Heavy Water Pollution

1. Introduction

Water pollution due to the disposal of heavy metals continues to be a great concern worldwide. Consequently, the treatment of polluted industrial wastewater remains a topic of global concern since wastewater collected from municipalities, communities and industries must ultimately be returned to receiving waters or to the land (Weber et al, 1991). Heavy metals pollution occurs in much industrial wastewater such as that produced by metal plating facilities, mining operations, battery manufacturing processes, the production of paints and pigments, and the ceramic and glass industries. This wastewater commonly includes Cd, Pb, Cu, Zn, Ni and Cr (Argun and Dursun, 2008). Whenever toxic heavy metals are exposed to the natural eco-system,

Thereafter it was washed with de-ionized water to get rid of unwanted materials and possibly some heavy metals attached to the surface. The corn cob was then sundried for 7 days after which it was pulverized. The samples were then passed through 100 µm mesh sieve to obtain the Corn Cob (CC).

2.1.3. Corn Cob-kaolinite composite (CCKC)

The modification of clay with corn cob was performed as described; The Raw corn cob was added to the raw clay at a percentage composition of 10, 20, 30 and 40 by weight. Distilled water was added to form a solid paste of the mixture, which was compounded using a pestle and a mortar to aid the coming together of the particles and to ensure proper blending. Thereafter it was sundried for several days, pulverized and passed through a mesh sieve of size 100 µm to obtain the Corn Cob-kaolinite composite (CCKC) adsorbent.

2.2. Adsorbent Characterization

The surface functional groups on the adsorbents responsible for binding of metal ions were determined by the Fourier-Transform Infrared (FTIR) spectrophotometer (Shimadzu FT-IR 8400s). The morphology of the adsorbents was analyzed by the Scanning Electron Microscope (SEM, Hitachi S4800

The pH of all the solutions was maintained at a constant optimum pH of 6.0 for adsorption. 0.5 g of the adsorbents were then placed in five 100 mL plastic bottles after which 20 mL of each solution was added, the plastics were corked and agitated for 5 sec and left to stand for 120 min at a room temperature of 300 K. The solutions were then filtered and taken to the AAS for residual metal concentration.

2.4.3. Determination of the effect of adsorbent dose

Different weights of the adsorbents of 0.5, 1.0, 1.5, 2.0 and 2.5 g were weighed and placed in five 100 mL plastic bottles. 20 mL of the metal ion solution of concentration 600 mg/L at optimum pH was added to the bottles, and then corked, agitated for 5 seconds and left to stand at 180 min at a room temperature of 300 K. The solution was then filtered and the filtrate taken to the AAS to determine the concentration of metal ions remaining after adsorption.

2.4.4. Determination of the effect of contact