Tropical fruit waste-derived mesoporous rock-like Fe2O3/Ccomposite fabricated with amphiphilic surfactant-templating approach showing massive potential for high-tech applications

Recently, the glycolipids biosurfactant materials have widely been utilized for many industrial applications due to their feasible surface activity, biodegradable as well as eco-friendly nature. Even though many of the earlier studies have been reported on such kind of surfactants, in this study we focused on porous rocks-like Fe2O3/C composites, which were magnificently synthesized from a novel tropical fruit biomass, using a glycolipid biosurfactant with high specific surface area of about 466.9 m2/g via a biofunctional single-step thermochemical method. They could be applied as an adsorbent to adsorb the pharmaceutical pollutants mainly, DCF from aqueous solution. Moreover, the highest adsorption capacity for DCF could be achieved, which is of about 77.51 mg/g. Furthermore, as-prepared glycolipid functionalized Fe2O3/C composites were used as electrode materials for high-performance supercapacitors. Galvanostatic charge-discharge results showed that the Fe2O3/C modified electrode possesses a specific capacitance of about 374 F/g with a current density of 0.2 A/g and it has retained 84% of capacitance, even after 3000 cycles. The remarkable performances are mainly due to the surface amendments of the Fe2O3/C composite, using biologically produced glycolipid surfactant, would have more favorable foreground towards the upcoming energy crises.publishedVersio

A review on occurrence and spread of antibiotic resistance in wastewaters and in wastewater treatment plants: Mechanisms and perspectives

This paper reviews current knowledge on sources, spread and removal mechanisms of antibiotic resistance genes (ARGs) in microbial communities of wastewaters, treatment plants and downstream recipients. Antibiotic is the most important tool to cure bacterial infections in humans and animals. The over- and misuse of antibiotics have played a major role in the development, spread, and prevalence of antibiotic resistance (AR) in the microbiomes of humans and animals, and microbial ecosystems worldwide. AR can be transferred and spread amongst bacteria via intra- and interspecies horizontal gene transfer (HGT). Wastewater treatment plants (WWTPs) receive wastewater containing an enormous variety of pollutants, including antibiotics, and chemicals from different sources. They contain large and diverse communities of microorganisms and provide a favorable environment for the spread and reproduction of AR. Existing WWTPs are not designed to remove micropollutants, antibiotic resistant bacteria (ARB) and ARGs, which therefore remain present in the effluent. Studies have shown that raw and treated wastewaters carry a higher amount of ARB in comparison to surface water, and such reports have led to further studies on more advanced treatment processes. This review summarizes what is known about AR removal efficiencies of different wastewater treatment methods, and it shows the variations among different methods. Results vary, but the trend is that conventional activated sludge treatment, with aerobic and/or anaerobic reactors alone or in series, followed by advanced post treatment methods like UV, ozonation, and oxidation removes considerably more ARGs and ARB than activated sludge treatment alone. In addition to AR levels in treated wastewater, it examines AR levels in biosolids, settled by-product from wastewater treatment, and discusses AR removal efficiency of different biosolids treatment procedures. Finally, it puts forward key-points and suggestions for dealing with and preventing further increase of AR in WWTPs and other aquatic environments, together with a discussion on the use of mathematical models to quantify and simulate the spread of ARGs in WWTPs. Mathematical models already play a role in the analysis and development of WWTPs, but they do not consider AR and challenges remain before models can be used to reliably study the dynamics and reduction of AR in such systems.publishedVersio

A review on the biomass pretreatment and inhibitor removal methods as key-steps towards efficient macroalgae-based biohydrogen production

(Red, green and brown) macroalgal biomass is a propitious candidate towards covenant alternative energy resources to be converted into biofuels i.e. hydrogen. The application of macroalgae for hydrogen fermentation (promising route in advancing the biohydrogen generation process) could be accomplished by the transformation of carbohydrates, which is a topic receiving broad attention in recent years. This article overviews the variety of marine algal biomass available in the coastal system, followed by the analyses of their pretreatment methods, inhibitor formation and possible detoxification, which are key-aspects to achieve subsequent H2 fermentation in a proper way

Synthesis, structural elucidation, microbial, antioxidant and nuclease activities of some novel divalent M(II) complexes derived from 5-fluorouracil and l-tyrosine

Novel N2O2 sequence of mononuclear amino acid metal(II) complexes (1a–1e) was synthesized from 5-fluorouracil (5-FU: A) and l-tyrosine (tyr: B) with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ions. The synthesized complexes were structurally characterized by analytical, spectral (FT-IR, UV–vis, 1H NMR, FAB-Mass, TGA/DTA and EPR) as well as molar conductance and magnetic studies. From spectral studies, both the ligands act as bidentate and they bind metal(II) ions through deprotonated-N3 and C4O atoms and amino-N and deprotonated carboxylato-O atoms, respectively, to form a stable metal chelate. The observed low molar conductance values suggest a non-electrolytic nature. Calculated g tensor values of Cu(II) complex (1d) at 77 and 300 K confirm their geometry. Thermal behavior of metal(II) complexes (1a–1c) shows loss of coordinated water molecules in the first step followed by decomposition of ligand moieties in a respective manner and leads to form air stable metal oxide as final residues. Powder X-ray diffraction and SEM studies illustrate that all the complexes have uniform microcrystalline with homogenous morphology. Mn(II), Ni(II) and Cu(II) complexes show significant in vitro antimicrobial and antioxidant activities than 5-fluorouracil(A). Moreover, the nuclease studies of Ni(II) and Cu(II) complexes (1c and 1d) show considerable DNA binding and oxidative DNA cleavage activities than other complexes

