Combined effect of enzyme inducers and nitrate on selective lignin degradation in wheat straw by Ganoderma lobatum

Environmental Science and Pollution Research - Lignin is one of the main barriers to obtaining added-value products from cellulosic fraction of lignocellulosic biomass due to its random aromatic...     

Oxidative damage to Pseudomonas aeruginosa ATCC 27833 and Staphylococcus aureus ATCC 24213 induced by CuO-NPs

Environmental Science and Pollution Research - The cytotoxicity of nanoparticles (NPs) and their properties are important issues in nanotechnology research. Particularly, NPs affect the metabolism...     

Integrated treatment and recycling of stormwater: a review of Australian practice

With the use of water approaching, and in some cases exceeding, the limits of sustainability in many locations, there is an increasing recognition of the need to utilise stormwater for non-potable requirements, thus reducing the demand on potable sources. This paper presents a review of Australian stormwater treatment and recycling practices as well as a discussion of key lessons and identified knowledge gaps. Where possible, recommendations for overcoming these knowledge gaps are given. The review of existing stormwater recycling systems focussed primarily on the recycling of general urban runoff (runoff generated from all urban surfaces) for non-potable purposes. Regulations and guidelines specific to stormwater recycling need to be developed to facilitate effective design of such systems, and to minimise risks of failure. There is a clear need for the development of innovative techniques for the collection, treatment and storage of stormwater. Existing stormwater recycling practice is far ahead of research, in that there are no technologies designed specifically for stormwater recycling. Instead, technologies designed for general stormwater pollution control are frequently utilised, which do not guarantee the necessary reliability of treatment. Performance modelling for evaluation purposes also needs further research, so that industry can objectively assess alternative approaches. Just as many aspects of these issues may have impeded adoption of stormwater, another impediment to adoption has been the lack of a practical and widely accepted method for assessing the many financial, social and ecological costs and benefits of stormwater recycling projects against traditional alternatives. Such triple-bottom-line assessment methodologies need to be trialled on stormwater recycling projects. If the costs and benefits of recycling systems can be shown to compare favourably with the costs and benefits of conventional practices this will provide an incentive to overcome other obstacles to widespread adoption of stormwater recycling.     

Environmental and human exposure assessment monitoring of communities near an abandoned mercury mine in the Philippines: a toxic legacy

Abandoned mines are an important global concern and continue to pose real or potential threats to human safety and health including environmental damage/s. Very few countries had government mine regulation and reclamation policies until the latter part of the century where legal, financial and technical procedures were required for existing mining operations. Major reasons for mine closure may be mainly due to poor economies of the commodity making mining unprofitable, technical difficulties and national security. If the mine is abandoned, more often than not it is the government that shoulders the burden of clean-up, monitoring and remediation. The topic of abandoned mines is complex because of the associated financial and legal liability implications. Abandoned mercury mines have been identified as one of the major concerns because of their significant long-term environmental problems. Primary mercury production is still ongoing in Spain, Kyrgzystan, China, Algeria, Russia and Slovakia while world production declined substantially in the late 1980s. In the Philippines, the mercury mine located southeast of Manila was in operation from 1955 to 1976, before ceasing operation because of the decline in world market price for the commodity. During this time, annual production of mercury was estimated to be about 140,000 kg of mercury yearly. Approximately 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining and roughly 1,000,000 t of these calcines were dumped into nearby Honda Bay to construct a jetty to facilitate mine operations where about 2000 people reside in the nearby three barangays. In October, 1994 the Department of Health received a request from the Provincial Health Office for technical assistance relative to the investigation of increasing complaints of unusual symptoms (e.g. miscarriages, tooth loss, muscle weakness, paralysis, anemia, tremors, etc.) among residents of three barangays. Initial health reports revealed significant elevation of blood mercury levels exceeding the then recommended exposure level of 20ppb in 12 out of the 43 (27.9%) residents examined. The majority of the volunteers were former mine workers. In this study the abnormal findings included gingivitis, mercury lines, gum bleeding and pterydium. The most common neurologic complaints were numbness, weakness, tremors and incoordination. Anemia and elevated liver function tests were also seen in a majority of those examined. The assessment also revealed a probable association between blood mercury level and eosinophilia. The same association was also seen between high mercury levels and the presence of tremors and working in the mercury mine. To date, there are very limited environmental and health studies on the impact of both total and methylmercury that have been undertaken in the Philippines. Thus, this area of study was selected primarily because of its importance as an emerging issue in the country, especially regarding the combined effects of total and methylmercury low-dose and continuous uptake from environmental sources. At present the effects of total mercury exposure combined with MeHg consumption remain an important issue, especially those of low-dose and continuous uptake. Results of the study showed that four (4) species of fish, namely ibis, tabas, lapu-lapu and torsillo, had exceeded the recommended total mercury and methylmercury levels in fish (NV>0.5 microg/gf.w., NV>0.3 microg/gf.w., respectively). Saging and kanuping also exceeded the permissible levels for methylmercury. Total and methylmercury in canned fish, and total mercury in rice, ambient air and drinking water were within the recommended levels, however, additional mercury load from these sources may contribute to the over-all body burden of mercury among residents in the area. Surface water quality at the mining area, Honda Bay and during some monitoring periods at Palawan Bay exceeded total mercury standards (NV>0.002 ng/mL). Soil samples in two sites, namely Tagburos and Honda Bay, exceeded the EPA Region 9 Primary Remediation Goal recommended values for total mercury for residential purposes (NV>23 mg/kg). The hand to mouth activity among infants and children is another significant route for mercury exposure. Statistically significant results were obtained for infants when comparing the results after one year of monitoring for methylmercury levels in hair for both exposed and control sub-groups. Likewise, comparing the initial and final hair methylmercury levels among pregnant women/mothers in the exposed group showed statistically significant (p<0.05) results. Comparing the exposed and control sub-groups' mercury hair levels per sub-group showed statistically significant results among the following: (a) initial and final total mercury hair levels among children, (b) initial and final methylmercury hair levels among children, (c) final total mercury hair levels among pregnant women, (d) initial and final total mercury hair levels among mothers, and (e) initial and final methyl hair levels among mothers.     

