The sorption of basic dyes onto magnetic nanosorbent is commonly used as a novel material to combat powdered activated carbon, which is difficult to handle and separate during water and wastewater treatment. This adsorption method is commonly implemented in water and wastewater treatment due to its low cost and high performance. To explore the feasibility of adsorption, six different nonlinear isotherm models were applied and introduced to evaluate the performance and adsorption mechanisms via Microsoft Excel, and they were then compared to those of MATLAB and OriginPro. The Langmuir best provided the sorption of methylene blue adsorbed for a two-parameter isotherm model. The three-parameter model Toth gave a goodness of fit indicating a heterogeneous sorbent surface. Error function analysis found that the Residual Sum of Squares Error, Chi-square, Coefficient of determination, Average Relative Error, Hybrid Fractional Error Function, Marquardt’s Percent Standard Deviation and Root Mean Square Error provided the best overall results. In comparison, it could be concluded that six isotherm models showed the confidence interval that is simply the best fit at all experimental data points provided by the three software tools. All error function results indicated that the Microsoft Excel Solver function spreadsheet method satisfied all the statistic measures to predict the real variance of the probability of experimental data for all six isotherm models of adsorption of basic dye removal. One added benefit of this Microsoft Excel software tool is the built-in function associated with the desired type of application, which designates the desired type of error/statistical functions not mentioned in this research to the adsorbent materials used.

There are increasing demands to substitute the plastic from the petrochemical industry with bacterial cellulose which were produced from microorganisms as Acetobactor xylinum strain. The aim of this study was to produce bacterial cellulose from banana peels which are agricultural waste around Walailak University area. The banana peels were used as a carbon source together with nutrient medium for the growth of bacteria. The ratio between Hestrin and Schramm nutrient medium (HS) with banana peel to DI water was 1:0.5, 1:1, and 1:1.5 (%V/V). Sugar content in banana peel (control) was 4.0% Degree Brix. The initial pH was 6.0 and sugar contents varied in this study were 5.5%, and 11% Degree Brix. A.xylinum dosages used in the cultivation were 5, 6.67, and 8.33 (%V/V) respectively. The cultivation times were 15 days at the temperature of 30 °C. As a result, the highest yield of produced bacterial cellulose was 19.46 gram and the best condition which maximum yield of bacterial cellulose 1.95% can be obtained was 11% (Brix) of sugar content, 6.67 (%V/V) of A.xylinum added, and 1:1.5 of banana peel to DI water. The physical properties of bacterial cellulose were studied with ATR-FTIR spectroscopy which shown adsorption spectrum at 3279, 2915, 1627 and 1013 cm-1 corresponding to the-OH,-CH,-CH2 and carboxyl function groups, respectively. Glass transition Temperature (Tg) was 116.85°C. Tensile strength was measured with UTM and had average value of 41.13±5.43 Mpa. The bacterial cellulose had moisture content of 90.00±0.02%. The synthesized bacterial cellulose can be used as adsorption media and also has its chemical properties like petroleum polymer. Result suggested that the similar property can be observed when compared with petroleum plastic, however with the exception of methyl group (CH3). Methyl group which can be found in plastic synthesized from petrochemical is responsible for the strength of plastic. Thus, bacterial cellulose, synthesized in this study, is not as strong as petrochemical plastic. But it can be used to produce bio-plastics because of the-CH and-CH2 functional group attached. With the similar physical and chemical properties to those of petrochemical plastic, bacterial cellulose can be used as biopolymer.

No abstract

This research focused on batch experiment using a new generation of chelating resins via an ion exchange process to describe the metabolic adsorption and desorption capacity onto iminodiacetic acid/Chelex 100, bis-pyridylmethyl amine/Dowex m4195, and aminomethyl phosphonic/Lewatit TP260 functional groups in bioleaching. The results showed that Dowex m4195 had the highest performance of adsorption capacity for copper removal in both H+-form and Na+-form. Results for Lewatit TP260 and Chelex 100 revealed lower adsorption performance than results for Dowex m4195. The investigation of desorption from chelating resins was carried out, and it was found that 2 M ammonium hydroxide concentration provided the best desorption capacity of about 64.86% for the H+-form Dowex m4195 followed by 52.55% with 2 M sulfuric acid. Lewatit with 2 M hydrochloric acid gave the best desorption performance in Na+-form while Chelex 100 using hydrochloric at 1 M and 2 M provided similar results in terms of the H+-form and Na+-form. As aspects of the selective chelating resins for copper (II) ions in aqueous acidic solution generated from synthetic copper-citrate complexes from bioleaching of e-waste were considered, H+-form Dowex m4195 was a good performer in adsorption using ammonium hydroxide for the desorption. However, chelating resins used were subsequently reused for more than five cycles with an acidic and basic solution. It can be concluded from these results that selective chelating resins could be used as an alternative for the treatment of copper (II) ions contained in e-waste or application to other divalent metals in wastewater for sustainable water and adsorbent reuse as circular economy.

Biodegradable of polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT) and polybutylene succinate (PBS), which were biodegradable aliphatic polyesters, composite films were contained with titanium dioxide (TiO2) as a photocatalyst to evaluate the photocatalytic activity of bidegradable composite films for toluene removal. The synthesized TiO2 was prepared by sol-gel method between titanium isopropoxide with acetic acid. To form the anatase structure, it was calcined at 500°C. TiO2 were added to PLA/PBAT/PBS as a biopolymer blend at 0, 5 and 10 wt% .The TiO2/Bio-composite films were fabricated via blown film technique to produce 40 μm films. Photocatalytic activity efficiency of TiO2/Bio-composite films was performed in an annular closed system under UV light. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the biopolymer matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the biopolymer matrix. The X-ray diffraction (XRD) ensures the deposition of TiO2 as crystalline anatase phase. In addition, the photocatalytic results shown that the toluene removal efficiencies increased with an increasing TiO2 dosages at 0 wt%, 5 wt%, and 10 wt% , respectively. As aspects, the photocatalytic degradation results showed the highest tolune photocatalytic degradation efficiency of 52.0% at 10 wt% TiO2 .