Algal Particles Research Articles

Optimization and Kinetic studies of biodiesel production from the green alga Ulva fasciata Delile

In this investigation, optimization experiments were carried on lipid extraction and biodiesel production parameters from Ulva fasciata as a potential feed stock. This study was carried by running one to one optimization model. The results showed that, the highest yield and the best quality of biodiesel was achieved at the optimum condition of <0.16 mm algal particle size, 55oC extraction temperature, 25:1 v/w solvent to solid ratio, 60 min extraction time and 250 rpm shaking speed, using chloroform: methanol: H2O (2: 2: 1) solvent mixture. The recorded lipid yield was 28.84 mg g-1 with total fatty acids ΣTFAs content 1148.94 µg g-1, saturated fatty acids ΣSFAs=979.43 µg g-1, monounsaturated ΣMUFAs=136.98 µg g-1 and polyunsaturated ΣPUFAs fatty acids =32.53 µg g-1. The quality of the produced biodiesel at these optimum conditions was determined by its physicochemical properties which showed a very high quality. Cetane number (CN) was 73.21, while kinematic viscosity (υ), density (ρ), higher heating value (HHV) and iodine value (IV) were 4.68 mm2s-1, 0.87 g cm-3, 39.85 MJ kg-1 and 18.48 gI2100g-1fat, respectively. Other properties such as degree of unsaturation (DU), saponification value (SV) and long chain saturation factor (LCSF) recorded 17.58, 200.66mg KOHg-1 and 23.06, respectively. On the other hand, Linolenic acid (C18:3) % and Polyunsaturated fatty acid methyl esters containing ≥ 4 double bonds % recorded 0.68% and 0.98%, respectively. The initial extraction rate (h) was 6.169 ml g-1 min-1; the extraction capacity (Cs) was 31.036 g ml-1; the second order extraction constant (k) was 0.0064 ml g-1 min-1 and the coefficient of determination (R2) was 0.9994.

The Performance and Emissions Investigations of Compression Ignition (CI) Engine Using Algal Biomass as an Antioxidant Additive in Coconut and Karanja Methyl Esters

The day-to-day human needs are strongly associated with the transportation and industrial sectors, which are influencing to deplete fossil fuel reserves. At this situation, the use of biodiesel in an efficient way is the only practical alternative to run compression ignition engines. The biodiesels fuel-borne oxygen may reduce carbon monoxide (CO), unburnt hydrocarbons (HC), and smoke emissions but increase carbon dioxide (CO2) and oxides of nitrogen (NOx) emissions. The scientists and researchers are starving to improve engine performance by reducing the most harmful NOx emissions. Because of this, the author has investigated naturally aspirated single-cylinder unmodified direct injection compression ignition (DICI) engine. Two grams of mixed culture algal biomass particles are added in highly saturated coconut and unsaturated Karanja biodiesel fuels. The brake thermal efficiency of algal particles-emulsified fuels increased due to the explosion of biodiesel-surrounded algal particles after attaining autoignition temperature. The reduction in NOx emissions is noticed with algal particles-emulsified fuels because the particles absorb heat from the combustion chamber.

Investigations of DI CI engine using algal particles contained coconut biodiesel

Day to day increasing vehicles usage for human activities is caused to accumulate greenhouse emissions into the environment. The biodiesel is a best alternative fuel to run diesel engines. But its lower Calorific value and higher NOx emissions makes the consumer should compromise with engine performance and emission characteristics. As we know, that the use of additives to improve engine Combustion and emissions are caused to increase the fuel cost due to the higher cost of additives. The biodiesel conversion process of third generation biodiesel is costlier and required technological advancements for qualitative fuel. In the present work, the author used mixed culture micro algal particles in Coconut biodiesel (CCNME+AP) to improve engine characteristics. The Brake Thermal Efficiency (BTE) was enhanced, and the NOx emissions were less due to the absorption of heat in the Combustion chamber, it led to cool combustion phenomena with the Algal particles contained Coconut Biodiesel (CCNME+AP).

