秘鲁亚马孙地区与毁林相联系的国家农业政策:Tambopata的案例研究,1986～1997

亚马孙流域的毁林速度随地区不同而异,其涨落由宏观经济政策和当地的社会因素而定.我们运用遥感和野外调查,研究了1986～1991年(当时有农村信贷和担保市场)和1991～1997年(其间施加了结构调整措施)秘鲁一边疆地区的毁林格局和原因.1986～1991年间,最高的毁林速度(总的比率1.5%)出现于道路两旁,1991～1997年,路旁的毁林速度下降(总的比率0.7%),同时,大面积的再生使森林覆被得以净增长(0.5%).河旁毁林速度相对稳定.直至今日,河旁农场还保留着更多的农田和森林,而路旁的农场则以牧场和演替生长为主.老住户要比新来者在农场保留更多的森林,但是对城市市场的邻近度是森林覆被最强的预测因子.未来的信贷计划必须反映出经济发展的空间格局和生态脆弱性,同时要有利于休耕地和次生林的恢复.     

Effect of Fe0 quantity on the efficiency of integrated microbial-Fe0 treatment processes

Batch experiments were conducted with different reaction systems to investigate how the treatment efficiency of integrated microbial-Fe0 processes is affected by the amount of Fe0 added. Abiotic experiments with hexavalent chromium and carbon tetrachloride mixtures corroborated that different pollutants could compete for reactive sites on the iron surface, which would hinder specific degradation rates when the available Fe0 surface area is relatively small (e.g., 11 m(2) l(-1)). In such cases, reductive precipitation of chromium could occlude reactive sites and significantly inhibit removal efficiency. Microbial participation in the cleanup process was also influenced by the amount of Fe0 added. Increasing the Fe0 dose (and thus the available surface area) had a stimulatory effect possibly due to a higher production of cathodic H2, which can be used as electron donor for reductive biotransformation of many pollutants. However, high Fe0 doses had an inhibitory effect due to a corrosion-induced increase in pH beyond the optimum range of the bacteria. This suggest that there may be a system-specific, optimum quantity of Fe0 that satisfies availability requirements to preclude contaminant competition for reactive sites and biological requirements for H2 production while minimizing inhibitory increases in pH. Results also confirmed extensive RDX mineralization in bioaugmented (but not in abiotic) Fe0 systems, and support the notion that permeable reactive iron barriers performance might be enhanced by the participation of some microorganisms.     

A holistic passive integrative sampling approach for assessing the presence and potential impacts of waterborne environmental contaminants

As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater. Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.     

Molecular phylogeny of the American <Emphasis Type="Italic">Callinectes</Emphasis> Stimpson, 1860 (Brachyura: Portunidae), based on two partial mitochondrial genes

The genus Callinectes encompasses 16 species of commercially important swimming crabs. Most (13) occur on the Pacific and Atlantic coasts of the Americas. We compare mtDNA regions corresponding to 964 basepairs of the large (16S) and small (12S) ribosomal subunits among American Callinectes in order to examine phylogenetic relationships. The status of Callinectes affinis Fausto-Filho and Callinectes maracaiboensis Taissoun is questioned, and C. maracaiboensis is concluded to be a junior synonym of Callinectes bocourti A. Milne-Edwards, from which it cannot be consistently distinguished. We find two major lineages, one of which includes C. affinis, C. bocourti, Callinectes rathbunae Contreras, Callinectes sapidus Rathbun, and Callinectes toxotes Ordway. A second lineage is comprised of Callinectes arcuatus Ordway, Callinectes bellicosus (Stimpson), Callinectes danae Smith, Callinectes exasperatus (Gerstaecker), Callinectes larvatus Ordway, Callinectes ornatus Ordway, and Callinectes similis Williams. Definition of these clades is supported by previously described morphological differences in the length of the gonopods and shared physioecological adaptations. A calibrated molecular clock is used to estimate divergence of the two lineages near 13 mybp. Our analyses suggest that C. ornatus is the closest relative of C. arcuatus, and that C. affinis is closest to C. bocourti.     

Water and waste remediation processes: an update

Environmental Science and Pollution Research -     

Potential economic costs of invasive structural pests: conehead termites,Nasutitermes corniger,in Florida†

Increased trade and human mobility result in sizable benefits to society, but are often accompanied by negative consequences, such as increased introduction of invasive pests to different landscapes and seascapes. In this paper, we couple an existing model of the biological spread of Nasutitermes corniger, an invasive neotropical termite recently introduced to Florida, with information on the costs to treat and repair affected structures, and use this coupled model to simulate the potential short-term costs of establishment of this structural pest. We construct empirical distributions of control and repair costs, using surveys of the pest control industry and homeowners, and use them to simulate treatment and damage costs through a re-sampling procedure. Our results suggest that the net present value of potential costs from an unchecked N. corniger invasion in Florida range between $6.9 and $9.9 million over the next 10 years.     

