Permeable reactive barriers containing zerovalent iron are being increasingly employed for in situ remediation of groundwater contaminated with redox active metals and chlorinated organic compounds. This research investigated the effect of chromate concentration on its removal from solution by zerovalent iron. Removal rates of aqueous Cr(VI) by iron wires were measured in batch experiments for ...

Recently developed man-made structures have caused environmental pollutions, and unfortunately, in spite of the deteriorating affairs and repeated warnings by scientists and experts, the degree of contamination is increasing considerably. One of the natural sources undergoing changes is the coasts. It is mainly due to human activities which have led to a change in the quality and quantity of se...

The objectives of this study are to evaluate the efficiency of removal of hexavalent chromium (Cr(VI)) in a sequencing batch reactor (SBR) and to ascertain the fate of Cr(VI) in the treatment process. An SBR was operated with the FILL, REACT, SETTLE, DRAW and IDLE periods in the time ratio of 2:12:2:1.5:6.5 for a cycle time of 24 h. The study was divided into 5 phases with the addition of 0.5, ...

Daily industrial activities especially in developing countries produce and discharge wastes containing heavy metals into the water resources making them polluted, threatening human health ecosystem. One such metal is Chromium, hexavalent form of which extremely toxic carcinogenic. Biosorption, process passive cation binding by dead or living biomass, represents a potentially cost-effective way ...

Hexavalent chromium, a highly toxic metal ion employed in industrial activities, is considered as a first priority pollutant. In this study, the capsule walls of the boll of cotton (cotton waste, CW) and the waste obtained from pruning barberry bushes (barberry waste, BW) were investigated as cheap and locally available adsorbents for Cr (VI) removal. The adsorption behavior, equilibrium, and k...

Adsorbent properties and aqueous characteristics are very important parameters in the removal efficiency (RE) of environmental pollutants. The main goal of this study was to investigate the effects of pH, particle size and porosity of raw rice husk and its silica on removing lead and hexavalent chromium (Cr+6) from aqueous solution. The raw rice husk was collected from north of Iran and the ric...

aims: heavy metals are the main pollutants in nature. chromium is a heavy metal which is widely used. hexavalent chromium solubility and mobility in aqueous solutions is so high and it is easily reduced. biosorption is a process in which heavy metals are uptake through passive binding by nonliving biomass from aqueous solutions. the present study aimed to determine the capability of powdered sp...

STATEMENT OF PROBLEM Dental alloys have different mechanical properties compared with enamel. However, few studies have been conducted to determine the effects of the retention forces of clasps when applied on different cast crowns. PURPOSE The purpose of this study was to evaluate the retention forces of cast circumferential clasps made of cobalt-chromium alloy on complete cast crowns made o...