Sea snot and succession

Marine Microbes Carbon in the open ocean is recycled by microorganisms that assemble on small polysaccharide particles of algae and decayed animals, most simply described as marine “snot.” These communities are dense and enzymatically highly active. Enke et al. grew organisms for a week or so on prepared substrates of alginate, chitin, agarose, and carrageenan and elucidated the dynamics of particle degradation. From genome sequencing of the communities through time, it was evident that the primary degraders were specific to each substrate and possessed specialized hydrolytic enzymes. Next to grow were apparent “free riders” that could import some oligosaccharides into their cells. Last in the succession were generalist organisms that occurred across the range of substrates. The generalists cannot harvest oligosaccharides at all and secondarily rely on metabolic intermediates produced by the specialists. Curr. Biol. 29 , 1528 (2019).

Auto/bio-flocculation conditions to separate algal particles without chemical coagulants for flotation and sedimentation processes

ABSTRACTAuto-flocculation (AF) leads to co-precipitation with inorganic salt ions at high pH levels, and bio-flocculation (BF) depends on the production of extracellular polymeric substances during algal growth phases. This study examines the separation efficiency of Chlorella vulgaris formed in AF/BF conditions, without the addition of chemical coagulants. To improve the efficiency of conventional gravity sedimentation (CGS) and dissolved air flotation (DAF), AF/BF conditions were considered as pH/mixing-induced stress. The higher efficiency of DAF was affected by the mixing-stagnation condition for Chlorella vulgaris and influenced by the high temperature and condition under which no nutrients were added to AF/BF for Anabaena sp.

Flotation of cyanobacterial particles without chemical coagulant under auto-flocculation

Although flotation techniques are often used for the removal of algal particles, the practicality of algae-harvesting technologies is limited owing to the complex and expensive facilities and equipment required for chemical coagulation. Here, we examined the feasibility of an approach to separating algal particles from water bodies without the need for chemical coagulants, depending on the condition of the algae, and to determine the optimal conditions. Using Anabaena sp., a cyanobacterium causes algal blooms in lakes, we stimulated auto-flocculation in algal particles without coagulants and conducted solid-liquid separation experiments of algal particles under various conditions. The six cultivation columns included in our analysis comprised four factors: Water temperature, light intensity, nutrients, and carbon source; auto-flocculation was induced under all treatments, with the exception of the treatment involving no limits to all factors, and algal particles were wellsettled under all conditions for which auto-flocculation occurred. Meanwhile, flotation removal of auto-flocculated algal particles was attained only when nutrients were blocked after algae were grown in an optimal medium. However, no significant differences were detected between the functional groups of the extracellular polymeric substances (EPSs) of floated and settled algal particles in the FT-IR peak, which can cause attachment by collision with micro-bubbles.

Phosphorus fractionation and release characteristics of sediment in the Saemangeum Reservoir for seasonal change

Periodical algal blooms result in deposition and release of phosphorus (P) from the sediment into the water. Therefore, during seasonal changes when algal particles begin to settle to the bottom, understanding the behavior and distribution characteristics of the P in sediment is the most important key to manage the water quality of the Saemangeum Reservoir. In this study, the variation of water quality and sediment composition including chlorophyll-a (Chl-a) and P was investigated to determine the interaction between water and sediment. The study focused primarily on algal particle sedimentation that affects the P release and mineralization of sediment. The Chl-a concentration in water showed a sharp decline in October when the algae began to die in the fall, and afterward the concentration of chemical oxygen demand (COD) and total P (TP) in the sediment increased due to the sedimentation of decaying algal particles in November. During the same period of time, the readily bio-available P (RAP) in the sediment showed a drastic increase in the upper region where the Chl-a concentration of water was high. In sequence, the high RAP zone shifted from the upper region to the lower region in the early winter. The RAP shift was considered to be derived from the physical flow of the overlying water from which the decomposing algae settled on the surface of the sediment. The Saemangeum Reservoir was constructed recently; therefore, all the types of inorganic P fractions except soluble reactive phosphorus (SRP) that exist on the bottom surface of the lake and the marsh's sediment layer were not sufficient to significantly influence the overlying water. On the other hand, the released P from the algae was distinct and sensitive to the seasonal change. In conclusion, the algal particle sedimentation was important to control eutrophication rather than P release from the mineralized inorganic P of the sediment surface layer in the Seamangeum Reservoir.

