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681.
二级活性炭生物流化床深度处理有机胺废水研究   总被引:1,自引:0,他引:1  
采用二级活性炭生物流化床工艺深度处理有机胺废水,研究了有机容积负荷、NH3-N容积负荷以及曝气间歇对COD、NH3-N去除效果的影响.结果表明:当有机容积负荷为0.94~2.38 kg COD/(m3·d)时,二级流化床对COD的去除率为80.6%~95.5%,比一级流化床的抗有机负荷冲击的能力更强;当NH3-N容积负...  相似文献   
682.
Song Y  Wu N  Han J  Shen H  Tan Y  Ding G  Xiang J  Tao H  Jin S 《Chemosphere》2011,85(3):329-334
Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were measured by high resolution gas chromatograph/high resolution mass spectrometer (HRGC/HRMS) in six food groups from Luqiao (LQ) where the e-waste has been recycled and from Yuhang (YH) where the agriculture dominates in Zhejiang Province in China. The total WHO-TEQ values of PCDD/Fs and DL-PCBs in selected foods from LQ were significantly much higher than those from YH. The highest level of the total WHO-TEQ was in crucian carp (10.87 pg g(-1) w.w.) followed by duck (3.77 pg g(-1) w.w.), hen eggs (2.80 pg g(-1) w.w.), chicken (2.43 pg g(-1) w.w.), rice (0.08 pg g(-1) w.w.) and vegetables (0.022 pg g(-1) w.w.) in LQ. By contrast, the highest levels were measured in duck (0.74 pg g(-1) w.w.) followed by hen eggs (0.69 pg g(-1) w.w.), crucian carp (0.55 pg g(-1) w.w.), chicken (0.44 pg g(-1) w.w.), vegetables (0.002 pg g(-1) w.w.) and rice (0.0002 pg g(-1) w.w.) in YH, respectively. The monthly intake of PCDD/Fs and DL-PCBs for the local residents was 401.75 pg WHO-TEQ g(-1) w.w. in LQ, which is above the provisional tolerable monthly intake (PTMI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). We determined a monthly intake of 37.13 pg WHO-TEQ g(-1)w.w. in YH, which is below the PTMI. Crucian carp was the predominant contributor to the estimated monthly intake (EMI), accounting for 67.74% and 36.51% in LQ and YH, respectively. High levels of PCDD/Fs and DL-PCBs in selected foods indicate severe contamination of these pollutants in the e-waste recycling site.  相似文献   
683.

Introduction  

The influence of sintering temperature on the physico-mechanical characteristics (such as water absorption, apparent porosity, bulk density, weight loss on ignition, firing shrinkage, and compressive strength), leachability, and microstructure of shale brick containing oil well-derived drilling waste (DW) was investigated.  相似文献   
684.
V/Ce共掺杂TiO2光催化降解甲醛的实验研究   总被引:1,自引:0,他引:1  
采用溶胶-凝胶法制备了不掺杂、V掺杂、Ce掺杂、V/Ce共掺杂纳米TiO2光催化剂,并将其分别负载于瓷砖上,利用X射线衍射分析(XRD)和扫描电镜分析(SEM)技术对薄膜样品的结构和形貌进行了表征。通过对甲醛的降解实验评价光催化剂的光催化活性。实验结果表明,光催化剂的负载量、共掺杂离子的掺杂量、掺杂配比、煅烧温度影响纳米TiO2的光催化活性。V/Ce共掺杂TiO2光催化剂产生了协同效应,其光催化活性优于纯TiO2和单掺杂TiO2样品。  相似文献   
685.
基于职业病报告数据的监测预警系统设计   总被引:3,自引:0,他引:3  
为了对单病种职业病的预防控制水平、某类职业病的预防控制水平进行动态评估和决策,运用信息监测预警的基本原理和理论,整理分析职业病报告数据,提出基于职业病报告的监测预警指标体系,构建出基于职业病报告数据的监测预警体系和运行模式。通过该监测预警系统的运行,可以科学的判断出应重点控制的职业病种(发病率高、发病工龄短、潜伏期短、病死率高、后果严重的职业病),应重点控制的高危地区、高危行业、高危工种、高危人群,针对具体职业病病种应重点控制的影响因素等。  相似文献   
686.
