稳健统计在快速生物降解性试验质量分析中的应用

快速生物降解性试验在新化学物质的生态毒理测试中占据重要地位,其测试数据的可靠性直接影响后续的测试策略和物质的申报登记、以及新化学物质进入环境后的风险管理。为研究OECD 301系列试验(301B、301D和301F)的质量,选用本机构近5年来积累的标准化物质苯甲酸钠14 d快速生物降解率数据,首次采用稳健统计技术,以稳健总计统计量的Z比分数作为评价指标,对各试验数据和试验系统的质量开展评估。结果显示,当301B、301D和301F试验的苯甲酸钠降解率分别在63.8%~88.0%、63.4%~89.2%和66.0%~99.8%范围内时,表明测试结果满意,该批次试验数据质量良好;若苯甲酸钠降解率不在此范围,则表明测试结果可能存在问题,甚至得到的可能是错误数据,需要进一步验证。据此提出了对实际测试工作具有指导意义的质量分析对照表,以期为测试机构开展新化学物质快速生物降解性试验时的质量分析提供参考。     

两段式还原工艺处理铬渣的生产性研究

利用焦亚硫酸钠和硫酸亚铁将铬渣中的六价铬进行两次溶出和两次还原,解毒后铬渣中总铬含量≤1.5 mg/L,六价铬含量≤0.5mg/L,远远低于HJ/T 301—2007《铬渣污染治理环境保护技术规范(暂行)》铬渣以一般工业固废进行固化填埋标准浓度值。该工艺技术解毒彻底,无返铬现象,过程简单,处理成本低,可实现规模化生产,具有广阔的推广应用前景,对周边环境的保护意义重大。     

海藻酸钠固定化Fe-Cu双金属去除Cr(Ⅵ)的作用机制

通过运用海藻酸钠(SA)固定化Fe-Cu双金属(SAB)来克服Fe0-PRB利用率低、易板结、堵塞的缺陷.结果表明,SA和Fe-Cu双金属的运用能极大地提高Fe0的利用率,SA的运用可以使Fe-Cu双金属以较低的镀铜量获得较高的Cr(Ⅵ)去除率,SAB镀铜0.9%(SAB0.9)为最佳的填料.FEI电镜扫描结果表明,SA跟2价金属阳离子Ca2+交联形成孔隙结构,为双金属的附着提供了大量的吸附点位,增大了金属颗粒的比表面积;场发射扫描电子显微镜(FESEM)及X-射线光电子能谱(XPS)结果表明,Cu负载于Fe0表面,呈疏松层状结构,在Fe0与Cr(Ⅵ)反应中起催化剂作用,通过自身化合态变化传递Fe0失去的电子,从而提高了Fe0的利用率.渗透系数实验结果表明,SAB0.9能控制Fe0与Cr(Ⅵ)反应产物的释放,缓解Fe0-PRB易板结、堵塞的缺陷.     

Structural alterations in compound eye of Drosophila melanogaster in response to sodium fluoride treatment

Sodium fluoride, used as a pesticide in agriculture, is also an ingredient of toothpastes which help to fight dental problems. In this study, Drosophila melanogaster, a non-target organism, is used to explore morphological changes in the adult compound eye as a function of exposure to fluoride at 20, 40, 80, 100 and 150 mg L^?1, using scanning electron microscopy. The experimental concentrations were much lower than the ones used in the studies of the British Association of Community Dentistry. Distinct morphological alterations in the eye of the treated insects revealed ommatidial ridges and disoriented mechanosensory bristles which were most prominent in the 40 and 80 mg L^?1 treatment groups. Since humans and Drosophila share homology in many genes that are involved in developmental pathways, the present findings raise concern on the use of sodium fluoride as a pesticide.     

过硫酸钠对砂壤土中三氯乙烯的氧化研究

以过硫酸钠(Na2S2O8)为氧化剂,柠檬酸(CA)螯合Fe(Ⅱ)溶液作为活化剂,对砂壤土中的三氯乙烯(TCE)进行处理.采用正交试验获得优化操作条件为: Na2S2O8浓度5mmol/L,Fe(Ⅱ)浓度2.5mmol/L,CA浓度0.25mmol/L,反应时间30min.在此条件下,土壤中不同浓度的TCE去除率均在93%以上.对于污染程度高的土壤,采用连续氧化处理可达到较高的修复目标要求.土柱实验结果表明经过Na2S2O8溶液氧化7d后,TCE氧化率达到88.9%以上,且去除效果与处理方式有关,分次加入方式的效果最好.     

