ELECTROCHEMICAL PURIFICATION OF WATER CONTAMINATED WITH COPPER AND NICKEL IONS

Comparative adsorption of heavy metal ions in wastewater on monolayer molybdenum disulfide

Engineered Bacillus subtilis Biofilm@Biochar living materials for in-situ sensing and bioremediation of heavy metal ions pollution

The removal of the metal ions in the ceramic printing wastewater was influenced by using, stirring and precipitating of the solution pH, coagulant PAC, coagulant aid PAM and heavy metal scavenger. This experiment investigated the removal effect of the metal ions in the wastewater under different conditions. Flame atomic absorption spectrometry was adopted for the determination of the concentration of metal ions in the wastewater. The studies have shown that alkalization, PAC coagulation treatment have a role in the removal of metal ions in the ceramic printing wastewater. And the chromium and iron removal rate can reached 74.0% and 61.6% respectively. Heavy metal scavenger also have a better role in the removal of metal ions. And the chromium and iron removal rates were 82.3% and 76.2% respectively without dosing PAC. The number of reaction cell has no significant effect on the removal of metal ions.

In this work, we have developed an optical fluorometric sensor for detection of lead (II) ion (Pb2+) and copper (II) ion (Cu2+) in wastewater using fluorescent amine‐modified graphene quantum dots (a‐GQDs). A simple preparation process, i.e., hydrothermal method is used for the preparation of a‐GQDs. The prepared a‐GQDs emits green luminescence and have an average particle size around 1.26 ± 0.16 nm with uniform distribution. The a‐GQDs utilized for detection of various biologically essential metal ions like Pb2+ and Cu2+ ions in aqueous solution using fluorescence‐based spectroscopic technique. Here, UV–visible absorption spectra of a‐GQDs with and without Pb2+ and Cu2+ ions, shows no variation in the absorbance of a‐GQDs. Further, lifetime analysis of a‐GQDs shows that lifetime of a‐GQDs changed from 2.02 ns to 1.37 ns in presence of Pb2+ and 2.02 ns to 1.62 ns in presence of Cu2+ ions, confirms the dynamic quenching mechanism. The a‐GQDs have detected Pb2+ and Cu2+ ions in the linearity range of 2–200 µM and 2–300 µM with limit of detection (LOD) of 1.60 µM and 1.66 µM, respectively. Therefore, this work demonstrates the sustainability of a‐GQDs as a favorable fluorescence (FL) probe that may be used to detect heavy metal ions in wastewater and aqueous solution.

Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrystalline ribbons (Fe-MNRs) were prepared by a simple way (through immersing the Fe-MNRs in Orange II solution). It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures (Fe-MNRs + FNs) exhibit good absorption property for a typical heavy metal ion (CrVI) in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs + FNs could remove 99% CrVI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between CrVI and surface hydroxyl groups (O–H) of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs + FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.

Effective adsorption and sensitive detection of Cr6+ by degradable collagen-based porous fluorescent aerogel

Dielectrophoresis-assisted removal of Cd and Cu heavy metal ions by using Chlorella microalgae

Boosting adsorption of heavy metal ions in wastewater through solar-driven interfacial evaporation of chemically-treated carbonized wood

Highly efficient photocatalyst fabricated from the recycling of heavy metal ions in wastewater for dye degradation

The effects of copper, chromium, and zinc ions, at trace levels, on the performance of a simulated activated sludge process were investigated. The results of batch adsorption experiments showed that the adsorption of copper, chromium, and zinc ions followed both the Langmuir and Freundlich isotherms. The presence of trace levels of these three metals not only reduced the adsorption rate of organic matters but also the chemical oxygen demand adsorption capacity (CAC) of the activated sludge. Metal ions competed with the organic substrate for adsorption binding sites on the surfaces of activated sludge bioflocs and reduced the CAC. Studies performed in a sequential batch reactor (SBR) showed that the presence of trace levels of heavy metal ions in wastewater affected the SBR performance to different extents depending on the hydraulic retention time (HRT). When the reactors were operated at short HRTs of 2.5 d or less, the presence of trace levels of heavy metal ions reduced substantially the CAC of activated sludge, which, in turn, affected significantly the performance of the SBR. However, under longer HRTs (e.g., 5 d), the heavy metal ions in the wastewater reduced the CAC but had no significant effect on the chemical oxygen demand removal efficiency.

The effects of copper, chromium, and zinc ions, at trace levels, on the performance of a simulated activated sludge process were investigated. The results of batch adsorption experiments showed that the adsorption of copper, chromium, and zinc ions followed both the Langmuir and Freundlich isotherms. The presence of trace levels of these three metals not only reduced the adsorption rate of organic matters but also the chemical oxygen demand adsorption capacity (CAC) of the activated sludge. Metal ions competed with the organic substrate for adsorption binding sites on the surfaces of activated sludge bioflocs and reduced the CAC. Studies performed in a sequential batch reactor (SBR) showed that the presence of trace levels of heavy metal ions in wastewater affected the SBR performance to different extents depending on the hydraulic retention time (HRT). When the reactors were operated at short HRTs of 2.5 d or less, the presence of trace levels of heavy metal ions reduced substantially the CAC of activated sludge, which, in turn, affected significantly the performance of the SBR. However, under longer HRTs (e.g., 5 d), the heavy metal ions in the wastewater reduced the CAC but had no significant effect on the chemical oxygen demand removal efficiency.Index EntriesHeavy metalschemical oxygen demand removalactivated sludgeadsorption capacitysequencing batch reactor

Making waves: Microbe-photocatalyst hybrids may provide new opportunities for treating heavy metal polluted wastewater

15 - Metal oxide for heavy metal detection and removal

Preparation of modified sodium alginate aerogel and its application in removing lead and cadmium ions in wastewater

Water contamination has become a worldwide severe environmental problem owing to the existence of heavy metal ions. Extension of industrializations is releasing heavy metals ions containing effluents into water bodies and causes damage to the aquatic environment. Treatment of industrial wastewaters using ion-exchange adsorbents has achieved attractiveness in comparison to other treatment methods. The present chapter deals with the preparation and characterization of Polyaniline (PANI)-Titanium-supported nanocomposites ion-exchanger materials. It generally focuses on the ion exchange behavior of nanocomposites for the detection of heavy metal ions in wastewater, industrial effluents, and synthetic mixtures. These nanomaterials have been characterized using advanced techniques of characterizations. Physico-chemical properties; ion uptake efficiency, pH titration, the effect of temperature as well as concentration and kinetic studies have been examined to establish the significant performance of these materials to achieve maximum adsorption towards heavy metal ions. These nanomaterials demonstrated significant ion uptake efficiency, high thermal and chemical stability as compared to pure organic or inorganic ion-exchanger adsorbents. Based on high ion-exchange capacity, the nanomaterials can be successfully used in the wastewater treatment. In spite of the detection of metal pollutants in contaminated waters, these nanocomposites ion-exchange adsorbents can also be effectively utilized in other fields (e.g., Photochemical degradation of organic contaminants, antimicrobial agents, and conducting material). On the basis of excellent performance of titanium-supported nanocomposite in terms of metal removal efficiency, it is anticipated that these nanomaterials could be open, innovative ways to show their excellent uses in diverse fields.