Natural Organic Sorbents Research Articles

Developing Green Sorbents Derived from Natural Materials for Microextraction and Determination of Emerging Contaminants

Developing Green Sorbents Derived from Natural Materials for Microextraction and Determination of Emerging Contaminants

MODIFICATION OF NATURAL OIL SORBENT FOR IMPROVEMENT OF HYDROPHOBICITY

A sorbent made of natural materials (moss) was selected for the sorption of diesel from the surface of the water. The sorbent was modified to increase its hydrophobic–oleophilic characteristics. Typical natural organic sorbent from moss was selected and modified in three different ways: processed with hot water (80 °C and 100 °C), mercerized and coated with oil–water (10% and 50%). Water, diesel sorption capacity, and oil retention tests were performed. Tests showed that simple treatment with hot water and alkali can change surface properties and improve sorption capacity. Modification with hot water at 80 °C enhanced sorbents’ oil sorption capacity and showed the best results but meanwhile, this method readily increased hydrophilicity. This method of sorbent treatment could not be applied in cases where sorbents are used to clean oil spills from water surfaces. Meanwhile, better sorption results would be obtained in cases where cleaning operations take place on soil and other solid surfaces.

Feldspar-banana peel composite adsorbent for efficient crude oil removal from solution

The problem of oil spill pollution associated with the transport of crude oil and its products across the globe is of serious concern. The sorption technique has proved to be promising for oil spill treatment but is limited by the hydrophilic nature of most natural organic sorbents. The combo of natural organic and inorganic sorbents have been found to enhance the hydrophobicity for oil sorption. Therefore this study was aimed at the preparation of a novel feldspar-banana peel biochar composite (FBPC) with enhanced hydrophobicity for the sorption of crude oil. The prepared sorbent was characterised by the scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, while the crude oil was characterised using standard methods. Batch sorption was used to determine the effect of contact time (30–150 min), temperature (25–100 °C), pH (2.0–10.0), oil concentration (4.0–12.0 g/L) and sorbent dosage (0.1–0.5 g) on sorption. SEM analysis of FBPC revealed a porous structure, while XRD confirmed the crystalline phases of feldspar. The crude oil samples had pH (6.40–6.60), density (0.960 0 0.962 g/cm3), kinematic viscosity (24.0–27.6 cSt) and API gravity (24.25–24.51°). The Langmuir model with R2 > 0.7781 presented the best fit than the Temkin and Freundlich model in the isotherm analysis, while the pseudo-second-order model with R2 > 0.9711 was applicable in the kinetics of sorption. The thermodynamic analysis revealed a decrease in randomness at the crude oil-FBPC interface. The prepared FBPC was found to be an efficient inorganic–organic composite sorbent with enhanced hydrophobicity for the sorption of crude oil.

Влияние температуры и парциального давления кислорода на глубину автоклавного окисления активного углерода в модельных смесях, имитирующих дважды упорный золотосодержащий концентрат.

The article considers the effect of partial pressure of oxygen and temperature on autoclave oxidation of active carbon of various sizes. Carbon is the main natural organic sorbent in gold-sulfide ores, which is involved in the preg-robbing process. In order to overcome preg-robbing, we developed an experiment plan of removing carbon from the reaction mixture. The results of this work are presented in the article.

Ultrasonic aided sorption of oil from oil-in-water emulsion onto oleophilic natural organic-silver nanocomposite

