Heavy Metal Removal and Leaching from Pervious Concrete Filter: Influence of Operating Water Head and Reduced Graphene Oxide Addition
01 Sep 2019-Journal of the Environmental Engineering Division (American Society of Civil Engineers (ASCE))-Vol. 145, Iss: 9, pp 04019049
TL;DR: In this paper, the effects of an operating water head (OWH) and reduced graphene oxide (RGO) addition on the pervious concrete filter (PCF) and heavy metals interaction were investigated.
Abstract: The effects of an operating water head (OWH) and reduced graphene oxide (RGO) addition on the pervious concrete filter (PCF) and heavy metals interaction were investigated in the present st...
Citations
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TL;DR: In this paper , the effects of initial concentration, contact time and competing ions on heavy metal removal using porous concrete are discussed and the effect of decalcification, atmospheric carbonation, acid influent and acid-influent on heavy metals removal is reviewed.
15 citations
TL;DR: In this paper , new enhanced infiltration materials (construction waste brick, coal gangue, activated carbon, multilayer carbon nanotube, multi-layer graphene) were applied in PPS and the control efficiency and mechanism of typical heavy metals (HMs, Mn2+, Pb2+, Zn2+, Cu2+, Cd2+, Ni2+) was investigated in runoff.
1 citations
TL;DR: In this paper , the properties of metakaolin (MK) based cement paste coating and the effects of the metakolin on removing methylene blue in water were investigated, and the results showed that the fluidity of the cement paste decreased and the cohesiveness increased with increase of the content of MK.
1 citations
TL;DR: In this paper , the impact of aggregate gradation band width and cement to aggregate ratio on the performance of conventional PC and recycled aggregate based pervious concrete (RPC) was analyzed.
Abstract: The present research particularly focuses to understand the synergistic effect of aggregate gradation band width and cement to aggregate ratio on the performance of conventional PC (CPC) and recycled aggregate based pervious concrete (RPC). Four various aggregate gradation bands, such as GB (22.5–4.75 mm), GB (22.5–10.0 mm), GB (22.5–12.5 mm) and GB (22.5–16.0 mm), and two different cement to aggregate ratios, such as 0.33 and 0.20, were used in this study. The research outcome inferences that the aggregate gradation band width and cement aggregate ratios have a great effect on the compressive strength, density, permeability and macroscopic pore characteristics of conventional PC and RPC. When using low cement to aggregate ratio of 0.20 along with these gradation bands, the compressive strength of CPC and RPC was found in the range of 6.34–12.89 MPa and 5.49–12.97 MPa, at the same while, the permeability of CPC and RPC was found in the range of 0.35–1.27 cm/s and 0.60–1.29 cm/s respectively and these values were also satisfied with in the limits as prescribed by ACI-522R-10. This paper elucidates the consensus behaviour of CPC and RPC from the material perspective that would enhance the utilization of CPC and RPC in the construction sector.
TL;DR: In this paper , the heavy metal removal in permeable concrete samples based on geopolymer and Portland cement was examined in a study, and their performance when exposed to strong acids and turbid water were also investigated.
Abstract: The permeable pavement efficiently manages stormwater, which is acidic and contains fine sediments and heavy metals exhausted by vehicles driving on this material. The heavy metal removal in permeable concrete samples based on geopolymer and Portland cement was examined in this study. Their performance when exposed to strong acids and turbid water were also investigated. They were able to infiltrate 28 litres of water in 60 min and gained a compressive strength greater than 25 MPa in 2 weeks after casting. However, it was found that its porous structure was clogged with fine sediments when water containing bentonite clay passed through them for multiple cycles. To evaluate their metal removal capacity, a concentration of 10 mg/l of cadmium-containing solution was passed through such samples for a continuous period of 8 hours. They were able to trap nearly 95% of the cadmium ions from the simulated wastewater during the column experiment. Their adsorption behaviour fits well with the pseudo-second-order kinetic and Langmuir isotherm models, implying that the main removal mechanism is chemisorption. To examine their acid resistance capacities, cement- and geopolymer-based mortar samples were exposed to acids for 2 weeks. The acid-exposed samples were severely degraded, as the mass loss in the geopolymer was determined to be 64% lower than that of the cement sample. Geopolymer-based permeable pavements are ecological, harden in moist air, gain higher strength at early ages, are acid resistant, and also remediate groundwater contamination.
