Maximum Recovery Value Research Articles

An insight into the utilization of high-sulfur green Saudi Arabian petcoke as an ecofriendly sorbent for enhanced simultaneous sequestration of heavy metal ions from industrial wastewaters

Developing effective and green sorbents for the sequestration of water pollutants has increased attention to safe and sustainable water generation. This study aimed to discover a new utilization and the ability of green, high-sulfur Saudi Arabian petcoke (SA-PET) for heavy metal ion uptake. The organic sulfur content and aromatic properties of SA-PET allowed for rapid and improved performance against various metal ions via strong complex formation reactions and cation-π interactions. Also, the effects of different analytical factors were carefully studied and optimized. At pH 6–7, the maximum recovery values of PbII, CuII, CdII, ZnII, MnII, NiII and CoII metal ions were 21.09–95.76%. The experimental results demonstrate single-layer adsorption at the binding sites on the petcoke’s surface, and they are in good agreement with the Langmuir model in explaining the adsorption process, which is driven by electrostatic interactions between the petcoke surface and the studied metal ions. The pseudo-second-order kinetics model fits the adsorption data for all the target metal ions well. Furthermore, the outstanding SA-PET's stability allowed for efficient extractions over the course of 10 successive runs with negligible loss in the metal recovery percentage. With extraction recoveries up to 96.6% and a relative standard deviation less than 5%, SA-PET's efficiency in removing the target metal ions from different industrial wastewater samples gives it excellent promise as a novel green sorbent for detoxifying heavy metals from aquatic life. In conclusions, our findings, SA-PET emerged as a viable substitute for traditional synthetic adsorbents of heavy metals, in keeping with the growing trend toward green adsorbents for more sustainable development.

A New Method for Optimizing Water-Flooding Strategies in Multi-Layer Sandstone Reservoirs

As one of the most important and economically enhanced oil-recovery technologies, water flooding has been applied in various oilfields worldwide for nearly a century. Stratified water injection is the key to improving water-flooding performance. In water flooding, the water-injection rate is normally optimized based on the reservoir permeability and thickness. However, this strategy is not applicable after oilfields enter the ultra-high-water-cut period. In this study, an original method for optimizing water-flooding parameters for developing multi-layer sandstone reservoirs in the entire flooding process and in a given period is proposed based on reservoir engineering theory and optimization technology. Meanwhile, optimization mathematical models that yield maximum oil recovery or net present value (NPV) are developed. The new method is verified by water-flooding experiments using Berea cores. The results show that using the method developed in this study can increase the total oil recovery by approximately 3 percent compared with the traditional method using the same water-injection amounts. The experimental results are consistent with the results from theoretical analysis. Moreover, this study shows that the geological reserves of each layer and the relative permeability curves have the greatest influence on the optimized water-injection rate, rather than the reservoir properties, which are the primary consideration in a traditional optimization method. The method developed in this study could not only be implemented in a newly developed oilfield but also could be used in a mature oilfield that has been developed for years. However, this study also shows that using the optimized water injection at an earlier stage will provide better EOR performance.

A pioneering study on the recovery of valuable functional compounds from olive pomace by using supercritical carbon dioxide extraction: Comparison of perlite addition and drying

In this study, supercritical carbon dioxide (SC-CO2) extraction was applied to the mixture of two-phase olive pomace (OP) with perlite and to the dried OP in order to prevent the environmental hazards that may arise from the leachate. Chemical oxygen demand (COD) and electrical conductivity (EC) of the leaching black water were detected as 131200 ± 21024 mg/L and 12300 ± 500 µS/cm, respectively, leading to toxicity. Total phenolic content (TPC) was determined in the raw OP and in the extracts as 8.9 ± 3.6 mg GAE/g and 2–14 mg GAE/g, respectively. Antioxidant capacity increased from 715 µM TE in the raw OP to 11000 µM TE in the extracts. The maximum extraction yield and TPC recovery values were obtained as 5.7 % and 3 %, respectively. Promising results were obtained on the recovery of phenolic substances and fatty acids (FAs). Main groups of the valuable compounds such as secoiridoids, flavonoids and phenolic alcohols were detected in the pomace as 400, 290 and 100 mg/kg, respectively, while their concentrations increased up to 16430, 7370 and 3280 mg/kg in the extracts.

