The measurement of corporate environmental performance and its application to the analysis of efficiency in oil industry

This paper addresses a measurement of corporate environmental performance, and its application to the analysis of efficiency in the petroleum firms. In order to measure firms' environmental performance, we suggest a framework called “Gscore” that consists of five categories, namely general environmental management (GEM), input, process, output, and outcome. Gscore is a proxy measure of corporate environmental performance based on voluntary environment, health, and safety (EHS) report and is calculated by aggregating the points of the above five-categories. We apply our measurement framework to the data of 39 firms' voluntary EHS reports which are available on the internet. Ten of them, on which efficiency analysis was conducted with Gscore, assets, employee, and profits, are in petroleum and refining industry. According to our results: (1) a gap is found between rhetoric and practical environmental management stemming from calculating the relation between GEM and data part in 39 EHS reports. (2) On the whole, EHS reports of petroleum firms have something in common, but there are significant differences in the type and amounts of disclosed data among the EHS reports. (3) From the results of efficiency analysis, it is found that the number of employee exerts a considerable influence on determining the relative efficiency of petroleum firms, then Gscore, profits, and assets in sequence. Furthermore, Exxon, Ashland, Phillips Petroleum, and ARCO are shown to be efficient among 10 petroleum firms.     

Analysis on biochemical methane potential of agricultural byproducts with different types of silage storage

The aim of this work is to estimate biogas production by anaerobic digestion of agricultural byproduct silage at the low carbon green village in South Korea. The composition of agricultural byproduct from hot pepper farms was analyzed and it was found to be favorable with anaerobic digestion. In the cases of silage materials, the theoretical methane potentials of all of the ensiled materials were increased with silage storage having an increased range from 103 to 120 % compared to that without ensiling. The biochemical methane potential (BMP) tests showed that the ultimate methane potential of ensiled material was measured to be higher than that of raw material without silage storage, while the first order hydrolysis constant was lower. All of the silage materials containing microbial additives used in this study showed higher ultimate methane potentials and first order hydrolysis constants than raw material and silage material without additives. The change of ultimate methane potential was analyzed over time, and all of the test materials, except Day 2, showed higher ultimate methane potential than raw material, Day 0, and the highest was found on Day 40.     

Characteristics of mercury emission from linear type of spent fluorescent lamp

In order to recycle the linear type of SFL (spent fluorescent lamp), mercury from SFL should be controlled to prevent leaking into the environment. For mercury emission from SFL, mercury concentration is estimated in the parts of SFL such as glass tube, phosphor powder, and base cap using the end-cutting unit. It is also evaluated mercury emission in the effluent gas in the end-cutting unit with changing flow rate. From the results of mercury emission from SFLs, phosphor powder has greater than 80% of mercury amount in SFL and about 15% of mercury amount contained in glass tube. The initial mercury concentration in vapor phase is almost decreased linearly with increasing airflow rate from 0.7 L/min to 1.3 L/min. It is desirable that airflow rate should be high until the concentration of mercury vapor will be stable because the stabilized concentration becomes to be low and the stabilized time goes to be short as increased airflow rate. From KET and TCLP results, finally, phosphor powder should be managed as a hazardous waste but base-cap and glass are not classified as hazardous wastes.     

Development of enzyme-linked immunosorbent assay (ELISA) for glutathione S-transferase (GST-S) protein in the intertidal copepod Tigriopus japonicus and its application for environmental monitoring

To utilize the GST-S protein as a useful biomarker for environmental contamination, we developed a polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) in the intertidal copepod Tigriopus japonicus. Two polyclonal antibodies, TJ-GST-S1 and TJ-GST-S2, were raised against two TJ-GST-S synthetic peptides. Also a recombinant TJ-GST-S protein was purified as a standard for ELISA development. Each polyclonal antibody was tested by Western blot analysis and indirect ELISA. Of two polyclonal antibodies, TJ-GST-S2 ELISA was further employed due to its wide range of detection and the limit of specificity compared to those of TJ-GST-S1 ELISA system. After exposure to 4 metals (Ag, As, Cd, and Cu) to T. japonicus, the amount of TJ-GST-S protein was significantly elevated in a concentration-dependent manner. Also, TJ-GST-S protein was upregulated at relative high concentrations of B[α]P, PCB, and TBT. In this paper, we suggest that T. japonicas ELISA for TJ-GST-S2 is useful as a potential indicator system for marine contaminants.     

