Takeo Katami

EFFECT OF ULTRAVIOLET-ABSORBING VINYL FILM ON ORGANOPHOSPHORUS INSECTICIDES DICHLORVOS AND FENITROTHION RESIDUES IN SPINACH

Dichlorvos and fenitrothion residues found in spinach grown in greenhouse covered either by regular vinyl film or UV-absorbing vinyl film (UV-A) were analyzed by gas chromatography. After one day, dichlorvos residues in spinach covered with regular vinyl film and UV-A degraded by 97% and 80%, respectively, and degraded 100% after three days covered with regular vinyl film and six days covered with UV-A. After three days, fenitrothion residue in spinach covered with regular vinyl film degraded by 72% and then by 97% after six days; residue in spinach covered with UV-A degraded by 50% after three days and by 95% after six days. These results indicate that UV-A used to prevent the occurrence of insects and fungi in greenhouses reduced the degradation rates of dichlorvos and fenitrothion.

Contribution of an industrial waste incinerator to the atmospheric concentrations of volatile chlorinated organic compounds

Abstract The contribution of five volatile chlorinated organic compounds emitted from waste incinerator to the surrounding atmosphere were investigated. The atmospheric concentrations of these compounds were low level as compared with those around the factories in which chlorinated organic compounds were used as solvent. It was found that the influence of the incinerator exhausts to the atmosphere was negligible or very small for these compounds.

Emission of chlorinated compounds by combustion of waste dry-cleaning materials

Abstract The formation of chlorinated compounds by combustion of waste dry-cleaning materials including tetrachloethylene solvent was investigated. Phosgene and hydrochloric acid in exhaust gas can be removed by passing through a wet scrubber using 10% sodium hydroxide solution. The concentration of phosgene, chloroform, carbon tetrachloride and trichloroethylene in exhaust gas were all below the detection limits when the afterburner exit temperature of the incinerator was raised to over 900°C.

A Role of Alkaline Elements in Formation of PCDDs, PCDFs, and Coplanar PCBs During Combustion of Various Paper Samples

Combustion of industrial and domestic wastes produces significant amounts of dioxins (PCDDs, PCDFs, and coplanar PCBs). These wastes contain numerous kinds of materials, including inorganic elements, which may play an important role in dioxin formation upon combustion. Six paper samples—impregnated with NaHCO3, NaCl + fly ash, polyvinyl chloride (PVC), and PVC + NaHCO3—were combusted in a well–controlled incinerator at 512–760°C and exhaust gases were analyzed for dioxins (PCDDs, PCDFs, and coplanar PCBs). Addition of fly ash, which contained high levels of Ca and Cl, to NaCl impregnated–newspaper increased total dioxin formation from 80.8 ngg–1 to 139 ngg–1 during combustion. Addition of NaHCO3 to PVC–impregnated newspaper increased total dioxin formation from 220 ngg–1 to 288 ngg–1. Formation of PCDDs from NaHCO3/PVC–impregnated newspaper were significantly less than that from newspaper impregnated with PVC alone. On the other hand, more PCDFs formed from NaHCO3/PVC–impregnated newspaper than from newspaper impregnated with PVC alone. Addition of NaHCO3 to a PVC–impregnated newspaper changed the production pattern of dioxins. PVC– impregnated newspaper produced the greatest amount of coplanar PCBs (12.3 ngg–1), which may be accounted for by the relatively high level of TEQ value (3.31 ng–TEQg–1) of this sample. Generally, addition of fly ash and alkali metals, such as Na, to paper samples increased the total dioxin formation in exhaust gases during combustion. The results suggest that alkali metals increase Cl concentrations at a reaction site by trapping chloride ions and/or chloride radicals and consequently increasing dioxin formation.

Emission of organic compounds by combustion of waste plastics involving vinyl chloride polymer

Abstract Organic compounds emitted from combustion of waste plastics involving vinyl chloride polymer were investigated in an actual waste incinerator. The amounts of volatile aliphatic hydrocarbons and volatile chlorinated organic compounds decreased when the secondary combustion temperature was controlled over 900°C. On the other hand, the amounts of some aromatic hydrocarbons increased with a rise of the secondary combustion temperature.