盐酸-次氯酸钙氧化法去除贫泥磷中的黄磷

分别采用次氯酸钙单一体系和盐酸-次氯酸钙复合体系对贫泥磷中的黄磷进行氧化处理,重点考察了盐酸浓度、次氯酸钙加入量、反应温度和反应时间等因素对贫泥磷中黄磷去除率的影响。实验结果表明:与单一次氯酸钙体系相比,盐酸的加入有效地破除了贫泥磷中的胶质结构,盐酸-次氯酸钙复合体系能有效地去除贫泥磷中的黄磷;在反应温度为60℃、盐酸浓度为2.4 mol/L、破胶反应时间为30 min、次氯酸钙加入量为250 g/L、氧化反应时间为3 h的最佳条件下,黄磷的去除率达到99.6%以上。     

聚丙烯酸钠-硅溶胶的合成及其对阳离子金黄染料的吸附

通过简单的水溶液聚合法成功合成了聚丙烯酸钠-硅溶胶复合吸附剂,并对其进行了SEM和热重分析,研究了吸附条件对该吸附剂对阳离子金黄染料吸附效果的影响。实验结果表明,当硅溶胶质量分数为20%、初始染料质量浓度为60 mg/L、初始溶液pH为7、反应温度为298 K时,聚丙烯酸钠-硅溶胶复合吸附剂对阳离子金黄染料的吸附量为64.64 mg/g。由二级吸附动力学模型获得的活化能(Ea=2.617 kJ/mol)表明,聚丙烯酸钠-硅溶胶复合材料对阳离子金黄的吸附属于物理吸附,低温有利于吸附。     

AN ASSESSMENT OF SEDIMENT PHOSPHORUS INACTWATION,KEZAR LAKE,NEW HAMPSHIRE1

ABSTRACT: Aluminum sulfate and sodium aluminate were utilized as sediment phosphorus inactivants to improve the water quality of a northeastern eutrophic lake. A four-year monitoring program has provided an extensive lake-database utilized to evaluate the short-and long-term effectiveness of sediment phosphorus inactivation as a lake restoration technique. An immediate impact of treatment was marked by a reduction in hypolimnetic BOD and dissolved oxygen deficit, lower chlorophyll-a and phosphorus concentrations, improved transparency, and the elimination of obnoxious blue-green phyto-plankton blooms. For two to three years after treatment, these pa-rameters continued to exhibit both less variability and improved values over the pre-treatment conditions. The improved water quality conditions warranted an upgrade of the lake trophic status from eutrophic to mesotrophic. Four years after the treatment, the mean hypolimnetic total phosphoru.s and chlorophyll-a have increased and transparency has decreased from initial post-treatment levels. Although long-term trends show water quality decreasing since the treatment, the water quality has stabilized at a level suitable for recreation. A major benefit is an increase in the average attendance at the lake by almost 2,000 people per summer.     

提高芒硝制硝酸钠产品质量的措施与方法

本文分析了芒硝复分解法制硝酸钠产品质量较差的主要原因，探索了解决方法，并确定出最佳工艺条件、试验产品质量达到国标标准．对开发芒硝资源的新用途具有实际意义。     

培育优势菌种处理腈纶厂硫氰酸钠废水

采用两段生物氧化法处理腈纶厂的硫氰酸钠废水，Ⅰ段去除易降解的有机物，Ⅱ段培育以自养性排硫杆菌为主体的生物膜，降解硫氰酸钠。试验装置的容积负荷达１．１—２．２ｋｇＮａＳＣＮ／ｍ￣３·ｄ，比单级氧化池处理同类废水试验的容积负荷提高２—４倍。文中介绍了试验装置运转情况，两段生物膜的特性，探讨了在第Ⅱ段氧化池中硫氰酸钠生物降解的动力学模型。