Assessment of potential soybean cadmium excluder cultivars at different concentrations of Cd in soils

The selection of cadmium-excluding cultivars has been used to minimize the transfer of cadmium into the human food chain. In this experiment, five Chinese soybean plants were grown in three soils with different concentrations of Cd (0.15, 0.75 and 1.12 mg/kg). Variations in uptake, enrichment, and translocation of Cd among these soybean cultivars were studied. The results indicated that the concentration of Cd in seeds that grew at 1.12 mg/kg Cd in soils exceeded the permitted maximum levels in soybeans. Therefore, our results indicated that even some soybean cultivars grown on soils with permitted levels of Cd might accumulate higher concentrations of Cd in seeds that are hazardous to human health. The seeds of these five cultivars were further assessed for interactions between Cd and other mineral nutrient elements such as Ca, Cu, Fe, Mg, Mn and Zn. High Cd concentration in soil was found to inhibit the uptake of Mn. Furthermore, Fe and Zn accumulations were found to be enhanced in the seeds of all of the five soybean cultivars in response to high Cd concentration. Cultivar Tiefeng 31 was found to fit the criteria for a Cd-excluding cultivar under different concentrations of Cd in soils.     

Toward rational design of amines for CO2 capture: Substituent effect on kinetic process for the reaction of monoethanolamine with CO2

Amines have been considered as promising candidates for post-combustion CO₂ capture. A mechanistic understanding for the chemical processes involved in the capture and release of CO₂ is important for the rational design of amines. In this study, the structural effects of amines on the kinetic competition among three typical products (carbamates, carbamic acids and bicarbonate) from amines + CO₂ were investigated, in contrast to previous thermodynamic studies to tune the reaction of amines with CO₂ based on desirable reaction enthalpy and reaction stoichiometry. We used a quantum chemical method to calculate the activation energies (E_a) for the reactions of a range of substituted monoethanolamines with CO₂ covering three pathways to the three products. The results indicate that the formation of carbamates is the most favorable, among the three considered products. In addition, we found that the E_a values for all pathways linearly correlate with pK_a of amines, and more importantly, the kinetic competition between carbamate and bicarbonate absorption pathways varies with pK_a of the amines, i.e. stronger basicity results in less difference in E_a. These results highlight the importance of the consideration of kinetic competition among different reaction pathways in amine design.     

黑龙江省大气污染防治思路研究

近年来,全国各地出现不同程度的雾霾天气,大气污染严重,黑龙江省部分城市大气也出现不同程度污染,本文通过分析导致大气污染的三个主要成因,即:气候条件不利于污染物扩散;煤炭消耗处于主导地位;机动车迅速发展.提出黑龙江省未来十年的大气污染防治思路和地区产业发展方向的几点建议,通过采取综合、系统的措施,完善大气污染治理制度和政策保障体系、建立分区管理、加强污染基础研究、发展绿色经济等多方面入手,冀希能够改善本省的空气质量.     

中国新型城镇化发展的“C 模式”研究

研究了以美国为首的发达国家城镇化的发展历程,称为“A模式”,主要特征为城市低密度蔓延、全民机动化、资源大量消耗、一次性产品泛滥、过度消费等,总结经验教训,对比中国特色城镇化的发展历程,称为“ B模式”,主要特点是起步晚、水平较低、速度快,从资源与环境的角度分析了中国城镇化发展状况以及面临的形势,指出中国继续以“B模式”的城镇化发展将不可持续,不再适应中国建设“新型城镇化”的发展目标和日益提高的环保要求,探索实现中国“新型城镇化”的发展目标的“C模式”,即是坚持以节约优先、保护优先、自然恢复为原则,走以新型工业化和农业现代化推动下的新型城镇化道路。     

混合酸浸提—原子吸收法测定土壤中铜

建立了混合酸浸提对土壤样品进行前处理,并运用空气-乙炔火焰原子吸收法(FAAS)分析土壤中铜的方法。结果表明:最佳前处理条件为混合酸HNO 3+HCl(1+1),浸提温度100℃,浸提时间120 min。该方法前处理简单,测定快速、结果准确,同时经多次进行加标试验验证,其结果样品测定相对标准偏差为2.2%,其回收率为95%~101%,方法可行,应用于土壤样品的微量元素分析。     

熏蒸废水一体化处理工艺分析研究——以四川某生物防治公司为例

四川某生物防治公司在利用磷化氢与二氧化碳混合气体熏蒸处理烟草和粮食杀菌生产过程中产生少量废水。废水主要含氢氧化铝等固体废物,具有产生量小、SS浓度大、颗粒物粒径极小、色度大、溢出气含腐蚀性等特点,对客户感官产生不适。结合该公司实例介绍了以"沉淀+一体化负压两级过滤"为主体的处理工艺的熏蒸废水处理过程。经过处理,该公司生产废水中SS和色度去除率可达到99.3%与98.1%,出水可满足相关标准与相应感官要求。     

精制棉废水处理技术进展研究

精制棉广泛用于食品、医药、电子和日化等行业,但废水量大,尤其是蒸煮黑液,色度高、COD值高和可生化性差,处理的工艺复杂、处理成本较高,一直是环境工程领域的难点.本文首先介绍了精制棉废水的来源及性质,重点分析和总结了精制棉废水的炉渣和粉煤灰、酸析、电解和高级氧化预处理技术,并对精制棉废水的生物处理技术和工程实践进行了概括总结.针对精制棉废水的来源和性质,对精制棉废水处理技术的发展方向进行了展望.     

Biogenic C-doped titania templated by cyanobacteria for visible-light photocatalytic degradation of Rhodamine B

Cyanobacteria, which occurred in eutrophic water harvest solar light to carry out photosynthesis with high efficiency. In this work, cyanobacteria （Microcystis sp.） were used as biotemplate to synthesize titania structure. The synthesized titania sample had similar morphology to that of the original template in spite of the fragile unicellular structures and extremely high water content of cyanobacterial cells. Incorporation of biogenic C, as well as the morphology inherited from biotemplate improved visible- light absorbance of the titania structure. The sample exhibited higher visible-light photocatalytic activity than commercial titania photocatalyst Degussa P25 for Rhodamine B （RhB） degradation. Compared with those C-doped titania photocatalysts prepared by other methods, cyanobacteria templated titania photocatalyst offer some potential for competitive advantages. The reported strategy opened up a new use for the cyanobacteria. It could also be used for titania in applications such as treatment of polluted water, dye-sensitized solar cells, or other regions.     

大牛地气田污水预处理药剂加量研究

大牛地气田污水水质总体呈现高浊度、高矿化度、高腐蚀性、高含铁量及低pH值"四高一低"的特点。预处理阶段对后续处理过程起着重要的作用,试验确定了该阶段的加药量,提出了"一控二适量"的加药原则,选定JH-1、JH-2、JH-3的加量分别为300、50和2mg/L配合使用,使污水pH值控制在8.0～8.4之间,既节省了运行费用,又极大地缓解了处理过程中设备的结垢堵塞现象。     

浅析应急救援队伍在抢险救援中的应急保障能力

通过对当前应急救援队伍的装备配置和维护保养情况进行调查,结合基层队伍的专项训练情况,分析现阶段应急救援队伍应急保障中存在的薄弱点,就如何提高应急救援队伍的救援能力提出建议。