Improvement of low-quality fine coal by ultrasonic hydrophobic flocculation

ABSTRACT In this study, the effect of ultrasonic pretreatment on hydrophobic flocculation of fine coal was investigated and named as ultrasonic hydrophobic flocculation (USHF) technique. First, it was found that the ultrasonic power of 150 W and the ultrasonic pretreatment time of 180 sec was required to achieve for more combustible and good-quality coal. Then, the effects of ultrasound on the hydrophobic flocculation of coal with kerosene as bridging liquid were investigated and optimum kerosene concentration value was obtained 4 g/dm3 under the experimental conditions. Also, it was found that a stirring speed of 750 rpm was sufficient to achieve the maximum combustible recovery and minimum ash content values of fine coal particles. The effects of sodium silicate, sodium hexametaphosphate, and sodium pyrophosphate used as inorganic dispersants on the ultrasonic hydrophobic flocculation of coal were also studied. Sodium silicate was more effective than other dispersants in the presence of kerosene. Thus, it was concluded that the ultrasonic pretreatment is an effective method for the beneficiation of fine particle coal. Coal with an ash content of 17.63% was enriched and clean coal was recovered with an ash content of 9.75% with the efficiency of 94.35% by ultrasonic hydrophobic flocculation technique.

A surfactant-mediated microextraction of synthetic dyes from solid-phase food samples into the primary amine-based supramolecular solvent

An effective and simple surfactant-mediated microextraction of synthetic dyes from solid-phase food samples into the primary amine-based supramolecular solvents is presented for the first time. The developed procedure involved two stages: (i) an isolation of dyes from a solid-phase food sample into a micellar solution of the primary amine; (ii) a preconcentration of the extracted dyes into the supramolecular solvent phase generated from the obtained micellar solution under a coacervation process. The microextraction procedure was applied for the determination of synthetic dyes in confectionery, dried fruits, and spices samples. The supramolecular solvent formed from aqueous micelle aggregates of 1-octylamine due to coacervation induced by thymol provided maximum extraction recovery values for synthetic dyes. In the proposed two-stage extraction procedure the micellar solution of primary amine was a media for analytes isolation from solid-phase and their followed preconcentration.

Prospects of CO2 capture via 13X for low-carbon hydrogen production using a Pd-based metallic membrane reactor

In this work steam methane reforming (SMR) was carried in a palladium-based membrane reactor and its performance was evaluated in terms of methane conversion, hydrogen recovery, hydrogen purity, and CO and CO2 selectivity. The membrane reactor was found to produce ultrahigh purity hydrogen with methane conversions as high as 40% at moderate operating conditions and in the absence of sweep gas.Permeation tests using pure hydrogen and inert gases indicate that the membrane reactor is highly selective toward hydrogen. The SMR reactions were performed at 673 K and operating pressures ranging from 100 to 400 kPa. A gas hourly space velocity of 2,600 hr-1 and a steam-to-carbon ratio of 3.5 were used. Methane conversion increased from approximately 23% at 100 kPa to 42% at 400 kPa while a maximum hydrogen recovery value of 43% was achieved at 400 kPa. Furthermore, the purity of the recovered hydrogen was >99.999%. The carbon capture experiments performed in this work consist of dehydrating the retentate stream and redirecting it to a zeolite 13X packed bed before analyzing the stream via mass spectrometry. The carbon capture studies reveal that approximately 5.96 mmol CO2 (262.25 mg of CO2) can be captured per gram of 13X. This value indicates that approximately 80% of the produced CO2 via the SMR, can be captured before the sorbent bed is completely saturated.SEM-EDS, XRD, and XPS techniques were used to characterize the crystal structure and morphology of the membrane surface. These studies reveal that the surface of the membrane underwent significant oxidation during the SMR reaction. This oxidation is only limited to a few nanometers within the top surface of the palladium.

