EFFECTS OF IMPROVED PRECIPITATION ESTIMATES ON AUTOMATED RUNOFF MAPPING: EASTERN UNITED STATES1

ABSTRACT: We evaluated maps of runoff created by means of two automated procedures. We implemented each procedure using precipitation estimates of both 5-km and 10-km resolution from PRISM (Parameter-elevation Regressions on Independent Slopes Model). Our goal was to determine if using the 5-km PRISM estimates would improve map accuracy. Visual inspection showed good general agreement among our runoff maps, as well as between our maps and one produced using a manual method. A quantitative uncertainty analysis comparing runoff interpolated from our maps with gage data that had been withheld showed slightly smaller actual and percentage interpolation errors for the 5-km PRISM-based maps. Our analyses suggest a modest region-wide improvement in runoff map accuracy with the use of PRISM-based precipitation estimates of 5-km (compared to 10-km) resolution.     

Degradation of acid orange 7 in an aerobic biofilm.

A stable microbial biofilm community capable of completely mineralizing the azo dye acid orange 7 (AO7) was established in a laboratory scale rotating drum bioreactor (RDBR) using waste liquor from a sewage treatment plant. A broad range of environmental conditions including pH (5.8-8.2), nitrification (0.0-4.0 mM nitrite), and aeration (0.2-6.2 mg O2 l(-1)) were evaluated for their effects on the biodegradation of AO7. Furthermore the biofilm maintained its biodegradative ability for over a year while the effects of these environmental conditions were evaluated. Reduction of the azo bond followed by degradation of the resulting aromatic amine appears to be the mechanism by which this dye is biodegraded. Complete loss of color, sulfanilic acid, and chemical oxygen demand (COD) indicate that AO7 is mineralized. To our knowledge this is the first reported occurrence of a sulfonated phenylazonaphthol dye being completely mineralized under aerobic conditions. Two bacterial strains (ICX and SAD4i) originally isolated from the RDBR were able to mineralize, in co-culture, up to 90% of added AO7. During mineralization of AO7, strain ICX reduces the azo bond under aerobic conditions and consumes the resulting cleavage product 1-amino-2-naphthol. Strain SAD4i consumes the other cleavage product, sulfanilic acid. The ability of the RDBR biofilm to aerobically mineralize an azo dye without exogenous carbon and nitrogen sources suggests that this approach could be used to remediate industrial wastewater contaminated with spent dye.     

A strategy for controlling deposition of struvite in municipal wastewater treatment plants.

This paper presents strategies to reduce the risk of struvite deposition by controlling its location of formation. Two technical routes were investigated: (1) to fix the phosphate into the dewatered sludge cake, and (2) to remove phosphate from centrate or filtrate. Chemicals used include magnesium hydroxide [Mg(OH)2], both of reagent grade and reclaimed from a flue gas desulfurization system, magnesium chloride (MgCl2), calcium hydroxide [Ca(OH)2], ferric chloride (FeCl3) and aluminum sulfate [Al2(SO4)3]. Research results indicate that (1) for anaerobically well-digested sludge, Mg(OH)2 is effective in fixing phosphate into sludge cake and improving sludge dewaterability, and (2) adding Mg(OH)2 into a reactor, located between the sludge dewatering facilities and the centrate or filtrate discharge line, and using air for mixing and carbon dioxide stripping, proves feasible in reducing struvite deposition in centrate or filtrate discharge lines and can generate a potentially valuable plant fertilizer--struvite.     

Environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (Chelydra serpentina serpentina) from the Great Lakes-St Lawrence River basin (1989-1991)

During 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpentina serpentina). Eggs were collected and artificially incubated from eight sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 polychlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans (PCDFs) and total mercury. We found a significant increase in abnormal development with increasing polychlorinated aromatic hydrocarbon exposure in eggs, particularly PCDD and PCDF concentrations. In contrast, the risk of abnormality was not significantly higher as toxic equivalent concentrations increased in eggs. We also found significant 7-ethoxyresorufin O-deethylase and Cytochrome P4501A responses in livers of hatchling turtles from Lake Ontario relative to hatchlings from a clean, inland site whereas we did not find any evidence of porphyria in the hatchlings from either site.     

Biochemical and morphometric study of growth in the stomach and intestine of the echinoid Lytechinus variegatus (Echinodermata)

In June 1990, previously starved Lytechnius variegatus were fed a 5% fish meal-agar diet for 32 d at 20°C and 32. Stomach and intestine indices increased by 139 and 66%, respectively, with the most growth occurring by Day 16. The stomach had a faster growth rate than the intestine, as indicated by an increase in the stomach: intestine ratio. Gonadal growth did not begin until Day 16, after substantial gut growth. DNA and morphometric analysis revealed that cellular growth in the stomach and intestine was first hyperplastic and then hypertrophic. DNA concentration and histological examination indicated that the stomach was composed of large voluminous cells, and the intestine of small cells. The stomach of starved individuals contained numerous depressions that significantly decreased in number during growth. The number of depressions significantly increased in the intestine. Lipid concentration and amount were higher in the stomach, and increased during growth by 43 and 258%, respectively, by Day 32; little change in lipid occurred in the intestine. The stomach lipid:DNA ratio increased by 66% by Day 16, with little change in the intestine. The concentration of soluble protein remained constant in the stomach, but had decreased in the intestine by Day 16. The total energy stored in the stomach and the intestine increased by 152 and 66%, respectively, by Day 32. The stomach mucosa increased in thickness and appeared to decrease its surface area. These data suggest that the stomach constitutes the primary storage organ of the gut. The intestinal mucosa also inreased in thickness but remained thinner than the stomich while apparently increasing in surface area, suggesting an enhanced role in residual nutrient absorption and ranslocation, respiration or water ion-transport.     

