scholarly journals Preparation of sustainable non-combustion filler substrate from waterworks sludge/aluminum slag/gypsum/silica/maifan stone for phosphorus immobilization in constructed wetlands

2019 ◽  
Vol 80 (1) ◽  
pp. 153-163 ◽  
Author(s):  
Guanghui Wang ◽  
Jingqing Gao ◽  
Rongxue Yang ◽  
Jingshen Zhang ◽  
Han Guo ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Adsorption Mechanism ◽  
High Efficiency ◽  
Removal Rate ◽  
Combustion Process ◽  
Speciation Analysis ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Phosphorus Adsorption

Abstract In this study, an artificial wetland filler matrix capable of effectively fixing phosphorus was prepared using a non-combustion process to save energy. To evaluate the adsorption performance of this filler, adsorption experiments were performed and the phosphorus adsorption mechanism characterization was studied. An alkaline environment was found to be conducive to the increase of adsorption capacity, but excessive alkalinity was not conducive to adsorption. Static adsorption experiments showed that the phosphorus removal rate could reach 95% in the simulated phosphorus-containing wastewater after adsorption completion. The adsorption process is closely simulated by the pseudo-second-kinetic adsorption model. The isothermal adsorption experiment data were consistent with the Langmuir and the Freundlich adsorption isotherms. The characterization results showed a large number of micropores and adsorption binding sites inside and on the surface of the filler. Speciation analysis on the adsorbed phosphorus revealed that chemisorption by calcium in this filler was the dominant adsorption mechanism. The research results of this study provide the basis and reference for the development of high-efficiency phosphorus removal filler in constructed wetlands.

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.

Phosphorus Removal in Constructed Wetlands Using Gravel and Industrial Waste Substrata

1993 ◽  
Vol 27 (1) ◽  
pp. 107-113 ◽  
Author(s):  
R. A. Mann ◽  
H. J. Bavor
Keyword(s):  
Adsorption Capacity ◽  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Industrial Waste ◽  
Large Scale ◽  
Maximum Adsorption Capacity ◽  
Phosphorus Adsorption ◽  
Freundlich Isotherms ◽  
Linear Profiles ◽  
Furnace Slag

The phosphorus removal efficiency of three gravel based constructed wetland systems (CWSs) has been investigated in a two year study in which secondary sewage effluent was treated. The constructed wetlands systems, 100m × 4m × 0.5m with an impervious liner, comprised an unplanted gravel “control” trench and gravel trenches planted with monoculture stands of either Typhaorientalis or Schoenoplectusvalidus. Inlet and outlet phosphorus concentrations and vertical and linear profiles of phosphorus were determined to characterise immobilisation/translocation through the systems. Laboratory phosphorus adsorption experiments were conducted with regional gravels and alternative adsorptive media including industrial slag and ash by-products. Phosphorus adsorption in the large scale gravel systems was variable and ranged from −40% to 40%. Laboratory adsorption capacity studies conducted with the gravel substratum indicated that field adsorption potential could be successfully simulated and modelled. Ion exchange experiments have been used to evaluate gravel and industrial conglomerates, with a view to improving phosphorus immobilisation through substratum selection and effluent flow management. Langmuir and Freundlich isotherms characterised phosphorus adsorption and the maximum adsorption capacity of regional gravels ranged from 25.8 to 47.5 μg P/g compared to blast furnace slag 160 to 420 μg P/g and fly ash 260 μg P/g. These results indicate that further investigations into the inclusion of industrial waste substrata in a CWS are warranted.