Exploring the Operation Factors that Influence Performance of a Spiral-Wound Forward Osmosis Membrane Process for Scale-up Design.

Forward osmosis (FO) technology has increasingly attracted attention owing to its low operational energy and low fouling propensity. Despite extensive investigations on FO, very few module-scale FO studies on the operation and design of the FO process have been conducted. In this paper, a simple and practical FO process design parameter called normalized membrane area is suggested based on a performance analysis of spiral-wound FO elements. The influence of operation factors on operating pressures and water recovery was investigated using 8-inch spiral wound elements in the continuous operation mode. The membrane area was adjusted by series connection of FO elements to a maximum value of 46 m2 (three elements). The feed and draw flow rates were varied between 5 and 15 LPM under various feed (10, 20, and 30 g/L) and draw (58.4 and 233.8 g/L) concentration combinations. The analysis of flow rates (feed, draw, and permeate flow rates) indicated not only high flow channel resistance on the draw side but also high permeate flow rates can induce higher operating pressures owing to strong mutual interaction of the feed and the draw streams. Feed water recovery was focused on as a key performance index, and the experimental recovery (RExp) and theoretical maximum recovery (RTh) values were compared. The results revealed the significance of the feed flow rate and the membrane area in terms of enhancing the water recovery performance. In addition, a clear relationship was observed between the membrane area normalized by the initial feed flow rates and the water recovery ratio (RExp/RTh), even though the applied operation conditions were different. Finally, an empirical equation to estimate the required membrane area of spiral-wound FO was proposed for the FO process design. The equation can be used to predict water recovery of FO systems as well, for example, if an FO system is operated at 0.08 m2L−1h of the normalized membrane area, the system is expected to offer 78% of the RTh value.

Optimization of aqueous two-phase partitioning for purification of recombinant Eupenicillium terrenum fructosyl peptide oxidase

Abstract Fructosyl peptide oxidase (FPOX), a flavoenzyme belonging to the class of oxidoreductases, has been used as a diagnostic enzyme for HbA1c measurement test. Design of experiments methodology was applied to evaluate the partition behavior of recombinant Eupenicillium terrenum FPOX in aqueous two-phase systems (ATPS). Different ATPS parameters including polyethylene glycol (PEG) molecular weight, PEG concentration, salt type, salt concentration, pH, system buffer type, system buffer concentration, temperature, neutral salt type, neutral salt concentration, and crude enzyme loading were investigated using a Plackett–Burman design (PBD). Taking into consideration an increase in partition coefficient (KE), PEG concentration, pH, system buffer concentration, and NaCl concentration, which played significant roles in enzyme partition, were chosen for further optimization by Box–Behnken design (BBD) in response surface methodology (RSM). The optimized condition led to maximum recovery (106.8%), yield (95.1%) and purification factor (42.4) values which were predicted to be achieved in ATPS formed by 14.0% (w/w) PEG-4000, 15.0% (w/w) Na2CO3, 5.0% (w/w) NaCl and 55.0 mM potassium phosphate buffer with pH 8.0. The partitioned recombinant FPOX was obtained as a single band into the upper PEG-rich phase and its specific activity was calculated to be 201.23 ± 2.1 U/mg. In summary, our data showed that the ATPS optimization using design of experiments can be an appropriate method for recovery of recombinant FPOX.