Mixed Culture Microalgae-Based Coconut Biodiesel as Fuel to Improve DI CI Engine Performance, Emission Characteristics

The depleting Fossil fuels reserves are caused to look into new Renewable energy sources to fulfill Diesel fuel demand in developing countries such as India. Increasing urbanization is lead to the search for new alternative sources like biodiesel. In India demand of diesel fuel in Industry and Transportation sector. To resolve all the above problems, researchers, scientists were produced biodiesel from first, second and third generation biodiesel sources. Among all the sources Algae was the most Oil rich sources. The byproducts in algae to biodiesel conversion process are most valuable than other. In the present work author tried to work in a new approach, i.e. the mixed culture algae particles are emulsified in pure Coconut biodiesel fuel by using TritonX-100 as a surfactant to prepare an emulsified fuel. This fuel sample was applied to DI CI engine to improve performance, emission characteristics. The experimental results were shown that there is the improvement in diesel engine performance; emission characteristics especially break thermal efficiency and NOx emission reduction than diesel fuel due to its clean combustion.

Water Quality Drivers in 11 Gulf of Mexico Estuaries

Coastal water-quality is both a primary driver and also a consequence of coastal ecosystem health. Turbidity, a measure of dissolved and particulate water-quality matter, is a proxy for water quality, and varies on daily to interannual periods. Turbidity is influenced by a variety of factors, including algal particles, colored dissolved organic matter, and suspended sediments. Identifying which factors drive trends and extreme events in turbidity in an estuary helps environmental managers and decision makers plan for and mitigate against water-quality issues. Efforts to do so on large spatial scales have been hampered due to limitations of turbidity data, including coarse and irregular temporal resolution and poor spatial coverage. We addressed these issues by deriving a proxy for turbidity using ocean color satellite products for 11 Gulf of Mexico estuaries from 2000 to 2014 on weekly, monthly, seasonal, and annual time-steps. Drivers were identified using Akaike’s Information Criterion and multiple regressions to model turbidity against precipitation, wind speed, U and V wind vectors, river discharge, water level, and El Nino Southern Oscillation and North Atlantic Oscillation climate indices. Turbidity variability was best explained by wind speed across estuaries for both time-series and extreme turbidity events, although more dynamic patterns were found between estuaries over various time steps.

Effects of non-uniform vertical constituent profiles on remote sensing reflectance of oligo- to mesotrophic lakes

ABSTRACTWe investigate the impact on remote sensing reflectance by the vertical non-uniformities of water constituents. Reflectance simulated for 210 pairs of in situ measured chlorophyll-a and turbidity profiles (z = 0–20 m) from Lake Geneva are compared to simulations for uniform constituent gradients and non-uniform profiles approximated by Gaussian curves, orthogonal layers and steady gradients. Relevant concentration ranges are between 0 and 17 mg m−3 for chlorophyll-a and 0 and 4.6 g m−3 for total suspended matter within the photic layer. Our results show that mesotrophic lakes are specifically sensitive to non-uniformities with 20% of the 210 samples used in this study showing deviations of the spectral angle > 5° between a uniform assumption and observations which mostly occur for deeper-laying water constituents. By stressing the different use of blue and red parts of the spectrum, we argue further that algorithms are affected by variable vertical structures of algal and inorganic particles. Finally, we demonstrate that approximation models of the vertical structure of water constituents are a good solution to better account for non-uniformities in the development of invertible bio-optical models.

Electrorheological properties of algae dispersed suspension: New application of harmful algae

The algae has been considered as a bane which should be removed due to its harmful influences on human health and aquatic ecosystems. Recently, various applications of the algae have been studied as a new alternative method instead of its sequestration, to treat vast algae blooms. Herein, algae particles dispersed suspensions have been investigated as a promising new application to electrorheological fluids without any further processing, such as chemical modification, extraction and carbonation. Algae particles dispersed silicone-oil suspensions exhibited good electrorheological properties under DC electric fields, and their electrorheological performances were enhanced with increase of electric fields. The alignment of algae particles along DC electric fields in the suspension, that inhibits the suspension flow by the drag of the dangling alignments and consequently increases the viscosity of the suspension, was observed under the electric fields. The ER properties of algae particles dispersed suspensions were same with (or similar to) those of cellulose phosphate dispersed suspension (yield stress: ca. 400 Pa at 3 kV/mm; polarizability, Δε: ca. 0.35) owing to the phosphate groups in the algae particles. Our research has demonstrated that the electrorheolgical fluids is very promising for the ecofriendly application of the mass-producing algae particles.

