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981.
982.
快速固相萃取法测定食品中多种有机磷农药残留 总被引:5,自引:0,他引:5
报道了一种简便、快速的石墨碳固相萃取(SPE)食品中多种有机磷农药残留及测定的方法.采用丙酮浸泡、超声提取食品中的有机磷农药,经石墨碳固相小柱净化萃取后,用气相色谱-火焰光度检测法直接测定,加标回收率在72.0%~107%之间,RSD为6.2%~12.7%,最低检出限可达0.001 mg/kg. 相似文献
983.
介绍了改进型气箱脉冲袋除尘器在铝电解烟气净化工程上的成功应用,实践结果表明,在保证净化效果的前提下,采用改进型气箱脉冲袋除尘器作为净化设备,可使其一次投资、能耗、年维修费与其他型式布袋除尘器相比均有所降低,为铝电解烟气净化工程扩大了除尘器的选择范围. 相似文献
984.
Pirkanniemi K Vuorio AM Vilhunen S Metsärinne S Sillanpää M 《Environmental science and pollution research international》2008,15(3):218-221
Goal, Scope and Background Complexing agents are one of the major environmental concerns in electrolytic and chemical surface treatment (ECST) industry;
e.g. the EU reference document on the best available technology (BREF) pays special attention to the usage of EDTA. However,
no comprehensive studies are available on usage of EDTA or other complexing agents or their load to the receiving waters from
ECST industry. In this study, the concentrations of complexing agents were analyzed to get an overview of their usage and
load and also to recognize their relevance in the environmental permitting and compliance monitoring of such facilities.
Methods Complexing agent concentrations of treated waste water samples of 23 ECST plants with vat volume exceeding 30 m3 was studied. HPLC and GC-MS were used to analyze and identify complexing agent concentrations, ICP-AES to analyze metals,
and TOC to analyse the organic load. The number of the plants in this study equals around 50% of such installations in Finland
subject to environmental permit as the IPPC directive provides.
Results EDTA, DTPA, and NTA were found in 11 samples out of 23 mainly in rather small concentrations. Their annual load to the receiving
waters may be estimated to be 0.3 tons and the total load from Finnish ECST industry can be extrapolated to be up to 1 ton.
Compared to the estimated use of 5–10 tons in the industry this finding is rather low, even though in Finland cast-off treatment
baths are typically delivered to the hazardous waste treatment plants.
Discussion Since the load of complexing agents is rather low, the chemical waste water treatment seems to be either capable of reducing
complexing agent concentrations to some extent or their usage is lower than expected. On the other hand, it is possible that
not all complexing agents were identified from the samples. The metal concentrations and TOC were well hand in hand with concentrations
found in the Finnish environmental database, which proves that the samples were of average quality of the waste water from
the facilities.
Conclusions According to the results, complexing agents cannot be considered as an environmental risk in the ECST industry in Finland;
EDTA concentrations are clearly below PNECaqua (2.2 mg/l) and the total discharge is very marginal compared to the discharge from the pulp and paper industry. However,
DPTA seems to be as commonly used as EDTA, but also biodegradable NTA was found.
Recommendations and Perspectives Since EDTA has gained plenty of attention in the BREF, DTPA and other, poorly biodegradable complexing agents should also
be taken into account when the BREF is updated within a few years. Also an EU risk assessment report especially for DTPA should
be supplied, since its use is obviously increasing. 相似文献
985.
采用固体废物磷化渣配制成复合磷化液,并用所配制的复合磷化液对A3钢试件进行磷化处理,形成磷化膜。通过正交实验确定了配制复合磷化液的较佳配方为:磷化液基础液加入量0.2L/L、氧化锌加入量5g/L、碳酸钠加入量6g/L、硝酸加入量12.5mL/L、浓磷酸加入量2.5mL/L、硫酸铜加入量0.3g/L。复合磷化液为浅绿色透明溶液,pH为4.0,总酸度为40,游离酸度为10,磷化温度为65℃,磷化时间为300~600s。所形成的磷化膜厚度为16.0μm,单位质量为26.875g/m^2,粗糙度为1.425μm,维氏硬度为124.27kgf/mm^2。磷化膜硫酸铜点滴时间为35s,耐盐水时间为8h,耐盐雾时间为4h,其物理性质和耐蚀性能均较佳。 相似文献
986.
