Partitioning of water soluble organic carbon in three sediment size fractions： Effect of the humic substances

Water soluble organic carbon (WSOC) in sediments plays an important role in transference and transformation of aquatic pollutants. This article investigated the inherent mechanisms of how sediemnt grain size affect the partitioning coeffcient (k) of WSOC. Influences of NaOH extracted humic substances were particularly focused on. Sediments were sampled from two cross-sections of the middle Yellow River and sieved into three size fractions (< 63 μm, 63-100 μm, and 100--300 μm). The total concentration of WSOC in sediments (CWSOC) and k were estimated using multiple water-sediment ratio experiments. Results show that CWSOC ranges from 0.012 to 0.022 mg/g, while k ranges from 0.8 to 3.9 L/kg. Correlations between the spectrum characteristics of NaOH extracted humic substances and k were analyzed. Strong positive correlations are determined between k and the aromaticity indicators of NaOH extracted humic substances in different sediment size fractions. Comparing with finer fractions (< 63 μm), k is higher in larger size fractions (63--100 and 100--300 μm) related to higher aromaticity degree of NaOH extracted humic substances mostly. While negative relationship between k and the area ratio of fourier transform infrared spectroscopy (FT-IR) at 3400 and 1430 cm-1 implied that the lowest k was related to the highest concentration of the acidic humic groups in particles < 63 μm. WSOC in finer fractions (< 63 μm) is likely to enter into pore water, which may further accelerate the transportation of aquatic contaminants from sediment to water.     

Atmospheric lead pollution in fine particulate matter in Shanghai, China

The Pb-monitoring program was extended for 6 years from 2002 to 2007 at 17 representative urban sites (6 traffic, 5 industrial, and 6 residential sites), and 3 suburban sites to assess the lead pollution in fine particulate matter (PM2.5) after phasing out leaded gasoline in Shanghai. Compared with Pb levels reported in other places, the Pb pollution in Shanghai is still serious after phasing out leaded gasoline, which remains at high concentration range (213–176 ng/m3) in PM2.5 in winter. Significant spati...     

A bioaugmentation failure caused by phage infection and weak biofilm formation ability

Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved di erently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9–18.     

Integrated assessment of river health based on water quality, aquatic life and physical habitat

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index. Based on the method of cluster analysis (CA) for water quality indices, it revealed that heavily polluted sites of Liao River are located at estuary and mainstream. The aquatic species surveyed were attached algae and benthic invertebrates. The result showed that the diversity and biomass of attached algae and benthic index of biotic integrity (B-IBI) were degrading as the chemical and physical quality of water bodies deteriorating. Physiochemical parameters, BOD5, CODCr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis. The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score. A comprehensive integrated assessing system of river ecological health was established. Based on the systimetic assesment, the assessed sites are categorized into 9 “healthy” and “sub-healthy” sites and 8 “sub-sick” and “sick” sites.     

Biodegradability of soil water soluble organic carbon extracted from seven di erent soils

Water soluble organic carbon (WSOC) is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils di erently managed. WSOC was extracted from soil with water (soil/water ratio of 1:2, W/V) for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on the both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, and provided useful information to soil fertility.     

氧化处理水中典型酚类污染物研究进展

环境激素是一类能干扰人类和动物正常内分泌的外源性物质,对生物体的生理过程产生很大的危害。本文介绍了水处理中,典型酚类污染物氧化剂降解技术的机理、特点、应用以及局限性,主要介绍了Fenton试剂、O3、二氧化氯等氧化剂及高铁酸钾新型氧化剂在酚类废水处理中的应用。并指出了复合氧化剂、新型氧化剂与其他水处理技术的联合应用将是酚类废水氧化处理的发展方向。     

城市水源地水质指标年内分配的不均匀变化

以昆明市主要供水水源（松华坝水库）的总氮、总磷、氮氨、高锰酸盐指数为研究对象,借鉴水文界经验,应用集中度、不均匀系数和调节系数概念,计算并分析比较了集中度、不均匀系数和调节系数在水质指标年内分配规律中的适用性。研究表明：集中度、不均匀系数和调节系数可从不同侧面反映了水质变化的年内分布特征,且3个指标在不同时间尺度间具有明显的一致性,因此,在水质监测中只需要应用每个季度的监测数据就能反映出水质变化的年内分配不均匀性。     

地下水资源的合理开发利用

地下水是我国城市和工农业用水的主要供水水源。但是,目前我国地下水开发利用不够合理,不仅直接破坏了地下水资源,而且诱发了一系列环境地质问题及次生生态环境问题。本文提出应当把地下水环境容量作为地质环境目标管理的基本依据和地质环境保护规划的主要约束条件,从而将容量概念引入到地下水开发利用管理中的观点。     

大学学生公寓用水及节水潜力分析

基于石河子大学学生公寓用水量和用水习惯的调查,分析学生公寓的节水潜力,并提出学生公寓给水排水改造设施建设的方案,对学校用水管理提出建议,为节约型校园建设提供新思路。     

含感潮河流的海岸带海水入侵特性的调查研究

以太平洋附近3.2 km2的区域为调查对象。首先,通过区域内的19口地质调查井,确认了含水层由透水性不同的多层土质构成,含水层以下的不透水层总体上从海岸开始呈逐渐隆起的山丘状。其次,通过测量距海岸不同距离的10口井水铅直方向电导率,确认了咸淡水混合区域特征点和地下水面伴随着潮汐的波动而变化的规律。即,在同一位置不同季节,其变化的特征不同;同一季节不同位置的调查井,因所处位置的地质构造及与海岸、感潮河流距离的不同,其变化特征也不同,这与迄今为止的众多研究结果不同。此外,通过分布于区域内的36个电法探测点的探查和井水铅直方向电导率的调查认为,海水入侵虽然受到感潮河流的一定影响,但从整个调查区域来看海水仍以"楔状"向着内陆入侵。同时,针对调查区域的不透水层的特征建立的数理模型对以上的部分调查结果给出了定性解释。