INTERDEPENDENCE AND INTERRELATIONSHIP AMONG WATER QUALITY PARAMETERS IN BIOLFOC SYSTEMS

Abstract

Biofloc technology is essentially a water quality management system. It is essential to monitor closely the water quality parameters in the system. However, some of the parameters may not be as easy to examine, either being more rigorous or fairly expensive. Therefore, the needs for development of theoretical models that can be readily available especially when there is an urgent need. The water quality parameters examined in biofloc system over the period of 10 weeks were subjected to correlation and regression to assess the interdependence and interrelationship among the water quality parameters and subsequently developing equations for future estimation some of the relatively difficult to measure water quality parameters. All the water quality parameters were within the recommended level for freshwater fish culture except the total suspended solids (TSS). The TSS had fairly strong and significant interdependence with temperature, total dissolved solids (TDS) and ammonia. Nitrate showed strong and significant interdependence with dissolved oxygen and pH. Ammonia also showed strong and positive interdependence with dissolved oxygen. TSS and nitrate had fairly high co-efficient of determination 0.462 and 0.412, with Fvalue of 14.393 and 11.6731 respectively. The predicted equation for TSS was 230.38T – 271.31DO – 204.17pH + 10.30TDS – 3419, and nitrate was 15.13T - 32.62DO – 28.39pH – 0.04TDS + 91.71. The results showed some good relationships among some of the water quality parameters and considering the high and significant coefficient of determination, the equations could be reliably used for estimation of the
dependent variables, especially total dissolved solids and nitrate in biofloc systems.