Selective sorption of perfluorooctane sulfonate on molecularly imprinted polymer adsorbents

Perfluorooctane sulfonate (PFOS), as a potential persistent organic pollutant, has been widely detected in water environments, and has become a great concern in recent years. PFOS is very stable and difficult to decompose using conventional techniques. Sorption may be an attractive method to remove it from water. In this study, the molecularly imprinted polymer (MIP) adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate (PFOS) from water. The MIP adsorbents using perfluorooctanoic acid (PFOA) as the template had good imprinting effects and could selectively remove PFOS from aqueous solution. The sorption behaviors including sorption kinetics, isotherms, and effect of pH, salt, and competitive anions were investigated. Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast, pH-dependent, and highly selective. The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents. The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations, which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface. The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS. The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.     

高铁酸钾处理废水中硝基苯的研究

本实验以高铁酸钾为水处理剂,对其在废水中的硝基苯的去除进行了研究,考察了高铁酸钾的用量、pH值、反应时间及硝基苯的初始浓度四个影响因素对硝基苯去除率的影响,最终确定了高铁酸钾去除硝基苯的最佳反应条件为：初始pH值为9,高铁酸钾与硝基苯的摩尔比为10：1,反应时间30min,初始浓度小于254．5mg/L时,硝基苯的去除率最佳,达到到6．2％。     

污染源在线监控设施市场化运营之思考

社会化运营是污染源在线监控系统发挥应用价值的基础,国内在线监控设施社会化运营以市场化运营、统一运营和特许经营三种模式为主流,比较三种模式的优势和劣势,形成的结论是大部分城市因缺少相对宽松的政策环境,只能选择市场化运营模式。结合南京市管理实践,着重分析污染源在线监控设施市场化运营所面临的问题,提出了解决设想。     

徒骇河沉积物和沿岸土壤对磷酸盐的吸附动力研究

通过实验模拟的方法,研究了徒骇河沉积物和沿岸土壤对磷酸盐的吸附作用,发现二者均具有较强的对磷酸盐的吸附作用,沉积物的吸附作用强于土壤,沉积物在2h内即可达到吸附平衡,土壤在12h内达到平衡;在中等扰动条件下,随着磷酸盐浓度的上升,沉积物和土壤的磷酸盐吸附容量均明显增加,沉积物的吸附容量大于土壤,这种吸附能力对徒骇河水体的磷酸盐缓冲作用起着积极的作用;徒骇河沉积物和沿岸土壤对磷酸盐的吸附等温曲线符合Langmuir等温吸附方程。     

UV-Fenton法处理中药废水的研究

采用UV-Fenton技术对中药废水进行氧化处理,对主要影响因素及其对废水处理效果的影响进行了实验研究。主要考察了废水pH、H2O2投加量,Fe2＋投加量,Fe2＋/H2O2投加比、温度等对废水中CODcr去除率的影响。实验结果表明,在pH=3.83,H2O2投加量为1倍理论投加量Qth,Fe2＋投加量为7.9×10-3mol.l-1,Fe2＋：H2O2=1：27,23℃的情况下反应80 min后CODcr去除率达到80.25%,UV-Fenton氧化系统对中药废水有比较好的处理效果,改善了废水的可生化性,有利于进一步进行生化处理。     

金川县沙耳干河坝泥石流治理工程研究

金川县境内的沙耳干河坝泥石流沟泥石流活动频繁,暴发频率属于中等。为了减少泥石流灾害的威胁和危害,进行现场踏勘,开展泥石流的治理工程研究,具有重要意义。拦砂坝、谷坊坝、单侧防护堤、排导槽和导流堤等工程对泥石流的预防与治理具有显著作用,采用多种措施相结合的方式相对于单一措施更为有效。在治理工程的建设过程中可能引发相应的环境问题,对其中影响较大的水土流失问题提出防治措施,并进行可行性研究,同时提出实施建议。     

A comparative investigation of NdSrCu_(1-x) Co_x O_(4-δ) and Sm_(1.8) Ce_(0.2) Cu_(1-x) Co_x O_(4-δ) (x:0–0.4) for NO decomposition

