Microalgae as a sustainable biological system for improving leachate quality

Khanzada, Zareen T.; Övez, Süleyman

doi:10.1016/j.energy.2017.08.112

Cited by 26 publications

(8 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…+ -N medium. The possible reasons for the acidic medium pH are explained in the authors recent work [45]. Production of algal biomass results in more oxygen (photosynthetic product) being produced [3].…”

Section: Environmental Data Of Other Parameters For Raceway Pond Cultmentioning

confidence: 99%

Growing Fresh Water Microalgae in High Ammonium Landfill Leachate

Khanzada¹,

Övez²

2018

AJMA

View full text Add to dashboard Cite

Municipal landfills are being employed for the disposal of communities solid waste. The compacted waste in landfills naturally generate leachate (liquid) which contain high concentrations of ammonium-nitrogen NH 4 +-N along with other toxic compounds. NH 4 +-N can be used as a cheap nitrogen source for microalgae biomass production, thereby facilitating tertiary treatment of landfill leachate. Two sets of studies, laboratory scale and pilot scale open raceway pond cultivation, were conducted to evaluate the potential of indigenous fresh water microalgal species to grow in ultra-membrane treated landfill leachate TL and simultaneously remove nutrients (NH 4 +-N-NO 3 etc.). Microalgae growth was better in 50% diluted TL (1.5 gL-1 dry biomass) with 66.27% NH 4 +-N removal in the lab study. Onsite raceway pond cultivation had reduced biomass growth and nutrient removal. Nitrate-nitrogen NO 3-N removal was minimum from both the setups. Microalgal assimilation and nitrification was the main cause of NH 4 +-N removal from both the setups. When lab study duration was extended, NH 4 +-N was found to be released back into the leachate medium. Batch cultures (when prolonged) were observed to be not an effective nutrient removal strategy in terms of NH 4 +-N removal via microalgal system. Further research is needed to optimize microalgal growth and nutrient removal from landfill leachate.

show abstract

Section: Environmental Data Of Other Parameters For Raceway Pond Cultmentioning

confidence: 99%

Growing Fresh Water Microalgae in High Ammonium Landfill Leachate

Khanzada¹,

Övez²

2018

AJMA

View full text Add to dashboard Cite

show abstract

“…Wastewater dilution has been a widely employed approach for avoiding the inhibiting effects of wastewater on microalgae cells because of the advantages of easy operation, low energy requirement, and wide applicability. But the microalgae biomass concentration and wastewater treatment performance were still not satisfactory using the available methods in terms of a constant dilution rate throughout the cultivation cycle. − Microalgae growth mainly experiences four stages, which include the adaption stage, growth stage, stationary stage, and decline stage. The nutrients requirement for microalgae in various stages are different .…”

Section: Introductionmentioning

confidence: 99%

“…The ROC generated from the reverse osmosis process of landfill leachate, a special kind of wastewater, contains an extremely high concentration of toxic organics (humic acid and unsaturated aromatics, etc.) and heavy chromaticity compared to that of regular wastewater, which intensifies the toxic effects on microalgae cells . An elaborate operation strategy for ROC feeding is necessary to simultaneously achieve high biomass accumulation, bioproducts generation, and ROC disposal.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Reverse Osmosis Concentrate Disposal and Nutrients Conversion to Microalgae Bioenergy with a Gradient-Fed Strategy

Chang

Zou

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Reverse osmosis concentrate (ROC) disposal with microalgae has attracted increasing interest because of its intrinsic advantages, like simultaneous wastewater remediation and bioenergy production. But these processes are currently suffering from inefficient nutrients removal and poor microalgae growth due to ROC toxicity. A gradient-fed strategy is proposed to enhance ROC disposal and nutrients conversion to microalgal Chlorella vulgaris lipid by adjusting the ROC feeding. Time-evolving profiles of nutrients and chemical oxygen demand (COD) during experiments as well as their influences on microalgae growth and metabolism have been investigated. Results indicate that the removal of NH4 + and COD using the gradient-fed process was improved by 104.3% and 214.2% compared to those obtained in batch mode, generating a high-quality ROC effluent with N and P nutrients almost totally removed. Microalgae biomass and lipid content were simultaneously enhanced with the gradient-fed process. Energy production analysis showed that the highest energy yield was achieved with use of the gradient-fed process at 30%–70%–100% as 39.0 kJ/L, which was higher than the volumetric heat value of natural gas (about 36.0 kJ/L) and significantly higher than that obtained in batch mode (21.6 kJ/L). This work provides a practical strategy for large-scale microalgae cultivation with ROC.

show abstract

“…This has a direct effect on the profitability of any processes that involve the production of microalgae [21]. One alternative to the use of synthetic media may be the use of wastewater [11,22] or landfill leachate [23,24], especially those from agro-industrial waste and landfill leachate, which are rich in nitrogen and phosphorus [21,25]. The recovery of nutrients from leachate using microalgae has two clear advantages: firstly, they act as a nutrient carrier at a very low cost, and secondly, the positive impact on the environment by avoiding contamination and unwanted eutrophication processes.…”

Section: Introductionmentioning

confidence: 99%

Influence of Leachate and Nitrifying Bacteria on Photosynthetic Biogas Upgrading in a Two-Stage System

et al. 2021

View full text Add to dashboard Cite

Photosynthetic biogas upgrading using two-stage systems allows the absorption of carbon dioxide (CO2) in an absorption unit and its subsequent assimilation by microalgae. The production of microalgae requires large amounts of nutrients, thus making scale-up difficult and reducing economic feasibility. The photosynthetic process produces oxygen (O2) (1 mol per mol of CO2 consumed), which can be desorbed into purified biogas. Two-stage systems reduce its impact but do not eliminate it. In this study, we test the use of landfill leachate as a nutrient source and propose a viable and economical strategy for reducing the O2 concentration. First, the liquid/gas (L/G) ratio and flow mode of the absorber were optimized for 20% and 40% CO2 with COMBO medium, then landfill leachate was used as a nutrient source. Finally, the system was inoculated with nitrifying bacteria. Leachate was found to be suitable as a nutrient source and to result in a significant improvement in CO2 absorption, with outlet concentrations of 0.01% and 0.6% for 20% and 40% CO2, respectively, being obtained. The use of nitrifying bacteria allowed a reduction in dissolved oxygen (DO) concentration, although it also resulted in a lower pH, thus making CO2 uptake slightly more difficult.

show abstract

Microalgae as a sustainable biological system for improving leachate quality

Cited by 26 publications

References 88 publications

Growing Fresh Water Microalgae in High Ammonium Landfill Leachate

Growing Fresh Water Microalgae in High Ammonium Landfill Leachate

Enhanced Reverse Osmosis Concentrate Disposal and Nutrients Conversion to Microalgae Bioenergy with a Gradient-Fed Strategy

Influence of Leachate and Nitrifying Bacteria on Photosynthetic Biogas Upgrading in a Two-Stage System

Contact Info

Product

Resources

About