Test for photosynthetic inhibition by bis(N′,N′-dimethylureido)biphenyl photoproducts of monuron

Five substituted biphenyl photoproducts were identified from the photolysis of 3-(4-chlorophenyl)-1, 1-dimethylurea (monuron) under varying solution conditions. These photoproducts contained functional groups that conferred phytotoxic properties to phenylurea herbicides. Therefore, a study was conducted to determine if these biphenyl photoproducts at 1, 10 and 100 μM concentrations could exhibit phytotoxic effects using the Hill reaction as the biological assay. The results show that virtually no inhibitory effects were observed from the bis-(N′,N′-dimethylureido)biphyenyl photoproducts at any of the above concentrations.     

Past, present, and future of MSW landfills in Japan

This article focuses on the historical development of landfill technology since the beginning of the nineteenth century in Japan. The regulations and guidelines that form a framework for the technology are reviewed, and the historical background and the current state of Japanese municipal solid waste (MSW) management are described. Through the analysis of data collected from facility leaflets, changes in the leachate treatment system are surveyed. Finally, the concept of the “sustainable bioreactor landfill with low organics” is proposed.     

Phosphorus dynamics associated with phytoplankton blooms in eutrophic Mikawa Bay,Japan

Changes in the phosphorus components of the particulate matter in seawater were studied in the eutrophicated waters of Mikawa Bay, Japan, during summer 1981. The contents of particulate phosphorus and hot-water extractable intracellular phosphorus displayed remarkable changes associated with phytoplankton blooms caused by wind-induced or upwelling-associated nutrient enrichment from the bottom water layers. Nanoplankton <10 m accounted for much of the particulate phosphorus (70 to 79% in June and July, and 44 to 78% in August and September); the contribution of large-sized phytoplankton >25 m varied from 9 to 49%, the peak values being attained under red-tide conditions. The capacity for phosphorus storage in cells was low in nanoplankton cells, high in large phytoplankton species. Differences in rates of phosphorus storage and growth between nanoplankton and large phytoplankton accounted for fluctuations in particulate phosphorus which were closely associated with fluctuations in phytoplankton blooms in Mikaw Bay.     

EFFECTS OF INCREASED DELTA EXPORTS ON SACRAMENTO VALLEY'S ECONOMY AND WATER MANAGEMENT1

ABSTRACT: Exports from the Sacramento‐San Joaquin Delta are an important source of water for Central Valley and Southern California users. The purpose of this paper is to estimate and analyze the effects increased exports to south of Delta users would have on the Sacramento Valley economy and water management if water were managed and reallocated for purely economic benefits, as if there were an ideal Sacramento Valley water market. Current Delta exports of 6,190 thousand acre‐feet per year were increased incrementally to maximum export pumping plant capacities. Initial increases in Delta exports did not increase regional water scarcity, but decreased surplus Delta flows. Further export increases raised agricultural scarcity. Urban users suffer increased scarcity only for exports exceeding 10,393 taf/yr. Expanding exports raises the economic value of expanding key facilities (such as Engle bright Lake and South Folsom Canal) and the opportunity costs of environmental requirements. The study illustrates the physical and economic capacity of the Sacramento Valley to further increase exports of water to drier parts of the state, even within significant environmental flow restrictions. More generally, the results illustrate the physical capacity for greater economic benefits and flexibility in water management within environmental constraints, given institutional capability to reoperate or reallocate water resources, as implied by water markets.     

High seagrass diversity and canopy-height increase associated fish diversity and abundance

Seagrass species function as typical foundation species that unifies most ecosystem processes. This ecosystem role depends largely on the morphological characteristics and structural complexity of seagrass beds, including their ecological importance for fish species. This study examined relationships between seagrass bed characteristics and associated fish communities in mixed seagrass beds. Correspondence analysis (CA) and canonical correlation analysis (CCoA) were performed to estimate relationships for individual seagrass bed characteristics. The CCoA results revealed that species richness and three-dimensional structure of seagrass had great effect on the biomass and richness of the associated fish community. The CA results revealed that the relative importance of seagrass bed characteristics differed among fish functional groups including fishes appearing on the surface of, inside, and on the bottom of seagrass beds. The fishes found on the surface of the beds preferred beds with low seagrass biomass and high three-dimensional structure, those inside the beds preferred beds with high seagrass biomass and high three-dimensional structure, and those on the bottom of the beds preferred locations with low seagrass biomass and low three-dimensional structure. The results of this study provide compelling evidence that seagrass beds with high species diversity and high three-dimensional structure, but intermediate biomass, may provide the great benefit to the associated fish community. Such niche complementarity among fishes may be a process facilitated by seagrass diversity for secondary production as an ecosystem functioning.     

