scholarly journals Surfactant removal and biomass production in a microalgal-bacterial process: effect of feeding regime

2020 ◽  
Vol 82 (6) ◽  
pp. 1176-1183 ◽  
Author(s):  
Mayara L. Serejo ◽  
Sarah L. Farias ◽  
Graziele Ruas ◽  
Paula L. Paulo ◽  
Marc A. Boncz
Keyword(s):  
Biomass Production ◽  
Nutrient Removal ◽  
Domestic Wastewater ◽  
High Rate ◽  
Organic Load ◽  
Microalgal Biomass ◽  
Feeding Regime ◽  
Treated Effluent ◽  
Domestic Wastewater Treatment ◽  
Continuous Feeding

Abstract The influence of the feeding regime on surfactant and nutrient removal and biomass production was evaluated in three high rate algal ponds for primary domestic wastewater treatment. Feeding times of 24, 12 and 0.1 h d−1 were studied in each reactor at a similar hydraulic retention time of 7.0 days and organic load of 2.3 mg m−2 d−1. Semi-continuous feeding at 12 and 0.1 h d−1 showed better microalgal biomass production (0.21–0.23 g L−1) and nutrient removal, including nitrogen (74–76%) and phosphorus (80–86%), when compared to biomass production (0.13 g L−1) and nitrogen (69%) and phosphorus (46%) removals obtained at continuous feeding (24 h d−1). Additionally, the removal efficiency of surfactant in the three reactors ranged between 90 and 97%, where the best result was obtained at 0.1 h d−1, resulting in surfactant concentrations in the treated effluent (0.3 mg L−1) below the maximum freshwater discharge limits.

scholarly journals Evaluating the sustainability of waste substrates for microalgal biomass production using different modes of cultivation

2018 ◽  
Author(s):  
◽  
Prathana Ramsundar
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Bacterial Load ◽  
Biomass Productivity ◽  
Domestic Wastewater ◽  
Microalgal Biomass ◽  
Domestic Wastewater Treatment ◽  
Cultivation Strategy ◽  
Production Strategy ◽  
Pre Treatment

The utilization of wastewater as a substrate for microalgal biomass cultivation is one of the few potentially viable routes for fuel and feed applications. In this study, the suitability of various liquid wastewater streams and waste biosolids from a domestic wastewater treatment plant was assessed for microalgal cultivation. The wastewater substrates were analyzed for nutrient content as a potential growth medium. For liquid waste substrates, physical, thermal and biological pre-treatment methods were evaluated to minimize the bacterial load. Biomass, physiology, nutrient removal efficiencies and biochemical constituents of Chlorella sorokiniana were investigated in influent (INF) and anaerobic tank centrate (AC) under mixotrophic (Mixo) and heterotrophic (Hetero) cultivation modes. Mixotrophic cultivation conditions demonstrated efficient ammonium (94.29%) and phosphate (83.30%) removal with promising biomass (77.14 mgL-1d-1), lipid (24.91 mgL-1d-1), protein (22.36 mgL-1d-1) and carbohydrate (20.10 mgL-1d-1) productivities. Urea supplementation (1500 mgL-1) further enhanced biomass (162.50 mgL-1d-1), lipid (24.91 mgL-1d-1), protein (22.36 mgL-1d-1) and carbohydrate (20.10 mgL-1d-1) productivities in Mixo AC. Therefore, the urea supplemented Mixo AC approach for microalgal cultivation was developed as a suitable biomass production strategy. This work also elucidated a novel algae cultivation strategy for utilisation of waste biosolids, where nutrient-rich waste activated sludge (WAS) and final effluent (FE) from the wastewater treatment process was used for microalgal biomass generation. This strategy reduced the use of synthetic nutrients, fertilizers and freshwater which contribute significantly towards the overall cost of biomass production. Strategy development included the investigation of physical, thermal and chemical pre-treatment methods to assist in effective nutrient release and bacterial load reduction. Evaluation of growth kinetics, photosynthetic performance, nutrient removal efficiencies and biochemical composition of microalgae under mixotrophic and heterotrophic modes of cultivation were performed. Furthermore, urea supplementation was studied to improve biomass productivity. Microalgae cultivation in acid pre-treated (pH 2) WAS + FE with urea supplementation (1500 mgL-1) showed enhanced biomass productivity of 298.75 mgL-1d-1. Microalgal biomass grown with WAS + FE using the developed strategy exhibited greater lipid (72.95 mgL-1d-1) and protein (72.84 mgL-1d-1) productivities and comparable carbohydrate yields (73.07 mgL-1d-1) to that of synthetic media. Thus mixotrophic mode of cultivation coupled with urea supplementation to WAS + FE proved to be a suitable cultivation strategy for C. sorokiniana. The study developed an efficient strategy to utilize AC and WAS + FE as a growth medium for microalgae. Furthermore, findings from this study have demonstrated the potential of waste streams and waste solids from domestic wastewater treatment plants for microalgal biomass generation

Evaluation of flocculation and dissolved air flotation as an advanced wastewater treatment

2001 ◽  
Vol 43 (8) ◽  
pp. 83-90 ◽  
Author(s):  
A. C. Pinto Filho ◽  
C. C. Brandão
Keyword(s):  
Wastewater Treatment ◽  
Domestic Wastewater ◽  
High Rate ◽  
Advanced Treatment ◽  
Dissolved Air Flotation ◽  
Anaerobic Reactor ◽  
Treatment Processes ◽  
Domestic Wastewater Treatment ◽  
Air Flotation ◽  
Dissolved Air

A bench scale study was carried out in order to evaluate the applicability of dissolved air flotation (DAF) as an advanced treatment for effluents from three different domestic wastewater treatment processes, namely: (i) a tertiary activated sludge plant ; (ii) an upflow sludge blanket anaerobic reactor (UASB); and (iii) a high-rate stabilization pond.

Performance of pilot Hybrid Reed Bed constructed wetland with aeration system on nutrient removal for domestic wastewater treatment

2020 ◽  
Vol 19 ◽  
pp. 100891 ◽  
Author(s):  
Omar Hamed Jehawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Setyo Budi Kurniawan ◽  
Nur ‘Izzati Ismail ◽  
Mushrifah Idris ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Aeration System ◽  
Domestic Wastewater Treatment ◽  
Reed Bed

High rate domestic wastewater treatment at 15 °C using anaerobic reactors inoculated with cold-adapted sediments/soils – shaping robust methanogenic communities

2019 ◽  
Vol 5 (1) ◽  
pp. 70-82 ◽  
Author(s):  
Evangelos Petropoulos ◽  
Yongjie Yu ◽  
Shamas Tabraiz ◽  
Aminu Yakubu ◽  
Thomas P. Curtis ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Low Temperature ◽  
Domestic Wastewater ◽  
High Rate ◽  
Cold Adapted ◽  
Anaerobic Reactors ◽  
Domestic Wastewater Treatment

To choose the reactor format in which to employ a low temperature adapted seed for wastewater treatment, we compared a UASB and an AnMBRUASB (UF)reactor at low HRT and temperature (15 °C).

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