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

Pre-Treatment of Municipal MBR Applications in Germany- Current Status and Treatment Efficiency

2006 ◽  
Vol 1 (3) ◽  
Author(s):  
F.B. Frechen ◽  
W. Schier ◽  
M. Wett
Keyword(s):  
Wastewater Treatment ◽  
Mechanical Treatment ◽  
Domestic Wastewater ◽  
Current Status ◽  
Gap Size ◽  
Treatment Efficiency ◽  
Domestic Wastewater Treatment ◽  
Operation Period ◽  
Treatment Stage ◽  
Pre Treatment

Since mid 1999 MBR technology is introduced into domestic wastewater treatment in Germany. First wwtps went in operation performing a conventional mechanical treatment (covering screens, grit chambers and grease traps) without any advanced mechanical pre-treatment stage. After a short operation period module-clogging and hence module sludging was observed. Thus, mechanical pre-treatment was upgraded introducing sieves, first of all to reduce hairs and fibrous substances. But today knowledge is relatively poor concerning effectiveness and treatment efficiency of the whole bunch of aggregates that had been brought to market and vary e.g. in gap size and gap geometry. This paper gives the basics of sieving, the current status of mechanical pre-treatment on German municipal MBR plants and exemplifies an investigation to determine treatment efficiency of two different sieve aggregates.

Domestic wastewater treatment and biofuel production by using microalga Scenedesmus sp. ZTY1

2014 ◽  
Vol 69 (12) ◽  
pp. 2492-2496 ◽  
Author(s):  
Tian-Yuan Zhang ◽  
Yin-Hu Wu ◽  
Hong-Ying Hu
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Wastewater Treatment Plant ◽  
Removal Rate ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Dry Weight ◽  
Biofuel Production ◽  
Domestic Wastewater Treatment ◽  
High Removal Rate

Cultivation of microalgae for biomass production is a promising way to dispose of wastewater and recover nutrients simultaneously. The properties of nutrient removal and biomass production in domestic wastewater of a newly isolated microalga Scenedesmus sp. ZTY1 were investigated in this study. Scenedesmus sp. ZTY1, which was isolated from a wastewater treatment plant in Beijing, grew well in both the primary and secondary effluents of a wastewater treatment plant during the 21-day cultivation, with a maximal algal density of 3.6 × 106 and 1.9 × 106 cells · mL−1, respectively. The total phosphorus concentrations in both effluents could be efficiently removed by over 97% after the cultivation. A high removal rate (over 90%) of total nitrogen (TN) was also observed. After cultivation in primary effluent for 21 days, the lipid content of Scenedesmus sp. ZTY1 in dry weight had reached about 32.2%. The lipid and triacylglycerol (TAG) production of Scenedesmus sp. ZTY1 was increased significantly with the extension of cultivation time. The TAG production of Scenedesmus sp. ZTY1 increased from 32 mg L−1 at 21 d to 148 mg L−1 at 45 d in primary effluent. All the experiments were carried out in non-sterilized domestic wastewater and Scenedesmus sp. ZTY1 showed good adaptability to the domestic wastewater environment.

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.

AN APPROACH ON ATTACHED GROWTH PROCESS FOR DOMESTIC WASTEWATER TREATMENT

2014 ◽  
Vol 13 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Alireza Valipour ◽  
Seyed Masoud Taghvaei ◽  
Venkatraman Kalyan Raman ◽  
Gagik Badalians Gholikandi ◽  
Shervin Jamshidi ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Growth Process ◽  
Domestic Wastewater ◽  
Attached Growth ◽  
Domestic Wastewater Treatment
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