Distribution of Trace Metals in the Surface Sediments of Two Pristine Subalpine Lakes in Taiwan

Sediment cores were collected from two remote subalpine lakes: the rather shallow (1.5 m) Little Ghost Lake at 2040 m elevation and the deeper, Great Ghost Lake (40 m) at 2150 m elevation. Different early diagenesis of metals were observed. the seasonally anoxic hypolimnion drives the annual iron redox cycle and causes the remobilization of metals in the mobile fractions of sediments in the Great Ghost Lake. These result in the redistribution of metals in the mobile fractions of sediment and poor correlation between metal concentrations. in the Little Ghost Lake, the shallow water column is always oxic with less change of metals in the mobile fractions of sediments. As a result, most metals have strong positive correlations with each other.

The distributions of metal/Al ratios, total metal contents and acid-leached metal concentrations in the near-surface sediments of these two lakes suggest that the anthropogenic inputs from the atmospheric fallouts in recent decades are one of the major factors affecting the distributions of metals such as cadmium, lead and, to a lessor extent, zinc. the Pb-206/Pb-207 ratios confirm the anthropogenic lead input in these surface sediments.     

Retention of nitrogen and phosphorous from liquid swine and poultry manures using highly characterized peats

This paper reports on research designed to test the hypothesis that differences in peat composition will cause differences in amounts of N and P retained during contact with liquid swine manure (LSM) and liquid poultry manure (LPM). Peat types representing a wide range of properties were tested in order to establish which chemical and physical properties might be most indicative of their capacities to retain N and P from LSM and LPM. Eight-percent slurries (peat/LSM and peat/LPM) were measured for total nitrogen (TKN) and total phosphorous (TP) after 6, 24 and 96 hours. Tests were done to determine the TKN and TP contents of these peats, the LSM, and the LPM, both before and after they were mixed together. The N and P retention results revealed that most peats worked reasonably well at retaining N and P from either LSM or LPM. However, some peats were more effective than others. These peats also decreased the N and P levels in the liquid portion of the LSM. Peats with higher N retention capacities tended to have lower ash contents, but higher macroporosities and total cellulose contents. Peats with higher P retention capacities tended to have lower bulk densities, ash contents, total guaiacyl lignins contents, fulvic acids contents, but higher microporosities, macroporosities, H contents, and total cellulose contents. Peats with higher N and P retention capacities also had humic acid contents between 5-7%. The results of this study suggest that if these peats are used to reduce odors and N and P contamination, possible byproducts could be the production of odorless fertilizers.     

Throwaways to go?

The Senior Advisory Group of the US government's Resource Conservation Committee is holding public hearing on two prominent materials conservation policy options - a national mandatory deposit system on beverage containers to eliminate ‘throwaways’, and a national system of ‘product charges’ on goods produced from virgin materials. A national hearing was held on 19 October 1977 to hear views on the controversial mandatory deposit issues, and is reported below.     

EVAPOTRANSPIRATION FROM WATER HYACINTH (Eichhomia crassipes (Mart.) Solms) IN TEXAS RESERVOIRS1

ABSTRACT: Water hyacinth, an attractive, floating aquatic plant, poses a substantial threat of unanticipated water loss from Texas reservoirs. A mature plant will lose about three times as much water through evapotranspiration as is lost from evaporation of an equivalent area of open water. The reservoirs of east and southeast Texas, which comprise the bulk of the state's existing and planned water storage capacity, seem likely to suffer a 20 percent average surface infestation of water hyacinth. A coverage that great will result in a yearly net loss of over 2,000,000 acre-feet of impounded water, based on present water development plans for the state. This would amount to nearly 20 percent of the anticipated yield from the reservoirs affected. An effective aquatic plant control program could head off the threat of this significant water loss.     

Timber harvest planning—A combined optimization/simulation model

A special cascading fixed charge structure can be used to characterize a forest management planning problem in which the objectives are to identify the optimal shape of forest harvest cutting units and simultaneously to assign facilities for logging those units. We describe a four-part methodology that has been developed to assist forest managers in analyzing areas proposed for harvesting. This methodology performs an analysis of harvesting feasibility, computes the optimal solution to the cascading fixed charge problem, undertakes a GASP IV simulation to provide additional information about the proposed harvesting operation, and permits the forest manager to perform a time-cost analysis that may lead to a more realistic, and thus improved, solution.