Estimation and evaluation of auto-flocculated algae harvesting efficiency using the population balance in turbulence model in flotation process.

Algae are considered water pollutants because they form algal blooms in stagnant water. Algae harvesting technology, however, can help convert them into a useful industrial material like biomass. The core technique (flocculation) separates microalgae from other flocculants, allowing for the harvest of clean and pure algal biomass. This study aims to estimate and evaluate algal separation (removal or harvesting) efficiency (X) to concurrently obtain the objectives of algal bloom management and algal particle collection. To simulate algal separation by auto-flocculation (no flocculants) related flotation, the population balance in turbulence (PBT) model is used. Model simulations are conducted under optimal conditions provided by previous studies about the biological impact factors of algae, operating parameters of the flotation process, and so on. This modeling study determines the efficiency (X) of separating algae from the water body in the separation zone after forming auto-flocculated bubble-floc agglomerates by making them collide and attach to each other in the contact zone of the flotation tank. The X is examined as a function of size distribution of agglomerates and bubbles and of the number of initially injected bubbles. Optimal conditions for forming and harvesting the agglomerates may be found through further modeling studies.

Effects of Algal Morphology and Al Species Distribution on the Coagulation-Ultrafiltration Process

In order to ensure drinking water quality, three different Al-based coagulants [Al2(SO4)3(AS), Al13, Al30] were used to treat water laden with different algae [Microcystis aeruginosa(cyanobacteria), Chlorella(green algae), Cyclotella (diatoms)]. Floc size, strength factor, and recovery factor under different conditions were measured to investigate the mechanisms in the coagulation-ultrafiltration process. The results indicated that the main mechanism in the coagulation process using Al13 or Al30 as coagulants was electrostatic patching and the main mechanism using AS was charge neutralization. In the Microcystis aeruginosa and Chlorella systems, when Al13 and Al30 were used as coagulants at low dosage, the coagulants that were adsorbed on the side (which existed on the surfaces of Microcystis aeruginosa and Chlorella cells) would lose their ability to aggregate the algal cells. When AS was used as coagulant, the electric double layer was effectively compressed. The repulsive force between algal particles decreased, and the flocs formed easily. In the Cyclotella system, Al13 and Al30coagulants effectively formed the flocs through electrostatic patch effects. There was a significant correlation between membrane flux and floc size, and the larger flocs formed a looser cake layer on the membrane surface.

Effect of Zeta Potential on Collision-Attachment Coefficient and Removal Efficiency for Dissolved Carbon Dioxide Flotation

Many researchers have studied the importance of zeta potential control for algae separation by flotation processes. This study focused on measuring and comparing the zeta potential of bubbles and algae (Anabaena spp.) at varying pH with and without chemicals, and simulating the flotation model to estimate the effect of the zeta potential on the collision-attachment coefficients and removal efficiency at pH ≥9. The findings of this study are as follows: (1) at pH 2–12, the zeta potential of CO2 bubbles without surfactants ranged from −14.69 to −32.38 mV and the mean zeta potential of algae ranged from −16 to −31 mV. (2) Bubbles showed positive zeta potential values at pH <9 in the presence of a cationic surfactant, while negative zeta potential values increased in the presence of anionic and nonionic surfactants. Nonionic chemicals did not have a significant effect on the zeta potential of the bubbles. (3) Model simulation results at pH >9 showed the sensitivity of zeta potential and size of bubbles and algal particles on the collision-attachment coefficient and removal efficiency. Optimum algae removal was achieved with CO2 bubble zeta potential between −0.5 and +2.5 mV at pH ≥9.

Characteristics of amino acids during the process of algae-originated particles decomposition in Lake Taihu

