Adsorption of oil from waste water by coal:characteristics and mechanism

The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.This allowed economical and highly efficient separation of oil from the waste water.The absorption time,coal type,coal particle size distribution,pH value and oil concentration were investigated.The results indicate that oil absorption by a coal increases for a period of 1.5 h and then gradually tends toward an equilibrium value.It appears that the absorption capacity of anthracite is more than that of lean coal or lignite,given the same coal particle size distribution.The absorption capacity of a coarse coal fraction is less than that of finer coal,given the same of coal type.The absorption capacity of anthracite decreases slightly as the pH increases from 4 to 9.The adsorption of oil on anthracite follows the Freundlich isothermal adsorption law:given initial oil concentrations of 160.5 or 1023.6 mg/L the absorption capacity was 23.8 or 840.0 mg/g.The absorption mechanism consists of two kinds of absorption,a physical process assisted by a chemical one.

Influence of monovalent cations and CuO nanoparticles on X-nanozeolite in uranium anionic species separation from contaminated drinking water

The main purpose of this work was the modification of NaX nanozeolite using copper oxide nanoparticles and various monovalent cations such as K^+, Cs^+, and Ag^+in order to make the negatively charged zeolite surface accessible for anionic forms of uranium which are the most dominant species of uranium in the contaminated radioactive waters at natural p H. Various methods such as the X-ray fluorescence(XRF), X-ray powder diffraction(XRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR), and atomic absorption spectroscopy(AAS) were used to characterize the final synthesized absorbents. Batch technique was used to study the adsorption behavior of uranium ions from polluted drinking water by Na X nanozeolite and its modified forms. In order to better understand the performance of them, the results were compared with those that were obtained for synthesizing bulk NaX zeolite and Na-form of clinoptilolite natural zeolite. Preliminary results indicated that uranium sorption increased as the loading level of CuO nanoparticles on NaX nanozeolite increased from 2.1 wt% to 11.2 wt%. In addition,from the obtained data, an increase in uranium removal efficiency resulted as charge/ionic radius ratio of exchanged cation decreased. Also, the effect of contact time, solid–liquid ratio, initial concentration and temperature on the adsorption process was studied. It is worth mentioning that, in this study, the sorption of uranium was performed under natural conditions of pH and the presence of competing cations and anions which are available in drinking waters.

Swedish Experience and Excellence in Wastewater Treatment Demonstrated Especially in Phosphorus Removal

Water quality protection in Sweden has a more than 80-year history. The needed knowledge has by large been imported. Now, to some extent the development of phosphorus removal technology may be Swedish contribution to advanced knowledge. This paper presents the development in Sweden, mainly a close to 50-year period. Starting in the late 1960s, a standard of <0.5 mg P/l was the normally raised effluent criteria, regardless of the magnitude of the discharge flow. The successive sharpening of the discharge levels has today resulted in a level of 0.2 to 0.3 mg P/l typically. As a matter of fact, even levels of 0.1 to 0.15 mg P/l have been discussed. The period should a large extent demonstrated both improved technologies and a far better efficiency with respect to the use of chemicals and energy. Some important points in this development may be the understanding of the Oxygen Consumption Potential, as well as the identified needs for an improved nitrogen removal. Lately the problems of complex pollution agents and predominantly the remains of pharmaceutical agents have been identified. To illustrate the development during the 50-year period, two examples are presented from the Swedish context. The main conclusion in this paper is that the Swedish history on phosphorus removal illustrates how empirical science in practice sometimes works, including a never-ending need for an open mind and a readiness to take revised and improved knowledge on board.

Extraction of Amino-J Acid from Waste-water by Emulsion Liquid Membrane

The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.

Assessment of Pollutants in Wet and Dry Depositions in a Suburban Area around a Waste-to-Energy Plant (WEP) in Northern Italy

Atmospheric concentrations of many trace elements are significantly affected by human activities, and their quantification in atmospheric deposition can be useful to ascribe to different sources of pollution. An important source of pollution, which creates concern in the inhabitants of neighboring areas, are waste-to-energy-plants, that nonetheless are necessary in the actual management of municipal solid waste. For this reason the waste-to-energy (WEP) plant of Bologna (Italy) was monitored from 2006 to 2008, collecting rainfall water in 6 sites around it. Moreover, dry deposition of pollutants was determined after leaching from leaves, with four samples collected during 2007. Trace elements were analyzed using spectrometry, deposition and fluxes were calculated. Results show that there is a large variability of concentrations of trace elements both in time and space. Moreover, the pollution in the area is quite diffused, with no clear determination of the role of the WEP. As a general remark, elements and trace elements found both in rainfall water and in leaching water from leaves showed a diffused pollution in all the monitored sites, probably due to the WEP but also to industrial/commercial area, large constructions and high traffic roads. In any case the values found in the area are comparable to values detected in similar area all over the world.

