Micro-plastic Characteristics and Removal of Ammonia-Nitrogen in Batch Culture

Plastic waste has become a sensitive issue in the world since this material needs a longer time to degrade. This material will take a month to a thousand years to decompose. Thus, would contribute to the environment pollution, which will affect human health and aquatic life. This research study focused on the biodegradation process of micro-plastic (PE, PP, PET and PS) in the batch culture system using a colony of bacteria obtained from leachate in Ayer Hitam Landfill, Puchong. After the batch experiment of micro-plastic degradation, percentage removal of ammonia-nitrogen, chemical structure and percentage weight loss were examined and evaluated. Succeeding through the incubation of micro-plastic in batch culture for fourteen (14) days period, biodegradation was verified by the estimation of the dry weight loss. From the result obtained, dry weight loss of polyethylene (PE) is the highest (3.46%) in 14 days and polyethylene (PE) shows the greater removal of ammonia nitrogen (NH3 -N) (44.17%). Besides that, polystyrene (PS) micro-plastic showed a significant change in chemical structural which was obtained by Fourier Transform Infrared (FTIR). Here, the new absorption peak C=O (aldehydes) was present in PS micro-plastic. Furthermore, PS micro-plastic has a high percentage mass loss in the second stage of thermal degradation by Thermogravimetric (TGA) analysis. It can be concluded that incubation time is needed to optimize the micro-plastic in the biodegradation process.

Solid-solid synthesis, characterization and thermal decomposition of a homodinuclear cobalt(II) complex

The homodinuclear cobalt(II) complex [Co2(dipic)2(H2O)5]?2H2O was synthesized with pyridine-2,6-dicarboxylic acid (H2dipic) and cobalt(II) acetate as raw materials by room temperature solid-solid reaction. The complex was characterized by elemental analyses, single crystal X-ray diffraction, X-ray powder diffraction, Fourier transform infrared spectroscopy, UV spectra, and thermogravimetry and differential scanning calorimetry. Its crystal structure belongs to monoclinic system and space group P2(1)/c. There are two types of the Co(II) ions, and they are all six-coordination, one Co(II) is coordinated by four carboxyl O atoms and two pyridine N atoms from two dipic2- anions, and another Co(II) is coordinated by five O atoms from five H2O molecules and one bridged carboxyl O atom from the dipic2- anion. The possible pyrolysis reactions in the thermal decomposition processes of the complex, the experimental and calculated percentage mass loss are also given.

Synthesis and Antibacterial Activities of Sulfur-Containing Bissalicylaldehyde Schiff Base and Binuclear Nickel(II) Nanorod Complex

Nickel(II) acetate tetrahydrate was treated with the ligand CH2(H2sal-sbdt)2in methanol heated at reflux to yield a novel binuclear Ni(II) nanorod complex of the formulaCH2{Ni(II)(sal-sbdt)(H2O)}2. The ligand of CH2(H2sal-sbdt)2was derived from 5,5′-methylene-bissalicylaldehyde andS-benzyldithiocarbazate. The complex was characterized by elemental analysis, UV-Vis, FT-IR spectra, thermal analysis (TG-DSC), and scanning electron microscopy (SEM). The nickel(II) was coordinated by imino nitrogen, thiolato sulfur, and phenolic oxygen from the Schiff base ligand, and oxygen from the coordinated water, respectively. The pyrolysis reactions in the thermal decomposition process of the complex, the experimental, and calculated percentage mass loss were also given. The Ni(II) complex belonged to nanocrystalline metal complex, and the average size of the nanorod complex was about 30 nm × 150 nm. The antibacterial activities were screened for the Schiff base ligand and the Ni(II) nanorod complex against four bacteria:Staphylococcus aureus,Escherichia coli,Bacillus subtilis, andStaphylococcus epidermidis. Both the ligand of CH2(H2sal-sbdt)2and the Ni(II) complex had the most intense antibacterial activities againstEscherichia coli.

Solid-Solid Synthesis, Characterization and Thermal Decomposition of Thiourea Complex of Antimony Trichloride

The solid complex of antimony trichloride with thiourea was synthesized by solid-solid reaction or liquid state reaction of antimony trichloride and thiourea. The formula of solid complex is all SbCl3[CS(NH2)2]3. The crystal structure of the complex belongs to monoclinic system and the lattice parameters are: a = 1.2426 nm, b = 1.6396 nm, c = 1.9254 nm and β = 96.24° for solid-solid reaction, and a = 1.2343 nm, b = 1.6585 nm, c = 1.9252 nm and β = 96.46° for liquid state reaction, respectively. The infrared spectra reveal that antimony ion in the complex is coordinated only by the sulfur atom of CS(NH2)2. The possible pyrolysis reactions in the thermal decomposition process of the complex, the experimental and calculated percentage mass loss were also given.

Solvent-Free Synthesis and Characterization of the Zn(II) Complexes with Amino Acid Schiff Base

Three zinc (II) complexes of the amino acid Schiff base were synthesized by the one step reaction of amino acid with aldehyde, zinc acetate in solvent-free. The compositions and structures of the complexes were characterized by elemental analyses, FTIR, XRD, TG-DSC. The compositions of the complexes are ZnL•nH2O (L = sal-leu, sal-ala, van-leu; sal = salicylaldehyde; van = vanillic aldehyde; leu = leucine; ala = alanine). Infrared spectra of the complexes indicate that the Schiff base ligands are formed, zinc ion is coordinated to the Schiff base ligands as terdentate with O, O and N donors from carboxylic, phenolic and imino groups respectively, the coordination numbers of zinc ion is four. The possible pyrolysis reactions in the thermal decomposition process of the complexes, the experimental and calculated percentage mass loss are also given.

Evaluation of the roughness and mass loss of the flowable composites after simulated toothbrushing abrasion

The purpose of this study was to measure mass loss and surface roughness changes of different brands of flowable resin composites after a simulated toothbrushing test. The null hypotheses were that there would be no differences in mass loss and no significant changes in surface roughness after this test and that there would be no correlation between the two variables. The tested materials were Aeliteflo (Bisco), Flow-It (Pentron), Flow-It LF (Pentron), Natural Flow (DFL) and Wave (SDI). Z100 (3M/ESPE) microhybrid and Silux Plus (3M/ESPE) microfilled resin composites were used as control materials. Twelve specimens (5 mm in diameter, 3 mm thick) of each material were prepared according to manufacturers' instructions. Toothbrushing abrasion was performed on all specimens from each of the materials using a simulator. The percentage mass loss and surface roughness were assessed before and after 100,000 brushstrokes, using a Sartorius analytical balance of 0.0001 g accuracy and a Hommel Tester T1000, respectively. The measurements of both properties were statistically compared by paired t-test and Tukey's test (p < 0.05). All materials presented a statistically significant mass loss comparing initial and final values, with the exception of Flow-It LF. However, no difference was revealed when comparing the mass loss of the different tested materials. All materials became rougher and Wave presented statistically higher roughness compared to the other resin composites. Flowable resin composites did not seem to be superior to the control groups, and they can be expected to wear by mass loss and to have an increased roughness of surface after toothbrushing action. The anticipated null hypotheses were partially accepted.