Rodrigo Navia

• University of La Frontera

A common challenge in hydrogel-based delivery systems is the premature release of low molecular weight encapsulates through diffusion or swelling and reduced cell viability caused by the low pH in gastric conditions. A second biopolymer, such as chitosan, can be incorporated to overcome this. Chitosan is usually associated with colonic drug deliver...

In this study, we evaluated the transformation of algal-based biochar into carbon nanotubes by irradiation in a microwave oven at low energies (100–300 W). Three species of algae (Macrocystis pyrifera, Sarcothalia crispata, and Scenedesmus almeriensis) were selected and pyrolyzed to obtain biochar for carbon nanotubes (CNTs) growth in the presence...

The use of mixed microbial cultures (MMCs) is seen as an attractive strategy for polyhydroxyalkanoate (PHA) production. In order to optimize the MMC-PHA production process, tools are required to improve our understanding of the physiological state of the PHA-storing microorganisms within the MMC. In the present study, we explored the use of flow cy...

Epoxidized oils are widely used in the polymer industry to obtain biodegradable, environmentally friendly epoxy resins. This work examines solvent extraction and oil epoxidation from a wet paste of the microalga Nannochloropsis gaditana using microwave technology. An appropriate extraction solvent containing a mixture of a polar and a nonpolar solv...

The use of antioxidants such as curcumin (Cur) or quercetin (Que) in biomedical and biotechnological applications has been studied owing to their capability to prevent oxidative stress and inhibit free radicals. Using polyhydroxybutyrate (PHB) electrospun fibers is presented as a proper option to encapsulate curcumin and quercetin due to its biocom...

Burkholderia sensu lato (s.l.) species have a versatile metabolism. The aims of this review are the genomic reconstruction of the metabolic pathways involved in the synthesis of polyhydroxyalkanoates (PHAs) by Burkholderia s.l. genera, and the characterization of the PHA synthases and the pha genes organization. The reports of the PHA synthesis fro...

Frost is an important abiotic stress for plants and crops because of the economic losses that are incurred. Plants have two mechanisms for freezing protection: freezing avoidance and freezing tolerance. The former prevents extrinsic and/or intrinsic ice nucleation, while the latter provides plants with tools to survive apoplastic ice formation, by...

Value addition of waste (or) residual biomass gain more interest because it is come under the category of “waste to wealth” and creates new pathway to biorefinery processes. Owing to high carbon contents, residual biomasses are considered as a potential raw material for the preparation of carbon materials which are eco‐friendly and can be the alter...

Polyhydroxyalkanoates (PHA) are bio-based polymers with the potential of replace petrochemical plastics. Nevertheless, PHA commercialization is still low, due to the high production cost associated with industrial-scale development. The most cost/efficient PHA recovery strategies use organochlorine compounds or harsh reagents implying a high enviro...

The production of fatty acid methyl esters (FAME) from waste frying oil (WFO) was studied using fly ash as received as a heterogeneous catalyst. The fly ash used in this research had a high content of both CaO and SO3, two compounds that have been previously proposed as catalysts in FAME production. The study was carried out on the basis of a respo...

This short review analyzed the recent trend towards, progresses towards the preparation of chemicals of, and value-added biomaterials from marine macroalgae resources, especially green seaweeds and their derived ulvan polysaccharides for various applications. In recent years, ulvan both in pristine and modified forms has gained a large amount of at...

In recent years, carbon dots have received immense attention not only due to their exciting structural, morphological as well as physicochemical properties but also because of the versatility in their fabrication and manipulation toward various applications. Traditionally, they have been synthesized using different carbon-rich precursors that are o...

Antioxidants can be encapsulated to enhance their solubility or bioavailability or to protect them from external factors. Electrospinning has proven to be an excellent option for applications in nanotechnology, as electrospun nanofibers can provide the necessary environment for antioxidant encapsulation. Forty-nine papers related to antioxidants lo...

Humanity is in a fight against time regarding the increase of CO2 emissions and its consequences. One of the technologies to reduce emissions is through mineral carbonation. Mineral carbonation by natural conditions is a slow process. Therefore, the operational variables are modified to increase the capture and also the speed of the process. Alkali...

BACKGROUND Bio‐oils can be effectively used for the preparation of bio‐based materials owing to their chemical compositions. In this study, brown macroalgal‐derived bio‐oil was used for the synthesis of graphene oxide‐carbon dot composite by a simple hydrothermal process. RESULTS A simple and facile hydrothermal process was explored for the prepar...

