Somsak Damronglerd

Lead recovery from waste frit glass residue of electronic plant by chemical-electrochemical methods

This work aims at recovering lead from frit glass waste of electronic plants by using the electrochemical method comprising two successive steps of lead leaching and electrodeposition. In the leaching step, it was found that nitric acid and acetic acid are better solutions for the dissolution of lead oxide compared with sodium hydroxide, hydrochloric acid, and sulfuric acid. More than 95% of the lead was leached by 0.1 M nitric acid or 0.5 M acetic acid at 0.5% weight by solid volume. In the electrodeposition step, more than 95% of lead can be removed with high current efficiency from the leaching solution at an optimum current density. The values of the optimum current density of 0.5 and 1 M acetic electrolytes were between 8.8–10 mA/cm2, whereas those for 0.1 M and 0.5 M of nitric acid were 15 and 27.5 mA/cm2, respectively.

Encapsulated AlCl3: a convenient catalyst for the alkylation of benzene with dodecene

Abstract A novel method for the encapsulation of AlCl 3 was successfully carried out using an insoluble polymer wall. The polymer wall was formed by the reaction of poly(styrene- co -dimethylaminoethyl methacrylate) and hydrogenated telechelic polybutadiene containing -COOH groups. The encapsulated AlCl 3 was used to catalyze the Friedel–Crafts alkylation of benzene with dodecene. The alkylbenzenes were obtained in excellent yields and the encapsulated AlCl 3 catalyst was separated by simple filtration.

Effect of the third acrylated vinyl comonomer on absorption and desorption properties of styrene–divinylbenzene–alkyl acrylate terpolymers, imbibing solvent on a water surface

A series of imbiber terpolymer beads was prepared by radical suspension copolymerization of styrene–divinylbenzene with varied contents of acrylated vinyl monomers, n-butyl acrylate and 2-ethyl hexyl acrylate, as the third comonomer. A DVB content of 6 wt % and a mixture of 60/40 wt % toluene/n-heptane as the diluent were used throughout this study. The influence of acrylated vinyl comonomers on bead properties and swelling properties was investigated. The imbiber beads are capable of absorption and desorption of organic solvents having solubility parameters in the range of 14.9–20.9 (MPa)1/2. Styrenic imbiber beads were swelled in a toluene/n-heptane mixture of 50% by volume and the kinetics of absorption was studied. The imbiber beads could absorb the toluene/n-heptane mixture completely within 20 min and yielded a maximum swelling ratio of 6.8. The diffusion coefficient values of these beads were in the range of 6.40 × 10−6 to 1.52 × 10−5 cm2 s−1.

Electrochemical Incineration of Organic Pollutants for Wastewater Treatment: Past, Present and Prospect

Water is a combination of two parts, hydrogen and oxygen as H2O. However, pure water is only produced in a laboratory, water in general is not pure composition of hydrogen and oxygen. Eventhough, distilled water still has measurable quantities of various substances such as ions, mineral or organic compounds (http://www.environmental-center.com). These substances should be considered as the impurities that dissolved into water during flow through hydraulic pathway. Nowadays, there are some increasing on both population and consumption of natural resources to serve endless needs. Water is most important resource and becomes limited of use due to contamination from discharge of both domestic and industry. The discharge of domestic wastewater contains a large amount of organic pollutants. Industry also contributes substantial amounts of organic pollutants. However, some organic substrates discharged from industry contain a high toxicity and refractory organic pollutants. Figure 1 presents the example of a partially closed water cycle. In the cycle the organic pollutants are neither removed by sorption nor biodegradation. Nevertheless, there are some organic pollutants pass all barriers such as wastewater treatment or underground passage and appear in raw waters used for drinking water production. The other group of organic pollutants may originate from consumer products used in household, pesticides applied in agriculture or chemicals used in industry (Reemtsma & Jekel,2006). Wastewater treatment consists of applying known technology to improve or upgrade the quality of a wastewater. Usually wastewater treatment will involve collecting the wastewater in a central, segregated location and subjecting the wastewater to various treatment processes (Hanze et al., 1995). Wastewater treatment can be organized or categorized by the nature of the treatment process operation being used such as physical, chemical or biological treatment. Biological treatment of polluted water is the most economical process and commonly used for the elimination of degradable organic

Degradation of Poly(methyl methacrylate) over Zeolites in a Batch Reactor

Thermal degradation is an attractive way to eliminate poly(methyl methacrylate) (PMMA) waste to which high temperatures are applied in the absence of oxygen. However, the process is not selective, resulting in a complex composition of products. Catalytic degradation over zeolites provides an effective route to selectively convert PMMA into desired products at lower temperatures, since zeolites have high acidity and shape-selectivity. In this work, the degradation of PMMA over various zeolites, including ZSM-5, BETA and USY, has been investigated in a batch reactor as a feasibility study to recover methyl methacrylate (MMA) as well as other valuable chemicals. The results showed that PMMA can be completely degraded at 300 oC and MMA was recovered as light oil. With increasing the degradation time, PMMA was converted over zeolites into more gaseous and light oil products, while the thermal degradation gave higher portion of heavy oil. From GC-MS analysis of light oil, MMA was found as the main product, co-existing with methyl 2-methyl propionate and methyl 2-methyl butyrate both of which can be used as synthetic fragrance.