Removal of TDS and TSS from Industrial Wastewater using Fly Ash

Fly ash is one of the most abundant waste materials; its major components make it a potential agent for the adsorption of pollutants contaminants in water and wastewaters. In this study, fly ash obtained from burning of mazut was dried and sieved into different fractions (600, 300, 150, 75µm). A pilot plant with an industrial discharge flow of 200L/hr was designed for reducing total Dissolved Solids (TDS), total suspended solids (TSS), conductivity and pH from industrial wastewater. The concentrations of (TDS), (TSS), conductivity and pH in industrial discharge flow had an average range of 80000, 750, 120000 mg/L and 13 respectively. The optimization of the treatment process using 5, 8, 12, 15 g/L fly ash dosage had succeeded in improving the removal efficiency of (TDS), (TSS), conductivity and pH to 90%, 92.3%, 90% and 93.5% respectively.

Failure Analysis of Industrial Discharge Hopper Pipe

This work presents the detailed investigation and root cause analysis of catastrophic failure of an industrial discharge hopper pipe. The hopper pipe investigated in the present work is made of austenitic stainless steel, 316 grade, a commonly used grade for valves, pipes and heat exchanger tubes. The pipe fractured in transverse direction, leading to the failure of discharge pipe. Visual inspection, dye penetrant test, chemical analysis, microstructural analysis, and fractography analysis were carried out on the failed part and it was concluded that stress corrosion cracking led to the failure of hopper pipe. The pipe constantly being under the exposure of industrial water and the presence of chlorine content in it made it susceptible for stress corrosion cracking. Transgranular fracture was clearly observed in the microstructure of failed sample and spot EDX at the fracture location confirmed the presence of chlorine content. Further, fractography showed striations indicating fatigue loading. The work concluded that stress corrosion cracking as the root cause of failure.

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

In this study, a polymer, prepared by crosslinking cyclodextrin (CD) by means of a polycarboxylic acid, was used for the removal of pollutants from spiked solutions and discharge waters from the surface treatment industry. In spiked solutions containing five metals, sixteen polycyclic aromatic hydrocarbons (PAH) and three alkylphenols (AP), the material exhibited high adsorption capacities: >99% of Co2+, Ni2+ and Zn2+ were removed, between 65 and 82% of the PAHs, as well as 69 to 90% of the APs. Due to the structure of the polymer and its specific characteristics, such as the presence of carboxylic groups and CD cavities, the adsorption mechanism involves four main interactions: ion exchange, electrostatic interactions and precipitation for metal removal, and inclusion complexes for organics removal. In industrial discharge waters, competition effects appeared, especially because of the presence of calcium at high concentrations, which competed with other pollutants for the adsorption sites of the adsorbent.