在实验条件下研究了高浓度蓝藻堆积后水体中的藻源性颗粒物中氨基酸的分解速率、分解量和氨基酸态氮形态的变化情况.在自然光照组中，颗粒态氨基酸（PAA）的浓度从实验前的0.46 mmol/L降至实验后的0.30 mmol/L；而在无光分解组中PAA从0.44 mmol/L降至0.06 mmol/L.两种处理下PAA的降解速率常数分别为0.03916和0.17424 d^-1.溶解态氨基酸（DAA）在分解过程中浓度比较低，随时间的变化表现出先增大后减小的趋势，在两种不同的处理下，最大值分别为10.94和7.94 μmol/L，21 d后减小到与实验开始时持平，甚至低于初始值.实验初期，PAA所占比例高达74%~80%，但迅速被分解转化为DAA和铵态氮（NH₄⁺-N），随着实验的进行NH₄⁺-N又逐渐转化为硝态氮，其中无光分解组中的分解更为彻底，而自然光照组中PAA分解量小于无光分解组.实验结果表明，氨基酸作为水体中浮游植物的潜在氮源，可以被分解为水华过程中藻类所需的NH₄⁺-N，对水华的维持具有一定的促进作用.;The characteristics of decomposition rate and quantity of amino acids, as well as the change of nitrogen forms, were explored during the process of decomposition of high-density cyanobacterial particles in this study. The results showed that the initial concentrations of particulate amino acids (PAA) were 0.46 mmol/L in natural light group and 0.44 mmol/L in the aphotic group. At the end of the experiment, the PAA was much stable with a concentration of 0.30 mmol/L in natural light group, while decreased dramatically to 0.06 mmol/L in the aphotic group. The degradation rate constants were 0.03916 and 0.17424 d^-1, respectively. The concentration of dissolved amino acids (DAA) was much lower in comparison to PAA in the process of decomposition. In detail, the DAA increased gradually and peaked at 10.94 and 7.94 μmol/L for the two groups, respectively, and then declined to around the initial value in the end of the 21st day. At the beginning of the experiment, PAA accounted for 74%-80% of the total amino acids, then PAA was transformed to DAA and ammonia (NH₄⁺-N) quickly, and finally the NH₄⁺-N was transformed gradually to NO₃^--N by nitrification. Compared with the natural light group, the decomposition of particles in aphotic group was more complete. Algal photosynthesis inhibited the decomposition of cyanobacterial particles in the natural group. Our results demonstrated that amino acids are potential nitrogen sources of phytoplankton and could be demineralized to NH₄⁺-N to support phytoplankton growth during cyanobacterial blooms. Therefore, the decomposition of high-density algal particles plays a key role in the maintenance of cyanobacterial blooms.

Variable toxicity of silver nanoparticles to Daphnia magna: effects of algal particles and animal nutrition.

Aquatic environments vary widely in aspects other than their physicochemical properties that could alter the toxicity of novel contaminants. One factor that could affect chemical toxicity to aquatic consumers is their nutritional environment as it can strongly affect their physiology and life history. Nutrition has the potential to alter an organism's response to the toxin or how the toxin interacts with the consumer through its food. Here we determined how growth and survival responses of Daphnia to an emerging contaminant, silver nanoparticles (AgNPs), are affected by the presence of food and its stoichiometric food quality. We used a series of survival tests, each slightly modified, to determine whether variable toxicity in different nutritional environments resulted from algal sequestration of AgNPs in a nontoxic form or from changes to the nutritional status of the test animals. We found that the presence of algae, of good or poor quality, reduced the toxicity of AgNPs on animal growth and survival. However, the decrease in AgNP toxicity was greater for animals consuming P-rich compared to P-poor food. We found evidence that this effect of food quality was due to greater algal uptake of AgNPs by P-rich than by P-stressed algae. However, we also found animal nutrition, in the absence of algal AgNP binding, could affect toxicity with P-nourished animals surviving slightly better when exposed to AgNPs compared to their P-stressed counterparts. Our results show an important role for algal particles and their P content in determining the toxicity of AgNPs in natural waters primarily due to their binding and uptake abilities and, less so, to their effects on animal nutrition.

Re-parameterization of a quasi-analytical algorithm for colored dissolved organic matter dominant inland waters