Field Utilization of Dried Water Hyacinth for Phosphorous Recovery from Source-Separated Human Urine

This research demonstrated the feasibility of converting source-separated human urine into a solid fertilizer by means of continuous absorption and solar thermal evaporation using dried water hyacinth as adsorbent. In a preliminary experiment, the dried petioles of water hyacinth (DWH) absorbed urine in a mean rate of 18.78 ml·g-1 within 7 d, retrieving about 3.46% urine dissolved solids (UDS). In an advanced experiment, the DWH’s capacity of urine absorption declined from an initial 2.73 L·kg-1·d-1 to 0.68 L·kg-1·d-1, with a requirement of material change in about 25 effective days and an average ratio of 25 (L) to 1 (kg). Phosphorus (P2O5) concentration in the adsorbent increased from 0.46% (material baseline) to 3.14% (end product), suggesting a satisfactory recovery of the element. In field application, the urine was discharged, not in wet weather, onto the DWH via a tube connected to a waterless urinal. There are several ways to use the UDS-DWH as P(K)-rich fertilizer, e.g., making soluble fertilizer for foliage spraying to encourage prolific flowering and fruiting. Apparently, utilization of water hyacinth waste to recover dissolved plant nutrient elements from source-separated urine will benefit the environment in a wide range of perspectives. The herein innovative use of water hyacinth is also expected to be useful in the recycling of certain dissolved hazardous materials.

基于响应面法的气浮旋流分离条件优化

随着油气工业的大规模发展,含油污水引发的环境问题日益严重,气浮旋流技术作为一种高效的分离方法得到广泛应用。为了进一步提高该技术的分离效果,利用实验方法对微气泡密度、旋转角速度、絮凝剂种类与浓度进行了单因素实验,利用响应面法对几种因素的组合进行了优化。单因素研究发现最优条件为:微气泡密度2.88×10^(4)个/ml、旋转角速度460 r/min,絮凝剂PAFC的分离效果较好。响应面法分析结论是X1、X3与3个变量的交互作用影响显著,最优组合:微气泡密度为2.47×10^(4)个/ml,旋转角速度为440 r/min,絮凝剂PAFC浓度为40 mg/L。

高含水钻井固废超细颗粒过滤分离实验研究

针对钻井固废处理的难点在于其含有大量10μm以下的超细颗粒难以分离问题,结合振动筛分和深层过滤处理方法,从减少整体固相含量和分离超细颗粒出发,开发了一种能有效去除高含水钻井固废中超细颗粒的新型处理方法。结果表明,在优选工艺参数下,高含水钻井固废经过振动筛分处理后,10μm以上的较大颗粒被去除,固相含量从30.42%降低至9.55%。筛下液再经过深层过滤处理,92.77%的超细颗粒被去除。研究结果表明,新型处理方法对高含水钻井固废超细颗粒有良好的去除效果,有利于实现高含水钻井固废回收利用要求。

绿色纤维素基水凝胶膜的制备及油水分离性能

以杨木粉(PF)中提取的纤维素木浆(PF-NA)为基底,通过冷冻盐析技术,利用聚乙烯醇(PVA)将LiCl颗粒包裹在纤维素骨架上制备了纤维素基(CLH)水凝胶膜。采用FTIR、SEM、XRD、XPS对CLH水凝胶膜进行了表征,对其机械、高温、耐酸碱和耐盐稳定性、自清洁和耐污性进行了测试。结果表明,CLH水凝胶膜具有三维层状结构,PVA的加入及冷冻盐析技术的利用提高了CLH水凝胶膜的力学性能。LiCl作为吸水单元分布在纤维素骨架周围,使CLH水凝胶膜具有超亲水性,水下油接触角为151°;在重力作用下,CLH水凝胶膜可以实现对油水混合物和水包油乳液的高效分离,在高温(60℃)、强酸(pH=3)和强碱(pH=13)条件下具有稳定的分离效率(≥99.8%);在循环分离12次水包机油乳液中,CLH水凝胶膜保持稳定的分离性能;CLH水凝胶膜对四氯乙烯油渍具有自清洁和耐污能力。

Highly hydrophobic oil−water separation membrane: reutilization of waste reverse osmosis membrane

The increasing applications of seawater desalination technology have led to the wide usage of polyamide reverse osmosis membranes,resulting in a large number of wasted reverse osmosis membranes.In this work,the base nonwoven layer of the wasted reverse osmosis membrane was successfully modified into the hydrophobic membrane via surface deposition strategy including TiO_(2) and 1H,1H,2H,2H-perfluorooctyltrichlorosilane(PFOTS),respectively.Various techniques were applied to characterize the obtained membranes,which were then used to separate the oil–water system.The optimally modified membrane displayed good hydrophobicity with a contact angle of 135.2°±0.3°,and its oil–water separation performance was as high as 97.8%.After 20 recycle tests,the oil–water separation performance remained more than 96%,which was attributed to the film adhesion of the anchored TiO_(2) and PFOTS layer on the surface.This work might provide a new avenue for recycling the wasted reverse osmosis membrane used in oily wastewater purification.

