Ballast water may be carried on-board by ships to maintain stability and improve manoeuvrability during transit. Introduction of which one of the following is regarded as the major threat in release of untreated ballast water?

A. Water vapour B. Chlorofluro carbon (CFC) C. Oxygen D. Carbon monoxide

A. Some microorganisms use carbon dioxide B. Some microorganisms provide nitrogen for plant growth C. Some microorganisms are used in sewage treatment D. All the above

A. pH B. Turbidity C. Hardness D. COD

A. Ion transfer B. Ionization C. Ion exchange D. Ion vaporization