Herein, we reported for the first time the application of silver nanoparticle (AgNP) based sorbent for the sorption of oil from simulated oil-polluted water. An oleophilic natural organic-silver nanocomposite (AgAW) was synthesized in a one-pot system by impregnation of AgNPs on a natural organic sorbent (AW), which was applied for the ultrasonic sorption of oil. The characterizations proved successful synthesis of the nanocomposite containing 18.92 nm average size AgNPs. A shift from the microporous structure (1.184 nm) of AW to the mesoporous structure (2.231 nm) of AgAW was obtained. The impregnated AgNPs enhanced the hydrophobic characteristics of AgAW for the oil phase, with a maximum oil uptake of 2.66 g/g and 6.11 g/g obtained for AW and AgAW respectively. Besides AgAW exhibited higher oil uptake than the pristine AW at variations in pH (2.0–10.0), sonication time (5–60 min), temperature (395–325 K), and oil concentration (200–1000 g/L). The presence of competing Pb(II) and Cd(II) ions in solution did not significantly affect the oil uptake on the sorbents. In addition, successful regeneration of the sorbents using n-pentane and petroleum ether was achieved with over 85.3% oil desorption. In addition, the sorbents were efficiently reused for oil uptake with a slight decrease in oil sorption capacity. The mechanism of oil sorption on AgAW was found to be purely hydrophobic interactions brought about by the impregnated AgNPs. The efficacy of the synthesized AgAW composite for oil spill treatment based on the oleophilic character, high oil uptake as well as the efficient regeneration and reuse was established.

Isotherm and Kinetic Evaluation of Dialium guineense Seed Husk and Its Modified Derivative as Efficient Sorbent for Crude Oil Polluted Water Treatment

Raw Dialium guineense seed husk (DGSH), a native west African plant, and its phosphoric acid modified form (PA-DGSH) were utilized as cheap natural organic sorbent for petroleum sequestration from aqua media. Characterizations of sorbents prepared were carried out by FTIR, BET surface area analysis, and TGA. Significant changes in the surface properties were observed on the sorbent after acid treatment. Different experimental factors such as sorbent dosage, temperature, petroleum concentration, contact time, and pH were used to assess the effectiveness of petroleum removal by DGSH and PA-DGSH using batch sorption methodology. The experimental factors affected the uptake of crude oil on both sorbents. The Langmuir model gave the best fit to the sorption of crude oil on DGSH with R2 of 0.994 and χ2 of 0.17. The Freundlich was applicable to PA-DGSH with R2 of 0.991 and χ2 of 0.23. The constant parameters of Freundlich and Langmuir revealed good affinity between both sorbents and crude oil molecules. The pseudo-first-order kinetics gave better fit than the pseudo-second-order model in the kinetic analysis, and intraparticle diffusion model showed that the sorption of crude oil on both sorbents was mainly a surface mechanism. Both DGSH and PA-DGSH were found to be useful sorbents for the treatment of oil spill-polluted waters.

Study of Acid Treated Mixed Sawdust as Natural Oil Sorbent for Oil Spill

Despite the presence of many techniques to clean up oil spills, sorbents are considered as one of the most attractive techniques due to the high rate of absorption or adsorption and ease of application. Organic-based sorbents have become the best type to use based on their abundance of resources and its biodegradability. Among the many natural organic sorbents available, sawdust has big potential to be used as oil absorbent due to its advantages of being low-cost source, low density and exhibiting hydrophobic-oleophillic characteristics. In this study, the utilization of mixed sawdust as oil sorbent was investigated. The mixed sawdust sorbent was treated using chemicals such as ethanol, sodium hydroxide and hydrochloric acid to further improve the efficiency for oil absorbency. The performance of as-prepared and acid-treated sorbent was characterized using sorption capacity (g/g). The effects of sorption time and surface condition (on seawater surface or on land) towards the performance of sorbent was then investigated. Besides that, the temperature, oil viscosities and reusability of treated sawdust were also studied. It has been proven that acid treated sawdust has higher sorption capacity of 4.82 g/g even after 90 minutes of sorption with four times reusability due to improved hydrophobic and oleophillic characteristics. It was also found that the viscosity of oil and temperature can also affect the sorption capacity. Crude oil, which poses lower viscosity (30.51cP) and at oil temperature of 27°C gave the highest sorption because of the migration of oil into the structure of sorbent was accelerated. This study indicated the possibility of using sawdust as sorbent for oil spill control.

