Nuri Azbar

Ege University · Center of Enviromental Studies

Green Deal published by the European Union (EU) aims to reduce greenhouse gas emissions by 40% by 2030 compared to 1990 levels, to increase the share of renewable energy in total energy consumption to 27%, and to increase energy efficiency by a minimum of 27%. Therefore, developed and developing countries and some international organizations have t...

In this study, the effects of different pretreatment methods on the biochemical methane potential (BMP) of hurds from two hemp species, namely Narlısaray (NS) and Futura 75 (F), were investigated. The effect of pretreatment on BMP was discussed on the basis of the change in the chemical constituents of the raw material. The highest BMP yields of 27...

Syngas fermentation via the Wood-Ljungdahl (WL) pathway is a promising approach for converting gaseous pollutants (CO and CO2) into high-value commodities. Because the WL involves several enzymes with trace metal components, it requires an adequate supply of micronutrients in the fermentation medium for targeted bioprocessing such as bioethanol pro...

Global energy demand has been escalating creating ever increasing pressure on climate crisis caused by fossil-based fuels. Humankind is now desperately in need of alternative and sustainable energy sources. Therefore, biofuels provide promising solution. Amongst the various biofuels, bioethanol from syngas, which is a mixture of, mostly, CO, CO2, N...

Hydrogenothrophic biomethanation of CO2 is an attractive alternative method for either to increase biogas production or upgrading biogas in biogas plants as a carbon capture and utilization (CCU) technology. The use of various packaging materials providing efficient cell immobilization can increase hydrogenotrophic biomethanation efficiency. For th...

Carbon capture and utilization (CCU) has been offered as a potential technological solution for mitigating the greenhouse gas emissions and climate change concern worldwide. Anaerobically carbon utilization has started to be in the agenda of researchers in recent years since this approach offers significant advantages such as use of catalysis react...

CO is one of the toxic components of syngas, which is the major source of air pollution. Syngas fermentation technology has the ability to convert toxic gases into valuable biofuels, such as ethanol. Fermentative ethanol production is an important method that can be used to promote environmental protection. CO can be converted into ethanol, via the...

Microbial community dynamics and PTA wastewater degradation performance of sequentially connected two-stage upflow anaerobic sludge blanket (UASB) bioreactors have been studied for 225 days. The working volume of acidogenic (R1) and methanogenic reactors (R2) have sixfold differences. Thus, the reactors operated under different hydraulic retention...

Compared to the conventional activated sludge, granular sludge has many advantages like good settling ability, high biomass retention and ability to withstand a high organic loading rate. In this study, the effects of boric acid and chitosan addition on granule formation was investigated in a novel custom made upflow aerobic granular sludge reactor...

In this study, the role of trace element (TE) supplementation and performance characteristics of a thermophilic anaerobic digester fed by food wastes (FW) is investigated in the long run, and a representative operational data set for field application is reported over the whole experimental period. Continuous feeding of food wastes with a dry matte...

Apart from other operational parameters such as temperature, pH, organic loading rate, the availability and concentrations of trace elements seem to be crucial for the successful operation of biogas plants, especially for the anaerobic digestion of chicken manure. In this study, the optimum basal medium composition was designed by using Taguchi Sta...

16s rDNA-based methods were used in order to identify the dynamics of microbial profiles in a HYBRID gas fermentation bio-methanization reactor. The effects of various H2 and CO2 ratios on microbial community were investigated. The HYBRID gas fermentation reactor was composed of granular anaerobic seed and the system fed with only H2 and CO2 gases....

The aim of this study was to comparatively evaluate the effect of hydrothermal carbonization (HTC) conditions on the yield and the fuel properties of hydrochar obtained from food waste (FW) and its digestate (FD). The mass yield of hydrochars from FW and FD were found between 47.0 and 69.8%, 43.0 and 58.2%, respectively, under tested conditions. Ba...

Fermentative hydrogen production from fruit and vegetable wastes (FVWs) through Dry Fermentation Technology (DFT) was studied through three independent experiments in order to find out the effect of particle size and autoclaving pretreatment on bio-hydrogen production from FVWs and as follows: (1) autoclaved FVWs with sizes < 5 cm (experiment I); (...

