Nanoflowers on Microporous Graphene Electrodes as a Highly Sensitive and Low-Cost As(III) Electrochemical Sensor for Water Quality Monitoring.

In this work, we report a low-cost and highly sensitive electrochemical sensor for detecting As(III) in water. The sensor uses a 3D microporous graphene electrode with nanoflowers, which enriches the reactive surface area and thus enhances its sensitivity. The detection range achieved was 1-50 ppb, meeting the US-EPA cutoff criteria of 10 ppb.

Remediation of arsenic-contaminated water by green zero-valent iron nanoparticles.

The optimal conditions for the green synthesis of nano zero-valent iron (G-NZVI) using mango peel extract were investigated using a Box-Behnken design approach. Three factors were considered, namely the ratio of iron solution to mango peel extract ratio (1:1-1:3), feeding rate of mango peel extract (1-5 mL min), and agitation speed (300-350 rpm). The results showed that the optimal conditions for the synthesis of G-NZVI for arsenate removal were a 1:1 ratio of iron solution to mango peel extract, a mango peel extract feeding rate of 5 mL min, and an agitation speed of 300 rpm.

Background species effect on aqueous arsenic removal by nano zero-valent iron using fractional factorial design.

This study describes the removal of arsenic species in groundwater by nano zero-valent iron process, including As(III) and As(V). Since the background species may inhibit or promote arsenic removal. The influence of several common ions such as phosphate (PO4(3-)), bicarbonate (HCO3-)), sulfate (SO4(2-)), calcium (Ca2+), chloride (Cl-), and humic acid (HA) were selected to evaluate their effects on arsenic removal.

Gas-bubbled nano zero-valent iron process for high concentration arsenate removal.

In this study, batch experiments were performed to investigate a novel process for high concentration arsenate removal in the presence of air and/or CO(2) bubbling. The pretreatment step, CO(2) bubbling at 300 mL/min for 5 min, was taken to adjust the solution pH to an acidic environment, followed by air bubbling at 300 mL/min for 10 min to increase dissolved oxygen in the solution. In the treatment period, the nano-scale zero-valent iron was applied to remove aqueous arsenate of 3000 μg/L, while the treatment system was continuously bubbled by 300 mL/min of air.

Impact of selected solution factors on arsenate and arsenite removal by nanoiron particles.

Introduction: The nano-scale zero-valent iron (NZVI) was used for the removal of arsenite (As(III)) and arsenate (As(V)) in aqueous solution. Batch experiments were conducted to investigate the effects of initial pH, initial arsenic concentration, dissolved oxygen (DO), and ratio of As(III)/As(V) on arsenic removal.

Materials And Methods: The NZVI synthesized by using NaBH4 and FeCl3 was put into use right after its synthesis.