Extractive Decontamination of Copper-Polluted Soils Using TCAS

2011 ◽  
Vol 183-185 ◽  
pp. 462-465
Author(s):  
Da Zhao ◽  
Tie Heng Sun ◽  
Xiao Jun Hu ◽  
Xiao Min Hu

Thiacalix[4]arenetetrasulfonate (TCAS) was investigated as an extractant for decontaminating copper-polluted soils with elevated total copper (2000mg/kg) from the national field research station of Shenyang agroecosystems. Batch experiments were performed to test the factors influencing remediation of copper-polluted soil. The effects of solid-liquid ratio, the ionic strength and temperature on the removal capacities of copper by TCAS reagent had been studied. The results showed that the TCAS reagent was effective for removal of copper from the contaminated soil, the optimum solid-liquid ratio was 1:10 for soil treatment. Adding Ca(NO3)2was of no advantage for copper removal, and the effect of Ca(NO3)2on the removl rate was less when its molarity was less than 0.1mol/L. The optimum temperature of TCAS for soil treatment was 5°C-25°C.

2011 ◽  
Vol 343-344 ◽  
pp. 374-377
Author(s):  
Da Zhao ◽  
Tie Heng Sun ◽  
Xiao Jun Hu ◽  
Xiao Min Hu

The performance of thiacalix[4]arenetetrasulfonate (TCAS) for the treatment of soils contaminated with lead was evaluated in this study. Batch experiments were performed to test the factors influencing remediation of lead-polluted soil. The effects of temperature, solid-liquid ratio and the ionic strength on the removal capacities of lead by TCAS reagent had been studied. The results showed that the TCAS reagent was effective for removal of lead from the contaminated soil, the optimum temperature of TCAS for soil treatment was 5°C-25°C. The optimum solid-liquid ratio was 1:10 for soil treatment. Adding Ca(NO3)2 was of no advantage for lead removal, and the effect of Ca(NO3)2 on the removl rate was less when its molarity was less than 0.01mol/L. This experimental work has also demonstrated the great importance of soil matrix for the evaluation of the TCAS leaching as a cost effective remedial option.


2014 ◽  
Vol 1065-1069 ◽  
pp. 3091-3095
Author(s):  
Da Zhao ◽  
Yue Zhao ◽  
Shi Bo Tao

The washing process in batch experiments was conducted to investigate the performance of fermentation solution on removal copper(Cu) from vineyard soil. The effects of solid-liquid ratio, pH value and contact time on the removal capacities of Cu by fermentation solution had been studied. The results showed that the optimum solid-liquid ratio was 1:10 for soil treatment. The fermentation solution showed a better removal efficiency of Cu in alkaline conditions, getting the highest removal efficiency of 34.3%. In addition, with the increase of contact time, higher removal efficiency was obtained.


2019 ◽  
Vol 4 (5) ◽  
pp. 80-87
Author(s):  
Mazen Ahmed Muherei

In this paper, batch experiments of shale/sandstone aqueous systems were conducted to evaluate desorption of spiked oil from shale and sandstone using surfactant solutions. The desorption experimental study was designed to determine if selected surfactants in aqueous solutions with varying pH, initial oil on shale/sandstone, surfactant concentrations, surfactant type, solid/liquid ratio, with and without sonication and at different contact time could enhance the desorption of spiked oil (Sarapar147) from pre-spiked shale and sandstone. The experiments tested the influence of the selected variables in batch experiments. The early screening results obtained for sandstone and shale show that sandstone are very much easier to clean than shales. Furthermore, the desorption efficiencies was lower for water compared to surfactant solutions particularly for sandstones.  Nevertheless, ultrasound was able to improve the desorption efficiencies for sandstone washings but not for shale washings. In the other hand, the results of the full factorial experiments showed that the variations of solution pH, mechanical interruption by ultrasound, and prolonged desorption times did not significantly improve the desorption process. These results give strong evidence to the existence of a considerable and irreversibly bound fraction of oil to shale.


