Evaluation of environmental impacts from municipal solid waste management in the municipality of Aarhus, Denmark (EASEWASTE).

A new computer based life cycle assessment model (EASEWASTE) was used to evaluate a municipal solid waste system with the purpose of identifying environmental benefits and disadvantages by anaerobic digestion of source-separated household waste and incineration. The most important processes that were included in the study are optical sorting and pre-treatment, anaerobic digestion with heat and power recovery, incineration with heat and power recovery, use of digested biomass on arable soils and finally, an estimated surplus consumption of plastic in order to achieve a higher quality and quantity of organic waste to the biogas plant. Results showed that there were no significant differences in most of the assessed environmental impacts for the two scenarios. However, the use of digested biomass may cause a potential toxicity impact on human health due to the heavy metal content of the organic waste. A sensitivity analysis showed that the results are sensitive to the energy recovery efficiencies, to the extra plastic consumption for waste bags and to the content of heavy metals in the waste. A model such as EASEWASTE is very suitable for evaluating the overall environmental consequences of different waste management strategies and technologies, and can be used for most waste material fractions existing in household waste.     

National and Regional-Level Human-Environment (Ecosystems) Interactions: Some Empirical Evidence from China

The state of human-environment (ecosystems) interactions—ecosystems (land cover classes), population, biodiversity hotspots and protected status—is examined in the eastern coastal zones, the eastern region, the middle region, the western region and the whole of China. The analysis is based on consistent, comprehensive, geo-referenced and recent datasets and advanced analytical Remote Sensing and Geographic Information System (GIS) techniques. A comparative national and regional priority ranking of the provinces was conducted using the total score of eight indicators, for the four dimensions of human-environment (ecosystems) interaction. Using, these ranks, all the provinces were grouped in low, high and medium priority provinces. The comparative ranking and categorization of provinces will be useful for designing policies and management operations for spatially-differential scientific planning and management of environment (ecosystems) at the regional and national levels in China.     

Cleanup of biological extracts by a Pasteur pipette column and a comparison of in vivo-accumulated chlorinated pesticide residues with other clean up systems

Biological samples are extracted with n-hexane/acetone (60:40) and 1 mL of the concentrated extract is eluted through a pasteur pipette column prepacked with alumina (0.3 g) and silicic acid (0.25 g) with 10 mL n-hexane (containing 4% acetone). The fat and other co-extractives are retained by the column and clear eluate is directly injected on a GLC column for determination on electron capture detector. A comparison of the Pasteur pipette cleanup with the modified method of Cole et al. (1967) on 41 samples of fish, One Step Method, (Ahmad and Marolt (1986] on 86 samples of fish and Maunder et al. (1964) on 10 type of wildlife (100 samples) was made. The Pasteur pipette method gives results which are significantly higher (p greater than 0.5) than the other methods except the One step method. The Pasteur pipette method has a detection limit of 0.01 microgram/g for DDT and its metabolites.     

Novel Biocomposites Sheet Molding Compounds for Low Cost Housing Panel Applications

Biocomposites were made by a novel high volume processing technique named biocomposite sheet molding compound panel (BCSMCP) manufacturing process. This process design was inspired by the commercial glass fiber–polyester resin composite fabrication method called sheet molding compounding (SMC). This process yields continuous production of biocomposites on a large scale, and thus can be easily adopted in industries. A unique fiber dispersion method, which enabled uniform distribution of natural fibers, was used in this process. Consistency of the process was tested by evaluating the repeatability of the resultant materials mechanical properties. The low cost biocomposites produced as a result of the processing will be used for various panel applications such as housing and transportation. The molded samples were tested for various mechanical and thermal properties, in accordance with ASTM procedures. The biocomposites were made with various natural fibers including, big blue stem grass, jute, and industrial hemp. By combining different natural fibers in varying mass fractions, hybrid biocomposites were made using this process. Grass fiber reinforced polyester biocomposites processed by the SMC line showed very promising results.     

