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12 Páginas.-- 2 Figuras.-- 6 Tablas, This study shows, for the first time, how the natural biodegradation of the Phaeophyceae Rugulopteryx okamurae (R.o.) affects its methane yield, by biochemical methane potential assays, and the methane production kinetics. Additionally, a mechanical (zeolite-assisted milling) and a thermal (120 °C, 45 min) pretreatments were assessed. The highest methane yield was obtained from the mechanically pretreated fresh ashore biomass (219 (15) NLCH4 kgVS-1), which presents the use of zeolite during milling as an economical alternative for heavy metal toxicity reduction. Moreover, no significant differences were observed between the other tests (with the exception of the lowest value obtained for the mechanically pretreated fresh R.o.). Low methane yields were linked to the heavy metal content. However, an increase of 28.5 % and 20.0 % in the k value was found for the untreated fresh R.o. biomass and fresh ashore biomass, respectively, when subjected to thermal pretreatment. Finally, an enhancement of 80.5 % in the maximum methane production rate was obtained for the fresh ashore biomass milled with zeolite compared to the untreated fresh ashore biomass., The authors wish to express their gratitude to Lisa Souvre for her fundamental assistance on the experimental procedure. We also wish to thank Dr. Menta Ballesteros and Dr. Ángel Rabdel Ruiz-Salvador for providing zeolite samples and scientific and technical support. Finally, the authors wish to express their gratitude to the Spanish Ministry of Science and Innovation for providing financial support through the project PID2020-114975RB-100/AEI/10.13039/5011000/11033. M.J. F-R is recipient of a “Juan de la Cierva Formación” grant from the Spanish State Research Agency (FJC2020-045654-I).

1 Figura.-- 5 Tablas, Microalgae are photosynthetic organisms able to grow faster than land plants and produce biomass with relatively high energy potential. Accumulated high-value compounds like lipids, minerals, or proteins have focused the attention of scientists due to the potential production of biofuels and other value-added products. However, several drawbacks regarding both the biochemical structure of these organisms and technological difficulties have prevented the industry for implementing a comprehensive low-cost process regarding energy and environmental contamination. Among these technologies, anaerobic digestion (AD) has greatly increased research attention because of its simplicity and the ability to produce easily recycle by-products. Moreover, anaerobic co-digestion (AcoD) has shown promising results as a method to bypass the AD problems of microalgae as a sole substrate. This review is focused on the recent trends and comparison of the AcoD process to maximize energy recovery from microalgae biomass and agro-industrial wastes. The yield of methane gas among the studied bibliography is compared and a critical review of published data and methods used is included., The authors wish to express their gratitude to the regional government of Andalucía, Junta de Andalucía, Consejería de Transformación Económica, Industria, Conocimiento y Universidades (Project FEDER UPO-1380782) and to the Spanish national R&D plan (PID2020-114975RB-100/AEI/10.13039/5011000/11033) for providing financial support.

5 Figuras.-- 3 Tablas, The invasive alien seaweed Rugulopteryx okamurae (R.o.) has spread quickly through the Mediterranean Sea causing an unprecedented ecological impact. A solution integrated into a circular economy model is needed in order to curb the negative effects of its presence. Anaerobic digestion (AD) is proposed as a feasible process able to transform biomass into renewable energy. Nevertheless, in order to improve the methane yield and surpass the drawbacks associated with AD processes, this research proposes a thermal pretreatment and a new developed method where the macroalgae is mechanically pretreated with zeolite. Chemical and microstructure characterization of the algal biomass after pretreatments involved scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The highest methane yields of 240 (28) and 250 (20) NLCH4 kg-1 VSadded were obtained with the new mechanical pretreatment and the thermal pretreatment at 120 °C for 45 min without zeolite, achieving a 35 % improvement against the non-pretreated algae. A direct relationship between the crystallinity index of the samples and methane production was observed. The experimental data of methane production versus time were found to be in accordance with both first-order kinetic and Transference Function mathematical models., The authors wish to express their gratitude to the Spanish Ministry of Science and Innovation for providing financial support through the project PID2020-114975RB-100/AEI/10.13039/5011000/11033. Assistant by Dr. Consuelo Cerrillos González on the SEM measurement and analysis is acknowledged. We also thank the CEPSA Foundation, Red Eléctrica de España (REE) and Port Authority of Algeciras Bay (APBA) for their additional financial support for the development of environmental monitoring campaigns for Rugulopteryx okamurae and for obtaining samples of this species used in this work.