壳聚糖及其改性膜的研究进展及在水处理领域的应用

壳聚糖及其衍生物具有功能基团丰富、化学活性强、亲水性高、易从可再生资源中获得等优势,是去除水体中杂质的理想材料。由于分子内和分子间的氢键作用、范德华力以及分子的规整性使壳聚糖易成膜,将壳聚糖与膜分离技术结合制备抗污染性能强、选择特异性高、活性吸附位点丰富、稳定性强且具有良好再生能力的壳聚糖膜,并应用在废水处理领域成为国内外学者研究的热点。本文围绕壳聚糖及其改性膜的研究进展及在废水处理上的应用进行综述,分别从壳聚糖作为成膜基质和膜表面修饰材料两个方面进行详细介绍。总结了共混改性、交联改性、印迹改性以及新型的磁性纳米粒子负载改性、表面等离子体改性、MOFs改性等改性方法对壳聚糖膜性能的影响及在水处理中的应用效果,最后对壳聚糖膜在分离领域的发展方向进行了展望。

膜分离工艺技术在制浆造纸废水处理中的应用分析

膜分离技术作为一种物理分离工艺,具有高效、环保的特点在多领域具有广泛的应用。制浆造纸废水中含有大量的有机物以及悬浮固体物质,传统的废水处理工艺难以对其进行有效的分离。从膜分离技术原理、优势入手分析,介绍了制浆造纸废水处理的现状以及膜分离技术在制浆造纸废水处理中的应用要点以及应用前景,旨在实现对制浆造纸废水的净化处理,减轻对环境的不良影响。

镧离子插层MoS_(2)膜的制备及印染高盐水处理

二维材料具有独特的层状结构、稳定的物理化学性质等特点。近年来,由二维材料层层堆叠构成的二维膜在膜分离领域展示了非同凡响的应用潜力。本文采用成膜中共混方法将La^(3+)插入到MoS_(2)膜层间,利用原子力显微镜(AFM)和X射线光电子能谱仪(XPS)技术表征了MoS_(2)片层结构和成分;利用扫描电镜(SEM)和X射线衍射仪(XRD)技术表征了膜结构与层间距;通过加压过滤装置和渗透装置考察了La^(3+)-MoS_(2)膜的渗透截留性能。实验结果表明,La^(3+)插层改性后的MoS_(2)膜由于层间距增加而显著地提高了纯水通量,La^(3+)-MoS_(2)膜的纯水通量相较于MoS_(2)膜提高了约18.5倍。La^(3+)-MoS_(2)膜对分子量300~800g/mol染料表现出了基于空间位阻理论的截留作用,对金属离子(Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)表现出了基于Donnan排斥理论的截留作用。重复性实验中,La^(3+)-MoS_(2)膜对Na^(+)的截留率仍能维持在95%以上,表现出了良好的性能稳定性。

废弃泥浆絮凝脱水试验研究

进行絮凝处理是目前废弃泥浆实现快速脱水减量的主要处理方法或者主要工序之一.然而由于各地泥浆性质差异较大,需要通过絮凝试验先初步确定合理的絮凝剂和最优的添加量.针对某隧道工程中产生的废弃泥浆,采用多种絮凝剂开展泥浆絮凝试验,确定最优絮凝及其添加量,并基于上清液水质及粒径分布变化规律探讨了不同絮凝剂的絮凝机理.结果表明:有机高分子类PAM絮凝剂对废弃泥浆具有较好的快速泥水分离效果,絮凝5 min时,泥浆的含水率就能达到220%左右,而添加无机絮凝剂时,泥浆絮凝1 h后,其含水率仍然在500%左右.综合比较,阳离子型PAM为最优絮凝剂,最佳添加量为0.2%,经其分离的上清液中,pH值与SS含量均满足《城镇污水处理厂污染物排放标准》的对应排放标准;相比于无机絮凝剂,有机高分子絮凝剂的吸附架桥与网捕作用能够促进泥浆颗粒聚集成粒径更大团粒.

