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Waste Inputs (waste + input)

Distribution by Scientific Domains

Earth and Environmental Science	75%

Selected Abstracts

Analyzing Polyvinyl Chloride in Japan With the Waste Input,Output Material Flow Analysis Model

JOURNAL OF INDUSTRIAL ECOLOGY, Issue 5 2009
Shinichiro Nakamura
Summary Effective life cycle management of polyvinyl chloride (PVC) calls for the separation of end-of-life PVC products at the time of collection not only from other wastes but among different PVC types as well. Information about the flow of PVC products in the economy is important for this purpose. Within the framework of the Japanese input,output (IO) table for the year 2000, with around 400 industry sectors, the flow of PVC is captured in terms of six PVC-embodying products and in terms of three PVC types, (1) flexible PVC (soft PVC), (2) rigid PVC (hard PVC), and (3) others. The degree of resolution; the consideration of different PVC types, which are seldom performed in the material flow analysis (MFA) literature; and the use of waste input,output material flow analysis (WIO-MFA) represent distinguishing features of our study. The use of WIO-MFA methodology enables one to convert a monetary input,output table into a physical interindustry flow table involving an arbitrary number of materials under full consideration of the mass balance. The results indicate that 40% of the PVC produced in Japan is exported (as resins and as products such as passenger motor cars), and the rest is accumulated mostly as capital stock. The largest share of accumulation goes to public construction in the form of plates, pipes, and bars, which are mostly hard-PVC products. [source]

ECOSYSTEM DYNAMICS AND POLLUTION EFFECTS IN AN OZARK CAVE STREAM,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2003
Gary O. Graening
ABSTRACT: Subterranean ecosystems harbor globally rare fauna and important water resources, but ecological processes are poorly understood and are threatened by anthropogenic stresses. Ecosystem analyses were conducted from 1997 to 2000 in Cave Springs Cave, Arkansas, situated in a region of intensive land use, to determine the degree of habitat degradation and viability of endangered fauna. Organic matter budgeting quantified energy flux and documented the dominant input as dissolved organic matter and not gray bat guano (Myotis grisescens). Carbon/nitrogen stable isotope analyses described a trophic web of Ozark cavefish (Amblyopsis rosae) that primarily consumed cave isopods (Caecidotea stiladactyla), which in turn appeared to consume benthic matter originating from a complex mixture of soil, leaf litter, and anthropogenic wastes. Septic leachate, sewage sludge, and cow manure were suspected to augment the food web and were implicated in environmental degradation. Water, sediment, and animal tissue analyses detected excess nutrients, fecal bacteria, and toxic concentrations of metals. Community assemblage may have been altered: sensitive species-grotto salamanders (Typhlotriton spelaeus) and stygobro-mid amphipods,were not detected, while more resilient isopods flourished. Reduction of septic and agricultural waste inputs may be necessary to restore ecosystem dynamics in this cave ecosystem to its former undisturbed condition. [source]

Trophic state, fish community and intensive production of salmonids in Alicura Reservoir (Patagonia, Argentina)

LAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 4 2001
P. F. Temporetti
Abstract The Governments of the Provinces located in Patagonia, Argentina, promote the intensive breeding of salmonids in the Andean Patagonian region. Although annual production is low (450 ton ha,1 year,1), some effects are significant. Waste produced by salmonid breeding (feed losses, faeces and excretion) increases nutrient and organic matter concentrations, which cause modifications of water quality, sediments and biota. A consequent risk is the elevation of eutrophication levels. Possible changes in water composition, sediments, algae and wild fish populations were studied. Sites affected by fish farming showed increased nutrient concentration, and phytoplankton and periphyton biomass. Chlorophyll a was similar at both sites (affected and unaffected by fish farm sites). Sediments clearly reflect fish farm waste inputs: total phosphorus and organic matter increased 12-fold and fourfold, respectively. The species present in the gill-net catches were the autochthonous Percichthys trucha, Odontesthes hatcheri, Diplomystes viedmensis, and the introduced salmonids Oncorhynchus mykiss, Salmo trutta, Salmo salar sebago and Salvelinus fontinalis. About 50% of the total catch was salmonids. A major portion of the catch per unit weight was composed of rainbow trout, followed by perch. The catch per unit weight obtained for this reservoir agrees with the range of values previously determined (Quiros 1990) for Patagonian reservoirs. Compared with previous studies by Freyre et al. (1991), a variation in catch composition exists. This consists mainly of an increase in the numbers and condition of O. mykiss and a decrease in P. trucha. Presence of fish that escaped from hatcheries, recognizable by their eroded fins, was observed; particularly in a sampling station near the fish cage systems. Variations in catches could be caused by cyclical changes in fish populations (Wooton 1991), by direct and indirect effects of intensive fish farming, or by a combination of both events, and can only be understood through long-term studies of catch variation. [source]