Assessing the demand of solid waste disposal in urban region by urban dynamics modelling in a GIS environment

The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050.     

Policy design for a multifunctional landscape

Landscapes consisting of several elements, such as wetlands and forests, are multifunctional in nature and produce both market and non-market goods. The need for policies arises from the existence of non-market ecosystem services that are not traded and thereby generally not subject to economic trade-offs in landowner decision making. An efficient incentive scheme for producing both types of goods would require policy designed for each non-market good. However, this may result in high transaction costs, possibly giving second-best solutions a comparative advantage when only one non-market good is regulated. This paper demonstrates that in the Hovran catchment area in mid Sweden, which produces the non-market goods water quality, biodiversity, and scenic beauty, compensation payments for biodiversity production alone provide almost maximum total net value of all market and non-market goods. On the other hand, payments for providing scenic beauty in the form of open landscape may result in lower total net value than no compensation payment at all, due to a negative impact on water quality.     

Stainless Steel Anti-Smog Mufflers—Cut Air Pollution

An automatic process gas chromatograph has been developed for use on the recovery furnace stack of a Kraft pulp mill. The instrument analyzes for widely varying concentrations of H₂S, SO₂, CH₃SH and higher order sulfur compounds. It is insensitive to the fixed gases and water vapor, and performs its analysis in approximately ten minutes. The instrument features a microcoulometric detector giving it sensitivity to H₂S as low as 0.1 ppm, and SO₂ and CH₃SH as low as 0.5 ppm. The major limit to even higher sensitivity at this stage of development lies with two problems: the background noise level in the detector and the sulfur compound absorption in the Porapak Q chromatograph column. At the reported sensitivity, a 40-ml gas sample was used. The instrument also contains a data analysis system supplementary to the usual strip chart recorder. This system is made up of a digital voltmeter, a digital translator, and a teletype and hence allows the transfer of the output data to a digital computer for processing. The processed data are usually presented in the form of ppm quantities of the component gases in the stack gas. The instrument has worked successfully on small furnace effluent for periods of 25 hr but has not been tried on recovery furnace stacks. It has also run on prepared samples for periods of up to seven days with no maintenance or attendance necessary.     

Comparison of Three Algaecides for Controlling the Density of Prymnesium parvum1

Rodgers, John H., Jr., Brenda M. Johnson, and West M. Bishop, 2010. Comparison of Three Algaecides for Controlling the Density of Prymnesium parvum. Journal of the American Water Resources Association (JAWRA) 46(1):153-160. DOI: 10.1111/j.1752-1688.2009.00399.x Abstract: Prymnesium parvum has become more prevalent in water resources of the southern United States. As the potential impacts of P. parvum are relatively well known, especially its capability to severely affect fish, managers have sought efficacious, environmentally sound, and socially acceptable strategies for mitigating this noxious species. Laboratory testing was used to identify an effective algaecide for control of P. parvum from Texas, Arizona, Florida, North Carolina, and South Carolina. Cutrine^®-Plus at 0.2 mg Cu/l significantly decreased the density of P. parvum in samples from all of these locations. Both copper sulfate and Phycomycin^® were less effective for controlling the population growth of P. parvum. The predicted response from the laboratory study was confirmed in the field at the Arizona site. Strategic use of Cutrine^®-Plus in larger water resources could provide toxin-free refugia to allow some fish to survive and repopulate the water resource when the golden alga infestation abates.     

Biodegradability of biofilm extracellular polymeric substances

This study discovered that biofilm extracellular polymeric substances (EPS) are biodegradable by their own producers and by other microorganisms when they are starved. The study was performed in a comparative fashion to examine the biodegradability of biofilm EPS by the microorganisms from the original biofilm (its own producers) and from activated sludge (other microorganisms). Four distinctive phases were observed during EPS biodegradation. In the first phase, instantaneous concentration increases of carbohydrate and protein in the test solutions were observed when EPS was added; in the second phase, easily biodegradable EPS from the added EPS was quickly utilized; in the third phase, microorganisms began to produce soluble EPS, using the minimally biodegradable EPS left from the previously added EPS; in the fourth phase, cells consumed the newly produced EPS and microbial activity gradually stopped. This study suggests that EPS can be used as a substrate, and that the EPS carbohydrate can be utilized faster than the EPS protein. The EPS utilization rates (including carbohydrate and protein) in the activated sludge suspension were greater than those in the biofilm suspension. It may take microorganisms longer to get acclimated to a new nutrient environment if they are in a starved state.