Characteristics of Phosphorus Adsorption of Aerated Concrete in Wastewater Treatment

2011 ◽  
Vol 183-185 ◽  
pp. 466-470 ◽  
Author(s):  
Wei Guo Fu ◽  
Ping Ping Li
Keyword(s):  
Adsorption Capacity ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Phosphorus Removal ◽  
Construction Process ◽  
Phosphorus Adsorption ◽  
Langmuir Adsorption ◽  
Engineering Measures ◽  
Aerated Concrete ◽  
Isotherm Equations

Constructed wetlands are widely used throughout the world to treat a wide variety of wastewater. Numerous researches on phosphorus removal have been reported, however, in practice, phosphorus removal efficiency through the constructed wetland is still relatively lower due to various reasons. In this paper, the phosphorus adsorption capacity of aerated concrete (a building material) was investigated by using Freundlich and Langmuir adsorption isotherm equations, and then the possibility, using aerated concrete waste residues for the treatment of effluent with relatively higher concentration phosphorus at the outfall of constructed wetland end through certain engineering measures, was explored. The results showed that aerated concrete not only had a higher phosphorus adsorption capacity (6.064mg/g), but also had a higher adsorption rate, compared with some other substrate materials commonly used for constructed wetlands. Coupled with the lightweight characteristic of aerated concrete, the imagination of the secondary purification pond was likely to be formed. If the imagination turns into a reality, it will not only effectively purify sewage emissions from the constructed wetland forever, but also realize the resource utilization of large quantities of aerated concrete waste residues resulting from the construction process.

scholarly journals Dewatered alum sludge: a potential adsorbent for phosphorus removal

2006 ◽  
Vol 54 (5) ◽  
pp. 207-213 ◽  
Author(s):  
Y. Yang ◽  
D. Tomlinson ◽  
S. Kennedy ◽  
Y.Q . Zhao
Keyword(s):  
Water Treatment ◽  
Adsorption Capacity ◽  
Phosphorus Removal ◽  
Adsorption Process ◽  
Study Groups ◽  
Phosphorus Adsorption ◽  
Langmuir Adsorption ◽  
Adsorption Capacities ◽  
Alum Sludge ◽  
Best Fit

Alum sludge refers to the by-product from the processing of drinking water in water treatment works. In this study, groups of batch experiments were designed to identify the characteristics of dewatered alum sludge for phosphorus adsorption. Air-dried alum sludge (moisture content 10.2%), which was collected from a water treatment works in Dublin, was subjected to artificial P-rich wastewater adsorption tests using KH2PO4 as a model P source. Adsorption behaviours were investigated as a function of amount and particle size of alum sludge, pH of solution and adsorption time. The results have shown that pH plays a major role not only in the adsorption process but also in the adsorption capacity. With regard to adsorption capacity, this study reveals the Langmuir adsorption isotherm being the best fit with experimental data (R2=0.98–0.99). The maximum adsorption capacities range from 0.7 to 3.5 mg-P/g when the pH of the synthetic P solution was varied from 9.0 to 4.3, accordingly. The outcome of this study indicated that alum sludge is suitable for use as an adsorbent for removal of phosphate from wastewater.

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.

Cold-climate constructed wetlands

1995 ◽  
Vol 32 (3) ◽  
pp. 95-101 ◽  
Author(s):  
T. Mæhlum ◽  
P. D. Jenssen ◽  
W. S. Warner
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Domestic Wastewater ◽  
Cold Climate ◽  
Cold Climates ◽  
Phosphorus Adsorption ◽  
Design Considerations ◽  
Northern Latitudes

This paper outlines design considerations for constructed wetlands with horizontal subsurface flow treating domestic wastewater in cold climates of northern latitudes. Particular attention is devoted to the use of a filter medium with high phosphorus adsorption capacity. Experience from two Norwegian multistage systems consisting of an aerobic pretreatment step followed by constructed wetland units indicates purification processes are nearly the same during winter and summer seasons, with quite high removal of organic matter (COD, BOD), phosphorus and nitrogen.