Natural oil sorbents modification methods for hydrophobicity improvement

In recent years, accidental and intentional oil discharges have been occurred frequently during transportation, production, and refining, which results in severe negative impact on organisms and ecological environment. Among existing techniques for the removal of oil from water, the use of sorbents is generally considered to be one of the most efficient techniques. Moreover, the application of natural sorbent materials is an attractive method for combating oil spill pollution, mainly due to the lower costs, high effectiveness and their properties such as reusability, biodegradability and recovery. Hydrophobicity (oleophilicity) is one of the major determinants of sorbents properties influencing the effectiveness of oil sorption in the presence of water. In order to improve these properties, the surface of the sorbent is modified using chemical or physical treatment methods. The purpose of this study is to analyze sorbents modification methods in order to increase their hydrophobic-oleophilic characteristics for oil spills cleanup taking into account environmental aspects. In this research natural organic sorbent – moss was treated with hot water (80 °C and 100 °C), mercerized, coated with oil and oil in water emulsions with concentrations 10 % and 50 %. The test of diesel sorption capacity was performed to compare the hydrophobic properties of modified sorbents. The results of this research demonstrate that simple hot water and alkali treatments can alter the surface characteristics of plant fibers and improve absorption capacity.

Извлечение фенола из сточных вод сорбентами на основе древесных отходов

The subject of the study is wastewater from synthetic phenol-formaldehyde resins production containing free phenol and formaldehyde as highly toxic organic substances. We have studied the process of phenol sorption by carbon-containing sorbents based on soft wood waste (sawdust and hydrolytic lignin) from model solutions under static conditions. The rate constants, activation energy and diffusion coefficients of the phenol sorption from aqueous solutions have been calculated. This enables to identify physical nature of the interaction of phenol with sorbents. The phenol extraction degree by natural organic sorbents is 93-96% wt. The choice of effective sorbent for the production of woodphenolic raw material mixture from industrial wastes was carried out on the basis of the experimental data. The resulting mixture can be used as a technogenic raw material for the production of wood-polymer thermoplastic structural composites.

INVESTIGATION OF HEMP WATER SORPTION CAPACITY / NATŪRALIŲ ORGANINIŲ KANAPIŲ SPALIŲ SORBENTO NAFTOS PRODUKTAMS ŠALINTI TYRIMAS

Effective clean-up of oil spills due to their negative environmental and economic impact is of capital importance. Clean-up of oil by sorption is considered one of the most desirable choices, because oil can be completely removed without causing any secondary pollution. Natural organic sorbents had been investigated and developed to control oil products‘ spills. Plant biomass is a renewable resource which can be converted into various materials and energy. Hemp (USO-31), as a textile industry waste, was used as an oil product sorbent material. The present study examines hemp sorption capacity of water using different fractions of hemp raw material to be used in oil/water mixtures. The experimental research revealed that water sorption capacity depends on fraction size and sorption time. The results of water sorption capacity of 2.5 and 5.0 mm after 1440 min were 4.74 and 4.67 g water/g dry sorbent, respectively. Labai svarbu efektyviai likviduoti išsiliejusius naftos produktus dėl jų neigiamo poveikio aplinkai ir ekonomikai. Naftos produktų valymo metodas pasitelkiant sorbentus yra laikomas vienu iš geriau­sių pasirinkimų, nes produktai yra absorbuojami sorbentų, nesukeliant jokios antrinės taršos. Natūralūs organiniai sorbentai buvo tiriami ir tobulinami, siekiant kontroliuoti naftos produktų išsiliejimus. Augalų biomasė yra atsinaujinantis išteklis, kuris gali būti naudojamas įvairioms medžiagoms ir energijai išgauti. Kanapių spaliai (USO-31), tekstilės pramonės atlieka, buvo tiriami kaip naftos produktų sorbentas. Buvo išnagrinėta kanapių vandens sorbcija naudojant įvairias šios medžiagos frakcijas. Eksperimentinis tyrimas parodė, kad vandens sorbcija priklauso nuo frakcijos dydžio ir sorbcijos laiko. Tyrimų metu buvo nustatyta vandens sorbcijos geba – 4,74 ir 4,67 g vandens/g sauso sorbento 2,5 ir 5,0 mm pavyzdžiams po 1440 min atitinkamai.

