Abstract
The algal-bacterial process has received more attention in the present scenario as a new low-cost method towards pollutant removal from wastewater because symbiotic relationship between algae and bacteria is efficient when compared to traditional secondary treatments. The present work evaluated the optimum concentration of microalgal-bacterial consortia for significant reductions in physicochemical parameters of raw domestic wastewater. In the study, three different concentrations (20%, 30% and 40%) of microalgal-bacterial consortia were studied at 8 hours and 16 hours HRT. Among the different concentrations of consortia studied, 30% consortia gave maximum removal efficiency at both the HRTs. The maximum removal efficiency of phosphate, ammonia, BOD and COD was about 99.79%, 94.85%, 89.02% and 88.96%, respectively, at 8 hours HRT. However, at 16 hours, HRT maximum removal efficiency observed was 97.40%, 94.05%, 83.52% and 88.40% for phosphate, ammonia, BOD and COD respectively. The study depicts that microalgal-bacterial consortia can efficiently remediate nutrients and organic matter from domestic wastewater in both cases when sunlight was ample and even with minimal / no sunlight; hence this system can work effectively throughout the day with much lesser HRT and higher removal efficiency.
Highlights
Urbanization and industrialization in developing countries like India, with a minimum focus on the environment, has resulted in rapid degradation of the environment
The present study focuses on the performance of various microalgal bacterial consortia concentrations in an open atmosphere for the removal of nutrients, organic matter and solids from the urban raw wastewater at lower HRT in the presence and absence of sunlight to determine the proficiency of the method, if incorporated in the sewage treatment plants of developing countries
The variation in raw domestic wastewater collected from nearby sewage pumping station for concentrations of phosphate, ammonia, nitrate, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were 2.08 ± 0.35 mg/L, 11.84 ± 1.46 mg/L, 0.51 ± 0.16 mg/L, 157.06 ± 19.88 mg/L and 288.2 ± 20.65 mg/L respectively
Summary
Urbanization and industrialization in developing countries like India, with a minimum focus on the environment, has resulted in rapid degradation of the environment. Though pollution is controlled to some extent, the environment gets more and more polluted because of an increase in the number of industries leading to the generation of domestic and industrial wastewater. The reduction in water quality would lead to water scarcity, which is a major issue around the globe. With time the everdegrading environmental quality has become an issue of concern, making it necessary to identify the polluting agents and develop the techniques to reduce them to such an extent that it does not harm the environment. A major requirement of wastewater treatment nowadays is to remove high concentrations of nutrients, which otherwise can lead to risks of eutrophication if these nutrients accumulate in rivers and lakes (Pittman et al, 2011). Removal efficiency of nitrogen and phosphorus in the treatment process could be improved by taking advantage of the synergy between multiple species of algae and microbes when compared to traditional single and multi-step treatments (Brenner et al, 2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
