Selective emulsion liquid membrane extraction of silver from photographic waste industries

The field of liquid membrane technology is currently undergoing a rapid expansion in research as well as its application as an industrial separation process. Liquid membrane can be manipulated to selectively separate a specific solute from a mixture and even to extract a solute against its concentration gradient. A liquid membrane system comprises of three liquid phases; feed phase, liquid membrane organic phase and receiving phase. Liquid membrane can be prepared using support or as emulsion (unsupported) liquid membrane. Emulsion liquid membrane is a liquid membrane in which the membrane phase of an emulsion is dispersed into the feed phase to be treated. This method was investigated as an alternative process for the recovery of silver from photographic waste, which contains various metals ions such as silver, iron, sodium and potassium. The important parameters governing the extraction process of silver such as agitation speed, homogenizer speed, surfactant and carrier concentrations, type of diluents, treat ratio and types of stripping solution were investigated. This process has been conducted in a batch system using a mixer-settler. The results show that the mobile carrier Cyanex 302 is selective towards silver and almost completely extract silver over the other metals that existed in the photographic waste. The optimum silver extraction was obtained by using 0.03 M Cyanex 302, 3 % (w/v) Span 80, 250 rpm stirring speed, 1.0 M thiourea in 1.0 M H2SO4 stripping agent, 1:5 of treat ratio, and kerosene as a diluents. The experimental result also shows that the emulsion liquid membrane system could be recycled twice having 80% of silver was extracted. In addition, theoretical studies show that the developed model could predict the extraction performance of the system understudied as obtained from experimental data

Gas adsoprtion phenomenon in microporous zeolite adsorbent

Gas adsorption on zeolites gains remarkable attention in this new era of nanotechnology since it has industrial importance in many process industries. Efforts of chemists during the past few decades have advanced the field of synthesis and accelerated the development of zeolites with different physicochemical properties for specific application. New technologies involving gas separation, gas purification, gas storage, high temperature gas sensor, semiconductor material hold a great promise for industrial applications. In order to develop and design an efficient and economically feasible industrial adsorption process, it is important to understand the adsorption phenomena between solid and gas phases. The presence of metal cations in the extra-framework structure determines the accessibility of gas molecules into the zeolite framework. In addition, the selectivity and capacity of adsorption is also being influenced by the adsorbate-adsorbent interactions. The molecules may interact through dispersion, induction, field-quadrapole and/or repulsion forces. Hence, information on physicochemical properties of zeolites as well as the properties of adsorbent is equally important in order to understand gas adsorption phenomena in zeolite microstructures. Results of this study show that structural properties and adsorbate-adsorbent interactions affect gas adsorptive characteristics of zeolites

Adsorptive removal of benzene from aqueous solution by surfactant modified banana trunk as adsorbents

The adsorptive removal of benzene from aqueous solution by four types of surfactant modified banana trunk (BT) adsorbents was investigated through batch adsorption experiments. The surface morphology and functional groups determination were conducted BT adsorbents indicating the significant changes were observed after modifications. The adsorption results indicated that the non-ionic surfactant (i.e. Triton-X 100) modified BT has the highest adsorption capacity (57.52 µmol/g) and its adsorption capacity significantly affected by the increase of temperatures, benzene concentrations and contact time

The catalytic activity of laccase immobilized onto free and surfactant modified silica aerogels

The free silica aerogel (FSA) and surfactant (cetyltrimethylammonium bromide) modified silica aerogel (MSA) were synthesized and used as supports for laccase immobilization carried out through adsorption process. The results show that the MSA performed higher laccase adsorption (0.71µmol/g) as compare to FSA (0.22µmol/g). In addition, the enhancement of the catalytic activity of the MSAL was also observed. These results demonstrated that the surface modification of silica aerogel using cationic surfactant (cetyltrimethylammonium bromide) gave higher immobilized mass and catalytic activity of laccase which can be potentially used for degradation of organic micropollutants such dyes, pesticides and antibiotics

Total phenolic content and antioxidant activity of roselle (Hibiscus sabdariffa) extracts

Introduction: Roselle (Hibiscus sabdariffa) is widely known for its benefits and medicinal properties. The aims of this study were to determine the total phenolic content (TPC) in H. sabdariffa extract, its antioxidant activity and relationship between TPC and its antioxidant scavenging capacity. Methods: The TPC value for each extract of free, bound soluble and bound insoluble phenolic acids was determined by using Folin-Ciocalteu assay. The antioxidant scavenging capacity was evaluated by using DPPH assay. Results: The results obtained in this study showed that bound soluble phenolic acids (7.63 + 0.28 mg GAE/g DW) had the highest TPC value than the free and insoluble phenolic acid extracts (2.78 + 0.20 mg GAE/g DW and 3.61 + 0.85 mg GAE/g DW, respectively) (p<0.05). As for the IC50 values, bound soluble phenolic acid extract exhibited the greatest value(0.62%) as compared to the free and bound insoluble phenolic acid extracts (0.90% and 1.14%, respectively). A positive correlation (R2 = 0.956) between three extracts (free, soluble and insoluble phenolic acids) of TPC and antioxidant radical scavenging capacity (DPPH) was obtained. Conclusion: It can be concluded that phenolic acids in H. sabdariffa extracts have an effect to the antioxidant scavenging capacity particularly in the bound soluble form. This finding proved that H. sabdariffa extracts could be a good source of natural antioxidant for food, cosmetic and pharmaceutical industries

