Session 32 - Environmental Biotechnology and Bioenergy

[CEST2019_00916] Co-Pyrolysis of Corn Stover Wıth Plastıc: Optımızatıon Based on Synergy
by Salvilla J., De Luna M., Rollon A.

The co-pyrolysis of lignocellulosic wastes such as Corn stover with plastic has been found to improve the both the yield and quality of pyrolysis oil and gas products. In this study, the co-pyrolysis of Corn stover (CS) with plastic (LDPE, and PP) were studied through thermogravimetric analysis. The parameter “change in weight loss rate” denoted by ΔW was used to quantify the synergistic effects on the yield during co-pyrolysis. The ΔW values were fitted using a combined mixture design to generate an RSM model relating the factors mixture component proportions, plastic type, and temperature to the response ΔW. From numerical optimization, the obtained optimum co-pyrolysis conditions are: (a) 0.60 CS proportion, 0.40 LDPE proportion, and 481.73 ℃ temperature for CS-LDPE, (b) 0.68 CS proportion, 0.32 PP proportion, and 492.15 ℃ temperature for CS-PP. The activation energy, and pre-exponential factor of the reactions in the co-pyrolysis process were also obtained using direct solution method. The activation energy of the reaction that took place from 420 to 510 ℃ was found to be lower in the co-pyrolysis of Corn stover and plastic than in the pyrolysis of pure plastic.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:27 to 16:30
Flash presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00920] Hierarchization of pure silica LTA zeolite
by Tarach K. A., Valencia S., Góra-Marek K., Rey F.

The effect of base leaching on pure silica ITQ-29 zeolite being the counterpart of LTA zeolite, was investigated. The extent of the desilication process over pure silica zeolite was controlled by partial detemplation followed by silicon extraction. The potential of hierarchically porous ITQ-29 zeolite in environmentally friendly applications concern selective adsorption of organic molecules in aqueous environments. The introduction of additional porosity by desilication process offers full usage of zeolite grains volume without diffusional limitations during the adsorption process.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:21 to 16:24
Flash presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00935] Bio-scrubber coupled with ozonation for enhanced VOCs abatement
by Senatore V., Oliva G., Zarra T., Belgiorno V., Naddeo V.

Volatile Organic Compounds (VOCs) are toxic for the environment and human health and their tendency to readily volatilize in the atmosphere leads to problems connected to odours annoyance. The conventional treatments for VOCs gaseous emissions conventionally entail the application of chemical-physical processes, only promoting the transfer of the contaminants from gas to liquid and/or solid phases. Advanced Oxidation Process (AOPs) and biological processes, conversely, support the oxidation of the organic pollutants, promoting their conversion into harmless and odourless compounds.
This study aims at evaluating the performance of an innovative treatment solution, at pilot scale, of AOPs pretreatment coupled with a bio-scrubbing unit for the abatement of toluene, selected as model VOCs. Different operating conditions have been evaluated to understand the behavior towards inlet load fluctuations.
The results exhibited that the ozonation applied as pretreatment to the biological process may promote an increase of the pollutant biodegradability along with synergic effects due to the absorption of the ozone derived compounds into the culture growth, resulting in a significant enhancement of removal performances respect to the conventional biotechnologies.

Session: 32, Room: B, at Fri, 09/06/2019 - 15:45 to 16:00
Oral presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00843] Heterotrophic growth of Chlorella vulgaris on crude glycerol
by Gougoulias N., Metsoviti M.N., Grigoriou M., Lamprakopoulos S., Mpesios A. , Papapolymerou G.

The heterotrophic growth of C. vulgaris using crude glycerol as the sole carbon source was studied in five 5L flasks. Air in each flask was provided at a rate of 300 L/hr and the contents were continuously stirred with a magnetic bar. Temperature, pH and initial inorganic nutrients (nitrogen, phosphorus, potassium and micronutrients) were kept the same in all flasks. The C/N ratio varied in each of the five flasks was set at 6, 13, 25.4, 61.5 and 118 respectively while the nitrogen initial concentration was equal to 45.4 mg/L in all flasks. The residual organic carbon was measured as a function of cultivation time. It was found that biomass growth rates as well the lipid and protein content were dependent on the C/N ratio. Lipid content was proportional to the C/N ratio while the protein content was inversely proportional to the C/N ratio. Carbon concentrations above 2500 mg/L inhibited the growth rate.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:15 to 16:18
Flash presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00774] Pyrolysis of Spirulina sp. Microalgae: Effect of Temperature on Chemical Compositions of Bio-Oil and Aqueous Phase
by Özçakir G., Karaduman A.