References
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TL;DR: The microstructure and phase composition of C-S-H indicate that they can play an essential role in the immobilization of heavy metals and the degree of Cd, Zn, Pb and Cr cations immobilization was very high.
43 citations
TL;DR: It is concluded that in the mixed paste during the early curing stage GGBS reduced a significant fraction of Cr(VI) to Cr( III) and that the Cr(III) adsorbed in the GGBS-PC mixture’s hydration products does not readily dissolve, even under carbonation conditions.
Abstract: Using ground granulated blast-furnace slag (GGBS) under different alkaline conditions, we studied the mechanisms and extents of Cr(VI) reduction and sorption and compared them to reactions with Portland cement (PC). We also investigated the effects of mixing PC/GGBS ratios on Cr(VI) dissolution after carbonating the substrates. We observed a complete sorption and reduction of Cr(VI) to Cr(III) in a GGBS-in-Ca(OH)₂ solution (pH > ~12.5) after 10 h, whereas in distilled water (pH = ~11.5) GGBS exhibited only marginal sorption and reduction (20%). Cr reactions with dissolved ions in supernatants derived from GGBS indicated that the anions dissolved from GGBS act as a reducing agent for Cr(VI) in a Ca(OH)₂ solution. Soft X-ray absorption microscopy identified a partial reduction of Cr(VI) to Cr(III) on the GGBS surface. The carbonation of pure PC paste substantially increased the amount of dissolved Cr(VI) in a solution phase whereas a 5 wt % replacement of PC with GGBS significantly reduced the amount of dissolved Cr(VI). We concluded that in the mixed paste during the early curing stage GGBS reduced a significant fraction of Cr(VI) to Cr(III) and that the Cr(III) adsorbed in the GGBS-PC mixture's hydration products does not readily dissolve, even under carbonation conditions.
39 citations
TL;DR: A review of the relevant efforts undertaken to utilize graphene in biology, sensing and water purification is described in this article, although certain specific important important examples of the past are also mentioned.
Abstract: The latest addition to the nanocarbon family, graphene, has been proclaimed to be the material of the century. Its peculiar band structure, extraordinary thermal and electronic conductance and room temperature quantum Hall effect have all been used for various applications in diverse fields ranging from catalysis to electronics. The difficulty to synthesize graphene in bulk quantities was a limiting factor of it being utilized in several fields. Advent of chemical processes and self-assembly approaches for the synthesis of graphene analogues have opened-up new avenues for graphene based materials. The high surface area and rich abundance of functional groups present make chemically synthesized graphene (generally known as graphene oxide (GO) and reduced graphene oxide (RGO) or chemically converted graphene) an attracting candidate in biotechnology and environmental remediation. By functionalizing graphene with specific molecules, the properties of graphene can be tuned to suite applications such as sensing, drug delivery or cellular imaging. Graphene with its high surface area can act as a good adsorbent for pollutant removal. Graphene either alone or in combination with other materials can be used for the degradation or removal of a large variety of contaminants through several methods. In this review some of the relevant efforts undertaken to utilize graphene in biology, sensing and water purification are described. Most recent efforts have been given precedence over older works, although certain specific important examples of the past are also mentioned.
38 citations
TL;DR: In this paper, a new plate microfiltration membrane was fabricated using low-cost cement and quartz to catalyze dissolved ozone, which increased the degradation efficiency of p -chloronitrobenzene (p -CNB) compared with the ozone-alone process in aqueous conditions under continuous flow.
32 citations
TL;DR: In this paper, the authors used 29 Si MAS NMR, X-ray diffraction, mercury intrusion porosimetry and EDX-microanalysis to evaluate the effect of the nanoparticles in the cement matrix nanostructure and in their impact on the evolution of the Ca leaching throughout time.
Abstract: The calcium leaching of the cement hydrated matrix is of vital importance for constructions like water containers, dams, bridges, etc which have to be in contact with water during their lifetime. The aim of this work is the study of the reduction of such a negative phenomenon by the addition of silica nanoparticles. Several characterisation techniques such as 29 Si MAS NMR, X-ray diffraction, mercury intrusion porosimetry and EDX-microanalysis have been used to evaluate the effect of the nanoparticles in the cement matrix nanostructure and in their impact on the evolution of the Ca leaching throughout time. Subsequent analysis of the results indicates that silica nanoparticles can reduce the Ca-leaching both decreasing the amount of portlandite in the matrix and controlling the degradation rate of the C-S-H gel.
30 citations