Abstract This chapter focuses on biohydrogen production from solid wastes. In particular, the waste (organic fraction of municipal solid wastes, forestry wastes, agricultural wastes, industrial wastes, livestock, etc.) that can be used for biohydrogen production and the proper pre-treatment methods (physical methods such as mechanical, irradiation;...

Organic solid wastes are the most abundant sources for biohydrogen production. Dry fermentation system has many advantages over continuously fed reactor systems for treatment of organic solid wastes. In this study the effect of percolation frequency on yield of biohydrogen production from fruit and vegetable wastes using dry fermentation system was...

Dark fermentative hydrogen production from organic waste is an attractive technique that simultaneously treats waste along with generation of renewable fuel. In this study, a relative new technology named dark dry fermentation was tested in a 55-L reactor to treat fruit and vegetable waste (FVW) along with simultaneous generation of biohydrogen. To...

The necessity for reduction of fossil fuel consumption and the increasing energy costs drives the interest in development of alternative renewable energies during past years. OFMSW (Organic Fraction of Municipal Solid Wastes) is a valuable source, while it can be converted to biogas via anaerobic digestion. In this study The anaerobic digestibility...

Trace elements are one of the important parameters for dark fermentative H2 production because they work as co-factors in H2 formation biochemistry. Lack or excess of trace element and its concentrations could be an important reason for the low yield of H2 production. In this study, the effects of 11 different trace elements (Fe, Ni, Zn, Co, Cu, Mn...

In this study, two thermochemical processes, namely steam gasification and supercritical water gasification (SCWG), were comparatively studied to produce hydrogen from food wastes containing about 90% water. The SCWG experiments were performed at 400 and 450 °C in presence of catalyst (Trona, K2CO3 and seaweed ash). The maximum hydrogen yield was o...

In recent years; energy resources have begun to decline and environmental pollution has increased, which has led to the need for renewable energy sources. Hydrogen is an important industrial renewable energy, which has a wide range of potential applications for our near future. Biohydrogen production from fruit and vegetable wastes was investigated...

In this study, anaerobic digestion of farmer’s market waste was studied in the long run and the monitoring of operating parameters is reported to provide detailed operational data for field applications. A continuous feeding of farmer’s market wastes with a dry matter of 5% for 160 days were carried out using a 100 L pilot scale CSTR type anaerobic...

The application potential of nanofiltration (NF) method on the separation of 1,3-propanediol (1,3-PDO) from synthetically prepared fermentation broth was investigated. The rejection tests at different pressures (10, 20, 30 bar) and pH values (7 and 10) were performed on laboratory scale using Desal DL-5 NF membrane. The rejection of succinic acid,...

Hydrogen is considered to be the fuel of the future due to its promising properties in terms of sustainability. Among common hydrogen production methods processes like thermo-chemical, physico-chemical, electro-chemical and biological have been gaining more and more interest lately. A special term “biohydrogen” has been coined which refers to hydro...

Biodiesel production, in which glycerol is produced as a by-product, has increased significantly and now vast amounts of glycerol have been considered as a waste product. Biotechnological conversion of glycerol into a valuable bioplastic raw material, namely, 1,3-propanediol (1,3-PDO) seems to be very promising. In this study, locally isolated Kleb...

Cell and enzyme immobilization are often used for industrial production of high-value products. In recent years, immobilization techniques have been applied to the production of value-added chemicals such as 1,3-Propanediol (1,3-PDO). Biotechnological fermentation is an attractive alternative to current 1,3-PDO production methods, which are primari...

Abstract Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each stud...

In this study, field-scale EGSB bioprocess with a working volume of 2280 m 3 was examined for 1 year in Turk Tuborg Bira ve Malt Sanayi A.Ş. factory, Izmir, Turkey. The aim of the study was to evaluate the performance of the EGSB reactor during anaerobic digestion of brewery wastewater, which was not reported before at a field scale. Even though, n...

