Anaerobic digestate as substrate for microalgae culture: the role of ammonium concentration on the microalgae productivity

In spite of the increasing interest received by microalgae as potential alternatives for biofuel production, the technology is still not industrially viable. The utilization of digestate as carbon and nutrients source can enhance microalgal growth reducing costs and environmental impacts. This work assesses microalgal growth utilizing the liquid phase of anaerobic digestate effluent as substrate. The effect of inoculum/substrate ratio on microalgal growth was studied in a laboratory batch experiment conduced in 0.5 L flasks. Results suggested that digestate may be an effective substrate for microalgal growth promoting biomass production up to 2.6 gTSS/L. Microalgal growth rate was negatively affected by a self-shading phenomenon, while biomass production was positively correlated with the inoculum and substrate concentrations. Thus, the increasing of both digestate and microalgal initial concentration may reduce the initial growth rate (µ from 0.9 to 0.04 d-1) but significantly enhances biomass production (from 0.1 to 2.6 gTSS/L).Peer ReviewedPostprint (published version

Anaerobic digestate as substrate for microalgae culture: the role of ammonium concentration on the microalgae productivity

In spite of the increasing interest received by microalgae as potential alternatives for biofuel production, the technology is still not industrially viable. The utilization of digestate as carbon and nutrients source can enhance microalgal growth reducing costs and environmental impacts. This work assesses microalgal growth utilizing the liquid phase of anaerobic digestate effluent as substrate. The effect of inoculum/substrate ratio on microalgal growth was studied in a laboratory batch experiment conduced in 0.5 L flasks. Results suggested that digestate may be an effective substrate for microalgal growth promoting biomass production up to 2.6 gTSS/L. Microalgal growth rate was negatively affected by a self-shading phenomenon, while biomass production was positively correlated with the inoculum and substrate concentrations. Thus, the increasing of both digestate and microalgal initial concentration may reduce the initial growth rate (µ from 0.9 to 0.04 d-1) but significantly enhances biomass production (from 0.1 to 2.6 gTSS/L).Peer Reviewe

Process for shave-joining of dissimilar materials and its application to mild steel

60.00; Translated from Japanese (J. Jpn. Soc. Technol. Plast. 1987 v. 28(322) p. 1158-1165)Available from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26482)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Enhancement of anaerobic digestion performance: which pretreatment for which waste?

When properly designed, pretreatment may enhance the methane potential and/or anaerobic digestion rate, allowing better digester performance. The purpose of this paper is to give guidelines and present a rationale on pretreatment techniques of the main types of waste used in biogas plants. The pretreatment strategies proposed are supported by a literature review and the experience of three research groups working on this topic: INRA-LBE, UPC and FORTH. Thermal pretreatment should be recommended for waste activated sludge as it increases its methane potential and digestion rate, it allows sludge sanitation and the necessary heat energy is produced on-site. In the case of microalgae, thermal pretreatment has shown to be the most effective in terms of biomass solubilization and methane yield improvement. As for sewage sludge, the heat needed is produced on-site, although depending on pretreatment conditions biomass thickening or dewatering could be required. Saponification is a pretreatment which is preferred to solubilize fatty residues and to increase their bioavailability in the digesters. For fatty residues originating from slaughterhouses, classified as category II waste, this pretreatment can be optimized to ensure both sterilization and solubilization in the same process. For lignocellulosic biomass, the first aim of pretreatment should be delignification, for which alkali pretreatments are effective.Postprint (published version

The synthesis of optically active chiral building blocks using enzymes

SIGLEAvailable from British Library Document Supply Centre- DSC:DX174158 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Microalgae production in wastewater treatment systems, anaerobic digestion and modelling using ADM1

An integrated microalgae-based system for urban wastewater treatment, microalgae production and bioenergy generation through anaerobic digestion was evaluated over a period of one year. The pilot HRAP was effective at removing COD (similar to 80%) and ammonium(similar to 95%) and robust, despite common variations in wastewater composition and weather conditions in the Mediterranean region. Biomass production showed a strong seasonality, reaching an annual average of 10 g TSS/m(2).day and the highest values in spring (23 g TSS/m(2).day). Conversely, the macromolecular composition was fairly constant (58% proteins, 22% carbohydrates and 20% lipids). Predominant microalgae species varied throughout the year, influencing biogas production. Indeed, the anaerobic biodegradability of harvested biomass was 20-25% in July-October 2012 and May-July 2013 and 25-38% in November 2012-April 2013. Adapting the content of particulate inert COD in Anaerobic Digestion Model No. 1 (ADM1) was crucial for model calibration. After adjustment, ADM1 was able to predict microalgae anaerobic digestion performance, which showed an average methane yield of 0.09 L CH4/g COD at 15 days HRT and 0.16 L CH4/g COD at 20 days HRT. (C) 2015 Elsevier B.V. All rights reserved

Enhancement of anaerobic digestion performance: which pretreatment for which waste?

When properly designed, pretreatment may enhance the methane potential and/or anaerobic digestion rate, allowing better digester performance. The purpose of this paper is to give guidelines and present a rationale on pretreatment techniques of the main types of waste used in biogas plants. The pretreatment strategies proposed are supported by a literature review and the experience of three research groups working on this topic: INRA-LBE, UPC and FORTH. Thermal pretreatment should be recommended for waste activated sludge as it increases its methane potential and digestion rate, it allows sludge sanitation and the necessary heat energy is produced on-site. In the case of microalgae, thermal pretreatment has shown to be the most effective in terms of biomass solubilization and methane yield improvement. As for sewage sludge, the heat needed is produced on-site, although depending on pretreatment conditions biomass thickening or dewatering could be required. Saponification is a pretreatment which is preferred to solubilize fatty residues and to increase their bioavailability in the digesters. For fatty residues originating from slaughterhouses, classified as category II waste, this pretreatment can be optimized to ensure both sterilization and solubilization in the same process. For lignocellulosic biomass, the first aim of pretreatment should be delignification, for which alkali pretreatments are effective