Removal of copper ions from an aqueous solution containing a chelating agent by electrosorption on mesoporous carbon electrodes

Recent Development on Determination of Low-Level 90Sr in Environmental and Biological Samples: A Review

In the context of the rapid development of the world's nuclear power industry, it is vital to establish reliable and efficient radioanalytical methods to support sound environment and food radioactivity monitoring programs and a cost-effective waste management strategy. As one of the most import fission products generated during human nuclear activities, ⁹⁰Sr has been widely determined based on different analytical techniques for routine radioactivity monitoring, emergency preparedness and radioactive waste management. Herein, we summarize and critically review analytical methods developed over the last few decades for the determination of ⁹⁰Sr in environmental and biological samples. Approaches applied in different steps of the analysis including sample preparation, chemical separation and detection are systematically discussed. The recent development of modern materials for ⁹⁰Sr concentration and advanced instruments for rapid ⁹⁰Sr measurement are also addressed.

Simultaneous separation and determination of seven chelating agents using high-performance liquid chromatography based on statistics design

We describe an optimization approach to determine simultaneously occurring chelating agents (glycine, malonic acid, citric acid, glycolic acid, lactic acid, DL-malic acid, and ethylenediaminetetraacetic acid) in an electroplating effluent using high-performance liquid chromatography. With chromatography signal area and overall resolution considered as responses, detection conditions were optimized via multiple functions combined with response surface methodology and Plackett-Burman design. Optimized detection conditions were as follows: 15 mmol/L ammonium phosphate buffer (pH 2.5), a 94:6 v/v ratio of ammonium phosphate buffer/acetonitrile, a column temperature of 23.3°C, and a mobile phase flow rate of 1 mL/min. The experimental values conformed to the predicted values and were repeatable (relative standard deviation < 6.4%) and linear (r²  > 0.991) over concentration ranges of 1-100 µmol/L. Moreover, the quantification limit (signal-to-noise ratio = 10) and the detection limit (signal-to-noise ratio = 3) ranged from 0.03 to 0.15 µmol/L and from 0.01 to 0.04 µmol/L, respectively. These results indicate that high-performance liquid chromatography coupled with statistical design may be a simple and rapid method for simultaneously determining multiple chelating agents in electroplating wastewater effectively.

Hazardous waste treatment technologies

This is a review of the literature published in 2018 on topics related to hazardous waste management in water, soils, sediments, and air. The review covers treatment technologies applying physical, chemical, and biological principles for contaminated water, soils, sediments, and air. PRACTITIONER POINTS: The management of waters, wastewaters, and soils contaminated by various hazardous chemicals including inorganic (e.g., oxyanions, salts, and heavy metals), organic (e.g., halogenated, pharmaceuticals and personal care products, pesticides, and persistent organic chemicals) was reviewed according to the technology applied, namely, physical, chemical and biological methods. Physical methods for the management of hazardous wastes including adsorption, coagulation (conventional and electrochemical), sand filtration, electrosorption (or CDI), electrodialysis, electrokinetics, membrane (RO, NF, MF), photocatalysis, photoelectrochemical oxidation, sonochemical, non-thermal plasma, supercritical fluid, electrochemical oxidation, and electrochemical reduction processes were reviewed. Chemical methods including ozone-based, hydrogen peroxide-based, persulfate-based, Fenton and Fenton-like, and potassium permanganate processes for the management of hazardous were reviewed. Biological methods such as aerobic, anaerobic, bioreactor, constructed wetlands, soil bioremediation and biofilter processes for the management of hazardous wastes, in mode of consortium and pure culture were reviewed.

Lead and copper removal from groundwater by spherical agglomeration using a biosurfactant extracted from Yucca decipiens Trel

The spherical agglomeration technique (SAT) has emerged as an innovative alternative for the removal of heavy metals from water at optimum levels of surfactant addition. This technique has achieved high removal efficiencies. In the present study, Yucca decipiens extracts were applied as the biosurfactant for the removal of heavy metals from groundwater of a mining community using SAT. Aqueous models were generated to explain the removal of copper and lead in solutions. It was possible to remove 99.96% and 99.62% respectively. The highest concentrations of copper and lead 209.5 and 2 mg L^-1, respectively, were observed at a waterhole in the mining community. This sample was used to test the efficiency of SAT, using optimal conditions of the models. It was possible to remove 99.22% of copper and 91.50% of lead present in the groundwater. High concentrations of sodium and calcium were found. To reduce the residual sodium concentration, the pH was decreased from 11 to 9.5. 99.84% of copper and only 93.49% of lead were removed; the remaining concentrations did not exceed the limit of Mexican regulations (NOM-001-SEMARNAT-1996, 1996). It was demonstrated that the Yucca extracts are effective or the treatment of water with high concentrations of heavy metals under the conditions of SAT.