Hybrid-Type Electrostatic Precipitator

Three experiments were designed to determine the effects of SO₂ concentration on two Southeastern oat varieties—Caroiee and Coker 227. The plants were grown under uniform conditions prior to and after the experimental growth period. During the 7 to 14 day experimental growth period the plants were subjected to four growth temperatures (18/14, 22/18, 26/22 and 30/26° C day/night temperatures) and exposed 2 or 4 times to specific concentrations of SO₂ (from 0 to 4 ppm) for 1.5 or 3.0 hr periods. In the first two experiments, the exposure temperatures were varied (18° to 30° C). In the third design, the exposure temperatures remained constant and two exposure relative humidities (55 and 80%) were used. Injury and growth reductions were more severe in Coker 227 than in Caroiee. Root dry weight (RDW) was affected more than top dry weight (TDW). Plants were more sensitive at the higher growth temperatures. Exposure temperatures had little to variable effects. Plants were more sensitive at 80% than at 55% relative humidity. Biomass was reduced at 0.4 ppm SO₂ after four 3 hr exposures and at 0.75 ppm after two 1.5 hr exposures, but growth was also increased as often. These concentrations approached the accepted threshold for adverse effects to sensitive vegetation. Foliar injury was highly correlated with growth reductions.     

Regulatory Off-Gas Analysis from the Evaporation of Hanford Simulated Waste Spiked with Organic Compounds

Abstract

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 °C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.     

Virus inactivation during coagulation with aluminum coagulants

We used the bacteriophages Qβ and MS2 to determine whether viruses are inactivated by aluminum coagulants during the coagulation process. We performed batch coagulation and filtration experiments with virus-containing solutions. After filtering the supernatant of the coagulated solution through a membrane with a pore size of 50 nm, we measured the virus concentration by both the plaque forming unit (PFU) and polymerase chain reaction (PCR) methods. The virus concentration determined by the PFU method, which determines the infectious virus concentration, was always lower than that determined by the PCR-based method, which determines total virus concentration, regardless of infectivity. This discrepancy can be explained by the formation of aggregates consisting of several virus particles or by the inactivation of viruses in the coagulation process. The former possibility can be discounted because (i) aggregates of several virus particles would not pass through the 50-nm pores of the filtration membrane, and (ii) our particle size measurements revealed that the virus particles in the membrane filtrate were monodispersed. These observations clearly showed that non-infectious Qβ particles were present in the membrane filtrate after the coagulation process with aluminum coagulants. We subsequently revealed that the viruses lost their infectivity after being mixed with hydrolyzing aluminum species during the coagulation process.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0-23 (mean: 13, median: 14) and 2.7-20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16-326 (mean: 107, median: 100) and 12-252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

Optimization of separation and logistics for recycling materials from wallpaper hanging sites

It is of huge importance for sustainability to find a pragmatic solution for recycling of a variety of wastes emitted in small mass such as the case of wallpaper replacements. A combination of two-step sorting scheme and transportation of the wastes in collaboration with the wholesalers was proposed to enhance the efficiency of recycling. The two-step sorting consists of the first sorting at the wallpaper hanging sites to separate and group wastes in a way to avoid heavy additional burden on the hanging job. Secondary sorting is conducted at a Sorting Center to re-group wastes to send to an intermediate processing company for recycling. To minimize the costs for transportation, the grouped wastes emitted at the hanging sites are brought back by the hangers and kept temporally and then moved to the wholesaler(s) on the way to receive new materials. When the wastes at the wholesaler(s) become sufficiently large for economic transportation, a truck is arranged to collect the wastes to transport them to the Sorting Center. A feasibility study to test the practicality of the method confirmed that it could be operable and the cost would be comparable or lower than that currently incurred for disposal of the wastes.     

Analysis method for PCBs in reclaimed oil using a fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method