Methods,fluxes and sources of gas phase alkyl nitrates in the coastal air

The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3–C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO₂ levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor.     

Analysis of indoor gaseous formic and acetic acid, using radial diffusive samplers

A diffusive sampling method for the determination of gaseous acetic and formic acids, using a radial symmetry diffusive sampler, has been optimised for a 7-day exposure time in this study. Sampling rate determinations were performed on data obtained from a dynamic exposure chamber, simulating the indoor conditions of an empty, closed, room, at room temperature and minimal wind speed. Analysis has been performed by means of ion chromatography. The sampling rates for formic acid concentrations of 128 microg m(-3) and 1248 microg m(-3) were determined to be 91.2 +/- 3.9 ml min(-1) and 111.6 +/- 2.8 ml min(-1), respectively. The acetic acid sampling rate was independent of the concentration in the range 160 microg m(-3)-1564 microg m(-3), and amounted to 97.3 +/- 3.1 ml min(-1). Experimentally determined sampling rates showed deviations of 3% for acetic acid, and 3-21% for formic acid, in relation to theoretically derived values. The blank values were as low as 1.69 +/- 0.07 microg for formic acid and 1.21 +/- 0.14 microg for acetic acid, and detection limits lower than 0.5 microg m(-3) could be achieved, which is an improvement of 98-99% compared to previously validated diffusive sampling methods. This study describes the first step of an extended validation program in which the applicability of these types of samplers for the measurement of organic acids will be validated and optimised for the environmental conditions typical for museum showcases.     

How size relates to oxygen consumption,ammonia excretion,and ingestion rates in cold (<Emphasis Type="Italic">Enteroctopus megalocyathus</Emphasis>) and tropical (<Emphasis Type="Italic">Octopus maya</Emphasis>) octopus species

The scaling of metabolic rates with body mass is one of the best known and most studied characteristics of aquatic animals. Herein, we studied how size is related to oxygen consumption, ammonia excretion, and ingestion rates in tropical (Octopus maya) and cold-water (Enteroctopus megalocyathus) cephalopod species in an attempt to understand how size affects their metabolism. We also looked at how cephalopod metabolisms are modulated by temperature by constructing the relationship between metabolism and temperature for some benthic octopod species. Finally, we estimated the energy balance for O. maya and E. megalocyathus in order to validate the use of this information for aquaculture or fisheries management. In both species, oxygen consumption and ammonia excretion increased allometrically with increasing body weight (BW) expressed as Y = aBW ^b . For oxygen consumption, b was 0.71 and 0.69 for E. megalocyathus and O. maya, respectively, and for ammonia excretion it was 0.37 and 0.43. Both species had low O/N ratios, indicating an apparent dependence on protein energy. The mean ingestion rates for E. megalocyathus (3.1 ± 0.2% its BW day⁻¹) and O. maya (2.9 ± 0.5% its BW day⁻¹) indicate that voracity, which is characteristic of cephalopods, could be independent of species. The scope for growth (P = I − (H + U + R) estimated for E. megalocyathus was 28% higher than that observed in O. maya (320 vs. 249 kJ day⁻¹ kg⁻¹). Thus, cold-water cephalopod species could be more efficient than tropical species. The protein and respiratory metabolisms of O. maya, E. megalocyathus, and other octopod species are directly dependent on temperature. Our results offer complementary evidence that, as Clarke (2004) stated, the metabolic response (R and U) cannot be determined mechanistically by temperature, as previously proposed (Gillooly et al. 2002).     

Mesoscale Meteorological Simulations of Summer Ozone Episodes in Mexicali and Monterrey, Mexico: Analysis of Model Sensitivity to Grid Resolution and Parameterization Schemes

Air quality in the Mexican cities of Monterrey, Nuevo Leon, and Mexicali, Baja California, has suffered great detriment in recent years. It is well known that meteorology is one of the main factors affecting the dynamics of pollutants in the atmosphere. Here, the Penn State/NCAR Meteorological Mesoscale Model (MM5) meteorological system was applied to identify meteorological conditions conducive to high-ozone concentrations in such regions. Two summer 2001 ozone episodes for each geographical domain were selected with the aid of a classification and regression tree analysis technique. Model response to changes in its physical parameterization, horizontal grid resolution, and data assimilation schemes were assessed. Once a suitable configuration was selected, performance statistics were computed for model validation. MM5 simulated satisfactorily the meteorology of such episodes, yielding indexes of agreement of 0.4–0.8 for wind speed and 0.67–0.95 for temperature, on average. However, MM5 tended to underestimated temperature and overestimated wind speed. Froude numbers were calculated to analyze the impact of the terrain complexity on wind circulation. It was concluded that in both cities, wind convergence zones might enhance high-ozone concentrations. These results improve our understanding of the atmospheric processes exerting effect on air pollution within these airsheds.