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Abstract Background The objective was to analyze the effectiveness and safety of dual therapy with rilpivirine plus boosted-darunavir (RPV + bDRV) in real-life patients. Methods Observational, retrospective, multi-center study in HIV+ patients who had received RPV + bDRV for 24 weeks to optimize/simplify their previous antiretroviral treatment. We determined the percentage of patients without virologic failure (2 consecutive viral loads > 50 copies/mL) at 24 weeks of treatment. Results The study included 161 patients from 15 hospitals with median age of 49 years; 29.3% had previous AIDS stage and median CD4+ lymphocyte nadir of 170 cells/uL. They had been diagnosed with HIV for a median of 17 years and had received 14 years of ART, with five previous treatment combinations, and 36.6% had a history of virological failure. The reasons for the switch were simplification/optimization (49.7%), toxicity/intolerance (17.4%), or inadequate effectiveness of previous ART (10.6%). Baseline VL of 50–1000 copies/mL was recorded in 25.5% of the patients. In the“intention-to-treat” analysis at 24 weeks, 87.6% of 161 patients continued the study treatment without virologic failure criteria. In the “on treatment” analysis (excluding patients who discontinued treatment with dual therapy for any reason other than virologic failure) the efficacy was 94.6% (141/149 patients). Conclusions Dual therapy with RPV + DRVb proved to be effective and safe in patients with advanced HIV infection, long exposure to ART, low CD4 nadir, previous virologic failure, and/or history of ineffective ART.

The presence of heavy metals in water resources brings hazard to health and the environment considering that most of these cannot be degraded and may result in bioaccumulation in the food chain. Its removal from aqueous solution can relatively be done through adsorption, a known technique that efficiently reduces heavy metal concentration. This study investigated the applicability and efficiency of waste chicken eggshells as an adsorbent for the removal of Cadmium (Cd) heavy metal in aqueous solution. The adsorbent dose, contact time and initial concentration were the chosen variables of the study that were optimized through the Central Composite Design of the Response Surface Methodology using Design Expert 7.0 software. The result of the study showed that the chicken eggshells as an adsorbent could remove Cd in an aqueous solution up to 73%. The optimum adsorption capacity was 146 mg g−1 obtained at 150 mg L−1 initial concentration, 75 min contact time, 0.75 g adsorbent dose, and pH 6 at room temperature. Heterogeneous adsorption occurred during the process as revealed by isotherm studies with Freundlich model emerged having a higher coefficient of determination (R2 = 0.91) than the Langmuir model (R2 = 0.86). Overall, the study demonstrated that the chicken eggshell that is generally considered as wastes in large quantities could become an economically advantageous raw material for the removal of carcinogenic Cd from the water body. Keywords: Cadmium removal, Calcium carbonate, Adsorption, Eggshell, Heavy metal

Low recovery coupled with intensive energy requirement due to long processing time makes the potential of bio-oil production not seamlessly appreciated. In this study, the optimization of bio-oil yield from non-edible Swietenia macrophylla seeds through microwave pretreatment before ultrasonic-assisted solvent extraction was investigated. Central composite design of response surface methodology was employed to analyze the effects to the bio-oil yield of the irradiation time (4–8 min) and irradiation power (90–450 W) as pretreatment variables using a microwave oven at 2.45 GHz frequency. Results showed that microwave pretreatment significantly increased the bio-oil yield by 5% with optimum recovery of 43% at shortened pretreatment time of 7 min instead of 6 h in the conventional oven heating method. The bio-oil yield increased when the irradiation time was increased, while irradiation power showed no significant effect. Analysis of the produced bio-oil through Fourier Transform Infrared Radiation spectroscopy identified similar functional groups present both in the extracted bio-oils from the microwave and the conventional pretreated seeds indicating that the former pretreatment, like the latter, did not destruct the compounds present in the seeds. The study demonstrated that the seeds of S. macrophylla have strong potential for bio-oil production and poise huge implications to the future of liquid biofuel and chemical industries. Keywords: Swietenia macrophylla, Microwave pretreatment, Oil extraction, Optimization, Response surface methodology

