Environmentally conscious manufacturing: A technology for the nineties

Editor's note: Companies embracing TQEM must evaluate and change their manufacturing processes to stay globally competitive in the nineties. This article shows how an environmentally conscious manufacturing program incorporating new approaches to waste reduction will help companies achieve their corporatewide TQEM and strategic goals.     

A land suitability model for the evaluation of land-use change

A land suitability model was developed to provide the planner with a quantitative tool for assessing the environmental limitations on proposed land-use changes in the area surrounding Lake Monroe in southern Indiana. The model incorporates a weighting procedure that allows the environmental evaluation of a decision to convert the present land use to another category. The data base for the model was assembled by a multidisciplinary team. A case study is included, which illustrates the advantages and limitations of the land suitability model as it is applied to the evaluation of a site for the Alumni Family Camp.     

A MANGANESE OXIDATION MODEL FOR RIVERS1

ABSTRACT: The presence of manganese in natural waters (>0.05 mg/L) degrades water-supply quality. A model was devised to predict the variation of manganese concentrations in river water released from an impoundment with the distance downstream. The model is one-dimensional and was calibrated using dissolved oxygen, biochemical oxygen demand, pH, manganese, and hydraulic data collected in the Duck River, Tennessee. The results indicated that the model can predict manganese levels under various conditions. The model was then applied to the Chattahoochee River, Georgia. Discrepancies between observed and predicted may be due to inadequate pH data, precipitation of sediment particles, unsteady flow conditions in the Chattahoochee River, inaccurate rate expressions for the low pH conditions, or their combinations.     

Assessment of Eutrophication in Estuaries: Pressure–State–Response and Nitrogen Source Apportionment

A eutrophication assessment method was developed as part of the National Estuarine Eutrophication Assessment (NEEA) Program. The program is designed to improve monitoring and assessment of eutrophication in the estuaries and coastal bays of the United States with the intent to guide management plans and develop analytical and research models and tools for managers. These tools will help guide and improve management success for estuaries and coastal resources. The assessment method, a Pressure-State-Response approach, uses a simple model to determine Pressure and statistical criteria for indicator variables (where applicable) to determine State. The Response determination is mostly heuristic, although research models are being developed to improve that component. The three components are determined individually and then combined into a single rating. Application to several systems in the European Union (E.U.), specifically in Portugal, shows that the method is transferable, and thus is useful for development of management measures in both the Unites States and E.U. This approach identifies and quantifies the key anthropogenic nutrient input sources to estuaries so that management measures can target inputs for maximum effect. Because nitrogen is often the limiting nutrient in estuarine systems, examples of source identification and quantification for nitrogen have been developed for 11 coastal watersheds on the U.S. east coast using the WATERSN model. In general, estuaries in the Northeastern United States receive most of their nitrogen from human sewage, followed by atmospheric deposition. This is in contrast to some watersheds in the Mid-Atlantic (Chesapeake Bay) and South Atlantic (Pamlico Sound), which receive most of their nitrogen from agricultural runoff. Source identification is important for implementing effective management measures that should be monitored for success using assessment methods, as described herein. For instance, these results suggest that Northeastern estuaries would likely benefit most from improved sewage treatment, where as the Mid and South Atlantic systems would benefit most from agricultural runoff reductions.     

Fluoride accumulation in pasture forages and soils following long-term applications of phosphorus fertilisers.

Ingestion of soils with high fluoride (F) concentration may cause chronic fluorosis in grazing animals. Analysis of New Zealand pasture soils with long-term phosphorus (P) fertilisation histories showed that total surface soil (0-75 mm depth) F concentration increased up to 217-454 mg kg-1 with P fertiliser application. One-third to two-thirds of F applied in fertilisers resides in the top 75 mm soil depth. Pasture forage accumulation of F was low, and therefore, F intake by grazing animals through pasture consumption is expected to be much lower than F intake by soil ingestion. Ten annual applications of single superphosphate (30 and 60 kg P ha-1 year-1) to a Pallic Soil (Aeric Fragiaqualf) significantly increased total F and labile F (0.01 M CaCl2 extract) concentrations to 200 and 120 mm depths, respectively, of the 300 mm depth investigated. The mobility of F in the soil profile was similar to two other elements, P and cadmium derived from the fertiliser.