Background: Photofermentation, usually used to convert organic acids into hydrogen, has the potential capacity to effectively use a variety of feedstocks. Hydrogen production by photofermentation via immobilized reactor systems has many advantages such as avoiding cell washout at low hydraulic retention times (HRTs) and keeping high biomass invento...

The effects of both biomass age and cell recycling on the 1,3-propanediol (1,3-PDO) production by Klebsiella pneumoniae were investigated in a membrane-supported bioreactor using hollow-fiber ultrafiltration membrane module in two separate experiments. It was determined that older cells have a negative effect on 1,3-PDO production. The concentratio...

Among the economically viable and ecologically acceptable solutions for the safe disposal of waste glycerol coming from biodiesel production, the biotechnological conversion of glycerol into a very high-value-added bioplastic raw material, namely 1,3 propanediol (1,3-PDO) seems to be very promising. This process is easy and environmentally friendly...

Immobilized cultures of locally isolated Klebsiella pneumoniae (GenBank no: 27F HM063413) were employed in the continuous production of the high value added biomonomer, 1,3-propanediol from waste glycerol. The effect of hydraulic retention time (HRT) was tested by increasing the dilution rate gradually. Three different immobilization materials (sta...

In this study, pumice stone (PS), which is a vastly available material in Turkey, was evaluated as an alternative immobilization material in comparison to other commercially available immobilization materials such as glass beads and polyurethane foam. All immobilized bioreactors resulted in much better 1,3-propanediol production from waste glycerol...

Glycerol is the main by-product of transesterification of fats in the biodiesel production. 1,3-Propanediol (1,3-PDO) is a valuable chemical that can be obtained from glycerol by microbial conversion. A number of Enterobacteriaceae species are able to produce 1,3-PDO from glycerol in stirred tank freely suspended cell bioreactors. Little is known a...

In this study, various chemical and advanced oxidation processes were tested for en-hancement of anaerobic biodegradation of olive mill effluent (OME). The experiments were carried out in a 20 L lab-scale ACF reactor packed with cross-flow filter material made of water-resistant cardboard with a specific surface area of ~300 m 2 m –3 . The ACF reac...

In this study, the performance of a new cell immobilization material, namely ceramic ball, was examined for continuous biohydrogen production in comparison to suspended cell culture system (CSTR). Production of biohydrogen in both systems was assessed under thermophilic conditions. Both systems were operated at varying hydraulic retention times (HR...

Cell and enzyme immobilization is a widely employed technique in many industrial applications. Over the recent years, researchers have been also focusing on benefiting from the merits of immobilization techniques in biohydrogen studies. In this chapter, various immobilization techniques and their application results in terms of enhancing biohydroge...

Hydrogen is seen as a "fuel of the future" that will replace the petroleum-based economy. It is a versatile energy carrier with the potential for extensive use as a transportation fuel, in power generation, and in many other applications. Hydrogen is currently produced from fossil sources (steam reforming of methane), but technologies utilizing ren...

Hydrogen (H2) is a versatile, clean burning, and renewable energy currency that can potentially displace the use of petroleum-based fuels in the transportation sector, which accounts for 74% of the total projected increase in liquid fuel consumption over the next 30 years. Demand for hydrogen is also expected to increase as it starts penetrating th...

Three of the great challenges facing humanity in the 21st century are energy supply, climate change, and global food security. Although global energy demand is expected to continue to increase, the availability of low cost energy will continue to diminish. Coupled with increasing concerns about climate change due to the CO2 release from the combust...

Hydrogen production methods include thermochemical, physicochemical, and biological processes. In contrast to thermo- and physicochemical processes, biological processes offer great potential for sustainable, renewable hydrogen production. In this article, hydrogen production by light-driven photobiological and anaerobic dark fermentation processes...

Ceramic ring and pumice stone were used as a support matrix for the enhancement of biohydrogen production in immobilized cell culture systems. The reactors were continuously operated for the hydrogen fermentation using sucrose as the major carbon source at varying hydraulic retention times (HRT) as an important operational factor. In terms of volum...

