An Interactive Tool for Simulation of Biological Models Into the Wastewater Treatment With Microalgae

This paper presents a novel simulation tool to understand and analyze biological models for wastewater treatment processes using microalgae. The models for this type of processes are very complex to be analyzed because of the very different phenomena, variables and parameters involved. The model already included in the tool has been validated at controlled conditions simulating outdoor ones, it being useful to simulate real outdoor cultures. The major contribution of the proposed tool is that these models can be easily and interactively simulated and compared. The tool allows simulating biological models only considering microalgae or including the microalgae-bacteria consortium. Moreover, the simulations can be done only using the solar radiation contribution or by adding the environmental and bacteria effects as cardinal terms. Furthermore, the effects of the wastewater properties or different microalgae strains can be evaluated. The interactive simulations can be performed for selected days as representative of the different year seasons that are already preloaded in the tool. However, the user can also load data from other locations to simulate the models under particular conditions.

Growth pattern of stock cultures of five selected species of marine microalgae maintained under indoor controlled environment and under outdoor conditions

Growth pattern of five species of microalgae viz., Chaetoceros calcitrans, Dunaliella sp., Isochrysis galbana, Tetraselmis tetrahele and Nannochloropsis salina were studied under indoor controlled conditions (at 230C) and under outdoor (at 28-30°C) conditions. The variations in ammonia and pH levels in the culture flasks over a period of 90 days were also studied. Results revealed that the pattern of growth of all five species of algae were significantly different (p<0.05) in the two different conditions. The results clearly showed that the growth of all the five species of algae were faster in outdoor conditions and outdoor cultures were able to maintain only for a maximum period of three months. Ammonia and pH levels recorded were higher in outdoor cultures which indicated higher physiological activities and growth. Ammonia and pH levels were found to increase gradually in all the cultures, upto 30 days under both conditions and subsequently found almost constant throughout the study. Even though ammonia levels were found to rise with increase in pH and temperature, it did not increase to a level that is detrimental to the microalgal cultures.