Pyrolysis of Spirulina sp. Microalgae was carried out in a semi-batch glass reactor system. Effect of temperature on the yields of pyrolytic products (gaseous, liquid and solid residue) and chemical composition of the liquid products were investigated. All experiments were performed in 25 mL/min nitrogen atmosphere with 15 g feedstock which was dry and powder form of Spirulina. Temperature was varied from 470 to 620 °C with 50 °C break by utilizing PID controller which was setted 10 °C/min heating rate. The aqueous phase and bio-oil (organic phase) of the liquid products were characterized by GC-MS. Maximum yields of bio-oil and aqueous phase were obtained approximately as 30 wt. % at 520 °C and as 20 wt. % at 470 °C. When temperature was increased, oxygenated compounds and aromatic hydrocarbons decreased. However, nitrogenous compounds and alkanes increased in the microalgal pyrolytic bio-oil.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:00 to 16:15
Oral presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00709] Anaerobic digestion of long-chain fatty acids (oleic, palmitic, stearic) with whey protein as the emulsifier
by Eftaxias A., Michailidis C., Stamatelatou K., Diamantis V., Aivasidis A.

Long chain fatty acids are major lipid constituents. In this study, anaerobic digestion of oleic, palmitic or stearic acid (5 g/L each) emulsified with whey protein (20 g/L) was examined in continuous (batch-fed) stirred tank digesters with 2 L working volume. Anaerobic co-digestion of oleic acid displayed high biogas yield (0.47 L/gCOD), compared to palmitic (0.42 L/gCOD) and stearic acid (0.30 L/gCOD). Oleic acid, despite its high biodegradability resulted in major inhibition of the acetoclastic methanogens, as demonstrated by VFA accumulation and by the methanogenic activity assay. Biogas production from palmitic acid was stable, with a biogas yield close (90%) to the theoretically expected values. This was not the case however for stearic which displayed negligible biodegradability. Application of the ADM1 revealed the maximum degradation rate constant of each LCFA. Based on the results of this study it can be concluded that stearic acid degradation is the rate limiting step of the anaerobic digestion process, and this attributed to its low solubility and thus bioavailability.

Session: 32, Room: B, at Fri, 09/06/2019 - 15:15 to 15:30
Oral presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00715] High-rate anaerobic co-digestion of agro-industrial wastes combined with ammonia recovery and biogas purification
by Eftaxias A., Georgiou D., Diamantis V., Koumara A., Koskinari M.D., Aivasidis A.

Screened dairy manure, pressure-sterilized animal by-products, and cheese whey were co-digested in a Plug Flow Reactor (PFR) over a period of 150 days. The PFR process was stable even under a hydraulic retention time of 3 days, corresponding to an organic loading rate (OLR) of 22 g/Ld. Effluent COD remained low (5.6±1.4 g/L) while VFA concentrations were negligible (< 0.5 g/L as COD). The biogas production rate from the PFR ranged from 2.6 up to 7.3 L/Ld. The anaerobic digestate was characterized by high ammonia content (1.7±0.5 g/L); therefore air-stripping was chosen for the effective removal of ammonia. Hydrated lime as a slurry was utilized for the necessary pre-treatment step (pH-raising), due to its fast reaction and low cost. A temperature of ≥ 45 °C was also needed for efficient ammonia removal. The final effluent was neutralized by CO2 absorption through biogas injection in a scrubber. Concurrently, the biogas was upgraded since its methane content increased substantially, while H2S was completely removed.

Session: 32, Room: B, at Fri, 09/06/2019 - 15:30 to 15:45
Oral presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00634] An innovative green iron-fertilizer, produced biotechnologically, for correcting iron chlorosis of soybean plants grown in calcareous soils
by Ferreira C., Lopez-Rayo S., Lucena J., Soares E., Soares H.

