南黄海海水中各种形态磷的分布变化特征

利用 1998年 5月南黄海大面调查所得到的数据和相关的历史资料 ,对南黄海海水中P的现状及其分布变化规律进行了分析 :南黄海海水中P的含量底层略高于表层 ,且主要存在形式是DOP ;底层水中颗粒态磷和溶解态磷的形态间转化与表层不同 ,可能是通过DOP为煤介进行的 ;在南黄海海水中 ,溶解态磷酸盐的分布主要是受生物活动的影响 ,可以作为赤潮发生的一个预测因子 ;南黄海的大部分区域N、P供应充分 ,属于中等营养海区。     

辽河流域面源污染负荷定量试验研究

本文通过对辽河流域面源污染物来源途径分析及系统采样进行试验测定，获得了不同面源污染类型的流失物中可进入水体的COD、总氮和总磷负荷，通过试验核算首次对辽河流域面源污染负荷进行了定量化研究。     

Efficient capture of aqueous humic acid using a functionalized stereoscopic porous activated carbon based on poly(acrylic acid)/food-waste hydrogel

Stereoscopic porous carbons have shown good potential in humic acid (HA) removal. In this work, a novel stereoscopic porous activated carbon (SPAC) was designed and synthesized via the self-assembly of a hydrogel based on food waste during in-situ polymerization, vacuum drying, carbonization, and activation. Then, the SPAC was functionalized with 3-aminopropyltriethoxysilane (APTES) and the adsorption behavior of the modified SPAC (SPAC-NH₂) was studied systematically. The effects of pH, contact time, initial concentration of HA, and adsorbent dose were investigated, showing that optimal HA removal efficiency (> 98.0%) could be achieved at an initial HA concentration of 100?mg/L. The experimental adsorption isotherm data was fitted to the Langmuir model with a maximum adsorption capacity of 156.0?mg?HA/g SPAC-NH₂. Analysis of the mechanism indicated that the removal of HA was mainly realized through the amidization reaction between the COOH groups of HA and the NH₂ groups of APTES. All of the above results showed that SPAC-NH₂ powder is an efficient, eco-friendly, and reusable adsorbent which is suitable for the removal of HA from wastewater.     

Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms.

A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community composition. Furthermore, because earthworm invasion can involve a predictable shift in community structure along invasion fronts or through time, the community dynamics of invasion are important in predicting the spatial and temporal effects of earthworm invasion on litter decomposition, especially at later stages of decay.     

棉铃虫大暴发原因探讨

本文在简述我国黄河流域棉区1992年棉铃虫大暴发的概况后,较为详细地分析了大暴发的原因。指出生境、食料、天敌、气象及人工防治五方面因素的影响作用,特别强调食料和防治因素的重要意义。认为近年来棉铃虫食料种类增多、数量增大、质量提高、提供时间延长、取食更加方便是该害虫大暴发的基本原因。恰遇适宜的气象条件和人工防治不力(害虫抗药性强、治虫整体水平下降、夏玉米等晚秋作物弃治),终使棉铃虫建立起空前庞大的种群。     

Retention behavior of hydrophobic organic chemicals as a function of temperature in soil leaching column chromatography

To study the transport mechanism of hydrophobic organic chemicals (HOCs) and the energy change in soil/solvent system, a soil leaching column chromatographic (SLCC) experiment at an environmental temperature range of 20-40 degrees C was carried out, which utilized a reference soil (SP 14696) packed column and a methanol-water (1:4 by volume ratio) eluent. The transport process quickens with the increase of column temperature. The ratio of retention factors at 30 and 40 degrees C (k'30/k'40) ranged from 1.08 to 1.36. The lower enthalpy change of the solute transfer in SLCC (from eluent to soil) than in conventional reversed-phase liquid chromatography (e.g., from eluent to C18) is consistent with the hypothesis that HOCs were dominantly and physically partitioned between solvent and soil. The results were also verified by the linear solvation energy relationships analysis. The chief factor controlling the retention was found to be the solute solvophobic partition, and the second important factor was the solute hydrogen-bond basicity, while the least important factors were the solute polarizability-dipolarity and hydrogen-bond acidity. With the increase of temperature, the contributions of the solute solvophobic partition and hydrogen-bond basicity gradually decrease, and the latter decreases faster than the former.     

Implications of rhizospheric heavy metals and nutrients for the growth of alfalfa in sludge amended soil

Rhizospheric distribution of nutrients and heavy metals in sludge amended soil was investigated using the rhizobag technique to give an indication of the release of metals from wastewater sludge. DTPA-extractable Zn, Cd, Ni and Mn, and available P, K and NH4+-N in the rhizosphere were markedly depleted when soil was amended with sludge. There was no conspicuous depletion or accumulation of DTPA-extractable Cu in the rhizosphere when the soil was amended with sewage sludge but DTPA-extractable Fe accumulated in the rhizosphere when the soil was amended with increasing amounts of sludge. The pH value in the rhizosphere increased with distance from the roots when soil was amended with larger amounts of sludge. The exchangeable fraction of Cu in the rhizosphere was depleted whether or not the soil was treated with sludge. Carbonate, oxide, organic and residual fractions of Cu and Zn were depleted in the rhizosphere at a distance of 0-2 mm from the roots when soil was amended with 50% sludge. Application of sewage sludge had a positive effect on alfalfa growth. With an increase in sludge amounts, the concentrations of Fe, Cu and Zn in alfalfa shoots did not change. Soil amendments with less than 25% sludge did not increase the availability or mobility of heavy metals. The depletion in rhizospheric DTPA-extractable Zn, Cd and Ni indicates that with the sole exception of Cu, release of metals from sludge amended soil was very limited.     

垃圾渗滤液烟气脱硫体系的实验研究

利用垃圾渗滤液中较高的碱度吸收二氧化硫是垃圾渗滤液湿法烟气脱硫工艺的第一阶段。试验证明 ,垃圾渗滤液可高效吸收二氧化硫 (去除率可达 90 %以上 ) ;同时垃圾渗滤液中氨氮浓度由 133mmol L降至 78mmol L。实验结果证实了所建立的垃圾渗滤液烟气脱硫体系的互补性     

污染土壤修复效果评定方法的研究

在实施污染土壤修复的环境工程后，需要通过灵敏和有效的评定方法对污染土壤修复的效果进行评定。然而，单纯依靠化学方法进行污染土壤修复效果的评定，不能揭示土壤的整体质量特征，因此需要生态毒理方法作为相互补充的手段。本文概述了植物毒性评定法、陆生无脊椎动物评定法和土壤微生物评定法及其在污染土壤修复效果评定中的应用，并对污染土壤修复效果评定方法的发展前景进行展望。