一株高效微生物絮凝剂产生菌株P33的最优发酵条件和絮凝特性研究

从活性污泥中分离筛选出一株高效絮凝剂产生菌B-6-1,使用紫外线进行原生质体诱变育种获得一株絮凝率为98.5%的菌株P33,经生理生化试验检测其属于肠杆菌属.传代稳定性实验表明,P33所产微生物絮凝剂的稳定性较好.菌株P33最优发酵条件和絮凝特性实验结果表明:菌株最佳发酵条件为每升发酵培养基中(蔗糖20 g,尿素0.7...     

交联负载铝壳聚糖树脂对氟的吸附性能研究

将聚合氯化铝与片状壳聚糖复合制备球状交联负载铝壳聚糖树脂,并研究其除氟性能。通过实验探讨吸附时间、氟初始浓度、树脂用量、pH等因素对树脂除氟效果的影响。研究发现,树脂对氟的吸附动力学规律能用Lagergren一级方程和Lagergren二级方程加以描述,并符合Freundlich吸附等温模型;在树脂用量100mL／g、吸附时间12h时,树脂对氟的去除率为80％左右,pH值影响较小,适用pH范围宽;树脂吸附性能稳定,可用NH3·H2O多次再生,除氟效率与原树脂相近。     

Distribution,sources, and toxicity assessment of polycyclic aromatic hydrocarbons in surface soils of a heavy industrial city,Liuzhou, China

As a heavy industrial city, Liuzhou has been facing a serious pollution problem. It is necessary to take steps to control and prevent environmental pollution wherever possible. Surface soil samples were collected from four communities in Liuzhou City, to determine the concentrations, distributions, sources, and toxicity potential of polycyclic aromatic hydrocarbons (PAHs) present. The mean concentrations of total PAHs in the surface soil are 756.43 ng/g for the heavy industrial area, 605.06 ng/g for the industrial area, 481.24 ng/g for the commercial–cum–residential area, and 49.93 ng/g for the rural area. Both the isomer ratio and principal component analyses for the PAHs prove that these pollutants originate mainly from coal, diesel, gasoline, and natural gas combustion. The pollution hierarchies and toxic equivalency factor of BaP prove that the city is subject to heavy pollution caused by industry, transportation, and daily human activities.     

Chemical content and source apportionment of 36 heavy metal analysis and health risk assessment in aerosol of Beijing

The concentration levels of 36 airborne heavy metals and atmospheric radioactivity in total suspended particulate (TSP) samples were measured to investigate the chemical characteristics, potential sources of aerosols, and health risk in Beijing, China, from September 2016 to September 2017. The TSP concentrations varied from 6.93 to 469.18 μg/m³, with a median of 133.97 μg/m³. The order for the mean concentrations of heavy metals, known as hazardous air pollutants (HAPs), was as follows: Mn > Pb > As > Cr > Ni > Se > Cd > Co > Sb > Hg > Be; Non-Designated HAPs Metals: Ca > Fe > Mg > Al > K > Na > Zn > P > Ba > Ti > Cu > Sr > B > Sn > I > V > Rb > Ce > Mo > Cs > Th > Ag > U > Pt. The median concentration of As was higher than China air quality standard (6 ng/m³). The gross α and β concentration levels in aerosols were (1.84?±?1.59) mBg/m³ and (1.15?±?0.85) mBg/m³, respectively. The enrichment factor values of Cu, Ba, B, Ce, Tl, Cs, Pb, As, Cd, Sb, Hg, Fe, Zn, Sn, I, Mo, and Ag were higher than 10, which indicated enriched results from anthropogenic sources. Pb, As, and Cd are considered to originate from multiple sources; fireworks released Ba during China spring festival; Fe, Ce, and Cs may come from stable emissions such as industrial gases. The health risks from anthropogenic metals via inhalation, ingestion, and dermal pathway were estimated on the basis of health quotient as well as the results indicated that children faced the higher risk than adults during the research period. For adults, the health risk posed by heavy metals in atmospheric particles was below the acceptable level.