Effect of mixing ratio of woody waste and food waste on the characteristics of carbonization residue

Biomass such as woody waste and food waste can be converted to a renewable energy source by means of carbonization processes. The basic characteristics of woody waste and food waste, such as proximate analysis and heating value, were evaluated before carrying out carbonization tests. Carbonization tests were carried out to obtain the basic characteristics of carbonization residue on changing the proportion of food waste from 0% to 30% in the mixture of woody waste and food waste. The effect of the food waste was estimated by basic characteristics of the residue such as the heating value, yield, and fuel ratio. As increased the food waste content, the bulk density, yield and chlorine content of the carbonization residue increased, but fuel ratio, the carbon content and heating value of the residue decreased. From the results of the basic characteristics of the residue, the optimum food waste content in carbonization tests was found to be 20%. Even if food waste is combined with woody waste at levels up to 30%, the sulfur and chlorine concentrations in the residue were much lower than the regulatory standard levels. From the results for the fuel ratio and heating value of the residue, the carbonization residue is suitable for use as a renewable energy source and can be categorized by the second grade level of solid fuel products.     

Microbial Degradation of PCBs in Contaminated Sediments

The extent of natural dechlorination varies widely in sediments and fails to reach its maximum potential. Recent laboratory and field studies have suggested that the potential for further dechlorination is low in the Hudson and St. Lawrence Rivers. Laboratory investigations have also indicated that polychlorinated biphenyl (PCB) dechlorination is directly coupled to the growth of dechlorinating microorganisms in that: (a) there was no growth of dechlorinating microorganisms below the threshold concentration, (b) the rate of chlorine removal per gram sediment was significantly correlated to the growth rate of the microorganisms, (c) the negative effect of lower moisture levels on dechlorination was correlated to the microorganism death rate, and (d) the extent of natural dechlorination in the St. Lawrence River appears to be related to the in-situ population size of dechlorinators. There also appear to be many dechlorinating populations, each with different requirements and competence. Therefore, the growth enhancement of these microorganisms is the key to promoting PCB dechlorination either in situ or ex situ. © 1999 John Wiley & Sons, Inc.     

A study on engineering characteristics of asphalt concrete using filler with recycled waste lime

This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.     

Microbial PCB dechlorination in dredged sediments and the effect of moisture

Evidence of reductive dechlorination of polychlorinated biphenyls (PCBs) in sediments was investigated in Hudson River sediments dredged and encapsulated in 1978 at Moreau, NY. The effect of different moisture contents in dredged sediments on dechlorination and dechlorinating microorganisms was also determined using PCB-spiked sediments in which the moisture level was adjusted by simulating a dewatering process. The congener pattern of PCBs indicated that the dechlorination in the dredged sediments was far less advanced than that in the river sediments collected from the general area of the dredged site (Ft. Edward site). Dechlorination in encapsulated sediments at the Moreau site appeared to have stopped soon after dredging. When microorganisms eluted from the encapsulated sediments were inoculated in clean sediments spiked with Aroclor 1242, an extensive dechlorination was observed, indicating that the encapsulated sediments still harbored dechlorinating microorganisms. However, the same inoculum failed to further dechlorinate residual congeners in the dredged sediments. On the other hand, an inoculum obtained in 1990 from the dredged site in the Hudson River dechlorinated the residual congeners further. In simulated dredged sediments, the maximum level of dechlorination was lower at reduced moisture contents. The population size of dechlorinating microorganisms, as determined by the most probable number (MPN) technique, was also smaller at the lower moisture levels. There was a significant correlation between the maximum extent of dechlorination and the specific death rate of dechlorinating populations. These results indicate that the underlying mechanism of the moisture-dependent maximum dechlorination is the moisture-dependence of the death rate of dechlorinating microorganisms.     

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH)(2) in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb>Cd>Cr, but the order was changed to Pb>Cr>Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.