A Summary Of Environmental Pollution

I. Introduction
Environmental pollution is currently one of the most important issues facing humanity. It was increased exponentially in the past few years and reached alarming levels in terms of its effects on living creatures. The presence of toxic metals in the environment specifically in various water resources is of major concern because of their toxicity, non-biodegradable nature and threat to human, animal and plant life. Electroplating, painting, metallurgical, mining, textile, municipal incineration and chemical manufacturing industries all generate toxic metals of various levels.[1] Strict regulations have been made by different countries for safe discharge standards of these effluents. Chromium ions and other toxic metal ions enter

Batch mode adsorption studies:
a. Effect of pH: pH variation is one of the most important parameters controlling the uptake of toxic metals from wastewater and aqueous solutions. The studies were conducted at room temperature with an initial metal ion concentration of 10ppm, 15ppm, 20ppm and constant adsorbent dose of 10gm/l solution, at an agitation period of 30min. Effect of pH on adsorption was conducted at ranges of 2, 4, 6, 8, and 10 in each solution. The maximum percentage of adsorption was found in range of pH between up 2 to 4, and there after it decreases with further decrease in pH between up 6 to 8.

Table 2.1. Effect of pH on percentage removal of chromium.

A. For 100mg/l concentration pH Adsorbent Dose(grams) Contact Time(min) Initial Metal Ion Concentration(mg/l) Final Concentration(mg/l) % Removal
2 10 30 100 5.89 94.11
4 10 30 100 7.12 92.88
6 10 30 100 15 85
8 10 30 100 26.25 73.75
10 10 30 100 35.95 64.05

B. For 150mg/l concentration pH Adsorbent Dose(grams) Contact Time(min) Initial Metal Ion Concentration(mg/l) Final Concentration(mg/l) % Removal
2 10 30 150 10.5 93
4 10 30 150 14.1 90.6
6 10 30 150 24.12