Experimental research of the hantavirus survival in complexes with environmental substrates

Survival of viruses in the environment is a very important problem in epidemiology, especially for infections with indirect transmission. This work describes the results of the experimental study of adsorption and survival of the hantavirus on different environmental substrates (natural organic and inorganic sorbents). Bovine serum albumin (BSA) solution (5-10%) was effective in the hantavirus elution and phosphate-buffer saline (PBS) pH- 7,2 was optimal for elution of specific RNA. Potential survival of the infectious hantavirus on environmental substrates was observed within up to 14 days at +4°C.

Remediation of Rare Earth Element Pollutants by Sorption Process Using Organic Natural Sorbents.

The effects of the sorption of environmental applications by various source materials of natural organic matter, i.e., bone powder, was examined. Sorption capacities and subsequent rare earth element retention characteristics of all metals tested were markedly increased by ionic task-specific. In this study, the abilities of three models’ isotherms widely were used for the equilibrium sorption data: Langmuir, Freundlich and Redlich-Peterson. For all studied metal ions the maximum adsorption capacity is close to those experimentally determined. The characteristic parameters for each isotherm and related coefficients of determination have been determined. The experimental data achieved excellent fits within the following isotherms in the order: Langmuir > Redlich-Peterson > Freundlich, based on their coefficient of determination values. The bone powder has developed higher adsorption performance in the removal process of Nd(III), Eu(III), La(III) from aqueous solutions than in the case of the removal process of Cs(I), Sr(II) and Tl(I) from aqueous solutions. The described relationships provide direct experimental evidence that the sorption-desorption properties of bone powder are closely related to their degree of the type of the metal. The results suggest a potential for obtaining efficient and cost-effective engineered natural organic sorbents for environmental applications.

Application of Natural Sorbents in Crude Oil Adsorption

In last decades, oil spill pollution has become an important issue of concern due to its serious environmental impacts; therefore, necessary actions should be taken to prevent or reduce these types of pollution and their environmental consequences. Natural organic sorbents are emerging as proper choices for oil spill cleanup due to their availability, eco-friendliness, and low cost. In this study, phragmites australis, sugarcane leaves straw, and sugarcane bagasse were used for crude oil sorption in dry (only oil) systems. The results indicated that sugarcane bagasse had a higher oil sorption capacity compared to the others. Therefore, sugarcane bagasse was selected as the preferred sorbent and the effects of sorbent contact time and its particle size on oil adsorption capacity were evaluated for the systems of dry and crude oil layer on water. The results showed that the maximum adsorption capacity of raw sugarcane bagasse for dry system and crude oil layer system was about 8 and 6.6 gram crude oil per gram sorbent respectively.

Polymerin and Lignimerin, as Humic Acid-like Sorbents from Vegetable Waste, for the Potential Remediation of Waters Contaminated with Heavy Metals, Herbicides, or Polycyclic Aromatic Hydrocarbons

