我国造纸行业清洁生产的思路及案例分析

在分析我国造纸行业的污染现状及治理现状的基础,雌出了造纸行业清洁生产的初步思路框架，在该清洁生产思路的指导下，以茂名市造纸厂为案例进行了较为详细的分析，最后，提出了我国造纸行业实施可持续发展的战略措施。     

沉积物中多环芳烃和有机氯农药定量分析的质量保证和质量控制

以美国ＥＰＡ为方法为基础,进行了沉积物中多环芳烃和有机氯农药分析的质量保证和质量控制实验,采用回收率指示物控制回收率,用内标法定量。结果表明多环芳烃的指示物回收率为５０．６７－９７．３３％,目标化合物的回收率为５８．６７－９６．３３％,方法检测限为３．３０－９．２６μｇ．ｋｇ＾－１。     

Polychlorinated biphenyls and organochlorinated pesticides in birds from a contaminated region in South China: association with trophic level,tissue distribution and risk assessment

Purpose  

Birds have been used successfully for biomonitoring of the levels and effects of persistent organic pollutants (POPs) in the environments; however, there is exceedingly little data on organochlorinated pesticide (OCPs) and polychlorinated biphenyls (PCBs) residues in bird inhabiting in China. In the present study, we detected the concentrations of PCBs, dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorocyclohexanes (HCHs) in muscle, liver and kidney of birds that inhabit in an e-waste recycling site. Associated with the stable isotope ratio (δ ¹⁵N), we investigated the effect of trophic level on the body burdens of persistent contaminants in birds. The tissue distributions of contaminants in these birds were examined, and a preliminary risk assessment was also conducted.     

Tissue distribution of Dechlorane Plus and its dechlorinated analogs in contaminated fish: high affinity to the brain for anti-DP

Information on tissue distribution of Dechlorane Plus (DP) and its dechlorinated analogs in wildlife is scarce. DP isomers and two dechlorinated compounds, anti-Cl₁₁-DP and anti-Cl₁₀-DP, were examined in the muscle, liver, and brain tissues of two bottom fish species collected from an electronic waste recycling site, South China. The median levels of syn-, anti-, and anti-Cl₁₁-DP isomers in the tissues ranged 0.18-39.1, 0.22-52.9, and 0.01-5.63 ng/g wet wt, respectively. Anti-Cl₁₀-DP was only detected in one muscle sample of mud carp (0.01 ng/g wet wt), although it was consistently detected in the sediments (0.42-0.83 ng/g dry wt). Preferential distribution in liver relative to muscle was observed for syn-DP and anti-Cl₁₁-DP. However, a high persistent retention in the brain compared to the liver was observed for anti-DP, suggesting that this isomer can across the blood-brain barrier of fish, and may cause adverse effects to the nervous system in the exposed biota.     

Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China

Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6-1658 ng/g, while concentrations of PCBs are in the range 10-339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812 ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic condition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment.     

Distribution of alkylphenols in the Pearl River Delta and adjacent northern South China Sea, China

The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.     

Role of the floodplain lakes in the methylmercury distribution and exchanges with the Amazon River, Brazil

Seasonal variability of dissolved and particulate methylmercury(F-MeHg, P-MeHg) concentrations was studied in the waters of the Amazon River and its associated Curuai floodplain during hydrological year 2005–2006, to understand the MeHg exchanges between these aquatic systems. In the oxic white water lakes, with neutral pH, high F-MeHg and P-MeHg concentrations were measured during the rising water stage(0.70 ± 0.37 pmol/L, n = 26) and flood peak(14.19 ± 9.32 pmol/g, n = 7) respectively, when the Amazon River water discharge into the lakes was at its maximum. The lowest mean values were reported during the dry season(0.18 ± 0.07 pmol/L F-MeHg, n = 10 and 1.35 ± 1.24 pmol/g P-MeHg, n = 8), when water and suspended sediments were outflowing from the lakes into the River. In these lakes,the MeHg concentrations were associated to the aluminium and organic carbon/nitrogen changes. In the black water lakes, with acidic pH and reducing conditions, elevated MeHg concentrations were recorded(0.58 ± 0.32 pmol/L F-MeHg, n = 16 and 19.82 ± 15.13 pmol/g PMeHg, n = 6), and correlated with the organic carbon and manganese concentrations. Elevated values of MeHg partition coefficient(4.87 Kd 5.08 log(L/kg) indicate that MeHg is mainly transported associated with the particulate phase. The P-MeHg enrichment detected in all lakes suggests autochthonous MeHg inputs from the sediments into the water column. The MeHg mass balance showed that the Curuai floodplain is not the source of P-MeHg for the Amazon River.     

扶梯乘员坠落的法律归责思考与对策

扶梯乘员坠落事故已经发生多起,如何进行相关风险的辨析并提出防范对策,是电梯从业者难以回避的课题.本文试从生产者、经营管理者之角度就此课题进行“归责”与“对策”的辨析与思考,希冀关注者有所借鉴,防范已经存在或可能发生的风险.     

溶解氧对固定气体流量曝气系统亚硝化特性的影响

通过实时控制系统并结合其他工艺参数的调控,在SBR系统中实现了垃圾渗滤液短程硝化过程的快速启动,并在稳定期考察了固定气体流量曝气系统中溶解氧(DO)对短程硝化的影响。结果表明:在线监测p H的"氨谷"可判断氨氧化反应的终点;采用固定气体流量的曝气方式,使得单周期好氧段后期ρ(DO)高达7.95 mg/L,出水亚硝态氮积累率维持在98.3%左右,氨氮去除率高达96.5%;好氧段后期高溶解氧并没有导致硝化菌(NOB)的再次增长,短程硝化系统稳定。