Potential Use of Constructed Wetlands for Wastewater Treatment in Northern Environments

1993 ◽  
Vol 28 (10) ◽  
pp. 149-157 ◽  
Author(s):  
P. D. Jenssen ◽  
T. Mæhlum ◽  
T. Krogstad
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Cold Climate ◽  
Cold Climates ◽  
Phosphorus Adsorption ◽  
Arctic Regions ◽  
Multi Stage ◽  
Maintenance Systems ◽  
Cost Efficient

Constructed wetlands consist of soil filled beds with aquatic plants. Wastewater is treated when flowing through these beds. It has been questioned if constructed wetlands will be able to operate when subjected to cold conditions in sub arctic regions. Experience from Norway indicates that significant biological activity occurs at temperatures between 0 and 5°C, and that high removal rates of nutrients and organic matter are achieved in ponds and soil amended with wastewater at these temperatures. Results from using constructed wetlands in Denmark, Sweden and North America show that winter performance is not significantly reduced as compared to other seasons, but in order to obtain high removal of organic matter and nitrogen in cold climates aerobic pretreatment is probably a prerequisite. Cold climates may also require careful installation of larger and deeper systems with a longer detention time. Results of 15 months operation of a Norwegian multi-stage constructed wetland pilot plant optimised for nutrient removal, show 55% nitrogen and 98% phosphorus removal. The large phosphorus removal is obtained by using sand with a high content of iron oxides and a fabricated porous medium that has a high phosphorus adsorption capacity. It remains to be seen if long term cost efficient phosphorus removal can be obtained in constructed wetlands. The results indicate that properly designed constructed wetlands can operate satisfactorily in a cold climate. When adequate design criteria are developed several possible applications exist for these simple low maintenance systems as main treatment system, or in conjunction with other treatment methods.

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.

Thermodynamic Properties of Modified Sepiolite Phosphorus Removal

2013 ◽  
Vol 726-731 ◽  
pp. 234-238
Author(s):  
Wen Quan
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Adsorption Capacity ◽  
Phosphorus Removal ◽  
Theoretical Foundation ◽  
Removal Rate ◽  
Adsorption Properties ◽  
Phosphorus Adsorption ◽  
Depth Study ◽  
Adsorption Amount

this thesis makes an in-depth study on the adsorption properties of modified sepiolite to phosphorus, and confirms how the factors such as, phosphorus wastewater flow, phosphorus removal agent dosage, temperature, additives and other factors effect on the phosphorus adsorption thermodynamic equilibrium of modified sepiolite. With the increase of phosphorus removal agent of modified sepiolite, adsorption capacity of modified sepiolite phosphorus removal to PO43- ions in wastewater decreases; the removal rate increases with the increase removal agent; improving the acid modified temperature favors the adsorption of compound phosphorus removal to sepiolite; adsorption amount increases with the calcination temperature of sepiolite. This thesis describes the adsorption capacity of the modified sepiolite to phosphorus changes with temperature. According to the experimental data, adsorption isotherms at different temperature are presented in this thesis. And a theoretical foundation is provided for the industrial application of modified sepiolite phosphorus removal.

scholarly journals Fabrication of Ceramsite Adsorbent from Industrial Wastes for the Removal of Phosphorus from Aqueous Solutions

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yue Yin ◽  
Gaoyang Xu ◽  
Linlin Li ◽  
Yuxing Xu ◽  
Yihan Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Phosphorus Removal ◽  
High Efficiency ◽  
Column Experiment ◽  
Industrial Wastes ◽  
Phosphorus Concentration ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Phosphorus Adsorption

A more applicable adsorbent was fabricated using industrial wastes such as red mud, fly ash, and riverbed sediments. The heavy metal inside the raw materials created metal hydroxy on the adsorbent surface that offered elevated adsorption capacity for phosphorus. The required equilibrium time for the adsorption is only 10 min. The theoretical maximum adsorption capacity of the adsorbent was 9.84 mg·g−1 inferred from the Langmuir adsorption isotherm. Higher solution pH favored phosphorus adsorption. Kinetics study showed that the adsorption could be better fitted by the pseudo-second-order kinetic model. The presence of coexisting anions had no significant adverse impact on phosphorus removal. The speciation of the adsorbed phosphorus indicated that the adsorption to iron and aluminum is the dominating adsorption mechanism. Moreover, a dynamic adsorption column experiment showed that, under a hydraulic time of 10 min, more than 80% of the phosphorus in the influent was removed and the surplus phosphorus concentration was close to 0.1 mg L−1. The water quality after adsorption revealed its applicability in real treatment. Consequently, the adsorbent synthesized from industrial wastes is efficient and applicable due to the high efficiency of phosphorus removal and eco-friendly behavior in solutions.