9 Páginas.-- 2 Figuras.-- 4 Tablas, The aim of the present research was to investigate the influence of the application of a novel cold-pressing system in olive oil manufacturing on the characteristics of olive pomace (OP) and on its valorization by anaerobic digestion (AD). Green olives and olives in veraison, both from the Picual variety, were used with the objective of assessing the effect of ripening level on the performance of the AD processes. The AD processes of these OPs were assessed in biochemical methane potential (BMP) tests. The maximum methane yield (327 ± 5 mL CH4/g VS) and biodegradability value (90.8%) were found for the OP derived from green olives without cold-pressing, which showed the highest soluble COD (113 g O2/L) and the lowest total phenolic concentration (9 g gallic acid/L). The first-order and Transference Function (TF) kinetic models were employed to evaluate the variation in methane production with time and to obtain the kinetic parameters of the anaerobic processes of the four OPs tested. The kinetic constant from the first-order model, k, did not show significant differences for the four OPs tested and ranged between 0.23 and 0.27 day−1. The TF revealed that the values for the maximum methane production rate (Rmax) were slightly higher for the OPs derived from green olives compared to those obtained from olives in veraison. For the green olives, the cold-pressing system caused a decrease in the value of Rmax from 87 ± 7 to 73 ± 6 mL CH4/(g VS·d)., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by Project PY18-616 funded by the regional government of Andalucía, Junta de Andalucía, Consejería de Economía, Conocimiento, Empresas y Universidad, Andalucía, Spain, and Project PID2020-114975RB-100/AEI/10.13039/501100011033 financed by the Spanish Ministry of Science and Innovation. The project FEDER UPO-380782 financed by the regional government of Andalucía, Junta de Andalucía, Consejería de Trasformación Económica, Industria, Conocimiento providing financial support to Dr. Fernández-Rodríguez.

This study evaluates the comprehensive valorization of the byproducts derived from the two-phase olive oil elaboration process [i.e., olive washing water (OWW), olive oil washing water (OOWW), and olive mill solid waste (OMSW)] in a closed-loop process. Initially, the microalga

This study evaluates the comprehensive valorization of the byproducts derived from the two-phase olive oil elaboration process [i.e., olive washing water (OWW), olive oil washing water (OOWW), and olive mill solid waste (OMSW)] in a closed-loop process. Initially, the microalga Raphidocelis subcapitata was grown using a mixture of OWW and OOWW as the culture medium, allowing phosphate, nitrate, sugars, and soluble chemical oxygen demand removal. In a second step, the microalgal biomass grown in the mixture of washing waters was used as a co-substrate together with OMSW for an anaerobic co-digestion process. The anaerobic co-digestion of the combination of 75% OMSW-25% R. subcapitata enhanced the methane yield by 7.0 and 64.5% compared to the anaerobic digestion of the OMSW and R. subcapitata individually. This schedule of operation allowed for integration of all of the byproducts generated from the two-phase olive oil elaboration process in a full valorization system and the establishment of a circular economy concept for the olive oil industry., Barbara Rincón-Llorente thanks the “Ramon y Cajal ” Program (Contract RYC-2011-08783) from the Spanish Ministry of Economy and Competitiveness. The authors also thank the Regional Government of Andalucía, Junta de Andalucía, Consejeria de Economía Innovación, Ciencia y Empleo (Project of Excellence RNM-1970) for funding the research.

The chelate complex [Pd(κ(2)-C,O-C6H4CH2O-2)(bpy)] () reacts with acetonitrile, cyanamides, or carbodiimides, in the presence of AgOTf (1 : 5 : 1 molar ratio) and residual water, to form complexes [Pd{κ(2)-C,N-C6H4{CH2OC([double bond, length as m-dash]NX)Y}-2}(bpy)](OTf), where X = H, Y = Me (), NMe2 (), NEt2 (), X = R, Y = NHR (R = (i)Pr (), Tol ()), as a result of the insertion of the unsaturated reagent into the O-Pd bond of and the protonation of one of the N atoms. In the absence of AgOTf the reaction of with TolN[double bond, length as m-dash]C[double bond, length as m-dash]NTol (Tol = p-Tolyl) results in the formation of the neutral complex [Pd{κ(2)-C,N-C6H4{CH2OC([double bond, length as m-dash]NTol)NTol}-2}(bpy)] (). Complexes and can be interconverted by deprotonation ( + KO(t)Bu) or protonation ( + KOTf + HOTf) reactions. When the reaction of with TolN[double bond, length as m-dash]C[double bond, length as m-dash]NTol in the presence of AgOTf is carried out in a 1 : 1 : 1 stoichiometric ratio, or for a short period of time, a mixture of and a mixed heterometallic Ag2Pd complex is obtained ( = [Ag(N-)2](OTf)). Complex is the major product when the AgOTf is added before the carbodiimide, and the reaction is stopped immediately. can also be obtained by reaction of with 0.5 equiv. of AgOTf. When complex [PdI(C6H4CH2OH-2)(bpy)] () reacts with (i)PrN[double bond, length as m-dash]C[double bond, length as m-dash]N(i)Pr in the presence of TlOTf, instead of AgOTf, a ca. 1 : 1 mixture of and [Pd{κ(2)-O,N-OCH2{C6H4{C([double bond, length as m-dash]NH(i)Pr)N(i)Pr}-2}}(bpy)](OTf) () forms. Complex is the result of the insertion of the carbodiimide into the C-Pd bond. Complexes have been extensively characterized by NMR spectroscopy, and the crystal structures of , , and ·2.5CHCl3·0.5Et2O have been determined by X-ray diffraction studies.

