Removal of 2-fluoro and 2-iodophenol from aqueous solutions using industrial wastes

Catalytic thermolysis at atmospheric pressure followed by adsorption in treatment of coking wastewater

Wastewater generated from the coking processes has high load of organic as well as inorganic pollutants which requires the application of effective treatment techniques. In the present work, treatment of coking wastewater (CWW) through catalytic thermolysis has been carried out in batch mode with varying parameters such as type of catalyst, catalyst mass loading, pH, temperature and time. This process was followed by adsorption as second stage treatment process. The final parameters obtained are as Chemical Oxygen Demand (COD) 20 mg/L, cyanide 0.42 mg/L and nil amount of phenol from the high initial organic and inorganic load. The study aims reduction of COD, phenol, and cyanide content in the wastewater to the permissible limits. The mechanism and kinetics of thermolysis process have been also presented in this study.

Characterization of dust from blast furnace cast house de-dusting

During casting of liquid iron and slag, a considerable amount of dust is emitted into the cast house of a blast furnace (BF). Usually, this dust is extracted via exhaust hoods and subsequently separated from the ventilation air. In most BFs the cast house dust is recycled. In this study a sample of cast house dust was split by air classification into five size fractions, which were then analysed. Micrographs showed that the dominating particle type in all size fractions is that of single spherical-shaped particles. However, some irregular-shaped particles were also found and in the finest size fraction also some agglomerates were present. Almost spherical particles consisted of Fe and O, while highly irregular-shaped particles consisted of C. The most abundant element was Fe, followed by Ca and C. These elements were distributed relatively uniformly in the size fractions. As, Cd, Cu, K, Pb, S, Sb and Zn were enriched significantly in the fine size fractions. Thus, air classification would be an effective method for improved recycling. By separating a small fraction of fines (about 10-20%), a reduction of the mass of Zn in the coarse dust recycled in the range of 40-55% would be possible.

Adsorptive removal of 2,4-dichlorophenol from water utilizing Punica granatum peel waste and stabilization with cement

The present study investigates the adsorption potential of Punica granatum (pomegranate) peel as an adsorbent for the removal of 2,4-dichlorophenol (2,4-DCP) from aqueous solutions. The adsorption was studied as a function of contact time, initial concentration and temperature by batch method. The adsorption capacity of pomegranate peel adsorbent for 2,4-DCP was found to be 65.7 mg g(-1). The equilibrium adsorption data was well described by the Langmuir model. Kinetic studies suggest that the present system of phenol adsorption on pomegranate peel adsorbent could be described more favorably by pseudo-first-order kinetic model. Column studies were also undertaken in order to test the practical utility of prepared adsorbent and found promising. After the adsorption studies, the phenol-laden adsorbent was stabilized in cement for its ultimate disposal. The results of the present study clearly reveal that prepared adsorbent can be used beneficially in treating industrial effluents containing phenols and safely disposed of by stabilizing into cement.

Removal of bromophenols from water using industrial wastes as low cost adsorbents

A comparative study of the adsorbents prepared from several industrial wastes for the removal of 2-bromophenol, 4-bromophenol and 2,4-dibromophenol has been carried out. The results show that maximum adsorption on carbonaceous adsorbent prepared from fertilizer industry waste has been found to be 40.7, 170.4 and 190.2 mg g(-1) for 4-bromophenol 2-bromophenol and 2,4-dibromophenol, respectively. As compared to carbonaceous adsorbent, the other three adsorbents (viz., blast furnace sludge, dust, and slag) adsorb bromophenols to a much smaller extent. This has been attributed to the carbonaceous adsorbent having a larger porosity and consequently higher surface area. The adsorption of bromophenols on this adsorbent has been studied as a function of contact time, concentration and temperature. The adsorption has been found to be endothermic, and the data conform to the Langmuir equation. The further analysis of data indicates that adsorption is a first order process. A comparative study of adsorption results with those obtained on standard activated charcoal sample shows that prepared carbonaceous adsorbent is about 45% as efficient as standard activated charcoal in removing bromophenols. To test the practical utility of this adsorbent, column operations were also carried out. The results were found satisfactory in removing bromophenols by column operations. Therefore, the present investigations recommend the use of carbon slurry waste as inexpensive adsorbent for small scale industries of developing/poor countries where disposal of solid waste of various industries and proper treatment of polluted wastewater is a serious problem.