scholarly journals Closing the loop in a constructed wetland for the improvement of metal removal: the use of Phragmites australis biomass harvested from the system as biosorbent

2020 ◽  
Author(s):  
Elisabetta Bianchi ◽  
Andrea Coppi ◽  
Simone Nucci ◽  
Alexandra Antal ◽  
Chiara Berardi ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Phragmites Australis ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Operation Mode ◽  
Batch Process ◽  
Practical Applications ◽  
Closing The Loop ◽  
Reed Plants ◽  
Fe Ions

Abstract Among the numerous clean-up techniques for water treatment, sorption methods are widely used for the removal of trace metals. Phragmites australis is a macrophyte commonly used in constructed wetlands for water purification, and in the last decades, its use as biosorbent has attracted increasing attention. In view of a circularly economy approach, this study investigated improvement of trace metal removal by recycling the biomass of P. australis colonizing a constructed wetland, which operates as post-treatment of effluent wastewater from an activated sludge plant serving the textile industrial district of Prato (Italy). After the annual mowing of the reed plants, the biomass was dried and blended to derive a sustainable and eco-friendly biosorbent and its sorption capacity for Fe, Cu, and Zn was investigated comparing the batch system with the easier-to-handle column technique. The possibility of regeneration and reuse of the biosorbent was also evaluated. The biomaterial showed an interesting sorption capacity for Cu, Fe, and Zn, both in batch and in column experiments, especially for Fe ions. The immobilization of the biosorbent in column filters induced some improvement in the removal efficiency, and, in addition, this operation mode has the advantage of being much more suitable for practical applications than the batch process.

Effects of sorption, sulphate reduction, and Phragmites australis on the removal of heavy metals in subsurface flow constructed wetland microcosms

2007 ◽  
Vol 56 (3) ◽  
pp. 193-198 ◽  
Author(s):  
E. Lesage ◽  
D.P.L. Rousseau ◽  
A. Van de Moortel ◽  
F.M.G. Tack ◽  
N. De Pauw ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Phragmites Australis ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Subsurface Flow ◽  
High Strength ◽  
Sulphate Reduction ◽  
Separate Experiment ◽  
Subsurface Flow Constructed Wetland ◽  
Removal Of Heavy Metals

The removal of Co, Ni, Cu and Zn from synthetic industrial wastewater was studied in subsurface flow constructed wetland microcosms filled with gravel or a gravel/straw mixture. Half of the microcosms were planted with Phragmites australis and half were left unplanted. All microcosms received low-strength wastewater (1 mg L−1 of Co, Ni, and Zn, 0.5 mg L−1 Cu, 2,000 mg L−1 SO4) during seven 14-day incubation batches. The pore water was regularly monitored at two depths for heavy metals, sulphate, organic carbon and redox potential. Sorption properties of gravel and straw were assessed in a separate experiment. A second series of seven incubation batches with high-strength wastewater (10 mg L−1 of each metal, 2,000 mg L−1 SO4) was then applied to saturate the substrate. Glucose was added to the gravel microcosms together with the high-strength wastewater. Sorption processes were responsible for metal removal during start-up, with the highest removal efficiencies in the gravel microcosms. The lower initial efficiencies in the gravel/straw microcosms were presumably caused by the decomposition of straw. However, after establishment of anaerobic conditions (Eh∼−200 mV), precipitation as metal sulphides provided an additional removal pathway in the gravel/straw microcosms. The addition of glucose to gravel microcosms enhanced sulphate reduction and metal removal, although Phragmites australis negatively affected these processes in the top-layer of all microcosms.

Phosphate and ammonium removal by constructed wetlands with horizontal subsurface flow, using shale as a substrate

1997 ◽  
Vol 35 (5) ◽  
pp. 95-102 ◽  
Author(s):  
A. Drizo ◽  
C. A. Frost ◽  
K. A. Smith ◽  
J. Grace
Keyword(s):  
Phragmites Australis ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Subsurface Flow ◽  
Ammonium Removal ◽  
Ammonium N ◽  
Horizontal Subsurface Flow ◽  
P Removal

The objective was to investigate the performance of constructed wetlands with horizontal subsurface flow, using shale as a substrate, in removal of phosphate (P) and ammonium (N) from sewage. Shale was selected on the basis of its physico-chemical properties and its potential for P removal, investigated in an earlier study. A laboratory-scale constructed wetland system (CWS) employing horizontal subsurface flow was set up in a greenhouse, with and without Phragmites australis (reeds), and its capacity for simultaneous phosphate and ammonium removal from a synthetic sewage was monitored over a period of ten months. Both the planted and unplanted systems showed an extremely high P removal of 98–100% over the whole period of investigation. Ammonium N was also completely removed in the planted tanks, whereas in the unplanted ones the rates of removal varied between 40 and 75%; removal of nitrate N varied between 85 and 95% in planted and between 45 and 75% in unplanted tanks. pH, Eh and temperature did not differ significantly among planted and unplanted tanks, but the inlet Eh was correlated with P removal (r2 = 0.73; p < 0.05). The presence of Phragmites australis contributed significantly (p < 0.05) to P and N removal. In addition the plants showed excellent growth (up to 2 m in the first year), with good root and rhizome development, and showed potential for heavy metal removal. It was concluded that the shale-based system (which uses a readily available material) shows promise as a substrate for constructed wetland systems.

