaerobic-aerobic) system. The wastewater was withdrawn downstream from the primary settling tank and conveyed to the anaerobic reactor of the pilot plant. A similar experiment was conducted in a three reactor (two anaerobic and one aerobic) bench scale plant, where a synthetic solution (peptone, sodium acetate and potassium phosphate) was fed under rigorously controlled conditions of temperature, pH and dissolved oxygen. Both bench and pilot scale tests were designed to verify and quantify the biological removal of phosphorus; the performances of both phosphorus removal test scale systems were compared with those from a reference aerobic plant operating under the same conditions. The impact of several parameters on the biological removal of phosphorus were examined. These parameters were: nature of carbonaceous substrate, carbonaceous/phosphorus ratio, sludge age; etc. Considerable care and attention was given to checking phosphorus balances, once the steady state conditions had been obtained. The results can be summarized as follows:-Phosphorus removal was found to be greater in plants with an anaerobic stage than in the reference plants. At pilot scale level this is clearly shown by the plot of the daily phosphate concentration in the effluents. At bench scale it is shown by comparison between P contents in sludges (9.9% vs. 5.0%) and by the fact that, at the end of the experiment, large deposits of inorganic phosphate (mainly of Ca and Mg) were found on the walls of both anaerobic reactors. The unstable operating conditions of the reference plant due to the poor sedimentation characteristics of the sludges leading to uncontrolled losses of biomass meant it was impossible to obtain a reliable mean phosphorus abatement value, which in any case was always well below that found for the P-removal plant.-As reported above, the deficit in the phosphorus balance was due to inorganic phosphate precipitation. In this connection an excellent quantitative agreement was found between the deficit in the balance and the quantity of phosphorus collecting in the anaerobic reactors.-Phosphorus release from the biomass under anaerobic conditions has already been completed in the first anaerobic reactor (where carbonaceous substrate uptake also occurs) and the use of the second anaerobic reactor seems to allow a more complete phosphate precipitation.-Part of the carbonaceous substrate which disappears during the first anaerobic stage is metabolized. In fact, in this reactor, the complete disappearance of organic nitrogen is accompanied by the release of large quantities of ammoniacal nitrogen. Lastly, despite the fact that the values of the main operative parameters, such as hydraulic retention time, sludge age, temperature, pH and dissolved oxygen, were kept rigorously constant, a certain instability was found in the biomass as regards the maintaining of such high phosphorus removal efficiencies over long periods of time. This may be due to the highly variable biological population dynamics.

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.

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