this research was conducted in continuous flow bench scale fixed activated sludge (fas) and anaerobic filter (af). the main objective of the research was to study the feasibility and efficiency of the mentioned systems for cr (vi) removal. in fas reactor, cr (vi) was adsorbed from influent to mlss in the range of 89 to 99 percent and the adsorption followed freundlich isotherm. in af reactor, c...

background: there are great resources of natural zeolite in iran. zeolite, an inorganic ion-exchanger, may be used as a suitable technical-economical solution for water treatment in many regions of iran. in this study, the characterization of natural zeolite natrolite and the feasibility of removing hardness, cations, and anions were investigated. methods: first, zeolite composition and type we...

background: chromium (cr) is the most important element used to plate other metals and electroplating factories are still consid­ered to be the most important industries which pollute the environment to this metal. this paper describes a study con­ducted to determine the efficiency of reverse-osmosis (ro) as a membrane technique for removal of cr from wastewater sam­ples synthetically prepared ...

background : hexavalent chromium ( cr (vi)) is an important contaminant in surface and groundwater and its removal from contaminated water and wastewater has received interest in recent years. this study aimed to explain the removal process of cr (vi) from aqueous solution using nano hydroxyapatite (n-hap) as an adsorbent material. methods: cr (vi) removal experiments with the prepared n-hap we...

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solu...

The current study both synthesizes and uses four compounds of graphene oxide (GO), nitrogen doped graphene oxide (ND-GO), high nitrogen doped graphene oxide (HND-GO), and three dimensional high nitrogen doped graphene oxide (3D-HND-GO) in order to remove a model anionic dye, Congo red (CR) from wastewaters. It also compares their carbon nano-structure, with regard to removal efficiency and find...

we evaluated the efficacy of a full-scale combined biophysicochemical system for treatingmolasses-based bioethanol wastewater in terms of organic substances, nutrient, and dark brown color removal. the main organic removal unit, i.e., the upflow anaerobic sludge blanket (uasb) reactor, achieved 80.7% removal and 4.3 nm3 methane production per cubic meter of wastewater with a hydraulic retention...

industrial processes release a range of gaseous and particulate pollutants containing heavy metals into the air. lack of enough attention to the design, installation, repair and maintenance of gas and dust filtration systems in industries, is one of reasons of increasing the emissions of these pollutants. hereon, the steel making processes is one of emission sources of heavy metals. according t...