Effect of acid-base solutions used in acid-base compartments for simultaneous recovery of lithium and boron from aqueous solution using bipolar membrane electrodialysis (BMED)

Application of bipolar membrane electrodialysis (BMED) for simultaneous separation and recovery of lithium and boron from aqueous solution was investigated using Astom Acilyzer EX3B model ED device. In the laboratory scale experiments performed, effects of acid and base solutions types and their concentrations employed in acid and base compartments, electrical potential applied on process efficiency were investigated. The results showed that separations and recoveries of both boron and lithium were effective when 0.05 M HCl and 0.05 M NaOH solutions have been used in acid and base compartments, respectively. The percent separations of boron and lithium were 86.9% and 94.7%, respectively, while their respective recoveries were 50% and 62% at 30 V. The maximum separation and recovery values for boron and lithium were obtained when a 30 V of electrical potential was applied. With optimal initial acid and base concentrations (0.05 M) used in acid and base compartments, the specific power consumption (SPC) was calculated as 7.9 kWh/m3 at 30 V.While higher initial acid and base concentrations showed higher boron and lithium separation efficiencies, relatively lower concentrations of acid and base solutions employed in acid and base compartments improved the recoveries of boron and lithium. Acid and base solutions generating a moderate conductive medium in acid and base compartments improved separations along with recoveries of boron and lithium from solution. When the solutions of 0.1 M HCl and 0.1 M NaOH were used in acid and base compartments, recoveries of boron and lithium were 27% and 33%, respectively. On the other hand, the recoveries of boron and lithium were 62% and 56%, respectively when 0.1 M H3BO3 and 0.1 M LiOH solutions were employed in acid and base compartments.

Online fully automated SPE-HPLC-MS/MS determination of ceftiofur in bovine milk samples employing a silica-anchored ionic liquid as sorbent.

Solid-phase extraction coupled online with high performance liquid chromatography and tandem mass spectrometry was successfully applied to determine low concentrations of ceftiofur antibiotic in bovine milk samples. A silica-anchored ionic liquid was applied as sorbent material to be used as extraction phase in the proposed online system. The material was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. In order to improve the system reproducibility, the following experimental parameters were optimized: organic solvent percentage, time and sample loading flow rate. Subsequently, the method was validated presenting satisfactory results as adequate selectivity, good linearity and correlation coefficient higher than 0.98. The limit of detection and quantification were 0.1 and 0.7 μg/L, respectively. The precision of the methodology was evaluated as repeatability and intermediate precision, with relative standard deviation values lower than 15%. The accuracy of the method ranged from 72.8 to 137% and the minimum and maximum recovery values were 73.4 and 111.3%, respectively. After the validation, seven milk samples were analyzed and although ceftiofur was not detected in any of them the method was demonstrated to be efficient when applied to the analysis of milk samples fortified with the pollutant of interest.

Effect of operating conditions on hydrothermal liquefaction of Spirulina over Ni/TiO2 catalyst

In this study, the effects of reaction temperature, holding time, algae/water ratio and catalyst dosage on the yield and quality of bio-oil produced via the HTL of Spirulina were investigated. The maximum bio-oil yield (43.05 wt%) and energy recovery (ER) value (64.62%) were obtained at 260 °C for 30 min, with an algae/water ratio of 1/4 and a catalyst dosage of 5 wt%. The bio-oil samples were characterized by elemental analysis, Gas Chromatography–Mass Spectrometry (GC–MS), Fourier Transform Infrared (FI-IR), and Thermo-gravimetric analysis (TGA). Results indicated that higher heating values (HHVs) of bio-oils were in the range of 27.28–36.01 MJ/kg, and main compounds of bio-oil were amides, esters, nitriles, hydroperoxide and alkanes. Adding of the Ni/TiO2 catalyst can decrease the contents of oxygenated and nitrogenous compounds and promote the formation of desirable components such as esters and alkanes.