The aryl palladium complexes [PdI(C6H4CH2OH-2)(N∧N)] (N∧N = bpy = 2,2′-bipyridyl (1a), tbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine (1b), tmeda = N,N,N′,N′-tetramethylethylenediamine (1c)) were synthesized by oxidative addition of 2-iodobenzyl alcohol to one equivalent of “[Pd(dba)2]” (dba = dibenzylideneacetone) in the presence of the N∧N ligands. By reaction of 1a with three equivalents of XyNC (Xy = 2,6-dimethylphenyl) the insertion complex trans-[PdI{C(═NXy)(C6H4CH2OH-2)}(CNXy)2] (2) was formed. The reaction of 1a with KOtBu resulted in the formation of the chelate complex [Pd(κ2-C,O-C6H4CH2O-2)(bpy)] (3), which crystallizes as pairs of molecules bridged by hydrogen bonds to water of crystallization. Complex 3 reacts with XyNC, forming the cyclic imidate N-(2,6-dimethylphenyl)-2-benzofuran-1(3H)-imine (4). By reaction of 3 with various primary alkyl halides RCH2X, the complexes [PdX(C6H4CH2OCH2R-2)(bpy)] (X = I, R = H (5a), X = Br, R = Ph (5b), p-C6H4CH2Br (5c), p-C6H4Br (5d), and p-C6H4I (5e)) were obt...

The dinuclear complexes [C6H2{PdBr(N∧N)}2-1,4-((E)-CH═CHPh)2-2,5] (N∧N = tbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine (1a), tmeda = N,N,N′,N′-tetramethylethylenediamine (1b)) have been synthesized by oxidative addition of trans,trans-2,5-distyryl-2,4-dibromobenzene to 2 equiv of “[Pd(dba)2]” (dba = dibenzylideneacetone) in the presence of the N∧N ligands. A similar reaction with N∧N = bpy = 2,2′-bipyridine afforded the mononuclear complex [PdBr{C6H2(Br-4){((E)-CH═CHPh)2-2,5}(bpy)] (2). The reaction of 1a,b with PhC≡CPh, MeC≡CMe, and PhC≡CMe in the presence of TlOTf or AgClO4 gave the dipalladated indacenediide complexes [(μ-η,η-C12H2Bn2-1,5-R4-2,3,6,7){Pd(N∧N)}2](OTf)2 (Bn = benzyl, R = Ph, N∧N = tbbpy (3a), tmeda (3b); R = Me, N∧N = tbbpy (4a), tmeda (4b)) and [(μ-η,η-C12H2Bn2-1,5-Ph2-2,6-Me2-3,7){Pd(N∧N)}2](A)2 (N∧N = tbbpy, A = OTf (5a), ClO4 (5a′); N∧N = tmeda, A = OTf (5b)). The reactions of 2 with the same alkynes afforded the indenyl complexes [Pd(η-C9H2Bn-1-R2-2,3-((E)-CH═CHPh)-5-Br-6)(bpy)](A) (R =...

[2 + 3] Cycloaddition reactions of the di(azido)-PdII complex trans-[Pd(N3)2(PPh3)2] (1) with an organonitrile RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PPh3)2] (3) [R = Me (3a), Ph (3b), 4-ClC6H4 (3c), 4-FC6H4 (3d), 2-NC5H4 (3e), 3-NC5H4 (3f), 4-NC5H4 (3g)]. The reaction of trans-[Pd(N3)2(PPh3)2] (1) with propionitrile (2h) also affords, apart from trans-[Pd(N4CEt)2(PPh3)2] (3h), the unexpected mixed cyano-tetrazolato complex trans-[Pd(CN)(N4CEt)(PPh3)2] (3h′) which is derived from the reaction of the bis(tetrazolato) 3h with propionitrile, with concomitant formation of 5-ethyl-1H-tetrazole, via a suggested unusual oxidative addition of the nitrile to PdII. The [2 + 3] cycloadditions of [Pd(N3)2(PTA)2] (4) (PTA = 1,3,5-triaza-7-phosphaadamantane) with RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PTA)2] (5) [R = Ph (5a), 2-NC5H4 (5b), 3-NC5H4 (5c), 4-NC5H4 (5d)]. All these reactions are greatly accelerated by microwave irradiation (1 h, 125 °C, 300 W). Taking advantage of the hydro-solubility of PTA, a simple liberation of 5-phenyl-1H-tetrazole from the coordination sphere of trans-[Pd(N4CPh)2(PTA)2] (5a) was achieved. The complexes were characterized by IR, 1H, 13C{1H} and 31P{1H} NMR spectroscopies, ESI+-MS, elemental analyses and, for 3b, also by X-ray structure analysis. Weak agostic interactions between the CH groups of the triphenylphosphines and the palladium(II) centre were found.

The first palladium complex with an indacenediide ligand has been obtained by an unprecedented process involving the reaction of diphenylacetylene with a dipalladated 2,5-distyrylbenzene complex.