Long-Term Performance of a Constructed Wetland for Metal Removal

2010 ◽  
Vol 19 (6) ◽  
pp. 667-685 ◽  
Author(s):  
Anna Sophia Knox ◽  
Eric A. Nelson ◽  
Nancy V. Halverson ◽  
John B. Gladden
Keyword(s):  
Constructed Wetland ◽  
Metal Removal ◽  
Long Term Performance ◽  
Term Performance

Heavy Metal Removal by the Waste Biomass of Penicillium chrysogenum

2001 ◽  
Vol 36 (4) ◽  
pp. 793-803 ◽  
Author(s):  
Tadeusz Skowroński ◽  
Jacek Pirszel ◽  
Barbara Pawlik Skowrońska
Keyword(s):  
Heavy Metal ◽  
Sorption Capacity ◽  
Penicillium Chrysogenum ◽  
Metal Removal ◽  
Binding Capacity ◽  
Heavy Metal Removal ◽  
Dry Weight ◽  
Waste Biomass ◽  
Metal Sorption ◽  
Maximum Sorption Capacity

Abstract Metal sorption capacity of the granulated biosorbent derived from the waste biomass of Penicillium chrysogenum was examined. The potential metal sorption abilities of the biosorbent were estimated as the cation-exchange capacity, using a potentiometric titration. The total binding capacity, calculated for the pH range 3 to 8 was about 511 µeq/g dry weight. The granular biosorbent was capable of Cd, Zn, Cu and Pb binding. The kinetics of the heavy metal sorption were typical of the microbial dead biomass; metals were bound in the first few minutes. Sorption was a saturable process and the maximum sorption capacity, calculated from the Langmuir equation for the particular heavy metals was: 96 mg Pb; 21.5 mg Cd; 13 mg Zn and 11.7 mg Cu (per g dry weight). Optimum pH values for Cd, Zn and Cu sorption were about 7, while for Pb about 6. Heavy metal removal from different solutions was examined using the biosorption columns packed with P. chrysogenum, which efficiently removed Cd from 1 mM Cd solution, or Cd and Zn from the industrial wastewater. The studied biosorbent was capable of accumulating Cd and Zn even at the high Ca concentration.

Determination of the base position and working area for mobile manipulators

2016 ◽  
Vol 36 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Shunan Ren ◽  
Xiangdong Yang ◽  
Jing Xu ◽  
Guolei Wang ◽  
Ying Xie ◽  
...  
Keyword(s):  
Operation Mode ◽  
Mobile Manipulator ◽  
Planning Problem ◽  
Mobile Manipulators ◽  
Line Planning ◽  
Content Type ◽  
Practical Applications ◽  
Base Position ◽  
Intersection Area ◽  
Intersection Line

Purpose – The purpose of this paper is to determine the base position and the largest working area for mobile manipulators. The base position determines the workspace of the mobile manipulator, particularly when the operation mode is intermittent (i.e. the mobile platform stops when the manipulator conducts the task). When the base of the manipulator is in the intersection area of the Base’s Workable Location Spaces (BWLSes), the end effector (EE) can reach all path points. In this study, the intersection line of BWLSes is calculated numerically, and the largest working area is determined using the BWLS concept. The performance of this method is validated with simulations on specific surface segments, such as plane, cylinder and conical surface segments. Design/methodology/approach – The BWLS is used to determine the largest working area and the base position in which the mobile manipulator can reach all path points with the objective of reducing off-line planning time. Findings – Without considering the orientation of the EE, the base position and the working area for the mobile manipulator are determined using the BWLS. Compared to other methods, the proposed algorithm is beneficial when the planning problem has six dimensions, ensuring the reachability and stability of the EE. Originality/value – The algorithm needs no manual configuration, and its performance is investigated for typical surfaces in practical applications.

Long term heavy metal removal by a constructed wetland treating rainfall runoff from a motorway

2017 ◽  
Vol 601-602 ◽  
pp. 32-44 ◽  
Author(s):  
Laurence W. Gill ◽  
Pamela Ring ◽  
Brian Casey ◽  
Neil M.P. Higgins ◽  
Paul M. Johnston
Keyword(s):  
Heavy Metal ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Rainfall Runoff

scholarly journals Heavy Metal Sorption by Sludge-Derived Biochar with Focus on Pb2+ Sorption Capacity at μg/L Concentrations

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1559
Author(s):  
Ida Sylwan ◽  
Hanna Runtti ◽  
Lena Johansson Westholm ◽  
Henrik Romar ◽  
Eva Thorin
Keyword(s):  
Experimental Data ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Sorption Capacity ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Metal Exposure ◽  
Isotherm Models ◽  
Metal Sorption ◽  
Heavy Metal Sorption

Municipal wastewater management causes metal exposure to humans and the environment. Targeted metal removal is suggested to reduce metal loads during sludge reuse and release of effluent to receiving waters. Biochar is considered a low-cost sorbent with high sorption capacity for heavy metals. In this study, heavy metal sorption to sludge-derived biochar (SDBC) was investigated through batch experiments and modeling and compared to that of wood-derived biochar (WDBC) and activated carbon (AC). The aim was to investigate the sorption efficiency at metal concentrations comparable to those in municipal wastewater (<1 mg/L), for which experimental data are lacking and isotherm models have not been verified in previous works. Pb2+ removal of up to 83% was demonstrated at concentrations comparable to those in municipal wastewater, at pH 2. SDBC showed superior Pb2+ sorption capacity (maximum ~2 mg/g at pH 2) compared to WDBC and AC (<0 and (3.5 ± 0.4) × 10−3 mg/g, respectively); however, at the lowest concentration investigated (0.005 mg/L), SDBC released Pb2+. The potential risk of release of other heavy metals (i.e., Ni, Cd, Cu, and Zn) needs to be further examined. The sorption capacity of SDBC over a metal concentration span of 0.005–150 mg Pb2+/L could be predicted with the Redlich–Peterson model. It was shown that experimental data at concentrations comparable to those in municipal wastewater are necessary to accurately model and predict the sorption capacity of SDBC at these concentrations.

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