A Study of Kinetics on Oily-Bubble Flotation for a Low-Rank Coal

ABSTRACTThe flotation performance and kinetics for a low-rank coal were investigated using air bubbles and oily bubbles. Five flotation kinetic models were applied to the test data to estimate the relationships between the flotation rate constant, the maximum recovery, and the collector dosage. The results showed that the oily-bubble flotation (OBF) obtained lower ash content and higher combustible recovery with less collector dosage than the air-bubble flotation (ABF). But this advantage of OBF gradually diminished with the collector dosage. It was found that the flotation of a low-rank coal in ABF and OBF can be best described with the second-order kinetic model and classical first-order model, respectively. The OBF had higher maximum combustible recovery values and lower maximum ash recovery values. The flotation rate constants of OBF were higher in all the models except the fully mixed reactor model. Furthermore, the effect of collector dosage on the low-rank coal flotation kinetics was evaluated. It was indicated that the maximum recovery values and modified rate constants increased with the collector dosage. The similar trend was observed in the flotation rate constants for all of the models except the fully mixed reactor model.

Improving the desorption of Inga edulis flavonoids from macroporous resin: Towards a new model to concentrate bioactive compounds

The cumulative recovery of Inga edulis flavonoids from a fixed-bed adsorber was evaluated using an empirical sigmoid model, aiming at optimise the maximum solute desorption. Ethanol:water mixtures (20–100%, v/v) were applied to desorb the bioactive compounds from the column filled with Amberlite XAD-7 resin. Flavanol and flavonol content of the eluate were monitored with fast spectrophotometric measurements and these determinations were then validated using chromatographic analysis. The modelling results showed that a three-parameter sigmoid model fitted well to the cumulative flavonoid recovery data and the coefficients of multiple determination were higher than 0.99 for all ethanol proportions. Moreover, the estimated parameters of the model provided qualitative and quantitative desorption information, including the rate of desorption and the maximum recovery value. Interestingly, the rate of desorption presented a linear relationship with the ethanol proportion, while a quadratic behaviour was observed for the maximum recovery. In the optimised condition, four bed volumes of an 80% ethanol–water mixture permitted the desorption of almost 100% of the flavonoids from the column. All fractions presented particularly elevated antioxidant capacity (17.84±5.23μmolTE/mg GAE), when measured by the oxygen radical antioxidant capacity per total phenolic content. This modelling procedure appears to be useful when one is focusing on rapidly concentrating bioactive compounds.

Trace determination of perchlorate using electromembrane extraction and capillary electrophoresis with capacitively coupled contactless conductivity detection

Electromembrane extraction (EME) and CE with capacitively coupled contactless conductivity detection (CE-C(4) D) was applied to rapid and sensitive determination of perchlorate in drinking water and environmental samples. Porous polypropylene hollow fiber impregnated with 1-heptanol acted as a supported liquid membrane (SLM) and perchlorate was transported and preconcentrated in the fiber lumen on application of electric field. High selectivity of perchlorate determination and its baseline separation from major inorganic anions was achieved in CE-C(4) D using background electrolyte solution consisting of 7.5 mM L-histidine and 40 mM acetic acid at pH 4.1. The analytical method showed excellent parameters in terms of reproducibility; RSD values for migration times and peak areas at a spiked concentration of 15 μg/L of perchlorate (US EPA recommended limit for drinking water) were below 0.2 and 8.7%, respectively, in all examined water samples. Linear calibration curves were obtained for perchlorate in the concentration range 1-100 μg/L (r(2) ≥0.999) with limits of detection at 1 μg/L for tap water and at 0.25-0.35 μg/L for environmental and bottled potable water samples. Recoveries at 15 μg/L of perchlorate were between 95.9 and 106.7% with minimum and maximum recovery values for snow and bottled potable water samples, respectively.

