Lipid Productivity of Algae Grown on Dairy Wastewater as a Possible Feedstock for Biodiesel

Woertz, Ian

doi:10.15368/theses.2008.1

Cited by 10 publications

(12 citation statements)

References 28 publications

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“…HRAPs with CO 2 addition could provide energy efficient tertiary-level nutrient removal for little additional energy cost (Benemann et al 1980;Woertz 2007). Algal biomass can, as stated above, exhibit N:P ratios ranging from nearly 4:1 to almost 40:1 and therefore nearcomplete assimilation of both N and P into algal biomass from wastewater is theoretically possible (Benemann 2003).…”

Section: Wastewater Treatment In Hrapsmentioning

confidence: 99%

Algal biofuels from wastewater treatment high rate algal ponds

Craggs

Heubeck

Lundquist

et al. 2011

Water Science and Technology

230

101

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This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO(2) has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

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Section: Wastewater Treatment In Hrapsmentioning

confidence: 99%

Algal biofuels from wastewater treatment high rate algal ponds

Craggs

Heubeck

Lundquist

et al. 2011

Water Science and Technology

230

101

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“…Microalgae are being cultivated for the generation of biomass for biofuels; however, microalgae require nutrients to grow and with growing water scarcity issues there is a need for an economical growth medium. With that being said, wastewater can be the best option to cultivate microalgae for biomass, since wastewater contains nutrients and water which can be reclaimed after treatment with microalgae (Woertz 2007). Microalgae growth in wastewater has been indicated as a cost-effective process.…”

Section: Introductionmentioning

confidence: 99%

“…Literature depicts that cultivation of microalgae in a controlled environment requires low initial capital, operational cost and low technical costs. It also states that low landcost areas enriched with sunlight and warm temperature will be advantageous for microalgae-based wastewater system (Woertz 2007;Yun et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Wastewater treatment by local microalgae strains for CO2 sequestration and biofuel production

et al. 2017

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Currently, the scientific community is keenly working on environmental-friendly processes for the production of clean energy and sustainable development. The study was conducted to cultivate microalgae in raw institutional wastewater for water treatment, enriched production of biomass and CO 2 sequestration. The strains which were used in this study are Scenedesmus sp. and Chlorella sp. which were isolated from Kallar Kahar Lake, Pakistan. Both strains were cultivated in synthetic growth medium (Bold's Basal Medium) to enhance biomass production. Afterward, microalgae cultures were inoculated in wastewater sample in mixotrophic mode under ambient conditions. The impurities in wastewater were successfully removed from the original sample by the 7th day of operation. COD 95%, nitrate 99.7% and phosphate 80.5% were removed by applying Scenedesmus sp. Meanwhile, Chlorella sp. reduced 84.86% COD, 98.2% nitrate and 70% phosphate, respectively. Interestingly, sulfates were removed from wastewater completely by both strains. Besides being useful in wastewater remediation, these microalgae strains were subsequently harvested for lipid extraction and potential biofuel production was determined. Therefore, the applied method is an environmentally safe, cost-effective and alternative technology for wastewater treatment. Furthermore, the achieved biomass through this process can be used for the production of biofuels.

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“…Unlike wastewater bacterial sludge, algae biomass has high crude protein content (~50%) and could be used as animal feed with the proper processing. Another novel use of algal biomass, if it is determined to be economically feasible, may be the conversion of algal biomass to biodiesel (Woertz, 2007).…”

Section: Problem Statement and Significancementioning

confidence: 99%

Bioflocculation for Control of Wastewater Pond Microalgae

Frost

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BIOFLOCCULATION FOR CONTROL OF WASTEWATER POND MICROALGAE DANIEL THOMAS FROSTWastewater treatment pond effluents often have high concentrations of total suspended solids (TSS) consisting mainly of colloidal microalgal cells. For many pond systems, TSS concentrations approach or exceed discharge limits. Conventional algae removal methods, such as coagulation followed by dissolved air flotation, negate much of the cost and simplicity advantages of pond systems. Bioflocculation, the natural agglomeration of cells, followed by sedimentation is a low-cost method to remove pond TSS, but one that is unreliable in current practice. In the present research, bioflocculation experiments were conducted at a central California pilot-scale high rate pond (HRP) facility, consisting of four identical 580-gallon HRPs. HRPs are shallow, paddle wheel-mixed raceways that provide more rapid treatment than conventional ponds. Settleability of the HRP TSS was compared using Imhoff cones.The experiments related to two aspects of bioflocculation -organic loading effects and inoculation with flocculent biomass, such as return activated sludge (RAS). For the first, analysis of data from HRPs around the world shows that high ratios of influent soluble organic loading-to-Pond TSS (sBOD in /TSS pond , where sBOD refers to the 5-day soluble biochemical oxygen demand or BOD 5 ) correlate to lower TSS concentrations in the effluent of subsequent algae settling units (TSS su The experiments indicated that RAS inoculation provided multiple benefits: (1) improved bioflocculation and settling, (2) apparent stimulation of autotrophic productivity, (3) improved BOD removal, and in some cases (4) improved ammonium-N removal.Despite higher pond TSS concentrations in the inoculated ponds than in the controls, the inoculated pond effluents settled to lower mean TSS concentrations (21 mg/L versus 34 mg/L). These settled TSS concentrations corresponded to TSS removal efficiencies of 92% for the inoculated ponds and 74% for the control ponds. The autotrophic growth in the inoculated ponds was as much as 15 g/m 2 /day higher than in the control ponds. In one experiment, inoculation seemed responsible for higher sBOD removal (91% versus 78%). After settling, the total BOD 5 for the inoculated ponds was 16 mg/L compared to 23 mg/L for the control ponds. Finally in two experiments, higher ammonium-N removal was observed in the inoculated ponds than in the control ponds (83% versus 62%). These RAS-induced benefits, in addition to better understanding of the effects of organic loading on bioflocculation, imply potentially significant improvements to the feasibility of HRPs as a reliable wastewater treatment technology.vi ACKNOWLEDGMENTS

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Lipid Productivity of Algae Grown on Dairy Wastewater as a Possible Feedstock for Biodiesel

Cited by 10 publications

References 28 publications

Algal biofuels from wastewater treatment high rate algal ponds

Algal biofuels from wastewater treatment high rate algal ponds

Wastewater treatment by local microalgae strains for CO2 sequestration and biofuel production

Bioflocculation for Control of Wastewater Pond Microalgae

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