As the world confronts a surging price of fuel along with various environmental issues, researchers around the globe are scrambling to identify and develop potential biofuel feedstocks that fall outside the “food or fuel dilemma”. This justifies the need for non-edible oilseeds that can be used as sustainable feedstock for biofuel production. In this study, non-edible Ricinus communis seeds were utilized in the production of bio-based fuel to support the crusade for the use of renewable energy. Extraction of bio-oil from R. communis seeds was done through ultrasonic-assisted solvent extraction. The effects of n-hexane to biomass (HB) ratio, extraction time, and resonance amplitude on bio-oil yield were investigated. Optimization of bio-oil yield was done through central composite design of the response surface methodology. The optimum bio-oil yield was found to be 42% at optimum conditions of 10:1 HB ratio, 25 min extraction time and 50 μm resonance amplitude. Characterization of the extracted bio-oil revealed a density of 0.9 g mL−1, kinematic viscosity of 18.6 cSt at 40 °C, and higher heating value of 29.5 MJ kg−1. The Fourier Transform Infrared Radiation spectroscopy analysis of the bio-oil revealed that it contained ester functional groups. Gas chromatography analysis showed that the major fatty acids present in the bio-oil are palmitic (2.2%), stearic (2.4%), oleic (6.7%), linoleic (8.8%) and ricinoleic (77.1%). The R. communis bio-oil is enriched with unsaturated fatty acids while there is a relatively low content of saturated fatty acid accounting 87.8% and 11.3% of the total fatty acids composition, respectively. As confirmed by this study, the results indicate the potential of R. communis bio-oil as a source for biodiesel production. Keywords: Ricinus communis, Bio-oil, Optimization, Ultrasonic-assisted solvent extraction, Response surface methodology

The demand for oil has been increasing vastly over time, and the source of this has slowly been diminishing. The use of non-food feedstock is seen as a promising alternative source for the production of bio-based fuel. In this study, rubber (Hevea brasiliensis) seeds were utilized as biomass in bio-oil production considering that these are non-edible and considered wastes in rubber tree plantations. In the oil extraction process, the rubber seed kernels were oven dried at 100 °C for 24 h, powdered and then dried further at 105 °C for 4 h. After characterization, optimization study was done using Design Expert 7.0 software through central composite design of the response surface methodology. Ultrasonication technology was employed in the oil extraction process which significantly reduced the reaction time needed for extraction to 15 min compared the conventional extraction method of at least 8 h. An optimum rubber seed oil (RSO) yield of 30.3 ± 0.3% was obtained using 15 g biomass, 5:1 n-hexane to biomass (mL gâ1) ratio, 50 μm resonance amplitude and 60 ± 5 °C temperature at 15 min reaction time. The oil yield at optimum condition was found to have 0.89 g mLâ1 density at room temperature, 26.7 cSt kinematic viscosity at 40 °C and high heating value of 39.2 MJ kgâ1. The Fourier Transform Infrared Radiation spectroscopy analysis of the RSO, at optimum condition, showed the presence of carboxylic acid and ester carbonyl functional groups which are good indicators as a potential source of biodiesel. Keywords: Hevea brasiliensis, Oil extraction, Optimization, Response surface methodology, Rubber seed oil, Ultrasonic-assisted solvent extraction

In this study, silica sand coated with groundwater treatment residuals was used as adsorbents for the removal of hexavalent chromium from synthetic wastewater. Batch adsorption experiments were conducted to evaluate the effects of initial Cr(VI) concentration, solution pH, adsorbent dosage, solution temperature, contact time, as well as ionic strength on Cr(VI) removal. Results show that low solution pH and high ionic strength improve Cr(VI) adsorption onto the residual coated sand. At pH 4, the highest adsorption capacity was computed at 0.27 mg g−1. The Freundlich isotherm model best described the adsorption process. From 298 to 318 K, the high correlation of the kinetic data with the pseudo-second order model (R2 > 0.981) and a highly positive activation energy value (22.7 kJ mol−1) indicate that chemisorption is the rate-controlling step of the adsorption process.

The optimization of bio-oil produced from sewage sludge using fast pyrolysis in a fluidized bed reactor was investigated. Effects of temperature, sludge particle size and vapor residence time on bio-oil properties, such as yield, high heating value (HHV) and moisture content were evaluated through experimental and statistical analyses. Characterization of the pyrolysis products (bio-oil and biogas) was also done. Optimum conditions produced a bio-oil product with an HHV that is nearly twice as much as lignocellulosic-derived bio-oil, and with properties comparable to heavy fuel oil. Contrary to generally acidic bio-oil, the sludge-derived bio-oil has almost neutral pH which could minimize the pipeline and engine corrosions. The Fourier Transform Infrared and gas-chromatography and mass spectrometry analyses of bio-oil showed a dominant presence of gasoline-like compounds. These results demonstrate that fast pyrolysis of sewage sludge from domestic wastewater treatment plant is a favorable technology to produce biofuels for various applications.