Effect of water pH and salinity on the survival of eggs and larvae of the euryhaline teleost, Gasterosteus aculeatus L

The effect of water acidification and salinity on the survival of the eggs and larvae of the euryhaline teleost, Gasterosteus aculeatus, was studied using tap water that was low in calcium and high in total aluminium as the basic medium. The survival of eggs from fertilisation to hatching increased with an increase in pH from 4.5 to 6.5. Survival was higher at a given pH at higher salinities (equivalent to 5% and 10% seawater) than in tap water. The salinity experienced by the female prior to spawning also had an effect on egg survival. Survival for 7 days after hatching was high except at the lowest pH levels. The salinity experienced by the female had no significant effect on larval survival.     

High-recycled-content hydraulic cements of alternative chemistry for concrete production

Sustainable hydraulic cements based on alkali aluminosilicate chemistry were developed with market-limited wastes acting as the primary aluminosilicate precursors. Two sets of formulations were developed with waste brick or impounded coal ash used at relatively large volume as aluminosilicate precursors. Supplementary materials were used to produce raw materials of viable chemistry. Blends of raw materials were transformed into hydraulic cements by input of mechanical energy without resorting to elevated temperatures. The resultant hydraulic cements exhibited viable strength development characteristics. FTIR, SEM, EDS and NMR analyses were conducted in order to gain insight into the structure of the hydraulic cements and their hydration products. The results pointed at the prevalence of calcium aluminosilicate hydrates among the products of hydration which thoroughly bound the non-hydrated cores of cement particles.     

Congener-specific detection of dioxins using jet-REMPI

Although 210 chemically different polychlorinated dibenzo-p-dioxin and dibenzofuran congeners can be produced during combustion, it is currently believed that fewer than 20 are toxic enough to warrant monitoring. SRI is developing a continuous emissions monitor to study the emission levels of these most toxic dioxins, leading eventually to an improved understanding of the formation of these molecules and to improved means of monitoring and control. We report here the first results of performing congener-specific detection for two dichloro dibenzo-p-dioxins present in low ppt concentrations in a mixture using the supersonic jet/resonantly enhanced multiphoton ionization time-of-flight mass spectrometer technique. In addition, we present preliminary data on the detection of chlorinated aromatic compounds using a two-color REMPI scheme with the same instrument.     

A systematic approach to in situ bioremediation in groundwater

In situ bioremediation (ISB) melds an understanding of microbiology, chemistry, hydrogeology, and engineering into a strategy for planned and controlled microbial degradation of specific contaminants. ISB creates subsurface environmental conditions, typically through reduction oxidation manipulation, which induce the degradation of contaminants via microbial catalyzed biochemical reactions. In turn, the microbes produce enzymes that are utilized to derive energy and that are instrumental in the degradation of target chemicals. To accomplish this chain of events, the type of microorganisms, contaminant, and the geological conditions at the site must be considered. Since in situ conditions are manipulated by engineered means, the most important consideration is the ability to transmit and mix liquids in the subsurface. The Interstate Technology Regulatory Council (ITRC)–ISB Team has recently completed a guidance document that describes a systematic approach to ISB in groundwater. ITRC is a state‐led coalition of more than 40 states working together with industry and stakeholders to achieve regulatory acceptance of environmental technologies. © 2003 Wiley Periodicals, Inc.     

Morphological study and performance deterioration of sustainable lignocellulosic corn fiber bio-composites

Journal of Material Cycles and Waste Management - Continuous efforts are paid to facilitate finding sustainable ecofriendly functional alternative materials for green products form low-cost...