In ex-situ washing, HCl, EDTA and H2O2 solutions can effectively extract heavy metals in river sediment. Nevertheless they often target different sediment components, possibly transforming metal species into more bioavailable and hence toxic ones. This study, in batch settings, investigated the influences of different types of washing agents (i.e. HCl, EDTA and H2O2) on metal (i.e. Cu and Zn) r...

Remediation of heavy-metal-contaminated sediment is often hampered by the availability of heavy metals to the added chemical agents because the heavy metals are often shielded by the sediment matrix. Effective heavy-metal extraction technique becomes an important factor in enhancing the treatment efficiency. A novel extraction/washing technique utilizing chelating agent and elevated pressure in...

The extraction efficiency of heavy metals from soils using three forms of gamma poly-glutamic acid (γ-PGA) as the washing agents was investigated. Controlling factors including agent concentrations, extraction time, pH, and liquid to soil ratio were evaluated to determine the optimum operational conditions. The distribution of heavy metal species in soils before and after extraction processes w...

Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, ...

Remediation of heavy metal polluted sediment by extracting the metals with sulfuric acid can be performed as follows: abiotic suspension leaching, microbial suspension leaching, abiotic solid-bed leaching, and microbial solid-bed leaching. Abiotic leaching means that the acid is directly added, while microbial leaching means that the acid is generated from sulfur by microbes (bioleaching). Thes...

a large volume of tailings has been produced in anjir-tangeh coal washing plant for 22 years of human activity. the coal washing activities have reduced plant diversity near the plant. the environmental impact of coal washing plant on the vegetation around the factory was studied in two seasons. the concentrations of pb, cd and cr, measured in different native plant species, were in normal rang...

A straightforward method is presented to produce catalyst particle-filled carbon nanotubes. Based on capillarity and surface tension, a simple strategy was developed to selectively fill carbon nanotubes with Fe, Co, and Ni species using a two-step method consisting of impregnation and selective washing. By chosing the impregnation and washing solution properly, metal particles are produced excl...

BACKGROUND, AIMS, AND SCOPE Heavy metal contaminants in environment, especially in drinking water, are always of great concern due to their health impact. Due to the use of heavy metals as catalysts during plastic syntheses, particularly antimony, human exposure to metal release from plastic bottles has been a serious concern in recent years. The aim and scope of this study were to assess metal...

In the context of peri-urban atmospheric pollution by industrial lead recycling emissions, metal can transfer to plant shoots. Home gardeners consuming their produce can therefore be exposed to metal pollution. The Human Health Risk Assessment Protocol (HHRAP) model from the United States Environmental Protection Agency (US EPA) classically used in risk assessment provides foliar metal uptake p...

Most methods for the colorimetric estimation of sodium depend upon the precipitation of the metal as sodium zinc uranyl acetate, a reaction first proposed by Barber and Kolthoff (1928). The precipitated salt, after washing, is treated in various ways to give coloured solutions. There are thus three distinct stages which have to be considered in the estimation: (1) precipitation, (2) washing of ...