It is necessary for companies supplying reclaimed oil to analyze polychlorinated biphenyls (PCBs), because there is a possibility of the presence of contaminants due to trace-level PCBs in the reclaimed oil. However, common analysis methods of PCBs are time-consuming and complicated. Fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method is an official method for analyzing PCBs in insulating oil in Japan. This method is extremely fast and simplified. The purpose of this study involves an investigation of the aforementioned fast and simple method for potential use in the analysis of reclaimed oil. Furthermore, it was attempted to combine the method with sample preparation involving only hexane dilution. The effect of sample dilutions corresponding to 100, 300, and 500 times was evaluated for reducing the matrix effect. The matrix effect was suppressed at a dilution ratio equal to or exceeding 300 times. Calibration curves of four points, namely 0.01, 0.05, 0.1, and 0.5 ng/mL, (ignored origin) by using an internal standard method were prepared for the 13 components. The square of regression coefficient (R²) values of all calibration curves exceeded 0.997. This method was adopted for the analysis of reclaimed oil containing 0.5 μg/mL PCBs, which corresponds to the judgment criteria, and accurate quantitation (accuracy value, 94.0–102%) and good repeatability (%RSD, 3.6%) were obtained. Furthermore, the required sensitivity was maintained even when 800 samples were analyzed without a cleaning ion source and an exchanging analysis column.     

Evaluation of operational parameters in thermophilic acid fermentation of kitchen waste

In this study, the effect of operational parameters, such as solids retention time (SRT), pH, and substrate total solids (TS) concentration, on acid fermentation efficiency was investigated. From batch tests, it was shown that the appropriate pH range for thermophilic acidogens was around 6–7 and that the optimum pH condition was 6. From the continuous experiment, pH and SRT were shown to be the most important operational parameters for solubilization and organic acid production. In contrast, TS concentration did not show any obvious effect on chromium chemical oxygen demand (CODcr) solubilization when TS was in the range 3.5%–10%. The optimum operational conditions for thermophilic acid fermentation were an SRT of 2 days and a pH of 6. This research was carried as a part of the CREST project of Japan Science and Technology Agency.     

PCDDs/PCDFs and dioxin-like PCBs: recent body burden levels and their determinants among general inhabitants in Japan

OBJECTIVE: The objective was to grasp the recent body burden levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and to investigate their determinants among general inhabitants in Japan. METHODS: This study was performed on 1374 participants aged 15-73 years, who were not occupational exposure to PCDDs/PCDFs and DL-PCBs, living widely in 75 different residential areas of 25 prefectures in Japan. Seven PCDDs, ten PCDFs, twelve DL-PCBs, which are assigned a toxicity equivalent factor, and biochemical factors were determined in fasting blood. A questionnaire survey on life-style was also performed. RESULTS: The median of total toxicity equivalent (TEQ) was 20pgTEQ/g lipid. The TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ increased with age. The intake frequency of fish-and-shellfish was positively associated with the TEQ of DL-PCBs in both sexes. Current smoking was negatively related to the TEQ of DL-PCBs in male subjects but not in female subjects. Feeding status was significantly related to the TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ, being lowest in breast feeding and highest in never and bottle feeding. According to the results of subgroup analysis, parity was not associated with the TEQs. CONCLUSIONS: The fish-and-shellfish consumption may contribute to the accumulation of DL-PCBs, and smoking may induce some biological action for the elimination of DL-PCBs from the human body. Breast feeding is considered to be one of the major excretory pathways of PCDDs/PCDFs and DL-PCBs in women, while parity may not largely contribute to the elimination of these pollutants.     

Effects of dioxins and polychlorinated biphenyls (PCBs) on thyroid function in infants born in Japan – the second report from research on environmental health

Dioxins (PCDD + PCDF) and polychlorinated biphenyl (PCB) are potentially hazardous compounds and have structural similarity to thyroid hormones. Our research group on “Dioxins and PCB in Human Milk” was organized in 1997 and has been active for the past three years. We collected breast milk from 80 mothers living in Tokyo, Saitama, Ishikawa and Osaka Prefecture in Japan at 5, 30, 150, 300 postpartum days and measured PCDDs, PCDFs and PCBs during 1998–1999. We added another 20 prefectures and cities during 1999–2000. Breast milk was obtained from 415 mothers at 30 postpartum days (breast-feeding group). Blood was taken from infants who were breast-fed at the age of 1 year for evaluation of thyroid and immune functions. Blood was also taken from 53 infants who were bottle-fed (bottle-feeding group) as a control. Serum T4, T3, FT4 and TSH levels in the breast-feeding (n=337) and bottle-feeding (n=53) groups were within normal ranges and were not significantly different between the two groups. Although there were a large geographic differences of dioxins and co-PCB content in breast milk, there were no differences in serum T4, T3, FT4, TSH levels and no significant correlation between the mean serum levels of TSH and TEQ in breast milk. There was a significant correlation between serum TSH at 1 year of age and that from blood on dried filter paper TSH at 5 days of age. We concluded that dioxin intake from breast milk in Japanese infants did not impair thyroid function. However, long-term effects remain to be evaluated.