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.     

Toxicity identification and reduction of wastewaters from a pigment manufacturing factory

In this study, major toxicants in pigment wastewaters (i.e. raw wastewater and effluent) were determined by toxicity identification evaluations (TIEs), and changes in their toxicities due to combined gamma-ray (gamma-ray) and ozone treatments were evaluated. From TIE results using Daphnia magna, Cr(VI) and o-toluidine were identified as major toxicants in the raw wastewater with concentrations of 2.47 and 25.3mg l(-1), respectively. This was confirmed by subsequent spiking and mass balance approaches. For effluent, TIE results suggested that organic anions were likely responsible for the observed toxicities. Toxicity reduction tests showed that gamma-rays with ozone treatment after coagulation was more efficient in reducing toxicities in the raw wastewater (3.9-2.0 TU) than gamma-ray treatment alone (3.9-3.1 TU). For pigment effluent, gamma-ray/O3 treatment resulted in a complete removal of the acute toxicity.     

Placental transfer of polychlorinated biphenyls, their hydroxylated metabolites and pentachlorophenol in pregnant women from eastern Slovakia

The aim of the present study was to understand the placental transfer of polychlorinated biphenyls (PCBs), specific hydroxylated PCB metabolites (OH-PCBs), and pentachlorophenol (PCP) in blood serum, in a birth cohort from eastern Slovakia. During the period 2002-2004, cord blood specimens were collected in parallel with maternal specimens from women delivering in the two eastern Slovak districts of Michalovce and Svidnik/Stropkov. A total of 92 pairs of mother-cord specimens at delivery were selected for this study. 4-OH-CB107, 3-OH-CB153, 4-OH-CB146, 3'-OH-CB138, 4-OH-CB187, and 4'-OH-CB172 were quantified. The median concentrations of Sigma(17)PCBs, Sigma(6)OH-PCBs, and PCP in cord serum were 0.92, 0.33, and 0.69 ng/g wet wt., respectively and highly correlated with the corresponding maternal serum levels (correlations were R(2)=0.61, 0.78, and 0.82, respectively). The median cord to mother ratios of the Sigma(17)PCBs, Sigma(6)OH-PCBs, and PCP were 0.18, 0.75, and 1.10, respectively. The median ratio of the Sigma(6)OH-PCBs to the Sigma(17) PCBs in the cord serum was 0.38 from wet weight based concentrations, which was about four times higher than the ratio of these compounds in maternal serum (0.09). PCP was more abundant than any PCB or OH-PCB congener measured in cord serum. The higher cord to maternal ratios of OH-PCB metabolites as compared with the parent compounds suggests either a higher placental transfer rate or greater metabolism in the fetus as compared with the maternal compartment. These findings are consistent with their preferential binding to TTR that can cross the placenta. The cord to maternal ratio varies by congener (e.g., 4-OH-CB107=0.58, 4-OH-CB146=0.74, 3'-OH-CB138=1.01).     

Manganese peroxidase-catalyzed oxidative degradation of vanillylacetone

When 4-(4-hydroxy-3-methoxy-phenyl)-2-butanone (vanillylacetone) was tested for manganese peroxidase (MnP)-catalyzed oxidation, it was found to be degraded with the cleavage of an aromatic ring. Among numerous products of vanillylacetone oxidation, four major ones were purified by thin-layer chromatography and identified using mass spectroscopy (MS) and nuclear magnetic resonance (NMR) analysis. Three of them maintained the aromatic ring structure and were identified as 4-[6,2'-dihydroxy-5,3'-dimethoxy-5'-(3-oxo-butyl)-biphenyl]-butan-2-one, 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, and 4-[6,2'-dihydroxy-5,3'-dimethoxy-5'-(3-oxo-butyl)-biphenyl]-3-buten-2-one. Even though the fourth product could not be purified to a single compound, data from infrared spectroscopy showed that it did not have a benzene ring. From MS and NMR analysis, 3-(3-oxo-butyl)-hexa-2,4-dienedioic acid-1-methyl ester was tentatively suggested as the dominant species. The reaction mechanism was suggested on the basis of the structural information of these products. To our knowledge, this paper is the first report on aromatic ring cleavage of the phenolic compound by MnP.     