Reversibility of the endothelial dysfunction after CPAP therapy in OSAS patients

BackgroundThe obstructive sleep apnoea syndrome (OSAS) is a common airways disease which often involves cardiovascular structures, causing vessel inflammation as well as hypoxia, induced by difficulties in the passage of air through the upper airways. Aim of our research is to evaluate the effects of Continuous Positive Airway Pressure (CPAP) on the syndrome itself and the patients cardiovascular risk profile, practically adopting Flow-Mediated Vasodilation (FMD) technique to evaluate endothelial function. Methods and resultsWe enrolled 63 patients (49 males and 14 female, mean age: 54±10years) subdivided into four groups: high cardiovascular risk factors, no CPAP therapy, CPAP therapy started less- and more than 3months before. The patients underwent FMD of the brachial artery using a high resolution ultrasonograph connected to an image analysis system. The maximum recovery value was calculated as the ratio (maximum-baseline) of the change in diameter over the baseline value. Data obtained from this study demonstrate the significant reversibility of FMD in patients treated for more than 3months with CPAP therapy (Group 4). ConclusionsOur study shows the importance of administering CPAP therapy for more than 3months in patients suffering from OSAS to improve EF to a level equal to high cardiovascular risk subjects probably due to a recovery from the systemic hypoxia. Besides, our work points out the importance of FMD as a “clinical” tool able to point out any improvement or regression after therapies.

Optimisation of batch membrane processes for the removal of residual heavy metal contamination in pretreated marine sediment

In this article, an innovative process that uses membranes to purify marine sediments contaminated with heavy metals is presented. The proposed process is composed of a centrifugation step, performed with a hydrocyclone, followed by a batch membrane step. The initial separation of sand from the raw stream appears to be very efficient and is important to avoid plugging the membrane separation step. The remaining stream, called silt, is then processed by a batch membrane separation step, capable of separating organic and inorganic pollutants from the purified water. Pilot tests were carried out to estimate membrane performance, including the maximum recovery value achievable, typical rejection values, the permeate and critical fluxes.

Clinical correlates of endothelial function in chronic heart failure

There is a close link between heart failure and endothelial dysfunction. Brachial flow-mediated dilation (FMD) is a validated non-invasive measure of endothelial function. The aim of this study was to investigate the clinical correlates of FMD in patients with chronic heart failure (CHF). We evaluated 60 CHF outpatients (age 62 ± 14 years; 49 males, NYHA class 2.2 ± 0.7, left ventricular ejection fraction, LVEF, 33 ± 8%) taking conventional medical therapy (ACE-inhibitors and/or ARBs 93%, beta-blockers 95%) and in stable clinical conditions. The maximum recovery value of FMD was calculated as the ratio of the change in diameter (maximum-baseline) over the baseline value. As compared with patients with a higher FMD, those with FMD below the median value (4.3%) were more frequently affected by ischemic cardiopathy (50 vs. 23%; p = 0.032) and diabetes mellitus (20 vs. 3%; p = 0.044), had a higher NYHA class (2.5 ± 0.5 vs. 1.9 ± 0.7; p < 0.001) and NT-proBNP (2,690 ± 3,690 vs. 822 ± 1,060; p = 0.001), lower glomerular filtration rate estimated by Cockcroft-Gault (GFRCG: 63 ± 28 vs. 78 ± 25; p = 0.001) and LVEF (29 ± 8 vs. 37 ± 9; p = 0.001), as well as more frequently showing a restrictive pattern (40 vs. 7%; p = 0.002). In a multivariate regression model (R (2) = 0.48; p < 0.001), FMD remained associated only with the NYHA class (p = 0.039) and diabetes mellitus (p = 0.024). This study demonstrates that a better functional status and absence of diabetes mellitus are associated to higher FMD regardless of the etiology of the cardiac disease.

