Global potential of phosphorus recovery from human urine and feces

This study geospatially quantifies the mass of an essential fertilizer element, phosphorus, available from human urine and feces, globally, regionally, and by specific country. The analysis is performed over two population scenarios (2009 and 2050). This important material flow is related to the presence of improved sanitation facilities and also considers the global trend of urbanization. Results show that in 2009 the phosphorus available from urine is approximately 1.68 million metric tons (with similar mass available from feces). If collected, the phosphorus available from urine and feces could account for 22% of the total global phosphorus demand. In 2050 the available phosphorus from urine that is associated with population increases only will increase to 2.16 million metric tons (with similar mass available from feces). The available phosphorus from urine and feces produced in urban settings is currently approximately 0.88 million metric tons and will increase with population growth to over 1.5 million metric tons by 2050. Results point to the large potential source of human-derived phosphorus in developing regions like Africa and Asia that have a large population currently unserved by improved sanitation facilities. These regions have great potential to implement urine diversion and reuse and composting or recovery of biosolids, because innovative technologies can be integrated with improvements in sanitation coverage. In contrast, other regions with extensive sanitation coverage like Europe and North America need to determine how to retrofit existing sanitation technology combined that is combined with human behavioral changes to recover phosphorus and other valuable nutrients.     

Behavioral type–environment correlations in the field: a study of three-spined stickleback

Behavioral type–environment correlations occur when specific behavioral types of individuals are more common in certain environments. Behavioral type–environment correlations can be generated by several different mechanisms that are probably very common such as niche construction and phenotypic plasticity. Moreover, behavioral type–environment correlations have important ecological and evolutionary implications. However, few studies have examined behavioral type–environment correlations in natural populations. In this study, we asked whether some behavioral types of three-spined stickleback were more likely to occur in certain social environments (alone or in a shoal with other stickleback) or in certain microhabitats in a river (in the open or under cover). We found that individuals that were in shoals with other stickleback at the time of collection from the field emerged from a refuge more quickly compared to individuals that were found alone. In addition, fish that were alone in an open microhabitat explored more of a pool compared to fish that were alone in cover, but this difference did not occur among fish that were in shoals at the time of collection. Subsequent analyses of gut contents suggested that differences in microhabitat use were consistent over time. Our study provides some of the first evidence for behavioral type–environment correlations in a natural population of non-human animals.     

STEP WISE,MULTIPLE OBJECTIVE CALIBRATION OF A HYDROLOGIC MODEL FOR A SNOWMELT DOMINATED BASIN1

ABSTRACT: The ability to apply a hydrologic model to large numbers of basins for forecasting purposes requires a quick and effective calibration strategy. This paper presents a step wise, multiple objective, automated procedure for hydrologic model calibration. This procedure includes the sequential calibration of a model's simulation of solar radiation (SR), potential evapotranspiration (PET), water balance, and daily runoff. The procedure uses the Shuffled Complex Evolution global search algorithm to calibrate the U.S. Geological Survey's Precipitation Runoff Modeling System in the Yampa River basin of Colorado. This process assures that intermediate states of the model (SR and PET on a monthly mean basis), as well as the water balance and components of the daily hydrograph are simulated consistently with measured values.     

SPATIAL VARIABILITY IN WATER‐BALANCE MODEL PERFORMANCE IN THE CONTERMINOUS UNITED STATES1

ABSTRACT: A monthly water‐balance (WB) model was tested in 44 river basins from diverse physiographic and climatic regions across the conterminous United States (U.S.). The WB model includes the concepts of climatic water supply and climatic water demand, seasonality in climatic water supply and demand, and soil‐moisture storage. Exhaustive search techniques were employed to determine the optimal set of precipitation and temperature stations, and the optimal set of WB model parameters to use for each basin. It was found that the WB model worked best for basins with: (1) a mean elevation less than 450 meters or greater than 2000 meters, and/or (2) monthly runoff that is greater than 5 millimeters (mm) more than 80 percent of the time. In a separate analysis, a multiple linear regression (MLR) was computed using the adjusted R‐square values obtained by comparing measured and estimated monthly runoff of the original 44 river basins as the dependent variable, and combinations of various independent variables [streamflow gauge latitude, longitude, and elevation; basin area, the long‐term mean and standard deviation of annual precipitation; temperature and runoff; and low‐flow statistics (i.e., the percentage of months with monthly runoff that is less than 5 mm)]. Results from the MLR study showed that the reliability of a WB model for application in a specific region can be estimated from mean basin elevation and the percentage of months with gauged runoff less than 5 mm. The MLR equations were subsequently used to estimate adjusted R‐square values for 1,646 gauging stations across the conterminous U.S. Results of this study indicate that WB models can be used reliably to estimate monthly runoff in the eastern U.S., mountainous areas of the western U.S., and the Pacific Northwest. Applications of monthly WB models in the central U.S. can lead to uncertain estimates of runoff.     

Removal of petroleum tar from bird feathers utilizing magnetic particles

A previously reported acute temperature dependency for the effective removal of tarry residue from feather clusters, utilising magnetic particles, has also been demonstrated to occur for the plumage of whole birds, whereby a maximum removal of up to 96% may be achieved. The experimental design allows an approximate equilibrium constant, for the distribution of contaminant between the residue and the magnetic particles, to be estimated at each temperature. This allows the thermodynamics of the process to be examined via application of the van't Hoff equation, suggesting an explanation for the phenomenon.