Removal Of Dissolved Cadmium Ions from Contaminated Wastewater using Raw Scrap Zero-Valent Iron And Zero Valent Aluminum as Locally Available and Inexpensive Sorbent Wastes

Abstract

The current study was to examine the reliability and effectiveness of using most abundant, inexpensive waste in the form of scrap raw zero valent aluminum ZVAI and zero valent iron ZVI for the capture, retard, and removal of one of the most serious and hazardous heavy metals cadmium dissolved in water. Batch tests were conducted to examine contact time (0-250) min, sorbent dose (0.25-1 g ZVAI/100 mL and 2-8 g ZVI/100 mL), initial pH (3-6), pollutant concentration of 50mg/L initially, and speed of agitation (0-250) rpm. Maximum contaminant removal efficiency corresponding to (90 %) for cadmium at 250 min contact time, 1g ZVAI/ 6g ZVI sorbent mass ratio, pH 5.5, pollutant concentration of 50 mg/L initially, and 250 rpm agitation speed were obtained. Langmuir and Freundlich isotherms were presumed to fit the batch kinetics data for the sorption of Cd(II) onto ZVAI and/or ZVI and found that Langmuir (I) was the most representative model type with coefficient of determination R 2 greater than 0.9115. Kinetics data for the sorption of Cd(II) onto ZVAI/ZVI mixture and due to the good agreement between the fitted and the experimental results; the data was found to obey the pseudo second order model. The scanning electron microscopy (SEM) for the ZVI and ZVAI was conducted before and after the sorbent-liquid reaction and revealed distinct morphological changes in the sorbent surface due to the contaminant saturation and pore channel blockages that ceased the sorption process.

Study of the Removal Efficiency of Chromium Ions Using a Membrane by Electro-Kinetic Technique from Sludge

“…For example, for preparing a sludge specimen with a chromium concentration of 599.8 mg/kg and an initial moisture content equal to 40% by weight, 4.889 g of Cr(NO 3 ) 3 ·9H 2 O was dissolved in 400 mL of distilled water, and the solution was added to 1 kg of dried sludge, which is in accordance with the same procedure adopted by Refs. [ 15 , 16 ].…”

Mathematical Modeling and Kinetics of Removing Metal Ions from Industrial Wastewater

“…Equation (10), which may be depicted as a linear relationship by plotting 𝑡 /𝑞 𝑡 vs t, was produced by integrating equation ( 9) at the boundary conditions from t= 0 to t= t and 𝑞 𝑡 = 0 to 𝑞 𝑡 = 𝑞 𝑡 and rearranging the components. The slope and intercept are represented by 1/𝑞 𝑒 and 1/𝑘 2 𝑞 𝑒 2 , respectively.…”

Flotation of Chromium Ions from Simulated Wastewater Using Air Microbubbles

“…The Environmental Protection Agency (EPA) sets 0.1 mg/L limit for hexavalent chromium in drinking water [14]. Traditional water treatment techniques, such as absorption, have been assessed for water and wastewater treatment [15], ultrafiltration [16], coagulation and direct microfiltration [17], electrochemical method [18], reverse osmosis [19], solvent extraction [20], using raw scrap with zero-valent iron and zero-valent aluminum [21] and ion-exchange methods [22]. Conventional water treatment methods remove contaminants but face issues such as energy use, complexity, and hazardous waste [23].…”