Use of Algae in Water Treatment Isolated from Some Regions of Baghdad

Abstract

In this work, wastewater was treated using a locally isolated microalga (Chlorella vulgaris Bejerinck) to reduce pollutant indices. By examining three factors, the effectiveness of Chlorella vulgaris in reducing COD, BOD5, and PO4 concentrations was investigated. At the wastewater treatment plant in Esala al-Sader, wastewater samples were taken from a main station. Three distinct wastewater dilutions—100% sludge, 75% sludge, and 25% sludge—were evaluated with distilled water.. During the early incubation period, During the incubation phase, there was a noticeable decrease in both the chemical and biological oxygen demands (BOD5 and COD). This is attributed to the efficient biodegradation of organic matter and the increased microbial activity driven by algal photosynthesisThe treatment process we carried out during the first seven days was effective and efficient. We observed a strong interaction between the algae and microorganisms, which enhanced oxygen production, nutrient absorption, and the decomposition of organic matter. However, we noted that the concentrations of biological oxygen demand (BOD5) and chemical oxygen demand (COD) and phosphorus increased during the incubation period in the treatment cycles. This was due to the autolysis of cells, the aging of the algal biomass, and the release of organic matter and phosphorus into the wastewater. All of this highlights the need to control the incubation period and maintain the biomass in a stable state to prevent pollution resulting from decomposition. The results also showed that sample C was more stable and performed more efficiently in removing pollutants. This was evident in the decrease in the levels of COD and phosphate in the later stages of the experiment. We also observed the effectiveness of the common alga (Chlorella vulgaris) in treating wastewater and removing organic pollutants and nutrients, especially when the operating environment or conditions are improved. However, the treatment performance is significantly affected by the incubation period, nutrient availability, biomass mobility, and interactions between the algae and microorganisms.. Therefore, this research recommends periodic harvesting of algal biomass, optimizing treatment duration, and minimizing the release of organic matter and nutrients to increase the efficiency of pollutant removal in treated wastewater.