Effect of inorganic salt ions on the adsorption of quinoline using coal powder

2018 ◽  
Vol 78 (3) ◽  
pp. 496-505 ◽  
Author(s):  
Yue Bian ◽  
Hao Sun ◽  
Yunxiao Luo ◽  
Qieyuan Gao ◽  
Guosheng Li ◽  
...  
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Inorganic Salt ◽  
Removal Rate ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Adsorbed Amount ◽  
Salt Ions ◽  
Coal Powder

Abstract In this study, coal powder was used as the adsorbent for quinoline. The effect of inorganic salt ions on the adsorption was explored, and the results suggest that the addition of inorganic salt ions can enhance both the removal rate and the amount of quinoline adsorbed. The removal rate and adsorbed amount of quinoline were 83.87% and 1.26 mg/g without inorganic salt ions. Under the same adsorption conditions, the removal rate and adsorbed amount of quinoline could reach 90.21% and 1.35 mg/g when Na+ was present in the solution, and 94.47% and 1.42 mg/g with the presence of Ca2+. In addition, the adsorption of quinoline using coal fitted the Freundlich isothermal adsorption model. Changes in the Gibbs free energy, entropy and heat of adsorption were all negative, indicating that the adsorption was spontaneous and exothermic. The changes in the absolute value of Gibbs free energy under both Na+ and Ca2+ were higher than that in the blank(without inorganic salt ions). The pseudo-second-order kinetic model was found to fit the adsorption kinetic data well, and the activation energy of adsorption under Na+ and Ca2+ were lower than that in the blank. These indicate that the addition of inorganic salt ions was beneficial to the adsorption process.

Study of oyster shell as a potential substrate for constructed wetlands

2013 ◽  
Vol 67 (10) ◽  
pp. 2265-2272 ◽  
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 Adsorption of As(III), Pb(II), and Zn(II) from Wastewater by Sodium Alginate Modified Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hongchuan Li ◽  
Rui Jin ◽  
Hongxiang Hu ◽  
Yusef Kianpoor Kalkhajeh ◽  
Yingying Zhao ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
High Efficiency ◽  
Removal Rate ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Solid Ratio ◽  
Composite Gel ◽  
Pseudo Second Order

Sodium alginate (SA), polyvinyl oxide (PEO), and ceramic nanomaterials were used to prepare alginate composite gel. The present study examined the removal rate and adsorption capacity of alginate composite gel for removal of wastewater As(III), Pb(II), and Zn(II). Batch experiments were conducted to study the influence of experimental parameters such as pH and temperature, as well as the mechanism of As(III), Pb(II), and Zn(II) adsorption with the new adsorbent. The results showed the high efficiency of sodium alginate composite gel for removal of wastewater As(III), Pb(II), and Zn(II). Under the condition of the best liquid-solid ratio and the contact time, the removal rates of As(III), Pb(II), and Zn(II) were 67.42%, 95.31%, and 93.96%, respectively. The pseudo-second-order kinetic equation was superior to fit the adsorption kinetics process. The isothermal adsorption models of As(III) and Pb(II) fitted well with the Freundlich model, and Zn(II) fitted well with the Langmuir model. The results of SEM, EDS, XPS, and FTIR analyses revealed that the adsorption process occurred mainly via chemisorption. The results of the present study suggest that new adsorbents can be effectively utilized for As(III), Pb(II), and Zn(II) removal from water.

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