Browsing by Author "Hosseini Yazdi, Seyed Mohammad Sadegh"

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    Bio-Refinery of Wastewater in Presence of Carbon Dioxide Utilizing Microalgae
    (2018-07-12) Hosseini Yazdi, Seyed Mohammad Sadegh; Chu, Angus; Nowicki, Edwin Peter; He, Jianxun
    In this research, three sets of experiments were conducted to assess the ability of Chlorella Vulgaris (Chlorella V.) to grow in different physical conditions such as light intensity, pH, temperature and mixing by measuring oxygen evolution. Chlorella V. thrives if the medium (Bold’s Basal Media) has a pH range of 7-8, temperature range of 25-30 ͦ C, light intensity of 4755 LUX, and 5% CO2 is introduced into the culture. Chlorella V. has illustrated the same growth rate in both sterile and non-sterile wastewater media under optimal physical conditions. It demonstrated uptake of 100% of dissolved nitrogen compounds and almost 30% of dissolved phosphorus compounds presented in the medium. This ability nominates Chlorella V. for potential tertiary treatment of wastewater. Finally, the ability of this specie for CO2 uptake was determined. Chlorella V. could sequester 20% CO2 in the total gas volume of the photobioreactor headspace in optimal physical conditions. The CO2 fixation rate was higher in the middle of the exponential growth phase compared to other growth phases.
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    Co-Fermentation Strategy for Augmented Carbon Source Availability in Biological Nutrient Removal Systems: Optimization and Performance Evaluation
    (2024-09-18) Hosseini Yazdi, Seyed Mohammad Sadegh; Chu, Angus; Achari, Gopal; Black, Kerry; Ponnurangam, Sathish; Hamza, Rania
    This research delves into an innovative approach within the field of wastewater treatment, focusing on the co-fermentation of Primary Sludge (PS) with Fermented Sludge (FS), Soft Drink Wastewater (SDWW), and Yeast Wastewater (YWW) to produce volatile fatty acids (VFA). The utilization of waste materials in wastewater treatment, particularly for the synthesis of VFA, represents a significant stride towards sustainable and eco-friendly practices. VFA is crucial intermediates in the biological nutrient removal (BNR) process and play a key role in the anaerobic digestion and biosynthesis of bioplastics and biofuels. The study employs batch fermentation experiments using PS obtained from wastewater treatment facilities, a critical step in the advanced treatment of wastewater. The aim was to investigate the impact of co-substrate addition and different feeding mode on VFA production and composition. Key VFA identified include acetic acid, propionic acid, iso-butyric acid, butyric acid, isovaleric acid, and valeric acid, with acetic acid and iso-butyric acid predominantly yielding the highest. Further, the research explores the optimization of Food-to-Microorganism ratios, temperatures, and mixing conditions. This is in line with the latest advancements in wastewater treatment which emphasize process optimization for enhanced efficiency and sustainability. The findings reveal substantial enhancements in VFA/SCOD ratios under specific operational conditions, indicating a promising avenue for improved biogas production. Microbial community analysis in the study provides deeper insights into the biological aspects of wastewater treatment. Dominant phyla like Bacteroidota, Campilobacterota, Firmicutes, Fusobacteriota, and Proteobacteria were identified, which are instrumental in the biodegradation and nutrient cycling processes in wastewater systems. The study's outcomes hold significant implications for the advancement of wastewater treatment technologies. The addition of biodegradable SDWW and YWW not only improves the fermentation profile but also substantially enhances VFA yields, showcasing the potential of co-fermentation in wastewater treatment. These findings underline the importance of integrating innovative biological processes for effective wastewater management, ultimately contributing to the development of more sustainable, efficient, and eco-friendly treatment strategies.