Sustainable Cellular Biocomposites from Natural Fibers and Unsaturated Polyester Resin for Housing Panel Applications

Increased environmental awareness and interest in long-term sustainability of material resources has motivated considerable advancements in composite materials made from natural fibers and resins, or biocomposites. In spite of these developments the lower stiffness and strength of biocomposites has limited their applications to non-load-bearing components. This paper presents an overview of a study aimed at showing that the shortcomings of biocomposites can be overcome through hybrid material designs and efficient structural configurations to make them suitable for load bearing structural components. Hybrid blends of natural and synthetic fibers can significantly improve the characteristics of biocomposites with minimal cost and environmental impact, and hierarchical cellular designs can maximize material efficiency in structural components. Periodic and hierarchical cellular plate designs made from natural fibers and unsaturated polyester resin were evaluated experimentally and analytically. Stiffness, strength, and dimensional stability of all-biocomposite and hybrid natural–synthetic material systems were evaluated through material tests while structural performance of cellular plate designs was assessed through flexural tests on laboratory-scale samples. The experimental results were correlated with analytical models for short-fiber composites and cellular structures. The results showed that biocomposites have adequate short-term performance and that they can efficiently compete with housing panels made from conventional structural materials.     

Flow of chemical energy in Alwar jheel of Yamuna basin near Allahabad

The water quality, rate of energy transformation, chemical composition of producers and flow of chemical energy were studied in both feeding river Yamuna and Alwar jheel near Allahabad. As the river Yamuna had high value of alkalinity (210.0 mgl(-1)), conductance (518.0 micromhos), dissolved solids (260.0 mgl(-1)), hardness (162.0 mgl(-1)) and chloride (54.6 mgl(-1)) jheel also showed high values of these parameters. The rate of energy transformation from kinetic radiant energy to chemical energy was very high in the jheel 32,315 Cal m(-2) day(-1) of which 25,620 Cal m(-2) day(-1) was contributed by aquatic plants. Out of 11,764 x 10(4) Kcal ha(-1) yr(-1) total energy fixed in the system, producers stored 7,154 x 10(4) Kcal ha(-1) yr(-1) and the rest was lost as heat of respiration. The pattern of storage of energy was different in two groups of producers and thus most of the energy fixed by phytoplankton was stored as protein (56.2%) and less as carbohydrate (11.7%) while aquatic plants stored more energy as carbohydrate (40.8%) than protein (23.2%). The chemical energy obtained from the system was 1,85,000 Kcal ha(-1) yr(-1) and thus only 0.260% of the chemical energy stored by producers was harvested. The potential chemical energy resource in the jheel was 81.4 x 10(4) Kcal ha(-1) yr(-1) of which only 22.6% was harvested in the jheel and there is enough scope for further enhancement.     

Cadmium accumulation and its influence on lipid peroxidation and antioxidative system in an aquatic plant, Bacopa monnieri L

Bacopa monnieri L. plants exposed to 10, 50, 100 and 200 microM cadmium (Cd) for 48, 96 and 144 h were analysed with reference to the accumulation of metal and its influence on various enzymatic and non-enzymatic antioxidants, thiobarbituric acid reactive substances (TBARS), photosynthetic pigments and protein content. The accumulation of Cd was found to be increased in a concentration and duration dependent manner with more Cd being accumulated in the root. TBARS content of the treated roots and leaves increased with increase in Cd concentration and exposure periods, indicating the occurrence of oxidative stress. Induction in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and guiacol peroxidase (GPX) was recorded in metal treated roots and leaves of B. monnieri. In contrast, a significant reduction in catalase activity in Cd treated B. monnieri was observed. An increase was also noted in the levels of cysteine and non-protein thiol contents of the roots of B. monnieri followed by a decline. However, in leaves, cysteine and non-protein thiol contents were found to be enhanced at all the Cd concentrations and exposure periods. A significant reduction in the level of ascorbic acid was observed in a concentration and duration dependent manner. The total chlorophyll and protein content of B. monnieri decreased with increase in Cd concentration at all the exposure periods. Results suggest that toxic concentrations of Cd caused oxidative damage as evidenced by increased lipid peroxidation and decreased chlorophyll and protein contents. However, B. monnieri is able to combat metal induced oxidative injury involving a mechanism of activation of various enzymatic and non-enzymatic antioxidants.     