Review on the production of medium and small chain fatty acids through waste valorization and CO2 fixation

The developing approaches in the recovery of resources from biowastes for the production of renewable value-added products and fuels, using microbial cultures as bio-catalyst have now became promising aspect. In the path of anaerobic digestion, the microorganisms are assisting transformation of a complex organic feedstock/waste to biomass and biogas. This potentiality consequently leads to the production of intermediate precursors of renewable value-added products. Particularly, a set of anaerobic pathways in the fermentation process, yields small-chain fatty acids (SCFA), and medium-chain fatty acids (MCFA) via chain elongation pathways from waste valorization and CO2 fixation. This review focuses on the production of SCFA and MCFA from CO2, synthetic substrates and waste materials. Moreover, the review introduces the metabolic engineering of Escherichia coli and Saccharomyces cerevisiae for SCFAs/MCFAs production. Furtherly, it concludes that future critical research might target progress of this promising approach as a valorization of complex organic wastes

Evaluation, characterization, and engine performance of complementary fuel blends of butanol–biodiesel–diesel from Aleurites moluccanus as potential alternative fuels for CI engines

© The Author(s) 2018.Biodiesel has gained worldwide attention due to its renewable aspects. However, it needs more quality improvement. Recently, butanol has been considered as a favorable alternative fuel or additive over methanol and ethanol in compression ignition (CI) engines. In this regard, the present work deals with the evaluation of butanol–diesel–biodiesel blends as potential alternative fuels. In this work, biodiesel has been produced from Aleurites moluccanus oil followed by blending with Euro-diesel and butanol. Important characteristics such as kinematic viscosity, density and cloud point besides FT-IR, UV-vis spectra, TGA, DSC and NMR (13C and 1H) were analyzed. Some important engine and emission performance parameters, such as BP, BSFC, CO, HC, NOx and EGT were also studied in this work. Results revealed that blending butanol and Euro-diesel with biodiesel improves the properties of pure biodiesel such as kinematic viscosity (2.41–3.55 mm2/s) and density (841.8–884.6 kg/m3), while maintaining an acceptable range for cold flow properties that are analogous to Euro-diesel. In addition, reduction in BP (24.65–26.35%), HC (52.57–38.71%), and CO (39.18–30.4%) was observed for all the blends at full load compared to Euro-diesel. However, increases in both BSFC (38.17–41.14%) and NOx (24.18–8.35%) were observed. Overall, the blends appear to be good alternatives to biodiesel–diesel blends. Thus, butanol–biodiesel–diesel blends can be considered as potential sustainable fuels for fossil diesel

A review on chemical mechanism of microalgae flocculation via polymers

Industrially, harvesting of the microalgal biomass is a techno-economic tailback, which essentially meant for the algal biomass industry. It is considered energy as well as cost-intensive in view of the fact that the dewatering process during harvesting. In this review chemical reactions involved in the flocculation of microalage biomass via various certain principal organic polymers are focused. Besides, it focuses on natural biopolymers as flocculants to harvest the cultivated microalgae. Commercially, bio-flocculation is suitable and cost-effective in the midst of a range of adopted harvesting techniques and the selection of an appropriate bioflocculant depends on its efficacy on the several microalgae strains like potential biomass fixation, ecological stride and non-perilous nature. The harvesting of toxin free microalgae biomass in large quantity by such flocculants can be considered to be one of the most cost-effective performances towards sustainable biomass recovery. Keywords: Microalage, Flocculation, Natural biopolymers, Chemical reaction

Valorization of spent coffee grounds recycling as a potential alternative fuel resource in Turkey: An experimental study

In this study, recycling of spent coffee ground (SCG) as a potential feedstock for alternative fuels production and compounds of added value in Turkey was assessed. SCG samples were collected from various coffee shops in Kayseri, Turkey. All samples were dried to free them from moisture content. Coffee waste oil was extracted from the dried samples using n-hexane as a solvent. The average oil content was found (&asymp; 13% w/w). All samples (before and after extraction) were tested for SEM, DSC, TGA, XRD, calorific value, surface analysis and porosity, FT-IR and elemental analysis to assess their potential. Elemental analysis indicated that carbon represents the highest percentage (49.59% and 46.42% respectively), followed by Nitrogen (16.7% and 15.5%), Hydrogen (6.74% and 6.04%) and Sulfur (0.851% and 0.561%). These results indicate that coffee waste can be utilized as compost as it is rich in nitrogen. Properties of the extracted oil were examined, followed by biodiesel production. The quality of biodiesel was compared with ASTM D6751 standards and all the properties complied with standard specifications. The fatty acid compositions were analyzed by Gas chromatography. It is observed that coffee waste methyl ester (CWME) is mainly comprised of palmitic (35.8%) and arachidic (44.6%) acids which are saturated fatty acids. The low degree of unsaturation provides an excellent oxidation stability (10.4 h). CWME has also excellent cetane number, higher heating value and iodine value with poor cold flow properties. The studies also investigated blending of biodiesel with euro diesel and butanol. Following this, a remarkable improvement in cloud and pour points of biodiesel was obtained. Coffee waste after oil extraction is an ideal material for garden fertilizer, feedstock for ethanol, biogas production and as fuel pellets. The outcome of such research work produces valuable insights on the recycling importance of coffee waste in Turkey</p