Polymerin is a humic acid-like polymer, which we previously recovered for the first time from olive oil mill waste waters (OMWW) only, and chemically and physicochemically characterized. We also previously investigated its versatile sorption capacity for toxic inorganic and organic compounds. Therefore, a review is presented on the removal, from simulated polluted waters, of cationic heavy metals [Cu(II), Zn, Cr(III)] and anionic ones [Cr(VI)) and As(V)] by sorption on this natural organic sorbent in comparison with its synthetic derivatives, K-polymerin, a ferrihydrite-polymerin complex and with ferrihydrite. An overview is also performed of the removal of ionic herbicides (2,4-D, paraquat, MCPA, simazine, and cyhalofop) by sorption on polymerin, ferrihydrite, and their complex and of the removal of phenanthrene, as a representative of polycyclic aromatic hydrocarbons, by sorption on this sorbent and its complexes with micro- or nanoparticles of aluminum oxide, pointing out the employment of all these sorbents in biobed systems, which might allow the remediation of water and protection of surface and groundwater. In addition, a short review is also given on the removal of Cu(II) and Zn from simulated contaminated waters, by sorption on the humic acid-like organic fraction, named lignimerin, which we previously isolated for the first time, in collaboration with a Chilean group, from cellulose mill Kraft waste waters (KCMWW) only. More specifically, the production methods and the characterization of the two natural sorbents (polymerin and lignimerin) and their derivatives (K-polymerin ferrihydrite-polymerin, polymerin-microAl(2)O(3) and -nanoAl(2)O(3), and H-lignimerin, respectively) as well as their sorption data and mechanism are reviewed. Published and original results obtained by the cyclic sorption on all of the considered sorbents for the removal of the above-mentioned toxic compounds from simulated waste waters are also reported. Moreover, sorption capacity and mechanism of the considered compounds on polymerins and lignimerins are evaluated in comparison with other known natural sorbents, especially of humic acid nature and other organic matter. Some of their technical aspects and relative costs are also considered. Finally, the possible large-scale application of the considered sorption systems for water remediation is briefly discussed.

Development of Engineered Natural Organic Sorbents for Environmental Applications. 4. Effects on Biodegradation and Distribution of Pyrene in Soils

The effects of engineered natural organic amendments on the biodegradation and distribution of pyrene in soils were assessed. Pyrene was aged for 105 days in soils amended with either raw or superheated water (SHW)-processed MI peat or soybean stalks, and then subjected to biodegradation with specifically selected microorganisms for 130 days. Initial rates of pyrene mineralization in the soils were increased by addition of raw MI peat, but markedly decreased by additions of SHW-processed MI peat and both processed and raw soybean stalks. Pyrene sorbed by the processed organic sorbents was, however, slowly but steadily degraded by microorganisms over a greater than 4-month test period. Pyrene distributions in the soils were examined by sequential extractions of samples before and after biodegradation. Fractions of pyrene extracted readilywith water or water/methanol mixtures were decreased substantially in both soils bythe addition of processed amendments, while the nonextractable fractions associated with humic and fulvic acids and humin were increased markedly. The results demonstrate that SHW-processed amendments effectively reduce the ecological and human availability and aqueous phase extractability of organic contaminants while facilitating their steady microbial degradation and eventually complete remediation.

Development of Engineered Natural Organic Sorbents for Environmental Applications: 3. Reducing PAH Mobility and Bioavailability in Contaminated Soil and Sediment Systems

The effects of engineered natural organic amendments on two measures of the environmental "availability" of polycyclic aromatic hydrocarbons (PAHs) associated with soil and sediment samples are assessed. Two soils spiked with pyrene alone and a sediment spiked with a mixture of 4 PAH compounds were amended with raw or superheated-water processed peat or soybean stalks, then aged for periods of either 62 or 105 days. The aged soils were then examined with respect to bioaccumulation of spiked pyrene by earthworms (Eisenia foetida), and to its human bioaccessibility as measured by extraction with simulated gastrointestinal fluid. Additions of processed amendments reduced both measures of availability by factors ranging from 7.6 to 27.0 for earthworm bioaccumulation and from 2.3 to 8.8 for gastrointestinal extractability. All PAH compounds spiked to the sediment were reduced to varying extents in their availabilities to E. foetida and leachabilities by water by both processed and raw organic amendments.