The immobilization of Candida rugosa lipase (CRL)onto biochar was studied in a series of batch experiments. CRL sorption behavior was evaluated as a function of pH, enzyme concentration, temperature and ionic strength. As the immobilized lipase was used for the catalytic esterification of oleic acid, its resistance to solvents and thermal stability...

Real-time particle size analysis, using an engineered focused beam reflectance measurement (FBRM), was studied for the fabrication of chemical composite materials, applying various (inorganic/organic/biological) filler powders with polyacrylamide via the in situ polymerization production process at 80 °C for 24 h. The measured diameter dimensions,...

The high energy consumption in buildings is a major contributor to climate change and atmospheric pollution in south cities of Chile. In this context, insulation materials are a key factor to reduce the energy demand during the operational stage of a building. These materials are however commonly fabricated from petrochemicals with high energy cons...

The objective of this research was to investigate the development of novel bio-based epoxides from microalgae Nannochloropsis gaditana lipids, which were extracted using hexane, petroleum ether and methanol:chloroform (2:1 v/v). In lipids epoxidation, conversions of 90.9%, 99.3% and 87.6% of epoxidized microalgae lipids (EML) were obtained for lipi...

Preparation of composite nanofibers by using whole microalgal biomass (Scenedesmus almeriensis) with poly(ethylene oxide) by electrospinning process was explored in presence of different solvents. Diameter and morphology index of the nanofibers were determined by using scanning electron microscopy (SEM) analysis. Out of the solvents examined, ethan...

Botryococcus braunii is a promising microalga for the production of biofuels and other chemicals because of its high content of internal lipids and external hydrocarbons. However, due to the very thick cell wall of B. braunii, traditional chemical/physical downstream processing very often is not as effective as expected and requires high amounts of...

Energy consumption linked to non-renewable resources such as fossil fuels contributes to greenhouse gas emissions and increases resource depletion. In this context, the use of agricultural solid residues such as rice husk, coffee husk, wheat straw, sugar cane bagasse, among others, has been widely studied as an alternative energy source in order to...

The objective of this study was the use of vacuum distillation to increase fatty acid methyl ester (FAME) content and quality of microalgae biodiesel produced through direct transesterification. Microalgae biodiesel obtained from direct transesterification of microalgae (crude biodiesel) has a FAME content of 64.98 ± 2.88%, viscosity of 17.7 ± 0.17...

Economic and environmental benefits may be obtained by extracting certain resources from industrial waste instead of natural sources. Flue dust from Cu smelting is a potential source of Ge, since relatively high contents of this element may be present in Cu-sulphide ores. This study focuses on evaluating Cu smelting flue dust as a potential source...

Thermal insulation materials play a significant role in improving the energy efficiency of buildings and therefore many studies focus their efforts on developing low environmental impact materials. In this context, the aim of this work was to study a natural polymer obtained from Hydrangea Macrophylla (HM) and its application as a thermal insulatio...

A life cycle assessment was conducted to study the environmental effects of a biochar-soil system and to identify the main environmental hotspots. Six scenarios were evaluated, which included the production of biochar from agricultural and forestry residual biomass pyrolyzed at 300, 400, and 500 °C, using a functional unit of 1 t of produced biocha...

The effects of the pyrolysis conditions in terms of temperature (400 to 600 °C), residence time (0.5 to 3.5 h), nitrogen flux (0 to 1 L/min), and temperature increase rate (1.5 to 3 °C/min) on the physicochemical properties of biochar were studied. The physicochemical properties evaluated in the biochar were specific surface area, pore volume, aver...

Rapid population growth and consumption of goods and services imply that demand for energy and resources increases continuously. Energy consumption linked to non-renewable resources contributes to greenhouse gas emissions and enhances resource depletion. In this context, the use of agricultural solid residues such as rice husk, coffee husk, wheat s...

The aim of this study was to characterize a compost blend prepared from sheep manure and oat straw in a co-composting process enriched with oat husk biochar (BC). For this, a co-composting trial was carried out in rota-tories bins of 200 L capacity. Three mixtures (piles) were assayed: BC0: sheep manure (SM) 65% w/w with 35% w/w oat straw (OS) and...

The objective of this work was to quantify the country’s NH3 emissions from livestock production. This calculation was based on the mass flow of total ammoniacal nitrogen (TAN). The analysis was performed for all 15 geographical regions in Chile. The definition of livestock subcategories was based on data from the Chilean Agriculture and Forestry C...