Quasi-Analytical Algorithms (QAAs) are based on radiative transfer equations and have been used to derive inherent optical properties (IOPs) from the above surface remote sensing reflectance (Rrs) in aquatic systems in which phytoplankton is the dominant optically active constituents (OACs). However, Colored Dissolved Organic Matter (CDOM) and Non Algal Particles (NAP) can also be dominant OACs in water bodies and till now a QAA has not been parametrized for these aquatic systems. In this study, we compared the performance of three widely used QAAs in two CDOM dominated aquatic systems which were unsuccessful in retrieving the spectral shape of IOPS and produced minimum errors of 350% for the total absorption coefficient (a), 39% for colored dissolved matter absorption coefficient (aCDM) and 7566.33% for phytoplankton absorption coefficient (aphy). We re-parameterized a QAA for CDOM dominated (hereafter QAACDOM) waters which was able to not only achieve the spectral shape of the OACs absorption coefficients but also brought the error magnitude to a reasonable level. The average errors found for the 400–750nm range were 30.71 and 14.51 for a, 14.89 and 8.95 for aCDM and 25.90 and 29.76 for aphy in Funil and Itumbiara Reservoirs, Brazil respectively. Although QAACDOM showed significant promise for retrieving IOPs in CDOM dominated waters, results indicated further tuning is needed in the estimation of a(λ) and aphy(λ). Successful retrieval of the absorption coefficients by QAACDOM would be very useful in monitoring the spatio-temporal variability of IOPS in CDOM dominated waters.

Image segmentation and particles classification using texture analysis method

Introduction: Ingredients of oily fish include a large amount of polyunsaturated fatty acids, which are important elements in various metabolic processes of humans, and have also been used to prevent diseases. However, in an attempt to reduce cost, recent developments are starting a replace the ingredients of fish oil with products of microalgae, that also produce polyunsaturated fatty acids. To do so, it is important to closely monitor morphological changes in algae cells and monitor their age in order to achieve the best results. This paper aims to describe an advanced vision-based system to automatically detect, classify, and track the organic cells using a recently developed SOPAT-System (Smart On-line Particle Analysis Technology), a photo-optical image acquisition device combined with innovative image analysis software. Methods The proposed method includes image de-noising, binarization and Enhancement, as well as object recognition, localization and classification based on the analysis of particles’ size and texture. Results The methods allowed for correctly computing cell’s size for each particle separately. By computing an area histogram for the input images (1h, 18h, and 42h), the variation could be observed showing a clear increase in cell. Conclusion The proposed method allows for algae particles to be correctly identified with accuracies up to 99% and classified correctly with accuracies up to 100%.

Effects of algae particle size on the breathing and feeding of filter-feeding silver carp (Hypophthalmichthys molitrix Val.)

A variety of parameters associated with breathing and feeding of silver carp were measured in response to declines in dissolved oxygen (DO) levels when the fish were fed microalgae Padorina morum (PM group) and Chlorella ellipsoidea (CE group), respectively, to explore the relationship between breathing and feeding while filtering microalgae particles at different DO levels. The results indicated that (i) respiratory frequency (fR) of the fish in CE group were higher significantly than those in PM group at DO levels of 0.98–7.49 mg/L (P < 0.05); respiratory stroke volume (VS.R), gill ventilation (VG) and VG/VO2 the fish in two groups began to increase sharply while DO levels declined to below 4.04 mg/L (P < 0.05); oxygen extraction efficiency (EO2) of the fish in two groups increased significantly with decline of DO levels from 7.49 mg/L to 0.98 mg/L (P < 0.05); (ii) the infiltration rate (FR) and filtering efficiency (E) of the fish in two groups began to decrease significantly while DO levels declined to below 4.04 mg/L (P < 0.05); clearance rate (CR) of fish in PM group was sixfold higher than that in CE group at DO levels of 0.98–7.49 mg/L (P < 0.05). In addition, antifiltering response appeared at DO levels of 2.21 mg/L and 0.98 mg/L in both groups. This study indicated that ‘filtration effect’ is dominant when the fish filter algae particles larger than its gill raker gaps, while the ‘food sinking effect’ is dominant when the fish filter algae particles smaller than its gill raker gaps.

Valorisation of macroalgae industrial by-product as filler in thermoplastic polymer composites

Poly(lactic acid) composites filled with algae industrial by-product were prepared using melt-mixing process at filler weight fractions of 20, 30 and 40wt%. Algae by-products were after the extraction of alginate (AW) and mixed with diatomaceous earth (DE). The composition and morphology of both fillers were analysed. Composites’ mechanical properties and thermal degradation were investigated as a function of filler type and content. The addition of DE-filler at 40wt% resulted in the increase of Young’s modulus by 20% compared to the neat PLA. The presence of small DE particles improved stress distribution and led to stronger composites as compared with AW-filled. Cold crystallization of PLA was induced by small algae particles. Thermal degradation of all composites started at lower temperatures compared with neat PLA. A glow-wire test was carried out to evaluate the effect of inorganic matter on the ignition of the material.