Growing Fresh Water Microalgae in High Ammonium Landfill Leachate

Abstract

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.

Ammonium Utilization in Microalgae: A Sustainable Method for Wastewater Treatment

“…The TAN abatement in wastewater treatment is usually divided into different approaches: Physical (e.g., membrane separation), chemical (e.g., coagulation, solvent extraction, ion exchange,), and/or biological [23,56,79]. The high effective cost and energy consumption of technologies for one-step tertiary treatment of WWT represent a problem for industries and municipalities [80]. A valid alternative to conventional treatments may be provided by microalgae, coupling the nutrient removal from wastewater with the production of valuable biomass.…”

“…In wastewaters, N concentration must be reduced to acceptable limits (generally <10-15 mg L −1 depending on discharge point, population, and region regulation as described by regulation 91/271/CEE) before being released into the water body [83]. Many studies demonstrated that microalgae have a great potential for N removal and reported successful cultivations [13,[23][24][25]52,80]. Green microalgae (Chlorophyceae) represent the more exploited algae in WWT (Table 2).…”

“…It was calculated that for 1-ton microalgal production, about 40-100 Kg of inorganic Ncompound and 11-13 ML/Ha/year of water are required. It was also estimated that about 2500 m 3 of wastewater to obtain 1-ton of microalgal biomass could be treated [80]. Therefore, at the same time, the utilization of wastewater for algal cultivation could allow the removal nutrients from effluents and reduce the use of precious freshwater.…”

Tratamento de lixiviado de aterro sanitário aplicando Chlorella sp. imobilizada em diferentes matrizes poliméricas

“…Alguns estudos com microalgas registraram queda do pH. Khanzada et al (2018) cultivando Chlorella vulgaris e Chlamydomonas reinhardii no tratamento de lixiviado, identificaram que o pH estava constantemente diminuindo, atingindo 5,7. A redução do pH, também foi observado por Mustafa et al (2012) no cultivo de algas em lagoas com alta taxa de N-amoniacal usando lixiviado a 4%.…”

Remoção De Nitrogênio Amoniacal Por Chlorella Sp. Em Diferentes Diluições De Lixiviado De Aterro Sanitário/Amoniacal Nitrogen Removal by Chlorella Sp. In Different Dillutions of Sanitary Terry Dillution

“…L -1 -N-amoniacal), compostos orgânicos tóxicos, xenobióticos dissolvidos, baixa razão de demanda química e bioquímica de oxigênio (DBO5: DQO → 0,2 ou menos) e metais pesados (KHANZADA et al 2018). O Lixiviado é considerado uma água residuária de alta força iônica devido a nutrientes inorgânicos dissolvidos, o que pode levar à salinidade com aumento dos níveis de íons cloreto (~ 5g Cl -.…”