POST TREATMENT OF POULTRY SLAUGHTERHOUSE WASTEWATER AND APPRAISAL OF THE ECONOMIC OUTCOME

Recovery of residual ammonium nitrogen (NH4+-N) from dissolved air flotation (DAF) pretreated poultry slaughterhouse wastewater was studied by means of magnesium ammonium phosphate hexahydrate (MgNH4PO4.6H2O, MAP) precipitation in a lab-scale batch study. The maximum recovery values were obtained as 80.2%, 97.1% and 53.6% with the addition of MgCl2.6H2O + KH2PO4, NaH2PO4.2H2O + MgSO4.7H2O, and MgOHCO3 + 85% H3PO4 at pH 9.5, respectively. Based on the physicochemical findings, subsequent batch experiments were conducted at pH 9.5 for eight different molar ratios (Mg2+:NH4+-N:PO43--P) applied as overdose (1.2:1:1, 1.5:1:1, 1:1:1.2, 1:1:1.5) and underdose (0.5:1:1, 0.8:1:1, 1:1:0.5, 1:1:0.8). Results indicated that the stoichiometric ratio (Mg2+:NH4+-N:PO43--P = 1:1:1) was found to be sufficient to obtain high recovery values. A detailed economic analysis of the present process demonstrated that the cost of NH4+-N recovery was estimated as 0.297 /m3 or 1.753 /kg NH4+-Nremoved for the proposed application. The rate of reaction was found to be very fast, being completed within minutes, and cost effective in large-scale poultry slaughterhouse facilities.

高齢者脳血管障害における運動機能の回復過程に関する検討

To investigate the recovery process in elderly patients with cerebrovascular disease for 10 months, from beginning 3 months after the onset of disease. This was done according to the evaluation of exercise capacity described in the interim-report on preventive long-term care services in city, town and village model research. Fourteen patients in whom cerebrovascular disease had been diagnosed within the previous 3 months, and who were still receiving rehabilitation treatment (8 men, 6 women, average age 76.4+/-8.3, and average number of hospitalization days 164.6+/-33.1) were enrolled. Evaluation items were: the grip power, one-leg standing time with eyes open, functional reach, timed up and go test (TUGT) and falling bar test. The maximum recovery value of individual measurements in each patient was considered 100%, in order to calculate the recovery rate. The maximum recovery value of the grip power test was obtained on both unaffected and affected body sides 6 months after the onset of disease, but the recovery values of both the unaffected and affected sides decreased to 76.1% and 68.6% respectively, after 12 months. The maximum recovery value of the one-leg standing time with eyes open test was 72.8% 7 months after the onset of disease, but it had decreased to 24.5% after 12 months. The maximum recovery value of the functional reach test was 86.9% 4 months after the onset of disease, but it had decreased to 57.5% after 12 months. The maximum recovery value of the falling bar test was 83.5% 6 months after the onset of disease, but had it decreased to 63.8% after 12 months. The maximum recovery value of the TUGT was 90.4% 5 months after the onset of disease, but it had decreased to 64.1% after 12 months. The TUGT reached the recovery peak level first, however, the one-leg standing test reached the maximum recovery value 7 months after the onset of disease, slightly later than the other measurements. After achieving the maximum recovery value, the grip power test maintained its value in comparison with the other tests, but the one-leg standing, functional reach, falling bar test and TUGT continued to decrease. In particular, the one-leg standing and functional reach tests, which relate to equilibrium function, showed a remarkable decrease in recovery values. Fall-prevention measures are urgently needed because the reduction of equilibrium function level increases the risk of falling, and producing a second any injury after cerebrovascular disease. This suggests that how rehabilitation treatment is performed should be examined after discharge from hospital.

土壌による非イオン界面活性剤の除去とその回収に関する基礎的研究 −土壌に捕捉された非イオン界面活性剤のアルコールによる回収−

In a previous study, it was determined that nonionic surfactants could be removed from wastewater using the typical soil. In this report, the recovery of nonionic surfactants was examined with the purpose of reusing the removed surfactants. It was found that a packed bed of soil employed with the nonionic surfactants and the use of alcohol as the recovery agent was most effective. In the case of polyoxyethylenenonylphenylether NP10 (50 ppm), 50 vol% i-PrOH was found to be the most effective for the recovery process. This resulted in a recovery rate of 100%. The following recovery rate was recorded in descending order of i-PrOH>t-BuOH>n-PrOH, EtOH>MeOH. Also, the maximum recovery value resulted between each of the 5 alcohol concentration and their respective recovery rates. The recovery rate of the nonionic surfactants of a low concentration was decreased. In addition, the recovery rate of nonionic surfactants decreased as the mole numbers of the added ethyleneoxide units increased for the nonionic surfactants NP10, NP15 and NP20.