Antimacrobial Properties of gynura procumbens (Sambung Nyawa) leaves In methanolic and acidic extracts

Introduction: Gynura procumbens, commonly known as ‘sambung nyawa’ in Malaysia has been used traditionally as remedies for anti-inflammatory, anti-hyperlipidimic and anti-hyperglycemic. The purpose of the present study was to qualitatively evaluate the antimicrobial effects of Gynura procumbens extracts. Methods: The sample was extracted using methanol and acid hydrolysis. The antimicrobial effects of the sample were determined by disc diffusion method against two bacteria and two fungi namely E. coli, S. aureus, C. albicans and S. cerevisiae. Results: The results showed that the acidic extract of G. procumbens has positive reactions towards E. coli, S. aureus and C. albicans with the presence of zone of inhibition at the concentration of 150 mg/mL. Following the positive reaction, the minimum inhibitory concentration (MIC) of the acidic extract was then evaluated by broth dilution method. The MIC of E. coli and S. aureus were determined at concentration 37.5 mg/mL and 75 mg/mL for C. albicans. It indicated that acidic extracts at lower concentration could inhibit the bacteria, but high concentration of extracts was required in the inhibition of the fungi. Conclusion: It can be concluded that, the present study proves that there is potential of antimicrobial effects in Gynura procumbens leaves extracts

Characterization of natural zeolite for adsorptive removal of antibiotics from aqueous solution

The persistent existence of antibiotics in sewage wastewater treatment plants in recent years has emerged as a serious concern. In this study, natural zeolite (NZ02) obtained from China was employed as an adsorbent to remove tetracycline (TC) from aqueous solution. The characterization results show that the NZ02 consists of quartz, clinoptilolite-Na and heulandite having the CEC of 62.18cmol/kg and the surface area of 36.646m2/g. Adsorption results show that the maximum adsorption capacity of TC on NZ02 was 19.30mg/g and the equilibrium data followed theLangmuir adsorption isotherm model

Evaluation of positive emotion in children mobile learning application

This paper presents the evaluation of positive emotion in children's mobile learning applications. The mobile learning application is a teaching aid that can help students to self-study and increase the students’ interest in learning especially children. This paper will discuss how mobile learning application affects the children interest in school. The evaluation method implemented to evaluate the rate of positive emotion elicited by the children using mobile learning applications was a mixed method of qualitative and quantitative methods. Since emotion can be either negative or positive, the identification of a proper method or perspective was required to prove that positive emotion was really elicited. Next, the data was collected through the children’s assessment score, Electroencephalograms (EEG) device, Emotion identification using micro-expression (facial expression), Kort Scale and interview to confirm the positive emotion felt by the students. The result shows that all five perspectives or methods have shown that positive emotion is produced. It is found that the Mobile learning application can really trigger the children’s positive emotions

Coupling ultrasound with enzyme-assisted extraction of essential oil from algerian artemisia herba-alba asso

The composition of the essential oil (EO) of Artemisia herba-alba Asso, extracted by Hydro-Distillation (HD) and by coupling Ultrasound with Enzyme-Assisted Extraction (UE-AE) prior to HD from the plant's aerial parts were analyzed by GC-MS. Antibacterial, antifungal and antioxidant activities of the obtained EOs were evaluated. The yield of EO extraction after pretreatment of the desert wormwood leaves by coupling ultrasound with enzymes was in the range of 1.56%±0.07 compared to 1.01% ±0.08 in HD process; also, the total time necessary to complete EO extraction is 180min for HD and 120min for UE-AE. GC-MS profiling of the EOs showed changes in chemo type obtained by HD from camphor/1,8-cineole/α-mujone/chrysanmenone to a new chemo type in the case of UE-AE: camphor/α-thujone/1,8-cineole/filifolone; Then, an increasing of filifolone, α-thujone, 3-octyne and cis-limonene oxide characterize the UE-EO. The antifungal activity of the EO has slightly increased when extracted by UE-AE, however, both antibacterial and antioxidant activities were interestingly increased

Development of K-Workers Employability Skills Measurements Indicators in Agricultural Sector in Malaysia

&nbsp;Issue of skilled and knowledge worker is an issue that frequently discussed among agricultural training institutions and employers in the sector. It is viewed seriously by Malaysian government through Agrofood Policy 2011-2015 by emphasizing agricultural workers that are highly skilled and knowledgeable to assist Malaysia achieves high-income developed nation status. However, what are the characteristics of those high skilled and knowledge workers? This question is the base of this research. By using qualitative approach, modified Delphi technique / method is chosen as the research framework. Eleven experts from various stakeholders such as agriculture lecturer, leaders of agricultural training institutions, agricultural instructor and agricultural industry employer in Malaysia. Finding reveals ten characteristics of k-workers that are needed to enable them to have high employability skill in order to satisfy / fulfil national requirement of skilled workforce. This finding can be used as a measurement basis for employability skill level of labour market in agricultural sector in Malaysia