A series of single-phase T-structured NdSrCu 1-x Co x O 4-δ with oxygen vacancies and T -structured Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ (x: 0–0.4) with oxygen excess were prepared using ultrasound-assisted citric acid complexing method, and characterized by means of techniques such as thermogravimetric analysis and NO temperature-programmed desorption (NO-TPD). The catalytic activities of these materials were evaluated for the decomposition of NO. It was found that the NdSrCu 1-x Co x O 4-δ catalysts were of oxygen vacancies whereas the Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ ones possessed excessive oxygen (i.e., over-stoichiometric oxygen); with a rise in Co doping level, the oxygen vacancy density of NdSrCu 1-x Co x O 4-δ decreased while the over-stoichiometric oxygen amount of Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ increased. The NO-TPD results revealed that NO could be activated much easier over the oxygen-deficient perovskite-like oxides than over the oxygen-excessive perovskite-like oxides, with the NdSrCuO 3.702 catalyst showing the best efficiency in activating NO molecules. Under the conditions of 1.0% NO/helium, 2800 hr -1 , and 600–900°C, the catalytic activity of NO decomposition followed the order of NdSrCuO 3.702 NdSrCu 0.8 Co 0.2 O 3.736 NdSrCu 0.6 Co 0.4 O 3.789 Sm 1.8 Ce 0.2 Cu 0.6 Co 0.4 O 4.187 Sm 1.8 Ce 0.2 Cu 0.8 Co 0.2 O 4.104 Sm 1.8 Ce 0.2 CuO 4.045 , in concord with the sequence of decreasing oxygen vacancy or oxygen excess density. Based on the results, we concluded that the higher oxygen vacancy density and the stronger Cu 3+ /Cu 2+ redox ability of NdSrCu 1-x Co x O 4-δ account for the easier activation of NO and consequently improve the catalytic activity of NO decomposition over the catalysts.     

Iron-doped Mn-Ce/TiO2 catalyst for low temperature selective catalytic reduction of NO with NH3

The catalysts of iron-doped Mn-Ce/TiO 2(Fe-Mn-Ce/TiO 2) prepared by sol-gel method were investigated for low temperature selective catalytic reduction(SCR) of NO with NH 3.It was found that the NO conversion over Fe-Mn-Ce/TiO 2 was obviously improved after iron doping compared with that over Mn-Ce/TiO 2.Fe-Mn-Ce/TiO 2 with the molar ratio of Fe/Ti = 0.1 exhibited the highest activity.The results showed that 96.8% NO conversion was obtained over Fe(0.1)-Mn-Ce/TiO 2 at 180°C at a space velocity of 50,000 hr 1.Fe-Mn-Ce/TiO 2 exhibited much higher resistance to H 2 O and SO 2 than that of Mn-Ce/TiO 2.The properties of the catalysts were characterized using X-ray diffraction(XRD),N 2 adsorption,temperature programmed desorption(NH 3-TPD and NOx-TPD),and Xray photoelectron spectroscopy(XPS) techniques.BET,NH3-TPD and NOx-TPD results showed that the specific surface area and NH3 and NOx adsorption capacity of the catalysts increased with iron doping.It was known from XPS analysis that iron valence state on the surface of the catalysts were in Fe3+ state.The doping of iron enhanced the dispersion and oxidation state of Mn and Ce on the surface of the catalysts.The oxygen concentrations on the surface of the catalysts were found to increase after iron doping.Fe-Mn-Ce/TiO2 represented a promising catalyst for low temperature SCR of NO with NH3 in the presence of H2 O and SO2.     

活塞式压缩机的降噪治理

对天然气活塞式压缩机产生噪声的原因进行了分析,依据噪声产生机理,提出了相应的治理措施和对策,经过治理,达到了GB12348-90《工业企业厂界噪声标准》Ⅱ级标准,减少了噪声危害;保证了设备的正常操作及维护。     

生物接触氧化+植物一体化装置处理小城镇污水试验研究

利用“生物接触氧化+植物”一体化装置处理城镇污水,试验最终选用悬浮多面球作填料,采用射流曝气,控制进水流量为0.45 m3/h,进水浓度为COD 63～467 mg/L、NH3-N 11.21～52.7 mg/L、TN 28.6 ～63.5mg/L和TP １.1～6.42 mg/L时,COD、NH3-N、TN和TP的去除率分别达到88％、86％、70％、60％以上,出水COD≤30 mg/L,NH3-N≤5 mg/L、TN≤13 mg/L、TP≤0.5 mg/L.水质优于《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准,具有较好的工程应用前景.