Tan J  Loganath A  Chong YS  Obbard JP 《Chemosphere》2009,74(3):428-433
Persistent organic pollutants (POPs) have the capacity to pass through the placental barrier and into the fetal blood stream, and pose health risks to fetuses and neonates who are believed to be more vulnerable to the effects of environmental pollutants. In this study, the prevalence of POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs), were determined in 41 cord blood samples collected during the year 2006 in Singapore. The effects of these xenobiotics and the maternal characteristics on fetal growth and development were explored using multivariate data analysis (MVA) techniques, including partial least-squares regression (PLSR) and discriminant analysis (PLS-DA). POPs were found in all cord blood samples, corroborating the transplacental transfer (TPT) of these xenobiotics. Chlordanes and PCBs were observed to have adverse effects on fetal growth (i.e. birth weight, length, head circumference) and health (as indicated by Apgar scores), indicating the chemical exposure in utero could also be deemed as an influential factor on fetal growth, even at the normal doses in general population. Maternal height, weight, ethnicity, dietary habits and lifestyle were also the determinants for the neonatal variables. Exposure to POPs may alter maternal hormone levels, which could regulate the offspring sex. Trans-chlordane, p,p'-DDE, p,p'-DDT and PCB 138 and 158 were speculated as testosterone triggers which lead to more baby boys, while the effects of beta-HCH and PCB 180 were opposite.  相似文献   
687.
Aqueous OH radical oxidation of methylglyoxal in clouds and wet aerosols is a potentially important global and regional source of secondary organic aerosol (SOA). We quantify organic acid products of the aqueous reaction of methylglyoxal (30–3000 μM) and OH radical (approx. 4 × 10?12 M), model their formation in the reaction vessel and investigate how the starting concentrations of precursors and the presence of acidic sulfate (0–840 μM) affect product formation. Predicted products were observed. The predicted temporal evolution of oxalic acid, pyruvic acid and total organic carbon matched observations at cloud relevant concentrations (30 μM), validating this methylglyoxal cloud chemistry, which is currently being implemented in some atmospheric models of SOA formation. The addition of sulfuric acid at cloud relevant concentrations had little effect on oxalic acid yields. At higher concentrations (3000 μM), predictions deviate from observations. Larger carboxylic acids (≥C4) and other high molecular weight products become increasingly important as concentration increases, suggesting that small carboxylic acids are the major products in clouds while larger carboxylic acids and oligomers are important products in wet aerosols.  相似文献   
688.
高价铬及双酚A在铁-乳酸体系中的同时光处理   总被引:1,自引:0,他引:1  
研究了Fe(Ⅲ)-乳酸配合物体系同时对Cr(Ⅵ)的光还原及双酚A(BPA)的光氧化处理,考察了光源、初始pH值、Fe(Ⅲ)、乳酸盐、Cr(Ⅵ)及BPA初始浓度等因素对Cr(Ⅵ)及BPA光处理效率的影响。结果表明:光照条件下,铁-乳酸配合物能有效实现对六价铬及BPA的同时光处理。同一体系中,Cr(Ⅵ)的光还原快于BPA的光氧化,Fe(Ⅲ)初始浓度的增加可同时提高Cr(Ⅵ)的光还原效率和BPA的光氧化效率;Fe(Ⅲ)-乳酸盐配合物光解产生的Fe(Ⅱ)是Cr(Ⅵ)的主要还原剂,其次级光反应中产生的.OH是BPA的氧化剂。  相似文献   
689.
软锰矿-污泥活性炭的制备及其对废水中铅离子的吸附   总被引:4,自引:2,他引:2  
以城市污水处理厂的剩余污泥为原料,掺杂一定量的软锰矿,采用氯化锌活化法制备一种软锰矿-污泥活性炭,并运用比表面积测定、电镜扫描、红外光谱分析及O2-TPO等表征手段对软锰矿-污泥活性炭及纯污泥活性炭进行了结构特性的比较分析,证明添加软锰矿将污泥活性炭的比表面积提高52.33%,是由于在制备过程中软锰矿催化了污泥中有机质的分解,同时也为新生炭提供了更多的骨架,促进了积炭反应的发生。软锰矿-污泥活性炭和纯污泥活性炭对废水中铅离子的吸附实验表明:当Pb2+初始浓度为40 mg/L、pH为5.0、活性炭用量为2 g/L、吸附时间为1 h时,软锰矿-污泥活性炭对废水中Pb2+的去除率可达88%,效果明显优于纯污泥活性炭。常温下软锰矿-污泥活性炭对Pb2+的吸附符合Lang-muir吸附等温式。  相似文献   
690.
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