The fermentative production of 1,3-propanediol (1,3-PDO) by Klebsiella pneumoniae under different initial substrate concentrations (between 5 and 110g/L) was investigated. It was found that glycerol was almost 100% utilized and 1,3-PDO production increased up to 20g/L of influent substrate concentration, but there was a significant decrease in both...

The feasibility of the continuous production of a valuable bioplastic raw material, namely 1,3-propanediol (1,3-PDO) from biodiesel by-product glycerol, using immobilized cells was investigated. In addition, the effect of hydraulic retention time (HRT) was also analysed. Ceramic balls and ceramic rings were used for the immobilization of a locally...

The continuous production of 1,3-propanediol (1,3-PDO) was investigated with Clostridium beijerinckii NRRL B-593 using raw glycerol without purification obtained from a biodiesel production process. Ceramic rings and pumice stones were used for cell immobilization in a packed-bed bioreactor. For comparison purpose, a control bioreactor with suspend...

Hydrogen production methods include thermochemical, physicochemical, and biological processes. In contrast to thermo- and physicochemical processes, biological processes offer great potential for sustainable, renewable hydrogen production. In this chapter, hydrogen production by light-driven photobiological and anaerobic dark fermentation processes...

BACKGROUND: Olive oil production is an important economical activity in the Aegean region of Turkey. However, the effluents of the olive oil producing mills with their high organic loads and toxic compounds are causing serious environmental problems. The anaerobic biological treatment of olive mill wastewater (OMWW) using the treatment plants of th...

In this study, H2 was produced from cheese whey wastewater in a two-stage biological process: i) first stage; thermophilic dark fermentation ii) second stage; the photo fermentation using Rhodopseudomonas palustris strain DSM 127 (R. palustris). The effect of both dilution and addition of l-malic acid on the hydrogen production was investigated. Am...

In this study, individual and combined effects of various advanced oxidation processes (individual experiments: UV, O 3, US, H 2O 2; combined experiments: UV/US, UV/O 3, US/O 3, UV/H 2O 2, US/H 2O 2, O 3/H 2O 2, UV/US/O 3, UV/US/H 2O 2, UV/O 3/H 2O 2, US/O 3/H 2O 2 and UV/US/O 3/H 2O 2) as a pre-treatment option for olive mill effluent (OME), which...

Klebsiella species are excellent 1,3-propanediol (1,3 PDO) producers. Klebsiella pneumoniae is a well-studied microorganism and, therefore, its metabolic pathway is known. Accordingly, a number of by-products are simultaneously produced together with 1,3 PDO. Optimization of medium composition significantly decreased these byproducts' concentration...

The primary objective of this study was to evaluate the performance of a 20 l lab scale anaerobic hybrid reactor (AHR) combining sludge blanket in the lower part and filter in the upper part under varying organic loading rates (OLRs) in order to study biodegradation of olive mill effluent (OME). For this purpose, some parameters, such as total phen...

Hydrogen (H2) production from cheese processing wastewater via dark anaerobic fermentation was conducted using mixed microbial communities under thermophilic conditions. The effects of varying hydraulic retention time (HRT: 1, 2 and 3.5 days) and especially high organic load rates (OLR: 21, 35 and 47 g chemical oxygen demand (COD)/l/day) on biohydr...

In this study, optimal basal medium composition for fermentative hydrogen production from cheese whey wastewater was investigated in batch tests. Twenty-five different basal medium formulas was prepared, each containing trace metals concentration (Co, Ni, Zn: 0–5 mg/l), macro elements concentration (Mg: 0–200 mg/l; Mn: 0–10 mg/l, Fe: 0–100 mg/l, Ca...

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Biological decolorisation of Cibacron Black W-NN, was comparatively studied using five commercial (Pleurotus djamor, P. ostreatus, P. citrinopileatus, P. eryngii and P. sajor-caju) and three wild types of (Pleurotus ostreatus, P. ostreatus and P. eryngii) white rot fungi strains on agar plates. The initial dye concentrations in the medium were 20,...

The primary objective of this study was to evaluate the effects of the organic loading rate on the performance of an up-flow anaerobic sludge blanket (UASB) reactor treating olive mill effluent (OME), based on the following indicators: (i) chemical oxygen demand (COD) removal efficiency; and (ii) effluent variability (phenol, suspended solids, vola...

