This paper addresses the treatment of waste engine oils (WEO) by acid/clay refining method using glacial acetic acid. An optimization of the process parameters in terms of settling time, stirring speed and mixing temperature for treating the WEO was performed using Response Surface Methodology to improve the quality of treated lubricating oil. The quality of the treated WEO (Castrol brand) was evaluated in terms of viscosity index and flash point value. The treated fuel quality is found to have about 95% similarity to the fresh oil used as a standard at the settling time of 24 hours, temperature of 50 °C and mixing speed of 150 rpm. Analysis of variances (ANOVA) showed that settling time plays the most significant parameters of the process followed by the mixing temperature. Solid contaminants which were collected after the treatment were analyzed using SEM-EDS. They contained rough heteregenous shaped particles with elements such as carbon (97%), calcium (1.12%), zinc (0.74%), sulphur (0.73%) and phosphorus (0.29%). Then, four different brands of WEO (Liqui Moly, Castrol, Shell and Pennzoil) were treated at the optimized conditions to determine the feasibility of the method to treat any brands of WEO. It can be concluded that the optimized treatement method is suitable to treat most of WEO. The findings of this study provide the information on the best process condition for treating WEO as well as the solid contaminants present in it.
Effective treatment of wastewater is crucial in order to achieve a sustainable development. For instance, highly efficient treatment processes with low capital requirements are the major prerequisite for implementation of the advanced wastewater treatment operations. Among various available treatment methods, the application of coagulation-flocculation process by using natural coagulant; chitosan has vast advantages such as low operating cost, environmental friendly and highly effective in the wastewater treatment operations. The application of nanotechnology in numerous treatment techniques are considered as the most significant advances in water and wastewater treatment practices. The utilization of magnesium oxide (MgO) as nano-adsorbent has recently gained attention as a potential treatment method in water remediation particularly for treating effluents with high amount of organic dyes and heavy metals due to its high treatment efficiency, low cost, versatility and environment compatibility. The purpose of this study was to determine the effectiveness of coagulation-flocculation process when using novel coagulant in which MgO coated with chitosan by investigating the percentage removal of several significant parameters which were turbidity, chemical oxygen demand (COD) and suspended solid. The removal efficiencies were determined throughout a series of experiments carried out using a standard jar test procedure in which three different coagulants; chitosan, MgO coated with chitosan and MgO were tested on water samples taken from Sg. Pusu. In addition, a set of experiments was designed using response surface methodology (RSM) in order to optimize adsorption of chitosan into MgO. The experiments were conducted at various concentrations of chitosan (10-30 mg/ml) and selected MgO dosage ranges (10-30 mg). From the obtained results, it was found that chitosan-MgO coagulant has good removal efficiencies of turbidity, chemical oxygen demand (COD) and suspended solids at 92%, 91%, and 98% respectively from the optimization of adsorption of chitosan-MgO. The MgO coated with chitosan is the best coagulant in this study compared to chitosan and MgO alone because of the ability of treating the river water with up to 90 % removal for all the main parameters. The results showed that coagulation-flocculation is effective as a treatment for treating river water.
Introduction: Traditionally, Mallotus paniculatus (Balik Angin) plant is used in the treatment of various
diseases in rural areas such as remedy after childbirth, wound healing and fever. In this present study, four
medicinal properties of the plant were investigated which included antibacterial, antifungal, anticancer and
antioxidant activities. Materials and Methods: Potential medicinal compounds were extracted from the plant
leaves by sonication with 3 different solvents namely ethanol, ethyl acetate and hexane respectively. The
antibacterial and antifungal properties were determined using disc diffusion agar and broth dilution assay,
the antioxidant activity by DPPH scavenging assay and the anticancer effect by MTT assay. Results: From the
screening of the medicinal properties, M. paniculatus leave extracts were shown to possess antibacterial,
antioxidant and anticancer properties but not antifungal properties. Ethanolic and ethyl acetate extracts of
the leave were active against gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) but not
gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The antioxidant activity of the
ethanolic crude extract was high; with IC50 of 30 μg/ml comparable with the positive controls; ascorbic acid
and butylated hydroxytoluene (BHT). Both ethanolic and ethyl acetate extracts were cytotoxic against breast
cancer (MCF7), colon cancer (HT-29), cervix cancer (Hela) cell lines. Conclusion: M. paniculatus leave
extract has many potential medicinal values for further studies.
Carbon nanoparticles have been widely used in various applications. However, they are commonly known to have low dispersibility and chemical inertness which limit their practical ability in medical or biological area. Some studies have been performed to modify carbon nanoparticles such as carbon nanotubes using ultraviolet (UV)-Ozone system. However, little is known on the effects of such system towards other types of carbon nanoparticles such as mesoporous hollow carbon nanoparticles (MHCNs). Thus, in this study, improvement of MHCNs physiochemical properties have been studied using UV-Ozone treatment for the first time. The treatment was conducted in water as dispersant agent at ozone flowrate of 1.0 L/min and exposure time of 45 min. SEM images observed that MHCNs morphology and surface structure remain intact after the treatment. Observations on the dispersibility of MHCNs in phosphate buffered saline (PBS) solution shows that the dispersibility was improved compared to the untreated ones. This was supported by the low Z-average and PDI values of treated MHCNs obtained at ~400 nm and 0.2, respectively when compared to the untreated MHCNs which was obtained at 970 nm and 0.417, respectively. Thermogravimetric analysis (TGA) showed an increased in weight loss of treated MHCNs at the lower temperature compared to untreated MHCNs. Results from Fourier Transform Infrared (FTIR) showed an increase number of new functional groups that includes carboxylic acid group presence at the surface of treated MHCNs which contributes to the improvement of their dispersibility, thermal properties and chemical functionality. These findings opened a new possibility of using UV-Ozone treatment to improve physicochemical properties of MHCNs for medical area such as in drug delivery application in addition to their excellent storage and carrier system.