A novel dismantling process of waste printed circuit boards using water-soluble ionic liquid

Recycling processes for waste printed circuit boards (WPCBs) have been well established in terms of scientific research and field pilots. However, current dismantling procedures for WPCBs have restricted the recycling process, due to their low efficiency and negative impacts on environmental and human health. This work aimed to seek an environmental-friendly dismantling process through heating with water-soluble ionic liquid to separate electronic components and tin solder from two main types of WPCBs—cathode ray tubes and computer mainframes. The work systematically investigates the influence factors, heating mechanism, and optimal parameters for opening solder connections on WPCBs during the dismantling process, and addresses its environmental performance and economic assessment. The results obtained demonstrate that the optimal temperature, retention time, and turbulence resulting from impeller rotation during the dismantling process, were 250 °C, 12 min, and 45 rpm, respectively. Nearly 90% of the electronic components were separated from the WPCBs under the optimal experimental conditions. This novel process offers the possibility of large industrial-scale operations for separating electronic components and recovering tin solder, and for a more efficient and environmentally sound process for WPCBs recycling.     

Possible alkylation of inorganic Hg(II) by photochemical processes in the environment

Contamination of surface waters by pesticides continues to be the focus of concern for water authorities due to the growing evidence of their deleterious effects on aquatic life. In this context, the present work investigates the occurrence of 16 selected pesticides belonging to the classes of triazines, phenylureas, organophosphates, chloroacetanilides and thiocarbamates in surface waters from the Llobregat River (NE Spain) and some of its tributaries (Anoia and Rubí) and assesses their potential impact on the aquatic organisms by applying a recently developed index, the Short-term Pesticide Risk Index for the Surface Water System (PRISW-1), which takes into account the pesticides concentrations and their overall toxicity against three aquatic organisms (algae, Daphnia, and fish). Chemical analysis, performed by means of a fully automated method based on isotope dilution on-line solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (on-line SPE-LC-ESI-MS/MS), revealed diuron and diazinon as the most ubiquitous and abundant compounds with levels up to 818 and 132 ng L⁻¹, respectively. Total pesticide concentrations, which in only 1 out of 66 samples surpassed 500 ng L⁻¹, were higher in the tributaries than in the river but their contribution in terms of mass-loads to the overall pesticide pollution of the Llobregat River was relatively small. Contamination increased downstream of the river and was clearly influenced by rainfall and hence river flow. Application of the PRISW-1 index indicated that, although pesticides levels fulfilled the European Union Environmental Quality Standards (EQS) for surface waters, the existing pesticide contamination poses a low to high ecotoxicological risk for aquatic organisms, that algae and macro-invertebrates are at higher risk than fish, and that the organophosphates diazinon and malathion and the phenylurea diuron are the major contributors to the overall toxicity and therefore the most problematic compounds.     

Halogenated organic contaminants (HOCs) in sediment from a highly eutrophicated lake, China: Occurrence, distribution and mass inventories

Halogenated organic contaminants (HOCs) including 16 polybrominated diphenyl ethers (PBDEs) and 37 polychlorinated biphenyls (PCBs) were determined in 49 surfacial sediments from Chaohu Lake, a highly eutrophicated lake, China. PBDEs were detected in almost samples with the range of the total concentration (defined as Σ₁₆PBDEs) from 0.84 to 86.6 ng g⁻¹. Compared with the occurrence of PBDEs in Pearl River Delta and Yangtze River Delta in China, lower percentage of BDE-209 over the concentration of Σ₁₆PBDEs was inferred by the high-volume application of penta-BDE mixture product for local domestic furniture purpose. The total concentration of 37 PCBs (Σ₃₇PCBs) ranged from 0.05 to 3.36 ng g⁻¹ with the most detection of PCB-1, -4, -52 and -71. Both the concentrations of Σ₁₆PBDE and Σ₃₇PCB poorly correlated with total organic carbon (TOC), suggesting the significant contribution of phytoplankton organic carbons to sediment TOC. The contamination by PBDEs and PCBs in western region of the lake was significantly more serious than in eastern lake. Our findings about the higher residues of PBDEs and PCBs in sediments at the estuary of Nanfei River compared to the other estuaries also supported the conclusion that urban area (Hefei city) was the main source of PBDEs and PCBs. The comparison with the concentration of HOC in the present study with those in other lacustrine sediments around the world suggested the contamination by PBDEs in Chaohu Lake is at middle of the global concentration range, whereas PCBs is at low end of the global range which could be elucidated by local economic development and historical usage of PBDEs and PCBs. The mass inventories of HOCs in the lake were estimated at 561 and 38 kg, which corresponds to only 0.000006% and 0.0001% of these global historical produce volumes, respectively.     