Hydrogen production from cheese whey wastewater via dark fermentation was conducted using mixed culture under mesophilic (36�C � 1) and thermophilic (55�C � 1) conditions, respectively. The hydrogen yields and specific hydrogen production rates were found as follows: mesophilic: 9.2 mmol H2 /g COD (chemical oxygen demand) and 5.1 mL H2 /g VSS h; th...

The olive oil has a healthy image during its consumption due to its oleic acid content, which may prevent some human diseases. Ironically, by-products of olive mill production such as olive mill effluent (OME) and olive cake pose a serious environmental risk where it is produced. In this study, feasibility of using some agro-industrial residue stre...

Biological decolorization of Benazol Black ZN, a reactive azo-type textile dyestuff, was comparatively studied using 3 different commercial-type white rot fungi strains (Pleurotus ostreatus, Pleurotus cornucopiae var. citrinopileatus, Pleurotus djamor, and 2 wild types of P. ostreatus (MCC07 and MCC20) isolated from the nature. The initial dye conc...

The pre-treatment using single H2O2, UV-H2O2 and Fenton's process as a pre-treatment option for olive mill effluent (OME), which is known to contain a significant amount of inhibitory compounds (e.g., phenolics and tannins) was carried out in order to enhance anaerobic degradation of OME. Biochemical Methane Potential (BMP) assay was employed in or...

In this work, feasibility of using chemical pretreatment to improve the anaerobic biological degradation of industrial effluents containing high concentrations of phenolic compounds was investigated. For this purpose, chemical pretreatment of the wastewater generated from olive oil production process, namely olive mill effluent (OME), was conducted...

In this study, cultivation of oyster mushroom, Pleurotus ostreatus, on wheat straw substrate containing tap water and olive mill effluent (OME) mixture containing varying volume of OME was studied in order to investigate the feasibility of using OME as an alternative wetting agent and OME's impact on some fundamental food quality characteristics of...

A screening test for five different white rot fungal strains (Pleurotus species: Pleurotus cornucopiae var. citrinopileatus, P. djamor, P. eryngii, P. ostreatus and P. sajor-caju) was carried out to assess their decolorisation capacities for five different textile dyestuffs, namely Indanthren yellow F3GC Collosiol (IYFC), Blue CC Dranix (BCCD), Ind...

In this paper, the performances of Fixed Bed (FXB), Fluidized Bed (FLB), and Hybrid (HYB, i.e. fluidized bed followed by fixed) operational conditions of biofilm reactors were investigated. The COD (chemical oxygen demand), TN (total nitrogen) and TP (total phosphorus) were taken as performance-indicator parameters. For that purpose, a pilot experi...

A screening test for five different white rot fungal strains (Pleurotus species: Pleurotus cornucopiae var. citrinopileatus, P. djamor, P. eryngii, P. ostreatus and P. sajorcaju) was carried out to assess their decolorisation capacities for five different textile dyestuffs, namely Indanthren yellow F3GC Collosiol (IYFC), Blue CC Dranix (BCCD), Inda...

Advanced oxidation processes (AOPs) are emerging and promising technology both as an alternative treatment to conventional wastewater treatment methods and enhancement of current biological treatment methods especially dealing with highly toxic and low biodegradable wastes. In this paper, the results of domestic wastewater treatment using H2O2/UV p...

In this paper, the results of COD and colour removal from textile effluent using homogeneous photochemical oxidation processes in a batch mode are presented. The results show that the best result was obtained using a combined O3/H2O2/UV process, with 97% removal for COD and 99% removal for colour. Optimum conditions for pH and hydrogen peroxide dos...

Difficulties in achieving low propionate concentrations in anaerobically treated effluents are frequently reported in the literature (Ahring, 1994; Kugelman and Guida, 1989; Rimkus et al., 1982), especially at thermophilic temperatures, with concentrations as high as 1000 to 9600 mg/L sometimes produced. This paper will detail the effect of several...