     

除草定在土壤中的降解和移动特性研究

除草定是一种新型嘧啶类除草剂,其在环境中的归趋备受关注。采用室内模拟试验方法,研究了除草定在不同土壤中的降解性、吸附性和移动特性。结果表明,除草定在江西红壤、太湖水稻土和东北黑土中的降解半衰期分别为693.1、173.3、138.6 d,该药在土壤中降解较慢,影响其在土壤中降解速率的主要因素为土壤有机质。除草定在江西红壤、太湖水稻土与东北黑土中的吸附较好地符合Freundlich方程,Kd值分别为0.34、1.86和2.94;3种土壤对除草定的吸附过程为自发的物理吸附。薄层层析试验显示,当溶剂展开至11.5 cm处,除草定在江西红壤、太湖水稻土和东北黑土中最远移至8~10 cm处。影响除草定在土壤中吸附性和移动性的主要因素为土壤有机质含量。除草定存在对地下水污染的潜在风险性,使用除草定应该引起足够重视。     

关于秦皇岛市科学发展中若干重要问题的探讨

按照国家统计局标准,秦皇岛市城市规模已达到大城市标准,应充分发挥辐射带动作用,加快城镇化步伐;抓住城市发展综合效益最佳期的机遇,促进可持续发展;坚持产业结构多元化,各产业协调发展。秦皇岛市生产总值在河北省属中上水平,在沿海开放城市中属落后水平,应尽快提高生产总值;秦皇岛市在科学发展中属比较先进水平,在民生发展方面属先进水平,其中生态方面优势明显,应进一步发挥生态优势,保护环境。秦皇岛市科技创新取得显著成绩,但任务艰巨,必须进一步实施创新驱动发展战略。     

Characteristics of oxytetracycline sorption and potential bioavailability in soils with various physical-chemical properties

Veterinary antibiotics are widely used for disease treatment, prevention and animal growth promoting. Frequent detection of veterinary antibiotics in environments, caused by land application of untreated or even treated antibiotics-containing animal wastes, has posed the growing concern of their adverse effect on natural ecosystems. Oxytetracycline (OTC) is one of the most widely-used veterinary antibiotics in livestock industry. OTC present as a cation, zwitterions, or net negatively charged ion in soils complicates predicting its sorption characteristics and potential bioavailability and toxicity. This study was to identify soil properties influencing OTC sorption and its subsequent bioavailability in five soils with various physical-chemical properties. A solution used to determine bioavailable analytes in soils and sediments, 1 M MgCl₂ (pH 8.5), was chosen to desorb the potentially bioavailable fraction of OTC sorbed onto soils. Our results demonstrated that soils with higher illite content and permanent cation exchange capacity have higher OTC sorption capacity, but increase the availability of sorbed OTC indicated by higher release of sorbed OTC from soils into aqueous phase in 1 M MgCl₂ (pH 8.5). Reversely, soil organic matter (SOM), clay, kaolinite, variable cation exchange capacity, DCB-Fe and -Al have lower OTC sorption capacity, but decrease the release of sorbed OTC from soils into 1 M MgCl₂. These findings indicate that SOM and clay greatly influence OTC adsorption and potential availability. This study contributes significantly to our understanding of the potential bioavailability of sorbed OTC and the effects of soil properties on OTC sorption behaviors in soils.     

谈堤防建设施工的安全管理

随着黄河二期标准化堤防建设的实施,郓城黄河又迎来了一个工程建设的高峰期。郓城黄河二期标准化堤防工程建设既有机淤固堤,又有堤防道路硬化,还有淤区盖顶等,可以说施工项目多,任务重,时间紧。做好施工工地安全管理,具有十分重要的意义。然而安全工作不是单一的部门和个人的工作,它是一项社会化、系统化的工程。     

曝气对电解除磷的影响研究

针对高浓度含磷废水,重点分析了电解除磷工艺中曝气对磷去除率、pH、电导率、电极钝化的影响.结果表明:(1)在电流密度为20 mA/cm2、磷初始质量浓度为200 mg/L,初始pH为5.5～6.5的条件下,当曝气量为1.0、1.5、2.0 L/min时,60 min内磷去除率均接近100%,而且出水中未检测出磷,符合<污水综合排放标准>(GB 8978-1996)中一级标准,30～40 min内,磷去除率达到了95%以上,磷残余质量浓度小于10 mg/L,相比未曝气的情况,磷去除率有了显著提高;(2)在电流密度为20 mA/cm2、磷初始质量浓度为200 mg/L、初始pH约为3的条件下,曝气溶液的pH在前30 min呈上升趋势.30 rain后趋于平缓,最终停留在8左右;(3)在电流密度为20 mA/cm2、磷初始质量浓度为200 mg/L、初始pH约为3的条件下,曝气溶液的电导率在整个电解除磷过程中先逐步下降,30～40 min后逐步趋于稳定;(4)曝气对于抑制电极钝化、提高磷去除率有着显著效果.