固相萃取-高效液相色谱-质谱联用法用于地表水中类固醇激素测定

建立了固相萃取-高效液相色谱-质谱联用法对雌三醇、氟哌噻吨、炔雌醇、雄烯二酮、雌二醇、雌酚酮、睾酮共7种类固醇激素的检测方法。样品经C18萃取小柱富集净化,采用内标法定量时,方法的检出限为0.66～1.95 ng/L,R0.998,回收率为78.5%～94.6%,相对标准偏差为1.1%～7.7%。采用该方法对上海市地表水进行测定,在2个采样点中检出雌酚酮(1.88 ng/L)和雄烯二酮(1.48 ng/L)。     

流动注射梯度稀释法在原子吸收分析中的应用

提出了应用流动注射梯度稀释法与原子吸收光度法相结合,样品不经稀释便可同时测定酸雨中不同浓度的钙。方法快速简便。     

Erroneous mass transit system and its tended relationship with motor vehicular air pollution (An integrated approach for reduction of urban air pollution in Lahore)

Air pollution is threat to the lives of people living in big cities of Pakistan. In Lahore 1,250 people die annually because of air pollution.Mass transit system that can be put forth as solution to urban air pollution is contingent with right choice of system and its affiliation with motorized vehicles and nature of urban air pollution.Existing mass transit system in Lahore due to untrue operation causes surfeit discharge of motor vehicular carbon monoxide. Tended relationships of mass transit system with motorized vehicles and urban air pollution are quite noteworthy. The growing motor vehicles (a consequence of flawed public mass transit system) are potential source of urban air pollution. This paper attempts to highlight correlations and regression curves of existing mass transit system. Further it recommends a two facet approach for reduction of motor vehicular air pollution in Lahore.     

异丙醇增感电感耦合等离子体质谱法直接测定土壤和沉积物中硒

提出了沸水浴混合酸法消解,以异丙醇为增感剂,电感耦合等离子体质谱直接测定土壤和沉积物中硒的方法。实验表明2mol/L硝酸-4mol/L盐酸混酸能有效溶出土壤和沉积物中各种形态的硒。相对于1%硝酸基体,4%(V/V)异丙醇基体中硒的ICP-MS响应值提高了12.1倍;而且4%(V/V)异丙醇基体可有效抑制硒的质谱干扰。ICP发射功率和雾化气流速是影响异丙醇在ICP-MS测定过程增敏效应的主要因素。以78硒为测定同位素,方法检出限为0.005mg/kg,实际样品测定精密度均小于5%。用于测定土壤和沉积物国家标准样品并对其消解液进行加标回收实验,结果令人满意。     

土壤中挥发性有机物的快速测定方法

本文建立了用便携式气相色谱-质谱仪快速测定土壤中VOCs的方法。该方法能够快速对土壤样品中VOCs进行定性分析和定量测定。当采样量达到5 g时,方法检出限0.02~2.11μg/L,相对标准偏差2.0%~13.5%;加标20μg/L时,回收率63%~123%。采用该方法测定北京地区5个土壤样品,总体质量浓度为0~873μg/kg。     

He mass spectrometry for very low-level measurement of organic tritium in environmental samples

The design, setup and performance of a mass spectrometric system for the analysis of low to very low-level tritium in environmental samples are described. The tritium concentration is measured indirectly by the ³He ingrowth from radioactive decay after complete initial degassing of the sample. The analytical system is fully computer-controlled and consists in a commercial helium isotope mass spectrometer coupled with a high vacuum inlet system. A detection limit of 0.15 Bq/kg is routinely obtainable for sample sizes of 20 g of water equivalent and an accumulation time of three months. Larger samples (and/or longer accumulation time) can be used to obtain lower detection limits. In addition to the benefit of a lower detection limit, another advantage of this non-destructive method lies in the simplicity of the analytical procedure which strongly limits the risk of contamination. An inter-comparison was successfully performed with the conventional beta counting technique on lyophilized grass samples, in a range of tritium concentrations of environmental interest. It shows that the ³He mass spectrometry method yields results that are fully consistent with the conventional liquid scintillation technique over a wide range of tritium concentrations.     

气相色谱/质谱联用法测定饮用水源水中苯胺类化合物

采用液液萃取-气相色谱/质谱联用法测定饮用水源水中19种苯胺类化合物,选择DB-5MS色谱柱,讨论了pH值对回收率的影响.方法在0.500 mg/L～5.00 mg/L范围内线性良好,19种苯胺类化合物的检出限为0.016μg/L～0.067 μg/L,标准溶液平行测定的RSD为1.2％ -13.2％,实际样品加标回收...