Modeling and inference of forest coverage ratio using zero-one inflated distributions with spatial dependence

This paper explores statistical modeling of forest area with two covariates. The forest coverage ratio of grid-cell data was modeled by taking human population density and relief energy into account. The likelihood of the forest ratios was decomposed into the product of two likelihoods. The first likelihood was due to trinomial logistic distributions on three categories: the forest ratios take zero, or one, or values between zero and one. The second one was due to a logistic-normal regression model for the ratios between zero and one. This model was applied to real grid-cell data and it fit better than zero-inflated beta regression models.     

Resident's concerns and attitudes towards Solid Waste Management facilities

Because of limited space, the siting and construction of a new SWM facility is a big challenge in Japan. An SWM facility should be socially accepted as well as environmentally and economically sound. This study aimed to investigate people's concerns about SWM facilities and their attitudes towards such facilities. A questionnaire was designed based on literature reviews and was sent to residents in three municipalities with different backgrounds. The questions covered concerns on the impact of an SWM facility, management aspects, unfairness of facility siting, and attitudes to facility construction. Of the many concerns, "pollution and health effect" had the highest rating, followed by "reliability", "damage to nature" and "cost". The rating was different between municipalities, reflecting their geographic and social backgrounds. Using factor analysis, correlations among concerns were analyzed, and five principal components were extracted, namely "pollution", "nuisance", "facility management", "planning of facility", and "merit/demerit". Although obvious correlations were not found between individual items of concern and attitudes to construction of a facility, the discriminant analysis indicated dominant concerns of attitudes, but the disagreement between actual impact and citizens were found. As for attributes, the "opposed" attitude decreased for residents who had visited an SWM facility, even if they had only seen it from outside.     

Behavior of metals in ash melting and gasification-melting of municipal solid waste (MSW)

In this study, metal behavior in ash-melting and municipal solid waste (MSW) gasification-melting facilities were investigated. Eight ash-melting and three MSW gasification-melting facilities with a variety of melting processes and feedstocks were selected. From each facility, melting furnace fly ash (MFA) and molten slag were sampled, and feedstock of the ash-melting processes was also taken. For the ash melting process, the generation rate of MFA was well correlated with the ratio of incineration fly ash (IFA) in feedstock, and this was because MFA was formed mostly by mass transfer from IFA and a limited amount from bottom ash (BA). Distribution ratios of metal elements to MFA were generally determined by volatility of the metal element, but chlorine content in feedstock had a significant effect on Cu and a marginal effect on Pb. Distribution ratio of Zn to MFA was influenced by the oxidizing atmosphere in the furnace. High MFA generation and distribution ratio of non-volatile metals to MFA in gasification-melting facilities was probably caused by carry-over of fine particles to the air pollution control system due to large gas volume. Finally, dilution effect was shown to have a significant effect on metal concentration in MFA.     

Evaluation of Virus Reduction by Ultrafiltration with Coagulation–Sedimentation in Water Reclamation

The evaluation of virus reduction in water reclamation processes is essential for proper assessment and management of the risk of infection by enteric viruses. Ultrafiltration (UF) with coagulation–sedimentation (CS) is potentially effective for efficient virus removal. However, its performance at removing indigenous viruses has not been evaluated. In this study, we evaluated the reduction of indigenous viruses by UF with and without CS in a pilot-scale water reclamation plant in Okinawa, Japan, by measuring the concentration of viruses using the real-time polymerase chain reaction (qPCR). Aichi virus (AiV) and pepper mild mottle virus (PMMoV) were targeted in addition to the main enteric viruses of concern for risk management, namely, norovirus (NoV) genogroups I and II (GI and GII) and rotavirus (RoV). PMMoV, which is a plant pathogenic virus and is present at high concentrations in water contaminated by human feces, has been suggested as a useful viral indicator. We also investigated the reduction of a spiked model virus (F-specific RNA bacteriophage MS2) to measure the effect of viral inactivation by both qPCR and plaque assay. Efficiencies of removal of NoV GI, NoV GII, RoV, and AiV by UF with and without CS were >0.5 to 3.7 log₁₀, although concentrations were below the detection limit in permeate water. PMMoV was the most prevalent virus in both feed and permeate water following UF, but CS pretreatment could not significantly improve its removal efficiency (mean removal efficiency: UF, 3.1 log₁₀; CS + UF, 3.4 log₁₀; t test, P > 0.05). CS increased the mean removal efficiency of spiked MS2 by only 0.3 log₁₀ by qPCR (t-test, P > 0.05), but by 2.8 log₁₀ by plaque assay (t-test, P < 0.01). This difference indicates that the virus was inactivated during CS + UF. Our results suggest that PMMoV could be used as an indicator of removal efficiency in water reclamation processes, but cultural assay is essential to understanding viral fate.