Carbon disulfide removal from gasoline fraction using zinc-carbon composite synthesized using microwave-assisted homogenous precipitation.

Carbon disulfide (CS2) is one of the sulfur components that are naturally present in petroleum fractions. Its presence causes corrosion issues in the fuel facilities and deactivates the catalysts in the petrochemical processes. It is a hazardous component that negatively impacts the environment and public health due to its toxicity. This study used zinc-carbon (ZC) composite as a CS2 adsorbent from the gasoline fraction model component. The carbon is derived from date stone biomass. The ZC composite was prepared via a homogenous precipitation process by urea hydrolysis. The physicochemical properties of the prepared adsorbent are characterized using different techniques. The results confirm the loading of zinc oxide/hydroxide carbonate and urea-derived species on the carbon surface. The results were compared by the parent samples, raw carbon, and zinc hydroxide prepared by conventional and homogeneous precipitation. The CS2 adsorption process was performed using a batch system at atmospheric pressure. The effects of adsorbent dosage and adsorption temperatures have been examined. The results indicate that ZC has the highest CS2 adsorption capacity (124.3 mg.g-1 at 30 °C) compared to the parent adsorbents and the previously reported data. The kinetics and thermodynamic calculation results indicate the spontaneity and feasibility of the CS2 adsorption process.

Sustainable ecofriendly recruitment of bioethanol fermentation lignocellulosic spent waste biomass for the safe reuse and discharge of petroleum production produced water via biosorption and solid biofuel production.

Sustainable lignocellulosic spent waste rice straw (SWRS) from bioethanol production inventively applied in this study to valorize petroleum production produced water (PPPW). SWRS expressed efficient pollutant removal over a wide range of petroleum concentration, temperature, pH, salinity, and mixing rate reaching approximately 217 mg/g, within four hours contact time. Kinetic studies revealed a pseudo-second-order chemisorption process with a boundary layer control and 16.97 kJ/mol activation energy where the intra-particle diffusion was not the only rate regulatory step. Thermodynamic studies revealed spontaneous, favorable, and endothermic adsorption, with a strong affinity between the SWRS and oil molecules. Biosorption mechanism studies proved the enrollment of SWRS components' lignin, cellulose, and hemicellulose in the oil uptake with the predominance of chemisorption over physisorption onto the rough and highly porous SWRS surface. A single-stage batch biosorption process was designed based on the best fitted Langmuir adsorption isotherm and applied on a real PPPW sample. The Egyptian standard limits for safe industrial effluents discharge into marine environment with a concomitant decrease in scale formation precursors were achieved recommending its safe reuse for enhanced oil recovery. Finally, for accomplishing zero-waste, SWRS disposed of PPPW treatment substantiated valorized solid biofuel with a sufficient calorific value 38.56 MJ/kg.

Designing Dual-Effect Nanohybrids for Removing Heavy Metals and Different Kinds of Anions from the Natural Water.

In the present study, well-designed nanohybrids are used to act as effective dual-function adsorbents for removing both anions and heavy metals from natural water, at the same time. In this trend, Zn-Al LDHs and graphene oxide are applied to build up building blocks to produce a series of nanohybrids. These nanohybrids were characterized by X-ray diffraction, thermal analyses, Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning and transmission electron microscopy. These techniques confirmed that the prepared nanohybrids contained nanolayered structures with three-dimensional porous systems. These porous systems were identified by the nitrogen adsorption-desorption isotherms and water purification experiments. The obtained results indicated that these nanohybrids included suitable structures to act as dual function materials. The first function was achieved by removing more than 80% of both cadmium and lead from the natural water. The second function was accomplished by eliminating of 100% of hydrogen phosphate and bromide anions alongside with 80%-91% of sulfate, chloride, and fluoride anions. To conclude, these well-designed nanohybrids convert two-dimensional nanolayered structures to three-dimensional porous networks to work as dual-function materials for removing of heavy metals and different kinds of anions naturally found in the fresh tap water sample with no parameters optimization.