Effect of farmyard manure application on boron adsorption-desorption characteristics of some soils

Boron (B) availability to crop plants depends on soil properties as well as management practices like liming, fertilization and use of organic manures. To assess the effect of farmyard manure (FYM) application on availability of added B, adsorption-desorption of B was investigated in five different soils receiving varying doses of FYM (0, 5 and 10 g FYM kg(-1) soil). Two surfaces Freundlich model was found best to account for B adsorption-desorption data of all soils. Application of FYM increased B adsorption capacities pertaining to low (K1) and high (K2) concentration ranges in all soils, except Soil C (Alfisol) having a pH of 9.8, in which the higher rate of FYM decreased the value of K2. Application of FYM did not change B desorption capacities of soils corresponding to low B concentration range (K(1)(1)) significantly, however, it increased B desorption capacity pertaining to high B concentration (K(1)(2)) in all soils, except Soils C (Alfisol) and E (Entisol) having pH of 9.8 and 5.1, respectively. Application of FYM increased the desorption slope factor applicable to low concentration range (1/n(1)(1)) in Soil A (Inceptisol), but decreased it in Soil E (Entisol). The 1/n(1)(2) (desorption slope factor applicable to high concentration range) decreased with FYM application in all soils except Soil E (Entisol), where it was increased. Boron desorption index (slope(ads)/slope(des)) decreased with FYM application in low B concentration range, but increased in high concentration range for all soils except soil E (Entisol, pH 5.1), in which a reverse trend was observed. Application of FYM increased the retention of added B in soils and may help reducing the leaching losses.     

Ammonium, nitrate and nitrite nitrogen and nitrate reductase enzyme activity in groundnut (Arachis hypogaea L.) fields after diazinon, imidacloprid and lindane treatments

Impacts of diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate), imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine] and lindane (1,2,3,4,5.6-hexachlorocyclohexane) treatments on ammonium, nitrate, and nitrite nitrogen and nitrate reductase enzyme activities were determined in groundnut (Arachis hypogaea L.) field for three consecutive years (1997 to 1999). Diazinon was applied for both seed- and soil-treatments but imidacloprid and lindane were used for seed treatments only at recommended rates. Diazinon residues persisted for 60 days in both the cases. Average half-lives (t1/2) of diazinon were found 29.3 and 34.8 days respectively in seed and soil treatments. In diazinon seed treatment, NH4(+), NO3(-), and NO2(-) nitrogen and nitrate reductase activity were not affected. Whereas, diazinon soil treatment indicated significant increase in NH4(+)-N in a 1-day sample, which continued until 90 days. Some declines in NO3(-)N were found from 15 to 60 days. Along with this decline, significant increases in NO2(-)N and nitrate reductase activity were found between 1 and 30 days. Imidacloprid and lindane persisted for 90 and 120 days with average half-lives (t1/2) of 40.9 and 53.3 days, respectively. Within 90 days, imidacloprid residues lost by 73.17% to 82.49% while such losses for lindane residues were found 78.19% to 79.86 % within 120 days. In imidacloprid seed-treated field, stimulation of NO3(-)N and the decline in NH4+NO2(-)-N and nitrate reductase enzyme activity were observed between 15 to 90 days. However, lindane seed treatment indicated significant increases in NH4(+)-N, NO2(-)-N and nitrate reductase activity and some adverse effects on NO3(-)N between 15 and 90 days.