A rapid immunochromatographic one-step strip test was developed to specifically determine bromoxynil in surface and drinking water by competitive inhibition with the nano colloidal gold-conjugated monoclonal antibody (mAb). Bromoxynil standard samples of 0.01–10 mg L−1 in water were tested by this method and the visual limit was 0.06 mg L−1. The assay only required 5 min and one-step by dispensing a drop of sample solution onto a strip. Parallel analysis of water samples with bromoxynil showed comparable results from one-step strip test and ELISA. Therefore, the one-step strip test is very useful as a screening method for qualitative detection of bromoxynil in water. 相似文献
987.
改性沸石去除地下水中铁锰实验研究 总被引:2,自引:1,他引:1
测定了2种改性沸石的基本特性,并选取0.6 m层高的交换柱,通过动态试验,研究其分别用于除铁和除锰的工艺性能。实验结果表明,2种沸石质量全交换容量分别为578.2 mmol/kg和722.2 mmol/kg;产水水质均能达到饮用水标准:含铁量≤0.3 mg/L,含锰量≤0.1 mg/L;减少进水中铁锰含量(≤2 mg/L)和降低运行流速(≤20 m/h),都有利于提高工作交换容量,但流速对除铁沸石影响较小;再生剂为1 mol/L的NaCl,再生速率1 m/h条件下,每升除铁沸石再生剂用量为1.2 L,洗脱率(再生废液中目标离子含量与原水中过滤时的去除量之比)达0.95,比耗(再生剂用量与工作交换容量之比)为16,每升除锰沸石再生剂用量为1.6 L,洗脱率达0.8,比耗为16。 相似文献
988.
铬渣污染场地污染状况研究与修复技术分析 总被引:8,自引:1,他引:7
选取某一化工厂铬渣堆放场地作为典型铬渣污染场地,对其钻孔并采集不同深度土壤和地下水样品进行分析。研究发现,该铬渣污染场地存在很严重的土壤和地下水污染。污染物地表扩散较小,剖面扩散很严重,污染深度达6 m,不同特性土壤对六价铬的截留作用不同。在此基础上,归纳总结了国外常用铬渣污染场地修复治理技术的优缺点,并提出具体污染场地修复技术的选取应该根据勘探情况选择合适的某些技术组合。 相似文献
989.
990.
湖南湘潭锰矿区蔬菜及菜园土重金属污染研究 总被引:2,自引:0,他引:2
本文对湘潭锰矿红旗分矿开采区和沙圹村恢复区的部分蔬菜(莴笋叶、小白菜、香葱、空心菜)及菜园土中Mn、Pb、Zn 3种重金属含量进行了测定分析。结果表明:根据国家卫生标准和中国食物成分表,从单因子污染指数看,所有蔬菜Zn(Pi<1)没有超标,除了开采区的香葱受Pb(Pi=1.95)轻度污染和恢复区的小白菜受Mn(Pi=2.54)中度污染外,其他都受重污染;用综合污染指数法评价,所有蔬菜都处于5级污染以上属重污染。开采区菜园土中Mn、Pb、Zn平均含量分别为:40839.5 mg/kg、1993.5 mg/kg、556.5 mg/kg;恢复区菜园土Mn、Pb平均含量则是2893.75 mg/kg、2213.5 mg/kg。用国家土壤环境标准的二级标准(Pb、Zn)和湖南省背景值(Mn)作为参照值,从单因子污染指数看,除开采区菜园土受Zn(Pi=2.26)中度污染外,污染指数均大于3,属重污染,两区菜园土综合污染指数都大于3,所以都处于5级污染以上属重污染,相比之下开采区的要更加严重。 相似文献