Wastewater Treatment With Polyelectrolytes

摘要

One of the major challenges today is to provide clean and clear water to a vast majority of the population. The need for clean water is particularly critical in the third world countries. Rivers, canals, and other water bodies are continuously being contaminated and polluted by the ever increasing population and its activities, indiscriminate discharge of industrial wastes and numerous other activities. The reuse of wastewater has therefore become an absolute necessity for the human race. The major water pollutants include metal ions like nickel, chromium, copper, zinc, manganese, etc pose a hazardous situation from the ecological point of view. Removal of these metal ions from industrial wastewater is inevitable for maintaining the ecological balance. Polyelectrolytes can ply an important role in treatment of water and wastewater. The use of the polyelectrolytes may reduce the costs of treatment substantially. Proper choice of a suitable polyelectrolyte for water to be treated is essential. The present work is a preliminary study on polyelectrolytes conducted to determine the efficiency of polyelectrolytes in removal of nickel from synthetic wastewater. Three different polyelectrolytes have been compared initially and it has been found that the anionic polyelectrolyte works most efficiently for the removal of cation like nickel. Further studies for optimization ofpH, dosage and time are conducted using the anionic polyelectrolyte megafloc which is a copolymer of amido amines and vinyl monomers. It has been found that megafloc removes more nickel at pH 11 as compared to pH 4. It has also been found that 60 minutes stirring time is enough to remove most of nickel ions. The percentage removal of nickel has reached upto 94% for 80 ppm nickel solution at pH 11 and 60 minutes of stirring time. It may be concluded that anionic polyelectrolyte may give excellent results for removal of nickel ions from wastewater.