Effects of copper chloride on formation of polychlorinated dibenzo-p-dioxins in model waste incineration

Combustion experiments in a laboratory-scale fluidized-bed reactor were conducted to elucidate the effects of copper chloride as a catalyst on polychlorinated dibenzo-p-dioxins (PCDDs) formation in municipal waste incineration. We used model wastes with and without copper chloride (CuCl₂ · 2H₂O), both of which contained polyvinyl chloride as a chlorine source. Combustion temperature was set to 900 °C, and the amount of air supplied was twice the stoichiometric ratio. The experimental setup was carefully planned to suppress the influences of experimental conditions except the waste composition. Results of these experiments showed that copper chloride in the waste increased the amount of PCDDs formed and made the homologue profile to shift towards the highly chlorinated species. Copper chloride contributes to the PCDDs formation by promoting chlorination, whereby the reaction is important in that organic matter is chlorinated directly by copper compounds. Copper chloride did not exert a great influence on the isomer distribution patterns of PCDDs, while there appeared a significant difference in the case of PCDFs. This points out the difference of the major formation mechanisms between PCDDs and PCDFs. PCDDs are less formed by the catalytic reactions from carbon/polycyclic aromatic hydrocarbons than PCDFs in our experimental conditions.     

Controlled release of molasses melanoidin-like product from hybrid organic–inorganic silica xerogels and its application to the phytoextraction of lead through the Indian mustard

Environmental Science and Pollution Research - In this study, we investigate the release of melanoidin-like product (MLP) from hybrid silica xerogels to control the quantity of MLP in the medium...     

Chlorinated polycyclic aromatic hydrocarbons in surface sediment from Maowei Sea,Guangxi, China: occurrence,distribution, and source apportionment

Environmental Science and Pollution Research - Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) with three to five aromatic rings have been documented to ubiquitously occur in environmental...     

Formation of cyanide ion or cyanogen chloride through the cleavage of aromatic rings by nitrous acid or chlorine. IX. On the reactions of chlorinated, nitrated, carboxylated or methylated benzene derivatives with hypochlorous acid in the presence of ammonium ion

Chlorinated, nitrated, carboxylated or methylated benzenes, phenols and anilines reacted with chloramine to give cyanogen chloride, independently of the positions and the numbers of the substituents. Among these compounds, 2,4,6-trichlorophenol afforded cyanogen chloride in a relatively high yield of 13.3%, and the intermediates in the reaction were 2,6-dichloro-1,4-benzoquinone-4-(N-chloro)imine and 4,6-dichloro-1,2-benzoquinone-2-(N-chloro)-imine, of which the latter was the main intermediate.     

Studies on automated survey system of environmental chemicals by gas chromatography-mass spectrometry-computer III. Construction of an automated survey system and its application

An automated survey system on the chemicals in environments by a gas chromatography-mass spectrometry-computer system has been constructed of Three Dimensional Mass Chromatography, Modified Probability Based Matching method, and Self Training Interpretive and Retrieval method. And it was applied to analyze environmental materials, with interesting results.     

Development of new footwear sole surface pattern for prevention of slip-related falls

In this study, a new rubber surface pattern for a footwear sole was developed to prevent slip-related falls. This pattern shows a high static coefficient of friction (SCOF) and a high dynamic coefficient of friction (DCOF) when sliding against a liquid contaminated surface. A hybrid rubber block, in which a rubber block with a rough surface (Ra = 30.4 μm) was sandwiched between two rubber blocks with smooth surfaces (Ra = 0.98 μm), was prepared. The ratio of the rough surface area to the whole rubber block surface area r was 0%, 30%, 50%, 80%, and 100%. The coefficient of friction of the rubber blocks was measured when sliding against a stainless steel plate with Ra of 0.09 μm contaminated with a 90% aqueous solution of glycerol. While the SCOF increased with an increase of the rough surface area ratio r, the DCOF during steady-state sliding decreased with an increase of the rough surface area ratio r. The rough surface area ratio of 50% achieved a SCOF value around 0.5 or more and a DCOF value greater than 0.5. Furthermore, the difference in the value of the SCOF and DCOF was the smallest for the rubber block with r of 50%. The results indicated that the rubber block with r of 50% would be applicable to a footwear sole surface pattern to prevent slip and fall accidents on contaminated surfaces.     

Estimating the mitigation effect of Tokai earthquake measures on housing damage: a counterfactual approach

This paper evaluates the mitigation effect of Tokai earthquake measures on housing damage using a counterfactual approach. It focuses on those measures that stimulate ex‐ante investment in disaster prevention in the supposedly affected area, including earthquake‐proof retrofitting and improved housing construction; the effect of the measures on housing losses is estimated monetarily. The study compares factual disaster damage computed using a real distribution of houses with counterfactual damage to a hypothetical housing distribution that would occur if the measures were not implemented. The key findings are: (i) the disaster mitigation effects of Tokai earthquake measures on housing amount to approximately JPY 18 billion (USD 0.18 billion) for Yamanashi Prefecture and JPY 0.26 trillion (USD 2.6 billion) for Shizuoka Prefecture, which would be at the centre of the event; (ii) a before–after comparison biases estimates of the mitigation effect; and (iii) statistically, the measures do not mitigate the housing damage predicted for an earthquake in Tokai.     

Studies on automated survey system of environmental chemicals by gas chromatography-mass spectrometry-computer I. Retrieval system of mass spectra

A retrieval system of mass spectra based upon the Probability Based Matching method was studied in order to apply it to survey the chemicals in environments by a gas chromatography-mass spectrometry-computer system. As retrieval indices, peak missing probability and relative confidence value were proposed.     

Material reuse and recycling in construction works in Japan

Journal of Material Cycles and Waste Management - The status of material reuse and recycling in Japan is reviewed with an emphasis on the efforts by the national government. First, the national...     

Characteristics of a bioxalate chelating extraction process for removal of chromium,copper and arsenic from treated wood

The disposal of wood waste treated with chromated copper arsenate (CCA) is a problem in many countries. We have proposed a novel chelating extraction technique for CCA-treated wood using bioxalate, a solution of oxalic acid containing sufficient sodium hydroxide to adjust the pH to 3.2, which is an effective way to obtain an extraction efficiency of 90% for chromium, copper, and arsenic. The purpose of the present study was to investigate the characteristics of bioxalate extraction of CCA-treated wood. Extractions of CCA-treated western hemlock chips with solutions of bioxalate, oxalic acid, and sodium hydroxide were carried out. The use of bioxalate was confirmed as the most effective extraction technique for chromium, copper and arsenic, with an efficiency of 90%. Extraction with simple oxalic acid was ineffective for copper (less than 40% extraction efficiency), but effective for chromium and arsenic, with 90% efficiency. Sodium hydroxide showed a similar tendency, being ineffective for chromium and copper (less than 20% extraction efficiency), but relatively effective for arsenic (around 70–80% efficiency). We also discovered an interesting phenomenon whereby the addition of sodium hydroxide to a simple oxalic acid solution during the oxalic acid extraction progress resulted in dramatically increased extraction efficiency for copper, chromium and arsenic, up to 90%. Although oxalic acid was ineffective for copper extraction, the addition of sodium hydroxide during the oxalic acid extraction process rendered it effective.