Biological Oxygen Demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
Published in Chapter:
Effect of Dyes on Water Chemistry, Soil Quality, and Biological Properties of Water
Kiran Meghwal (Mohanlal Sukhadia University, India), Srishti Kumawat (Mohanlal Sukhadia University, India), Chetna Ameta (Mohanlal Sukhadia University, India), and Nirmala Kumari Jangid (Banasthali Vidyapith, India)
Copyright: © 2020
|Pages: 25
DOI: 10.4018/978-1-7998-0311-9.ch005
Abstract
As the textile industries use aqueous method for dyeing processes, the color that is released in the environment is associated with the incomplete absorption of dyes on fibres. So, there is a strong need to reduce the amount of residual dye in textile effluent. Large amounts of liquid wastes are produced from textile industries that contain both organic and inorganic compounds. The degradation of azo dyes is difficult using the conventional processes. These complex azo dyes containing N=N bond have been found to show carcinogenic evidences on reductive cleavage. Azo dyes have capability to alter physical and chemical properties of soil, causing harm to the water bodies. Dyes are toxic in nature, which is lethal for microorganisms present in soil affecting agricultural productivity. The presence of azo dyes in water decreases its water transparency and water gas solubility. This reduces light penetration through water, decreases its photosynthesis activity, causing oxygen deficiency and de-regulating the biological cycles of aquatic system.