Iron deficiency is one of the main causes of chlorosis in plants, which leads to the loss in the field crops quality and yield. Iron-deficiency is a worldwide problem, particularly sever in calcareous soils (about 30% of world´s land surface). The current use of synthetic iron-chelates to prevent or correct iron-deficiency in plants raises environmental concerns due to their poor biodegradability. Thus, new, more environmentally-friendly efficient solutions are needed to solve iron deficiency-induced chlorosis (IDIC) in crops grown in calcareous soils. In this work, a new green freeze-dried iron fertilizer was produced (patent submitted) from a culture of A. vinelandii containing siderophores of a natural source able to bind iron at pH 9. Soybean plants cultivated under calcareous soils and treated with the green iron-fertilizer responded more significantly and comparable to the positive control, ethylenediaminedi(o-hydroxyphenylacetic) acid, than those treated with the negative control, when evaluated by their growth (dry mass) and chlorophyll concentration (SPAD index). On average, iron content was also greater on green iron-fertilizer treated plants than on negative control treated ones. Results suggest that the freeze-dried product, prepared from A. vinelandii culture, can be a viable alternative for mending IDIC of soybean plants grown in calcareous soils.

Session: 32, Room: B, at Fri, 09/06/2019 - 15:00 to 15:15
Oral presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00541] Screening strains of genus Pleurotus for biomass production in solid state fermentation of agricultural residues
by Diamantopoulou P., Melanouri E.-M., Papanikolaou S.

The ability of several strains belonging to Pleurotus ostreatus and P. eryngii mushroom genera to grow on various agricultural residues was examined and their mycelium growth rates and biomass production (estimated as glucosamine content) were compared. Four P. ostreatus (AMRL 137, 144, 147, 150) and four P. eryngii (AMRL 160, 163, 166, 173-6) strains were cultivated on wheat, barley and oat straw, poplar and beech-wood sawdust, cotton and coffee residues, corn-cobs, rice bark, olive cake supplemented with wheat bran on a final C/N 20-30. Colonization rate measurements of mycelium demonstrated faster colonization on wheat, beech, barley and oat, corn-cobs and rice with values of ~1.5 mm/day, yet the faster colonizers were P. ostreatus 144, 150 and P. eryngii 166, 173-6. Glucosamine content was similar for P. ostreatus and P. eryngii strains and the most pronouncing substrates for more biomass production were barley and oat straw, beech-wood sawdust, cotton and coffee residues, corn-cobs (max 450 mg/g d.w.). However, in most of the cases, glucosamine content was opposite to mycelial growth rate, as strains with high colonization rates produced the least biomass. These results are evaluated in the view of bio-converting agricultural wastes into mushrooms, an added value food with medicinal properties.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:24 to 16:27
Flash presentation in Environmental Biotechnology and Bioenergy
[CEST2019_00346] Characterization of Xylanase-Treated Karagumoy Fiber Reinforced Composite (KFRC)
by Mina M.T.M., Tumolva T.P.

This work determined the effects of enzyme treatment on the mechanical properties of natural fiber-reinforced composite using Pandanus simplex (karagumoy) fibers. Physical modification using enzyme improved chemical and mechanical properties of fibers and the karagumoy fiber-reinforced composites (KFRCs) produced. Enzyme concentration and soaking time were used as treatment parameters. The treatment scheme improved the mechanical properties of fibers and composites, as well as, the composites’ water absorption property. The composites’ mechanical properties- tensile and flexural strength- were measured using universal testing machine (UTM). The morphology of fibers and composites was determined through a scanning electron microscope (SEM) and results indicated a reduced fiber diameter for the treated fibers and an increase in fiber surface roughness, thereby resulting to improved adhesion or compatibility between the hydrophilic fiber and the hydrophobic matrix. FTIR analysis results of the fibers further supported this finding as evidenced by the reduction in OH groups of the enzyme-treated karagumoy fibers.

Session: 32, Room: B, at Fri, 09/06/2019 - 16:18 to 16:21
Flash presentation in Environmental Biotechnology and Bioenergy