Removal of VOCs Using Sludge-Based Adsorbents

2012 ◽  
Vol 599 ◽  
pp. 305-308 ◽  
Author(s):  
Ping Fang ◽  
Chao Ping Cen ◽  
Hong Tao Zhang ◽  
Zi Jun Tang ◽  
Ding Sheng Chen ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Physical Adsorption ◽  
Low Cost ◽  
Fixed Bed ◽  
Cost Effective ◽  
Langmuir Adsorption Isotherm ◽  
Fixed Bed Reactor ◽  
Dynamic Adsorption ◽  
Langmuir Adsorption ◽  
Isotherm Equations

Efficient and cost-effective sludge-based adsorbents were developed and the adsorption of VOCs on the sludge-based adsorbents was studied in a fixed bed reactor. The results indicate that the adsorption of VOCs on sludge-based adsorbents is typical physical adsorption, the dynamic adsorption capacity of VOCs on adsorbents sharply increases as the VOCs concentration is increased at first, then increasing gradually, at last retains stable with the change of VOCs concentration. The dynamic adsorption capacity of sludge-based adsorbents for VOCs is O-Xylene > Butylcetate > Toluene > Ethylacetate > Benzene > Propanone > n-Hexane, the maximum dynamic adsorption capacity is 0.247, 0.225, 0.192, 0.186, 0.180, 0.176, 0.133g/g, respectively. Meanwhile the adsorption of VOCs on sludge-based adsorbents corresponds to the Langmuir adsorption isotherm equations. The sludge-based adsorbent is a low-cost alternative to activated carbon for VOCs treatment, and this technology is a promising method for the VOCs removal.

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.

Influence of substrate depth and particle size on phosphorus removal in a surface flow constructed wetland

2017 ◽  
Vol 75 (10) ◽  
pp. 2291-2298 ◽  
Author(s):  
Cui Lijuan ◽  
Li Wei ◽  
Zhou Jian ◽  
Zhang Yan ◽  
Zhang Manyin ◽  
...  
Keyword(s):  
Particle Size ◽  
Constructed Wetlands ◽  
Total Phosphorus ◽  
Constructed Wetland ◽  
Organic Phosphorus ◽  
Subsurface Layer ◽  
Iron Phosphate ◽  
Inorganic Phosphorus ◽  
Surface Flow ◽  
Phosphorus Adsorption

Substrate adsorption is one of the main processes by which redundant phosphorus is removed from wastewater in surface flow constructed wetlands (SFCWs). The physical properties of the substrate, such as depth and particle size, will influence the amount of phosphorus adsorption. This study was carried out in a long-running intermittent inflow constructed wetland that covered a total area of 940.4 m2 in the Shunyi District of Beijing, China. We investigated how the concentrations of four phosphorus fractions, namely calcium phosphate (CaP), iron phosphate (FeP), adsorbed phosphorus (AdsP), and organic phosphorus (OP), varied between the surface (0–10 cm) and subsurface (10–20 cm) substrate and among the different substrate particle sizes. The total phosphorus concentrations in the substrate ranged from 154.97 to 194.69 mg/kg; CaP accounted for more than 80% of the total phosphorus content. The concentrations of OP were significantly higher in the surface layer than in the subsurface layer, but the concentrations of inorganic phosphorus were not significantly different between the two layers. The CaP, AdsP, and OP adsorption capacities were greater for small-sized substrate particles than for large-sized substrate particles. The results from this study provide a theoretical basis for the construction of constructed wetlands.

Behavior of Phosphorus Adsorption from Aqueous Solutions on Modified Activated Alumina

2010 ◽  
Vol 152-153 ◽  
pp. 945-949
Author(s):  
Chun Sheng Ding ◽  
Ying Long Zou ◽  
Fang Ming Ni ◽  
Qian Fen Zhu
Keyword(s):  
Phosphorus Removal ◽  
Adsorption Process ◽  
Langmuir Adsorption Isotherm ◽  
Phosphorus Concentration ◽  
Activated Alumina ◽  
Phosphorus Adsorption ◽  
Langmuir Adsorption ◽  
Ph Values ◽  
Monolayer Adsorption ◽  
Adsorption Data

In the study, activated alumina was modified by calcium chloride, and after modification the phosphorus removal from aqueous solution increased by 13% or so. Then the activated alumina with and without treatment were subjected to characterization by the methods of the BET and SEM, and the adsorption characteristics of modified activated alumina were further studied at different contact time, pH values, adsorbent dosage levels and initial phosphorus concentration. Moreover, the equilibrium adsorption data for phosphorus were better fitted to Langmuir adsorption isotherm, and it means that the uptake of phosphorus preferably followed the monolayer adsorption process.

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.

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