Two-generation toxicity study on the copepod model species Tigriopus japonicus

Previous studies on the intertidal copepod Tigriopus japonicus have demonstrated that it is a suitable model species for the assessment of acute toxicities of marine pollutants. In order to standardize T. japonicus for use in environmental risk assessment involving whole life cycle exposure, we tested nine pollutants for their effects on growth and reproduction during a two-generation life cycle exposure test. Nauplii (F 0) were exposed to a range of concentrations of each chemical in a static renewal culture system. Broods of the second generation (F1) were subsequently exposed to the same concentrations for one full life cycle. Of the seven traits (nauplius phase, development time, survival, sex ratio, number of clutch, nauplii per clutch and fecundity), only the length of the nauplius phase and development time showed a greater sensitivity to chemical exposure. Between the two sensitive traits, the period of the nauplius phase was more sensitive than cohort generation time. Biocides significantly increased the maturation period of nauplii as well as copepodids in F 0 generation. In this study, it was demonstrated that T. japonicus could also be used in reproduction and life cycle tests and it provides an opportunity for testing the chronic and subchronic toxic effects of marine pollutants. Further validation and harmonization in a multi-centric study involving other laboratories of the region will strengthen its use as a supplement to existing model species.     

Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long-term after the Chernobyl accident.

Rural settlements located in areas of the Russian Federation contaminated after the Chernobyl accident and exceeding an annual dose of 1 mSv a-1 have been classified according to 137Cs contamination density, internal dose and the neighbourhood of forests. It has been shown that, with the exception of the most contaminated areas, the internal doses decreased in accordance with a decline in 137Cs availability for plant root uptake. An inverse tendency was observed in areas with 137Cs contamination above 555 kBq m-2 which can be explained by a reduction or even termination of countermeasure application and by an increasing consumption of forest products in areas where restrictive countermeasures are still implemented. Twenty-seven settlements have been studied to estimate the effectiveness of countermeasures applied previously and to identify the most important factors governing the radiation exposure to the population and its change with time. It has been shown that the effectiveness of countermeasures which resulted in a decrease of up to 40% of doses has a tendency to decline in the long term. The need for continuation of remediation in rural settlements was evaluated both for selected settlements and extrapolated to the whole contaminated area and it has been shown that the application of countermeasures will be of importance at least up to the year 2045. Rather high effectiveness in terms of internal dose reduction (factor of 2-2.5) of radical improvement (disking, ploughing and reseeding) and administration of Cs binders to animals (Ferrocyn) was demonstrated for the selected settlements. It could be demonstrated that for forest-remote settlements there is a linear dependence between internal dose normalised to the density of contamination and the proportion of peat soils around settlements. For near-forest settlements, this dependence was less pronounced which can be explained by the high contribution of forest food products to the internal dose. Milk is still the major dose-forming product in rural Russian settlements (its contribution to internal dose in forest-remote settlements is above 70%); however, in near-forest settlements, the contribution of mushrooms to the internal dose is comparable to the contribution from milk.     

Applications of Satellite Remote Sensing to Marine Pollution Studies

There are two approaches in the application of satellite sensors to marine pollution studies. Satellite sensors are used to observe and characterize ocean pollutants such as industrial wastes and oil. in addition, satellite observations provide information useful in illuminating processes such as eutrophi-cation or air-sea exchange of CO₂, that are important in determining the distribution and fate of pollutants.

Satellite technology is an important tool in monitoring and studying ocean pollution. Visible sensors have been used to observe and characterize sewage sludge and industrial wastes dumped at sea. Oil slicks have been observed with Landsat, AVHRR and SAR imagery. Besides directly detecting pollutants, satellite sensors are useful for analyzing ocean processes that are influential in the fate of pollutants. These processes include eutrophication of coastal waters and the distribution of suspended matter. the fate of excess CO₂ can be addressed using scatterometer-derived estimates of wind speeds to determine the CO₂ exchange coefficient at the sea surface on a global scale.     

A DYNAMIC SYSTEM MODEL FOR SIMULATING SEDIMENT DISCHARGE1

ABSTRACT: A dynamic sediment discharge model was developed and proposed for the simulation of watershed systems. It war developed from an expansion of splash and flow erosion relationships under steady state conditions. It was described as a general erosion model that can be reduced to forms comparable to many conceptual soil erosion and sediment yield models. The model incorporates eight parameters such as rainfall intensities, runoff rates, and previous sediment discharges. The model was tested with two small watersheds with simulation results which were very satisfactory compared to the data.     

CONSIDERATIONS IN CHOOSING THE APPROPRIATE MIX OF URBAN AND AGRICULTURAL NONPOINT POLLUTION CONTROL1

ABSTRACT: In developing strategies for nonpoint pollution control in designated 208 areas, one of the issues facing planners is the relative emphasis which should be placed upon urban versus agricultural non-point control. Five criteria which should be considered in designing an appropriate BMP strategy mix are discussed: 1) BMP cost effectiveness; 2) information and administrative cost; 3) flexibility, which relates to the cost of reversibility given substantial uncertainties; 4) associated effects, both direct and indirect; and 5) acceptability to local jurisdictions and groups. Whatever an evaluation on the basis of the first four criteria may suggest, acceptance of agricultural BMPs will be difficult to achieve, thus favoring urban oriented strategies, unless local revenue sources are developed to offer payments to farmers for BMP adoption.