Anaerobic co-digestion of aquatic flora and quinoa with manures from Bolivian Altiplano

Quinoa stalk (Chenopodium quinoa Willd.) from agricultural crop residue, totora (Schoenoplectus tatora) and o-macrophytes (aquatic flora) from Lake Titicaca (on the Bolivian Altiplano) were studied in a wet anaerobic co-digestion process together with manure from llama, cow and sheep. Anaerobic semi-continuous experiments were performed in (10) 2-l reactors at a temperature of 25 degrees C with 30 days of hydraulic retention time (HRT) and an organic loading rate (OLR) of 1.8kgVSm(-3)d(-1). Totora was found to be the best co-substrate. In mixture ratios of 1:1 (VS basis), it increased the biogas productivity by 130% for llama manure, 60% for cow manure, and 40% for sheep manure. It was possible to use up to 58% (VS basis) of totora in the substrate. Higher concentrations (including pure totora) could not be digested, as that caused acidification problems similar to those caused by other lignocellulosic materials. When quinoa and o-macrophytes were used as co-substrates, the increase in biogas productivity was slightly less. However, these co-substrates did not cause any operational problems. An additional advantage of quinoa and o-macrophytes was that they could be used in any proportion (even in pure form) without causing any destabilization problems in the anaerobic digestion process.     

Benzo[a]pyrene degradation by Sphingomonas yanoikuyae JAR02

Batch experiments were conducted to characterize the degradation of benzo[a]pyrene, a representative high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH), by Sphingomonas yanoikuyae JAR02. Concentrations up to the solubility limit (1.2 microg l(-1)) of benzo[a]pyrene were completely removed from solution within 20 h when the bacterium was grown on salicylate. Additional experiments with [(14)C]7-benzo[a]pyrene demonstrated 3.8% mineralization over 7 days when salicylate was present is solution, and one major radio-labeled metabolite was observed that accounted for approximately 10% of the initial radio-label. Further characterization of the radio-labeled metabolite using HPLC/MS and HPLC/MS/MS identified radio-labeled pyrene-8-hydroxy-7-carboxylic acid and unlabeled pyrene-7-hydroxy-8-carboxylic acid as novel ring-cleavage metabolites, and a benzo[a]pyrene degradation pathway was proposed. Results indicate that biostimulation of HMW PAH degradation by salicylate, a water-soluble, non-toxic substrate, has significant potential for in situ bioremediation.     

Unsaturated dicarbonyl products from the OH-initiated photo-oxidation of furan, 2-methylfuran and 3-methylfuran

This study presents the application of O-(2,3,4,5,6)-pentafluorobenzyl-hydroxylamine hydrochloride (PFBHA) on-fibre derivatisation Solid Phase Microextraction (SPME) to the sampling and quantification of the unsaturated 1,4-dicarbonyl products obtained in the photo-oxidation of furan, 2-methylfuran and 3-methylfuran with HONO: butenedial, 4-oxo-2-pentenal and 2-methylbutenedial, respectively. The use of Proton Transfer Reaction Mass Spectrometry (PTR-MS) is also considered and the advantages of the combined use of both methodologies is discussed. The 1,4 unsaturated dicarbonyl products sampled by SPME were quantified by GC-FID.The experiments were carried out in the EUPHORE outdoor simulation chambers. The results confirm that 1,4-dicarbonyls are the main products of the OH-initiated oxidation of furan and its methylated derivatives, a fact with environmental implications. Molar yields of (1.09 ± 0.41) and (0.90 ± 0.36) were obtained in two experiments of furan photo-oxidation. The yields of 4-oxo-2-pentenal and methylbutenedial were estimated to be (0.60 ± 0.24) and (0.83 ± 0.33) respectively, assuming the same SPME response factor as for butenedial. Furthermore, the unsaturated 1,4-dicarbonyls have also been identified in the chemical characterisation of the aerosols formed in the reactions. The yield of aerosols quantified were (8.5 ± 0.8)% in the photo-oxidation of furan, (1.85 ± 0.18)% in the photo-oxidation of 2-methylfuran and (5.5 ± 0.5)% in the photo-oxidation of 3-methylfuran, at the following concentrations of their precursors: 829 ± 249 ppbV and 748 ± 224 (in two furan experiments), 633 ± 190 in the 2-methylfuran and 641 ± 192 ppbV in the 3-methylfuran experiment.     

Minimization of water use and wastewater contaminant load

This communication describes a project concerning the minimization of water use and wastewater contaminant load in an industrial setting. The location was a plant manufacturing cast aluminum parts for the automotive industry. The water used for industrial purposes was some 16 000 m³/yr with COD values sometimes higher than 5000 mg O₂/l. After a preliminary assessment, a global reduction in industrial water consumption of 33%, by means of re-circulation of the aqueous solution used for de-molding was achieved, implying a 95% reduction in de-molding solution. To minimize water use even further, recommendations to the company included a revision of the refrigeration closed-circuit and a better control of water used for general services.