Binding of Pb(II) in the system humic acid/goethite at acidic pH

The study of Pb(II) binding to the system humic acid/goethite in acidic medium is reported in the present paper. From a macroscopic point of view, we have constructed the experimental sorption isotherms (using atomic absorption spectroscopy) and compared them with the prediction of the additivity rule. It is found that this system presents positive deviations, that is, the amount sorbed is about an order of magnitude higher than predicted. Apart from this, microscopic and structural aspects have also been studied using in situ and ex situ infrared spectroscopy. These results suggest that the presence of Pb(II) increases the amount of humic acid bound to the oxide. It is proposed that proton displacement due to the interaction between humic substances and the oxide, along with the formation of ternary complexes with the Pb(II) cation bridging the oxide and the humic substances (Type A complexes), cause the deviation from additivity.     

Chemical and biological characterization of non-extractable sulfonamide residues in soil

For sulfonamides, the formation of non-extractable residues has been identified by laboratory testing as the most relevant concentration determining process in manured soil. Therefore, the present study has been focused on the chemical and biological characterization of non-extractable residues of ¹⁴C-labeled sulfadiazine or sulfamethoxazole. In laboratory batch experiments, the test substances were spiked via standard solution or test slurry to microbially active soil samples. After incubation periods of up to 102 d, a sequential extraction technique was applied. Despite the exhaustive extraction procedure, sulfadiazine residues mainly remained non-extractable, indicating the high affinity to the soil matrix. The remobilization of non-extractable ¹⁴C-sulfadiazine residues was monitored in the activated sludge test and the Brassica rapa test. Only small amounts (<3%) were transferred into the extractable fractions and 0.1% was taken up by the plants. In the Lumbricus terrestris test A, the release of non-extractable ¹⁴C-sulfamethoxazole residues by the burrowing activity of the earthworms was investigated. The residues mainly remained non-extractable (96%). The L. terrestris test B was designed to study the immobilization of ¹⁴C-sulfamethoxazole in soil directly after the test slurry application. The mean uptake by earthworms was 1%. Extractable and non-extractable residues amounted to 5% and 93%, respectively. Consequently, the results of all tests confirmed the high affinity of the non-extractable sulfonamide residues to the soil matrix.     

无排泥运行MBR处理不同浓度氨氮废水及其生物特性

考察了水力停留时间(HRT)为10 h时无排泥运行下膜-生物反应器(MBR)处理不同浓度氨氮无机废水的运行性能及微生物特性.结果表明,在处理NH₄⁺-N≤500 mg/L的废水时,氨氮转化率可达99%且反应器内微生物增长缓慢,比硝化速率从0.2kg/(kg·d)升至0.52 kg/(kg·d);当NH₄⁺-N≥700 mg/L时,出水亚硝酸氮和氨氮相继出现明显累积,比硝化速率随之下降至0.4kg/(kg·d)以下,反应器内生物量从3 200 mg/L上升至6 700 mg/L.反应器中的氨氧化菌维持在10⁷CFU/mL,亚硝酸盐氧化菌从10⁶CFU/mL下降至10³CFU/mL.系统内的溶解性微生物产物(以TOC表示)升至65 mg/L后保持稳定,出水TOC一直维持在3～4mg/L;细胞外分泌物(EPS)在膜的截流作用下随运行时间的延长积累至600 mg/L.     

Assessing the anti-estrogenic activity of sodium pentachlorophenol in primary cultures of juvenile goldfish (Carassius auratus) hepatocytes using vitellogenin as a biomarker

Both pentachlorophenol and 2,3,7,8-tetrachlorodibenzo-p-dioxin （TCDD） had been studied widely because of their probable anti-estrogenic activity. Sodium pentachlorophenol （PCP-Na）, as a industrial product used in many fields, usually contains a trace of TCDD. The aim of this study was to assess the anti-estrogenic effect of PCP-Na in juvenile goldfish （Gurassius auratus） hepatocyte cultures using vitellogenin （VTG） as the biomarker. The ID50 of PCP-Na was investigated and then a series of concentrations （0.001 0.5 μg/ml） of PCP-Na were evaluated to estimate the anti-estrogenic activity. Results showed that PCP-Na was cytotoxic for hepatocytes even at very low concentration 〈1.21 μg/ml, and it could not induce VTG at any concentrations tested. Since it failed to stimulate VTG production, the possibility of its anti-estrogenic effect was tested, and a well-known anti-estrogenic compound-tamoxifen was used as positive control. PCP-Na caused a reduction in VTG synthesis in juvenile goldfish （Carassius auratus） hepatocytes at concentrations 〉0.1μg/ml when co-exposure with 1μg/ml 17β-estradiol （E2）, making its anti-estrogenic activity approximately as potent as tamoxifen. Our results indicate that PCP-Na can act as negative modulators of estrogenic function in juvenile goldfish （Carassius auratus） hepatocytes.     

微生物絮凝剂产生菌的初步筛选及条件试验

从活性污泥中筛选到18株絮凝剂产生菌,经复筛得到一株高效絮凝剂产生菌L-3.分别研究了碳源、氮源、无机盐、初始pH值、培养温度等对其产生絮凝剂的影响.结果表明,葡萄糖、玉米淀粉是较好的碳源,酵母膏为最佳氮源,最适宜培养温度为30 ℃,初始pH为7～9,摇床转速为160 r/min.     

