WASTEWATER AND AQUACULTURE

Editor/Mohamed Shihab

Water is the main supporting element of human life but its pollution and wastage have led to a number of problems. The practice of wastewater treatment is now being adopted as a medium to save water. Wastewater treatment is the removal of impurities from wastewater before they reach natural bodies. The factors controlled under the wastewater treatment standards usually include biochemical oxygen demand (BOD), suspended solids, acidity, and coliforms.

The aquaculture industry suffers criticism from environmental groups because of the negative effect on the environment from the release of wastewater. Wastewater treatment is an essential step in the aquaculture industry as the wastewater treatment technology in the aquaculture industry will not only minimize ecological and social problems but also provide greater long-term economic safety for operation of the industry.

Wastewater generation in aquaculture is a result of its operation from hatcheries and farming systems. Bio-engineering have given methods of wastewater treatment in the aquaculture industry. It is done through the process of oxygen injection, automated feeding, on-site re-pelleting technology,

The steps for treatment include primary, secondary, and tertiary. Primary treatment removes about 60% of total suspended solids, secondary treatment removes more than 85% of both suspended solids and BOD and tertiary processes can remove more than 99% of all the impurities from sewage. Use of bio-filters is being adopted to treat water. A bio-filter is a bed of media on which micro-organisms attach and grow to form a biological layer of beneficial bacteria that extract dissolved chemicals from the water and convert them to particulate biomass. The two major bacterial genera involved in the processes of waste removal are Nitrosomonas and Nitrobacter. Nitrosomonas is responsible for nitrifying ammonia to nitrite, while Nitrobacter converts nitrite to nitrate.

There is a tremendous need to develop reliable technologies for the treatment of wastewater in developing countries. Many harmful effects to the aquatic plant and animal life have been reported due to this. Such treatment systems must fulfill many requirements, such as simple design, use of non-sophisticated equipment, high treatment efficiency, and low operating and capital costs. Technology for the treatment of wastewater is not only essential for the growth of the industry but, also, important for environmental sustainability.