煤炭资源型城市街尘重金属污染特征及其生态风险——以宿州市为例

为了解煤炭资源型城市宿州市街尘重金属污染特征和生态风险,对23个采样点进行了12个月的连续采样。利用X射线荧光光谱分析仪对采集到的276个街尘样品进行了Cr、Cu、Mn、Pb、V和Zn等重金属含量检测。结果表明:Cr、Cu、Mn、Pb、V和Zn均值含量分别为112.9、27.5、410.3、45.2、75.6和225.3 mg/kg,除Mn和V外,其他四种重金属均超过土壤背景值。地累积指数评价结果表明,Cu、Mn和V无污染,而Cr和Pb为无污染至中度污染,Zn为中度污染。6种重金属各月份的污染负荷指数介于1~2之间,污染等级为无污染至中度污染。尽管单个重金属及6种重金属联合所致的潜在生态风险均为轻微生态风险等级,但空间分析结果表明,潜在生态风险指数的高值区一般多分布在人为活动较频繁的地段,说明重金属含量及其生态风险明显受人为活动影响。同时,风向风速对街尘重金属含量和时空变化也有重要影响。     

低碳经济型电子商务的发展与研究

介绍了中国电子商务发展的趋势,主要有电子商务销售规模大幅度高,电子商务企业发展迅速,交易日益多样化,移动网络成为交易平台,探讨了中国电子商务实施低碳发展的困境,它们是B2C小订单零售模式,小企业电子商务基础差,效率较低,建立科学的电子商务线路问题,促进电商低碳发展,提出了中国电子商务与低碳发展的趋势,主要是电子商务产业的信息服务平台,电子商务采用公车模式,鼓励电子商务大订单交易,电子商务交易不断优化创新,提高中国低碳发展水平.     

高州水库底泥磷吸附与解吸模拟研究

通过室内实验模拟高州水库底泥中磷的吸附与解吸过程,分别对比不同样点底泥和不同磷浓度上覆水对底泥磷释放和吸附的影响,研究了水库底泥中磷的吸附与解吸动态变化规律.结果表明:高州水库不同样点底泥对磷的吸附和解吸的动态平衡浓度为0.03 mg/L~0.05 mg/L,不同磷浓度上覆水底泥对磷的吸附和解析动态平衡浓度为0.05 mg/L.上覆水和底泥中磷含量的高低均会影响磷的吸附和解吸动态变化.底泥中磷含量与磷吸附速率成反比;上覆水中磷含量与磷吸附速率成正比关系.     

Physical and chemical characteristics of waste activated sludge treated with electric field

This study investigates the physical and chemical characteristics of sludge treated with controlled levels of electric field. The results indicated that the potential gradient and contact time strongly influenced the physical and chemical characteristics of sludge. Based on the settling velocity measurements, a potential gradient of 6 V/cm with a treatment time of 10 min is recommended as an optimal condition for improving sludge settling. For sludge disintegration, applying a higher potential gradient and a longer treatment time to the sludge are more efficient than applying lower levels. The results of the experiments presented here show that an electric field not only disintegrates sludge and destroys microbial cells but also removes and solubilizes organic substances. Possible mechanisms of electric field treatment are also discussed.     

我国湿热海上风电大气区金属重防腐涂料的性能研究

目的对海上风电涂料在我国湿热海洋地区的环境适应性、耐久性开展针对性研究,积累试验数据。方法通过对国内外共7家知名风电涂料企业大气区样板展开征集,参考国内外相关行业测试标准及技术,结合我国湿热海上大气环境特点,并向风电主机企业及涂料企业征集意见,设计并开展实验室环境模拟试验,包括紫外老化试验、圆盘耐磨试验、中性盐雾试验等。结果大部分企业的涂层样板耐老、耐盐雾等性能均较好,海洋大气区涂料相对成熟,国外企业、合资企业和国内企业的涂料上差异较小。结论大气区涂料体系的技术相对成熟,国外知名企业在性能市场上仍占主导地位,但对于设计要求的15年以上使用寿命是否能够实现仍有待进一步研究。     

模糊层次分析法在保定市城镇污水处理技术综合评价中的应用

基于保定市城镇生活污水处理技术,采用改进的模糊层次分析法建立一个4层12个指标8种方案的综合评价体系,从经济、技术和管理等角度对氧化沟工艺、CASS工艺、UNITANK工艺、百乐克工艺、CAST工艺、A2/O与百乐克结合工艺、倒置A2/O工艺、A2/O工艺8种处理工艺进行综合评价。同时采用专家打分法对8种技术进行评价,结果表明CASS工艺的分值最高。     

Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies

The effects of dissolved organic matter (DOM) on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 (A300) and Purolite A 520E (A520E), would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Freundlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t 1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.     

Life cycle and economic assessment of enhanced ecological floating beds applied water purification

Environmental Science and Pollution Research - The ecological floating beds (EFB) are widely used in water quality restoration because of its low cost, high efficiency, and green characteristics....     

采暖锅炉氧腐蚀的原因与防腐对策

热水锅炉及其采暖系统在运行和停运期间都存在较严重的氧腐蚀,但由于主客观原因的限制,并没有引起人们的高度重视.氧腐蚀对锅炉及其采暖系统运行的安全性和经济性造成重大影响,严重时引起爆管,被迫停炉等危害.大力提倡节能减排的今天,延长锅炉的寿命,促进安全经济生产意义重大.本论文分析总结采暖锅炉目前的水质与防腐工作的现状,同时提出了对采暖锅炉今后锅炉及热力管网防腐的对策.     

液桥凝聚用于办公废纸脱墨的研究

研究了混合办公废纸脱墨的选择性凝聚技术，在废纸浆中添加分散在水中并不与水相溶的长链烷作凝聚剂，这些凝聚剂选择性地将印刷墨粉通过液桥连结在一起，且形成大颗粒的球形聚团，再分选脱除。研究表明只需要加入占纸重量4％的廉价长链烷，即可获得95％以上的脱墨率。因此在混合办公废纸脱墨时加入凝聚剂进行液桥凝聚，可降低脱墨浆中的尘埃度并增加产品的白度。