Sewage sludge was evaluated as high available and low cost microbial oils feedstock for biodiesel production. Samples from four different wastewater treatment plants from La Araucanía Region in Southern Chile presented total lipids content ranging between 7.7 and 12.6%, being Vilcún sewage sludge that with the highest transesterifiable lipids conte...

Non-polar and polar solvents as well as their mixtures were tested for the extraction of microalgae lipids and thus, to evaluate their effect on total and esterifiable lipids extraction yields with potential to be converted to biodiesel. The obtained results show an increase in lipids and esterifiable lipids extraction yields when non-polar and pol...

The global use of nitrogen (N) fertilizer has increased 10-fold in the last fifty years, resulting in increased N losses via nitrate leaching to groundwater bodies or from gaseous emissions to the atmosphere. One of the biggest problems farmers face in agricultural production systems is the loss of N. In this context, novel biological nitrification...

Purpose This study compares transport performance of residual biomass using different pre-treatment options. Life cycle inventory data was obtained from forestry companies in southern Chile, databases, scientific and technological literature, as well as equipment operational manuals. Methods Three different scenarios were evaluated: residual biomas...

ABSTRACT Innovative biocomposites from residual microalgae biomass (RMB), a by-product of biodiesel production, and PBAT (Poly(butylene adipate-co-terephthalate)) have been prepared in this study. RMB was characterized by infrared spectroscopy (FT-IR) and its thermal stability was determined. Subsequently, RMB and PBAT biocomposites were prepared b...

This study proposes to select the most appropriate sewage sludge (greasy, primary and secondary) for in situ transesterification and to compare the technical, economic and energetic performance of an enzymatic catalyst (Novozym®435) with sulfuric acid. Greasy sludge was selected as feedstock for biodiesel production due to its high lipid content (4...

Biochar constitutes a promising support material for the formulation of controlled-release fertilizers (CRFs). In this study we evaluated the effect of different polymeric materials as encapsulating agents to control nitrogen (N) leaching from biochar based CRFs. Nitrogen impregnation onto biochar was performed in a batch reactor using urea as N so...

In situ transesterification of biomass has the potential to simplify and reduce the cost of biodiesel production from microalgae. This route has the advantage of reducing the number of unit operations, by avoiding the lipid extraction step, prior to transesterification reaction. Thus, the biomass is directly contacted with the alcohol and the catal...

The use of biochar in agricultural soils appears to be promising because it is known to improve soil properties and increase crop production. However, few studies have been conducted with biochar on volcanic soils. Two field experiments were conducted simultaneously to evaluate the effect of oat hull biochar (OBC) on various physical-chemical prope...

The aim of this work was to evaluate fatty acid methyl esters (FAME or biodiesel) microfiltration dynamics during transesterification of rapeseed oil using a ceramic membrane of 0.2 m size pore. Moreover, ternary phase diagrams were studied and applied for glycerol separation. At the beginning, membrane filtration causes TG (Triglycerides) retentio...

Fly ash from petroleum coke combustion was evaluated for CO2 capture in aqueous medium. Moreover the carbonation efficiency based on different methodologies and the kinetic parameters of the process were determined. The results show that petroleum coke fly ash achieved a CO2 capture yield of 21% at the experimental conditions of 12gL(-1), 363°K wit...

Technological, energetic, economic and environmental feasibilities of a production system should be analyzed for the best conditions for implementing a process to be established. Refined soybean oil is a high-cost feedstock for biodiesel production, because it involves crop production, oil extraction and refining. Desolventizing and refining steps...

The agriculture activities produced an important amount of residues and in the agroecosystems of South Chile the burning of these is a widely practiced management causing some problems such as air pollution and nutrients lost mainly soil organic matter. Indeed, the transformation and reutilization of agricultural wastes by the pyrolysis methods obt...

Increasing fertilizer nitrogen use efficiency is one of the challenges agriculture faces nowadays. Agriculture is highly dependent on the use of fertilizers, which can produce high N losses, resulting in detrimental effects on the environment, also affecting the stability of agricultural ecosystems. A strategy to increase N fertilization efficiency...

Enzymatic biodiesel production kinetics under previously optimized conditions were investigated. Waste frying oil (WFO) was used as the raw material, Novozym 435 as catalyst, methanol as acyl acceptor and tert-butanol as co-solvent. To investigate pure transesterification kinetics improving product properties, 3Å molecular sieves were incorporated...

Very much attention has been focused on lipases as these enzymes can be used as biocatalysts, allowing a cost effective and environmentally friendly method to efficiently catalyze specific reactions. However, its application at industrial scale is still limited due to several shortcomings including low stability in their native state, inhibition by...