高炉渣制备光催化剂及其催化活性的研究

以废弃的冶金高炉渣为原料,采用混酸酸溶-水热合成法制备了光催化剂,并对其进行了SEM、UV-Vis、XRD、比表面积等物性测试分析;通过处理甲基橙模拟废水,探讨了制备过程中渣酸比、混酸配比、渣用量、溶渣时间等条件对高炉渣制光催化剂活性的影响。将所制光催化剂与P25光催化剂进行对比分析,结果表明,高炉渣制光催化剂不仅具有较高的光催化活性,而且制备成本低廉,仅为P25光催化剂的1/10,这对于冶金高炉渣的循环再利用及光催化氧化技术的工业化应用具有重要的实际意义。     

不同物质对铬价态测定结果的影响

采用单波长法和双波长法,分别考察了KH2PO4、H3PO4、H2SO4、KNO3、牛肉膏和蛋白胨对Cr(III)和Cr(VI)质量浓度测定的影响。结果显示,Cr(III)和Cr(VI)在测量中是相互影响的,并且Cr(III)对Cr(VI)影响较显著。在单波长法测定中,牛肉膏、蛋白胨及2种酸对Cr(III)和Cr(VI)的影响较钾盐对其影响更为显著,H3PO4和H2SO4对Cr(III)和Cr(VI)的特征吸收峰值影响最大,降低幅度在20%～50%。这些物质对双波长法测定Cr(VI)几乎没有影响;但对Cr(III)测定中,H2SO4和H3PO4的影响较大,其相对误差分别为14.57%和8.87%,其余物质产生的相对误差均小于1.6%。因此,双波长法可用于生物样品中Cr(III)和Cr(VI)的测定,线性范围分别为0～160 mg/L和0～80mg/L。     

Mesoscale variability related to iron speciation in a coastal Ross Sea area (Antarctica) during summer 2014

Dissolved iron (Fe) distribution and speciation was determined in water samples (0–200?m) collected in a coastal area near Terra Nova Bay during the austral summer of 2014. Nutrients, dissolved oxygen, chlorophyll-a, phytoplankton composition and prokaryotic biomass distribution were investigated in combination with measurements of the physical properties of the water columns and its dynamics. The dFe value was above the limiting growth concentration, ranging from 0.52 to 4.51?nM, and it showed a spatial variability with a horizontal length scale of about 10?km, according to the variability of the water column physical properties and to iron sources. The organic ligands (L) maintained the concentrations of dFe at levels much higher than the inorganic solubility of Fe, keeping it available for phytoplankton and the log K’_FeL values found (from 22.1 to 23.6) highlighted the presence of complexes of differing stabilities.     

Effectiveness of a physical activity program on weight,physical fitness,occupational stress,job satisfaction and quality of life of overweight employees in high-tech industries: a randomized controlled study

Introduction. This study aimed to examine the effectiveness of a physical activity (PA) program on weight control, physical fitness, occupational stress, job satisfaction and quality of life of overweight and sedentary employees in high-tech industries. Methods. Participants in the intervention group (n?=?37) were instructed to carry out a PA program at moderate intensity for 60?min/session, 3 sessions/week for 12 weeks. Those in the control group (n?=?38) received no PA program and were asked to continue their routine lifestyle. Evaluations were performed at baseline and at the end of the intervention. Results of structured questionnaires and blood biochemistry tests and evaluations of physical fitness were analyzed. Results. The PA program effectively reduced the number of risk factors for metabolic syndrome and body fat percentage, and improved physical fitness such as flexibility, muscular strength and endurance and cardiorespiratory endurance. The intervention also significantly decreased levels of serum triglyceride, total cholesterol and low-density lipoprotein cholesterol. Significant positive effects on work control, interpersonal relationships at work, global job satisfaction and quality of life were also demonstrated. Conclusion. This study showed that a PA program can be helpful in improving physical, physiological and psychological outcomes for overweight and sedentary employees in high-tech industries.     

河北省不同盐渍化土壤类型的微生物多样性与种群结构

为了探索盐渍化土壤中微生物多样性及群落构成，有效筛选盐渍土壤中耐盐微生物菌群.采用高通量测序技术对采集的河北省滨海盐渍土（原生盐渍化）、设施盐渍土（次生盐渍化）和高产粮田（健康土壤）3个生境的耕层土壤样本细菌和真菌多样性、群落结构、网络关系及其影响因子进行测定.结果表明，与大田土壤相比，设施土壤中OM、AP、AK、TS和EC显著升高，滨海盐渍土壤的TS和EC显著升高，其他养分指标则显著降低.细菌α多样性依次为：设施盐渍土>高产粮田>滨海盐渍土，真菌α多样性则为高产粮田显著高于设施盐渍土和滨海盐渍土.在门和属水平上分析盐渍化土壤的菌群结构，细菌群落中绿弯菌门（Chloroflexi）及其菌属和真菌群落中子囊菌门（Ascomycota）及其中有益菌Trichocladium和病原菌Fusarium为盐渍化土壤中的优势微生物类群.土壤EC和TS两个盐分因子是对细菌和真菌菌群分布贡献最大的因子，与绿弯菌门中unclassified_A4b和unclassified_Chloroflexi以及变形菌门中unclassified_α-Proteobacteria等细菌菌属和子囊菌门中Trichocladium、unclassified_Chaetomiaceae、Crassicarpon、Cephaliophora和Sodiomyces等真菌菌属呈显著正相关.研究结果为盐渍化土壤修复所需的微生物资源筛选提供了理论依据.