Author(s):  
Emine Elmaslar ÖZBAŞ ◽  
Nilgün BALKAYA

This study aimed to remove heavy metals (Cu, Ni, Zn, Pb, Cd) from composts using molasses hydrolysate, produced from molasses by-product of the sugar industry. Batch experiments were conducted to examine the effects of differing experimental conditions on the removal of heavy metals, according to contact time and solid–liquid ratio. Batch experiments achieved removal efficiencies of 66% for Cu(II), 52% for Ni(II), 57% for Zn(II), 51% for Pb (II), and 77% for Cd(II) at 60 minutes and 1:12.5 solid–liquid ratio. Column experiments achieved removal efficiencies of 91% for Cu, 86% for Ni, 99% for Zn, 61% for Pb, and 99% for Cd at 0.55 mL/minute flow rate and a solid–liquid ratio of 1:12.5 g/mL. Producing large quantities of highly acidic and heavy metal contaminated solution, compost with low pH, and decreasing some parameters’ concentrations of compost such as C, TKN, total P are the disadvantages of suggested technology.


2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Eugenia Pantru ◽  
Gheorghit Jinescu ◽  
Rozalia R�dulescu ◽  
Antoneta Filcenco Olteanu ◽  
Cosmin Jinescu

This paper presents an intensive procedure used for the decontamination of the soils, which were radioactively contaminated by uranium, due to the occurrence of some antropic accidents, in order to limit the area�s pollution. The procedure used for the chemical decontamination of the polluted soils was the washing one and the decontamination degree is comparatively presented depending on the ultrasounds� presence and absence. The lab testes were performed on five types of soils , which were characterized from the granulometric, structural and chemical composition viewpoint, all these aspects represent the main factors, which determine the applied decontamination procedure�s limits and performances correlated with its utilization costs. The decontamination procedure�s kinetics for each type of soils was analyzed, using successively three different types of reagents (water, 0.1 M sulphuric acid solution and chloro-sodic solution � 100 g/L sodium chloride + 10 g/L sodium carbonate in water) for a solid to liquid ratio of 1:2, during 2 h, at a temperature of 20oC in a mechanic stirring system respectively in ultrasounds field. It was observed that the decontamination degree increases with up to 15-20% in case of the ultrasound field utilization comparing to the first case.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.


2020 ◽  
Vol 10 (23) ◽  
pp. 8440
Author(s):  
Lavinia Lupa ◽  
Laura Cocheci ◽  
Bogdan Trica ◽  
Adina Coroaba ◽  
Adriana Popa

A closed-cycle technology regarding the use of an exhausted Pd-based adsorbent as a photocatalyst in the degradation process of phenol is presented. Pd (II) represents a precious metal of great economic importance. Its obtained from natural sources become more difficult to achieve. Therefore, also considering the regulations of the “circular economy,” its recovery from secondary sources turn out to be a stringent issue in the last years. Pd(II) ions are removed from aqueous solution through adsorption onto Florisil (an inorganic solid support—magnesium silicate) impregnated with Cyphos IL 101 (trihexyl tetradecyl phosphonium chloride). It was observed that the presence of the ionic liquid (IL) in the adsorbent structure doubles the adsorption efficiency of the studied materials. The newly obtained Pd-based photocatalyst was exhaustively characterized and was used in the degradation process of phenol from aqueous solutions. The phenol degradation process was studied in terms of the nature of the photocatalyst used, time of photodegradation and solid: liquid ratio. It was observed that both the presence of IL and Pd lead to an increase in the efficiency of the phenol degradation process. The new Pd-based photocatalyst could be efficiently used in more cycles of phenol photodegradation processes. When is used as a photocatalyst the Florisil impregnated with IL and loaded with 2 mg/g of Pd, a degree of mineralization of 93.75% is obtained after 180 min of irradiation of a phenol solution having a concentration of 20 mg/L and using a solid:liquid ratio = 1:1.


2013 ◽  
Vol 805-806 ◽  
pp. 281-285
Author(s):  
Zhong Xu

Bioconversion of potato pulp to fuel ethanol, analysing the potato pulp chemical composition and determining the potato pulp in the role of microorganism produce ethanol under the best conditions is the major research. An analysis of the chemical composition of potato pulp showed that : the basic ingredients are Protein (9.72%), Starch (25.52%), Cellulose (17.90%). The effects of ethanol production rate of solid-liquid ratio, fermentation temperature, inoculumconcertration, fermentation time. The results showed that: the best conditions producting ethanol from potato pulp obtained by single factor experiments are: solid-liquid ratio: 1:15, fermentation temperature: 35°C, inoculumconcertration: 3mL, fermentation time: 20h. Under this occasion, the ethanol production rate was 0.183mL·g-1.


Sign in / Sign up

Export Citation Format

Share Document