Variability of dissolved organic matter in northern adriatic coastal waters

The results obtained in the four seasonal cruises planned in the PRISMA II project are reported. These concern dissolved and colloidal organic carbon, free amino acids and total dissolved carbohydrates and heterotrophic activity. Main factors controlling organic matter degradation, resulting from laboratory tests not planned in the above project, are also discussed. Dissolved organic matter shows seasonal accumulation, which may be markedly different from year to year, and large contributions by colloidal and saccharide components. Heterotrophic activities play an important role in the carbon cycle, although laboratory runs highlight limitations caused by aging of organic matter and phosphorus deficiency.     

Chemical characterization of Tan‐Sui River sediment in North Taiwan

Surface sediment samples from four downstream sites of Tan‐Sui River in Taipei metropolitan area were collected from 1997 to 1999. The semivolatile organic pollutants present in the sediments were screened by GC/MSD. Several target compounds including sixteen polycyclic aromatic hydrocarbons (PAHs), seven chlorobenzenes, two phthalates and the total amount of C8‐C32 aliphatic hydrocarbons were quantified. The concentration of the 16 PAHs ranges from 0.21 to 5.69 μg/g of which fluoranthene, pyrene and phenanthrene were the highest. The concentration of the total chlorobenzenes ranged from 0.04 to 5.85 μg/g. The concentration of bis(2‐ethylhexyl)phthalate ranges from 3.8 to 35.3 μg/g and that of the total C8‐C32 aliphatic hydrocarbons ranges from 0.94 to 10.6 μg/g. Some of these values are higher than similar sediment survey in Japan in the eighties. The concentration of bis(2‐ethylhexyl)phthalate is much higher than the no‐effect level (0.184 μg/g) set by McDonald. Some of the PAHs have already reached the level of biological effects. As compared with the sediment samples collected from Tou‐Chien River and Pu‐Ze River located at the west of Taiwan, the chlorobenzene concentrations of sediments in Tan‐Sui River are 5–6 times higher, the PAHs are 6–10 times higher and the phthalates are 11–20 times higher. Nonylphenol was also commonly found in the Tan‐Sui River sediment. There is a decreasing tendency of PAHs and phthalates concentration from surface to bottom for the core sample at Taipei Bridge site. Such tendency is less obvious for chlorobenzenes.     

松花江鱼类有机污染物的研究

测定了松花江哨口至松花江村江段、扶余至三岔河口江段和嫩江下游鱼类肌肉中5类33种有机污染物的平均含量。其中,可疑致癌物6种,促癌或助癌物3种。鱼类有机污染物的平均含量以扶余至三岔河口江段最高,其次为嫩江下游,而哨口至松花江村江段由于近年来加强了对吉林市区有机污染源的治理,使其污染程度降低。     

城市生活垃圾复混肥示范工程工艺设计

提出了适合我国中小城市生活垃圾的处理办法,即利用城市生活垃圾生产有机复混肥。对有机复混肥的效益分析表明,利用城市生活垃圾生产复混具有明显的环境效益,社会效益和的经济效益,是一条利国利民,造福子孙后代的城市生活垃圾处理的好办法。     

零价铁降解氯代有机污染物的QSPR研究

利用密度泛函理论B3IYP/6-31G(d)水平计算氯代有机污染物绝热电子亲合能(EAad)、垂直电子亲合能(EAvert)及C-Cl键键离解能(BDE),据此研究零价铁对该类化合物脱氯降解的定量结构-性质关系(QSPR).结果表明,描述符EAad和BDE所建QSPR模型效果均较好,同时EAad可以很好地体现还原过程,BDE则对于降解途径预测具有较大价值.     

Attenuation of landfill leachate by UK Triassic sandstone aquifer materials: 2. Sorption and degradation of organic pollutants in laboratory columns

The sorption and degradation of dissolved organic matter (DOM) and 13 organic micropollutants (BTEX, aromatic hydrocarbons, chloro-aromatic and -aliphatic compounds, and pesticides) in acetogenic and methanogenic landfill leachate was studied in laboratory columns containing Triassic sandstone aquifer materials from the English Midlands. Solute sorption and degradation relationships were evaluated using a simple transport model. Relative to predictions, micropollutant sorption was decreased up to eightfold in acetogenic leachate, but increased up to sixfold in methanogenic leachate. This behaviour reflects a combination of interactions between the micropollutants, leachate DOM and aquifer mineral fraction. Sorption of DOM was not significant. Degradation of organic fractions occurred under Mn-reducing and SO₄-reducing conditions. Degradation of some micropollutants occurred exclusively under Mn-reducing conditions. DOM and benzene were not significantly degraded under the conditions and time span (up to 280 days) of the experiments. Most micropollutants were degraded immediately or after a lag phase (32–115 days). Micropollutant degradation rates varied considerably (half-lives of 8 to >2000 days) for the same compounds (e.g., TeCE) in different experiments, and for compounds (e.g., naphthalene, DCB and TeCA) within the same experiment. Degradation of many micropollutants was both simultaneous and sequential, and inhibited by the utilisation of different substrates. This mechanism, in combination with lag phases, controls micropollutant degradation potential in these systems more than the degradation rate. These aquifer materials have a potentially large capacity for in situ bioremediation of organic pollutants in landfill leachate and significant degradation may occur in the Mn-reducing zones of leachate plumes. However, degradation of organic pollutants in acetogenic leachate may be limited in aquifers with low pH buffering capacity and reducible Mn oxides. Contaminants in this leachate present a greater risk to groundwater resources in these aquifers than methanogenic leachate.     

Chemometric characterization of soil and plant pollution: Part 1: Multivariate data analysis and geostatistical determination of relationship and spatial structure of inorganic contaminants in soil

Geostatistical and multivariate methods of data analysis are used to describe patterns of soil pollution with inorganic contaminants in Celje County, Slovenia. Groups of contaminants and polluted sites were identified using cluster analysis and confirmed with multidimensional variance and discriminant analysis. Factor analysis yields an identification of not directly observable relationships between the contaminants. The spatial structure and distribution of contaminants were assessed by applying semivariogram analysis and kriging interpolation method. Zinc, Cd and Cu were identified as a pollutant emitted from the zinc smelter, Pb also from other sources, and Cr and Ni mostly from geological parent material.     

Predicting the degradation pattern of organic materials in the composting of a fed-batch operation as inferred from the results of a batch operation

The degradation pattern of organic materials was confirmed by continuously measuring the quantity of CO₂ evolved during the composting process in both batch and fed-batch operations. It was possible to predict the degradation pattern for organic material during a fed-batch operation from that observed during a batch operation after corrections made on the basis of two suppositions. First, it was assumed that the degradation of dog food (which degrades easily) occurred prior to the degradation of the bulking agent and seeding material that were contained in the raw compost mixture; second, it was assumed that the dog food thrown into the fed-batch operation, where the microorganisms were already proliferating, began to be actively degraded with only a short lag time. Received: June 16, 1998 / Accepted: August 7, 1999     

小清河水体中有机污染物的测定及其扩散迁移初探

对山东省小清河流域的地表水、地下水、底泥、土壤、农作物等进行了有机化合物的系统分析,检出有机化合物13类93种。对其毒性效应以及在环境中的扩散、迁移进行了分析和探讨。      

Ecological Responses to Trout Habitat Rehabilitation in a Northern Michigan Stream

Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids), even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a 3^rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention, seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity) following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality. Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter retention may enhance stream biota in the long term.