A lab-scale study imitating microalgae-based wastewater treatment systems was conducted to evaluatethe impact of microalgae Chlorella vulgaris on the removal of Escherichia coli from raw blackwater. The study consisted of three tests, each with a different dilution of blackwater: 10%, 30%, and 50% blackwater. A machine-learning method (Decision Trees induction) was employed to extract functional dependencies between the measured parameters: E. coli and C. vulgaris concentrations, electric conductivity, pH, chemical oxygen demand, total nitrogen, ammonium-nitrogen, and orthophosphate. The results showed that electric conductivity was the most crucial parameter influencing E. coli inhibition. The removal of E. coli was achieved at an electric conductivity of ? 1569 µS/cm and C. vulgaris concentration )1 x 107 cells/mL depending on the pH value. These results indicate a shift in C. vulgaris and E. coli interaction from mutualistic to competition at a threshold value of electric conductivity 1569 µS/cm at a light intensity of 5000 lux in 16/8 h light/dark intervals, constant temperature and regulated pH.
COBISS.SI-ID: 8866145
This study assessed the biodegradation kinetics of BPF and BPS during biological wastewater treatment with activated sludge using GC-MS/MS, and the identification of biotransformation products (BTPs) using LC-QTOF-MS. The results showed that BPF and BPS degrade readily and unlikely accumulate in biosolids or wastewater effluent. The first-order kinetic model revealed that BPF degraded faster than BPS and that degradation rate decreases with an increasing initial concentration of BPS. The absence of any additional organic carbon source significantly slowed down degradation, in particular, that of BPS. The machine-learning algorithm adopted as part of the non-targeted workflow identified three known BTPs and one novel BTP of BPF, and one known and ten new BTPs of BPS. The data from this study support possible new biodegradation pathways, namely sulphation, methylation, cleavage and the coupling of smaller bisphenol moieties.
COBISS.SI-ID: 29781507
High rate algal ponds (HRAP) are an alternative to conventional wastewater treatment with the potential for wastewater reuse and biomass production. In this study, we report the development and validation of methods for analysing 18 bisphenols in the aqueous and biomass phase of high rate algal ponds. BPA was found to be most abundant, followed by BPS and 4,4’-BPF. Only BPA was quantified in the algal biomass. The average removal efficiency was much higher for BPA than for BPS. To our knowledge, this is the first study analysing a wide range of BPs in both aqueous and biomass phase of high rate algal ponds treating real wastewater. With reliable analytical methods we have the tools to study the behavior of bisphenols further.
COBISS.SI-ID: 48987395
Water has been pushed into a linear model, which is increasingly acknowledged of causing cumulative emissions of pollutants, waste stocks, and impacting on the irreversible deterioration of water and other resources. Moving towards a circular model in the water sector, the configuration of future water infrastructure changes through the integration of grey and green infrastructure, forming Nature-based Solutions (NBS) as an integral component that connects human-managed to nature-managed water systems. In this study, a thorough appraisal of the latest literature is conducted, providing an overview of the existing tools, methodologies and indicators that have been used to assess NBS for water management, as well as complete water systems considering the need of assessing both anthropogenic and natural elements. Furthermore, facilitators and barriers with respect to existing policies and regulations on NBS and circularity have been identified. The study concludes that the co-benefits of NBS for water management are not adequately assessed. A holistic methodology assessing complete water systems from a circularity perspective is still needed integrating existing tools (i.e. hydro-biogeochemical models), methods (i.e. MFA-based and LCA) and incorporating existing and/or newly-developed indicators.
COBISS.SI-ID: 23012099
High-rate algal ponds (HRAP) are an alternative to conventional wastewater treatment that could contribute to the circular economy by valorising reclaimed water and algal biomass. This paper presents the removal of nutrients and contaminants of emerging concern (CEC) in a pilot-scale HRAP treating primary municipal wastewater. Average removal of total organic carbon, total nitrogen, NH4-N, total phosphorus and PO4-P, was 67%, 76%, 87%, 41% and 46%, respectively. In addition, 12 CECs were detected in the influent and five in the effluent. Removals were as follows: naproxen 60%, ibuprofen 51%, methylparaben 92%, 2,4-dihydroxybenzophenone 76% and oxybenzone 80%, and are comparable with literature data for conventional wastewater treatment and other HRAPs. Studies of nature-based solutions such as HRAPs show encouraging results but need further research to understand the risks and requirements of safe wastewater and biomass reuse.
COBISS.SI-ID: 58688003