G K Suraishkumar

Sustainable development requires wastewater management. Heavy metals such as copper, cadmium, lead and zinc are the critical metals in wastewater. The treatment of wastewater is vital functions in any society; hence securing them for current and future generations is an important part of sustainable development. The main objective of this work is to increase water use efficiency and recycling water which is an integrated approach to sustainable development. In this present work, copper biosorption by formalin washed Aspergillus niger was characterized. The nature and binding mechanism of chemical groups in the formalin washed biomass responsible for copper biosorption was investigated as a function of pH and metal concentration, combined with Scanning Electron Micrograph (SEM), Image Analysis System (IAS), a nitrogen adsorption-desorption technique and Fourier transform infrared spectroscopy (FTIR). The retention capacity of the biomass was determined at pH 6.0 to be equal to 23.62 mg of copper/g of biomass. The Langmuir and Freundlich isotherm equations were then used to describe the behavior of the system. Based on the experimental data and surface analysis an efficient method was established for copper removal from wastewater so that it can be reused for domestic cleaning and industrial reuse.

In this present work, a kinetic model for biosorption of copper was developed considering the possibility of different forms of functional groups being present on the surface of the biomass prepared from Aspergillus niger. Results showed that metal uptake by A. niger was a mass transfer driven process, requiring only 30 min to achieve 70% adsorption efficiency. Copper sorption by A. niger was influenced by the biomass dose, initial metal ion concentration, and pH of the solution. The Langmuir and Freundlich adsorption isotherms were used to describe the behavior of the system at different pH. The retention capacity of the biomass was determined at pH 6.0 to be equal to 23.62 mg/g of biomass. The pretreatment with formalin improved the uptake of metal ion. © 2006 Elsevier Ltd. All rights reserved.