Development of Engineered Natural Organic Sorbents for Environmental Applications. 2. Sorption Characteristics and Capacities with Respect to Phenanthrene

The effects of superheated water processing on enhancement of phenanthrene sorption by various source materials of natural organic matter (NOM) were systematically examined. Sorption capacities and subsequent phenanthrene retention characteristics of all organic materials tested were markedly increased by superheated water processing. Temperature effects on enhancement of the sorption behaviors of the test materials were greater than those of processing time, moisture content, and the presence of mineral catalysts. Greatest enhancement was observed for processing at 250 degrees C for 5 h with a moisture content of 50%. Strong correlations of sorption capacities and isotherm nonlinearities with processing temperature, and with the atomic ratios of oxygen to carbon (O/C), aromaticity, and hydrophobicity of the processed materials were observed. The sorption/desorption hysteresis indices of the processed materials also increased linearly with processing temperatures and O/C ratios. This is consistent with our observations of increased condensation and aromatization of NOM during superheated water processing presented in the first paper of this series. The relationships described provide direct experimental evidence that the sorption-desorption properties of NOM geosorbents are closely related to their degree of aromatization and condensation, and the work suggests strong potential for production of efficient and cost-effective engineered natural organic sorbents for environmental applications.

Development of Engineered Natural Organic Sorbents for Environmental Applications. 1. Materials, Approaches, and Characterizations

A technology for effecting diagenesis-like transformations in young natural organic matter (NOM) derived from common plant materials is described. Thirteen such materials were processed in liquid-phase water at superheated temperature/pressure conditions. In all cases significant changes in the physical and chemical properties of the raw NOM source materials occurred. Their carbon and nitrogen contents increased, their hydrogen and oxygen contents decreased, their surface areas initially increased dramatically, then sharply decreased, and their bulk densities and equilibrated aqueous phase pH values increased as functions of increasing temperature and pressure. Spectroscopic analyses confirmed marked changes in the molecular structures of the NOMs resulting from superheated water processing; e.g., fractions of alkyl and aromatic carbons increased while oxygen-associated functional organic carbon decreased. These changes in elemental composition and molecular structure indicate that the organic fractions of the raw materials became less polar, increasingly condensed, and more aromatic as a result of the reactions induced by superheated water processing, the changes correlating directly with the temperature/ pressure conditions employed. The results presented confirm that the long-term biogeochemical processes that in nature effect geologically slow advances in the chemical states of organic carbon can be simulated and markedly accelerated by superheated water processing.

Oil Spill Pollution Treatment by Sorption on Natural <i>Cynanchum</i> Acutum L. Plant

The aim of this work is to use cheap, available, biodegradable and recyclable natural organic sorbent for oil spill clean – up. White Silky Hairs (WSH) that is collected from the smooth seeds of Cynanchum Acutum L. plant is used before treatment and after thermal and chemical treatment, to remove crude oil; 0.6 g, below which mechanical means for removing crude oil becomes less more effective, from the surface of saline water of volume 750 mL at temperature 30oC. The plant was treated mechanically by squeezing and then chemically by naphtha, a petroleum product of boiling range 30oC - 165oC, to remove sorbed crude oil from its surface for further reuse and contaminated naphtha are processed to be distilled for reuse. WSH absorbs hydrocarbons quickly and encapsulates oil on contact. WSH absorbs, on average, three times its weight. De-waxed WSH absorbs four times its weight, in case of de-waxing by n-hexane and six times its weight in case of de-waxing by methanol. Dehydrated WSH at 120oC absorbs seven times its weight. WSH absorbs eleven times its weight when it is used after soaking in 10-4 M dodecyl benzenesulphonic acid. WSH absorbs twenty times its weight when it is soaked in dodecyl benzenesulphonic acid and dehydrated at 120oC. Characteristics of crude oil and Cynanchum Acutum L. plant were investigated by FTIR, X – Ray Fluorescence, pour point and centrifuge instruments. Determination of amount of crude oil in saline water was done by extraction the crude oil with tricholorotrifluoroethane and measuring absorbance by Infra Red Spectrometer. Journal of Applied Sciences and Environmental Management Vol. 7(2) 2003:63-73