BACKGROUND Biodiesel production is not economically competitive with petroleum diesel particularly when using virgin and refined vegetable oils. Rich-in-oil miscella obtained from the extraction of soybean oil with ethanol may be a promising feedstock for taking off the refining process, simultaneously introducing an environmental friendly step by...

The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, prev...

Microalgae can produce and contain lipids, proteins and carbohydrates, which can be extracted and marketed as potential novel added-value bio-products. However, microalgae cell wall disruption is one of the most important challenges involved while processing this type of biomass. In this context, white-rot fungi, responsible for the biodegradation...

This research paper provides a brief discussion about the relevance of third generation biodiesel co-products diversification. This diversification can be performed through the utilization of residual microalgal biomass (RMB) after oil extraction process. The present work analyses the use of RMB as potential filler for biocomposite production by means...

The use of biochar (BC) as an amendment for agricultural soils is a promising practice, because it improves some soil parameters and could contribute to increase crop yields. The aim of this study was to evaluate the use of BC on some soil physical-chemical parameters and yield of barley (Hordeum vulgare) in two volcanic soils of southern Chile. Fo...

Microalgae biomass is becoming an interesting raw material to produce biodiesel, where several approaches in the transesterification process have been applied such as different catalysts, different acyl acceptors, incorporation of co-solvents and the different operational conditions. However there are some drawbacks that must be solved before any i...

The use of FGD-gypsum as material for selenium removal from re-circulated waters at a coal-fired power plant equipped with a wet limestone flue gas desulphurisation (FGD) system with use of an Al-additive (to boost the desulphurisation efficiency), has been evaluated by adsorption studies. Potentiometric titration experiments for FGD-gypsum samples...

DOI 10.1007/s11157-013-9308-0

This article presents a review of the porous physical characteristics, phenomena and simulation models so far investigated and applied in the management of biodegradable wastes (BW), summarising the main properties of porous media and the dynamics of fluids within its voids. The aim is to highlight how the description of biodegradable wastes as por...

This work improved the fatty acid methyl esters (FAMEs) quality produced using a stoichiometric methanol to oil molar ratio, removing monoglycerides (MGs), diglycerides (DGs) and glycerol by using a ceramic membrane. This work improved the conventional biodiesel batch reactor (CBR) performance, adding a refining stage using a ceramic membrane accor...

The use of biochar has traditionally been focused on agronomic applications. Today it is possible to find a wide range of research devoted to study the use of biochar in the most varied fields. This is mainly due to its properties and the diversity of materials that can be used in their synthesis. Also, the conditions of operation in the process of...

A novel three-phase solid–gas–liquid bioreactor (SGLB) concept using gaseous alcohol and liquid rapeseed oil with immersed microorganisms overlying a nutrient agar phase (solid) is proposed for biodiesel (fatty acid alkyl esters, FAAE) production based on the high hydrophobicity and negative surface charge showed by the fungi Rhizopus oryzae. This...

One major problem in the lipase-catalyzed production of biodiesel or fatty acid methyl esters (FAME) is the high acidity of the product, mainly caused by water presence, which produces parallel hydrolysis and esterification reactions instead of transesterification to FAME. Therefore, the use of reaction medium in absence of water (anhydrous medium)...

The waste management of a chlor-alkali and calcium chloride industrial facility from southern Chile was the object of this study. The main solid waste materials generated in these processes are brine sediments and calcium chloride sediments, respectively. Both residues are mixed in the liquid phase and filtered in a press filter, obtaining a final...

Sodium hydroxide is the most commonly used basic homogeneous catalyst in biodiesel production. However, residual amounts of this catalyst in crude biodiesel may form sodium soaps during reaction and storage. In this paper, a dry washing process for biodiesel using polyesters synthesized from glycerol and adipic acid is proposed. Three formulations...

This work focuses on the development, characterization and use of a non-conventional sorbent (NCS) using a blend of petroleum coke fluidized bed combustion fly ash and the organic waste fraction from a Kraft cellulose wastewater facility. In addition to an increase in specific surface area and particle size distribution, NCS showed a similar chemic...

This work deals with the characterization of a circulated fluidized bed combustion (CFCB) Chilean petroleum coke fly ash (FA) from a petroleum coke power plant, and its potential use in neutralization and heavy metals removal from acid wastewaters. FA presents a high Ca and content, being anhydrite the major crystalline mineral phase, with minor pr...