粉煤灰基A型沸石的制备与应用进展

我国能源消费结构以煤为主,煤炭的大量燃烧产生数量庞大的固体废弃物粉煤灰,粉煤灰的长期堆积不仅占用土地资源而且会带来严重的污染问题。简要介绍了粉煤灰的物理化学性质、A型沸石的结构特点,从粉煤灰基A型沸石的合成与应用两方面进行综述及展望。粉煤灰的主要成分为SiO_(2)、Al_(2)O_(3),是合成沸石的理想原材料。粉煤灰基A型沸石具有优秀的阳离子交换能力与吸附性能,在废水处理、吸附分离气体等方面有良好的应用前景。此外粉煤灰基A型沸石还能在建筑建材领域中发挥独特的作用。虽然粉煤灰基A型沸石的性能良好、应用较广,但是存在将合成规模扩大化、将实验室研究成果应用到实际工厂中等方面的问题,需要进一步的研究。

废旧海绵的改性及其油水分离回收性能的研究

为有效去除废水中的油污,采用溶剂热法制备了Fe3O4纳米颗粒;以废旧聚氨酯海绵为载体,纳米Fe3O4在多巴胺的聚合作用下附着在海绵的骨架上,然后用硬脂酸处理,使海绵获得超疏水性。通过扫描电子显微镜和X射线衍射仪对磁性超疏水海绵(PU@Fe3O4@PDA@SA)进行形貌及晶型结构表征。PU@Fe3O4@PDA@SA海绵表现出优越的超疏水性和98.3%的回弹率。在外加磁场的驱动下,磁性超疏水海绵可快速吸附水中的油性物质,其中对大豆油-水混合物的分离效率达到98.5%,表现出良好的油水分离能力。此外,PU@Fe3O4@PDA@SA海绵可实现连续的油水分离作业,且在循环利用150次后仍保持良好的疏水性和油水分离能力。

改性废弃口罩熔喷布疏水膜的制备及油水分离性能

通过原位化学沉积在废弃口罩熔喷布表面负载均匀分散的二氧化硅(SiO_(2))纳米颗粒,进而接枝十八烷基三氯硅烷(OTS),得到具有多级粗糙结构的疏水膜。改性膜的水接触角达到142.5°,重力作用下四氯化碳通量达到12224 L·m^(-2)·h^(-1),油水分离效率大于98%。结果表明改性膜能够在酸性、碱性、盐溶液以及超声等条件下保持性能稳定,具有很好的应用前景,为废弃口罩的绿色、低碳、资源化利用提供了新思路。

水基钻井液废弃物处理及循环利用技术研究进展

废弃水基钻井液是钻井过程中的一种废弃物,直接排出不但造成钻井液成本高昂,还对环境造成不良影响。对废弃水基钻井液进行一系列操作,以达到回收再利用的目的,既满足绿色经济需要又符合现代发展趋势。本文对比总结了蒸馏、固液分离、固化、生物复原、热处理等废弃水基钻井液典型处理方法,列举了热处理在促进废弃水基钻井液循环利用、优化絮凝动力学条件以提高固液分离效果、复合固化剂在固化技术中的绝对优势等方面的新进展,以期为钻井液废弃物处理的应用提供参考。

废氨水洗涤N1923负载有机相降钼试验研究

N1923+异辛醇+磺化煤油体系萃取的负载有机相中,低钨钼比是制约后续反萃液中钨钼蒸发结晶分离效率的关键因素。研究了用车间废氨水作为洗涤剂,从N1923负载有机相中洗脱钼,提高钨钼比的工艺方法;考察了pH值、反应温度、反应时间、水油比对钼洗脱率的影响。结果表明:在pH=9.0、反应温度25℃、反应时间25 min、水油比4∶1、静置时间10 min条件下,钼的单极洗脱率高达88.18%。对洗脱后的负载有机相进行二级逆流洗涤,发现继续增加洗涤次数对钼洗脱率影响甚微。采用车间废氨水洗涤N1923负载有机相提高钨钼比经济可行、环境友好、简单有效、钼洗脱率高、钨损失少。本研究对N1923负载有机相中钨钼分离具有一定参考意义。

顶管施工废弃泥浆的泥水分离特性研究

泥水平衡盾构、顶管工程施工过程中会产生大量的废弃泥浆,将泥浆进行快速泥水分离是解决泥浆堆置场地短缺的必要途径.开挖地层的变化以及泥浆掺加剂的变化,导致了盾构、顶管工程废弃泥浆性质的多变,易降低后续的泥浆脱水效率.针对此问题,本文以典型顶管施工废弃泥浆的脱水工程为研究对象,测定并研究了该工艺中顶管废弃泥浆的泥水分离特性及脱水产物的物理化学特性.研究发现,絮凝-过滤工艺处理废弃泥浆得到泥饼的含水率与泥浆初始粒径及过滤压力有关,未来的相关工程可以基于废弃泥浆的初始粒径,选取相应的过滤压力;顶管废弃泥浆的性质随着开挖地层的变化而发生大幅度变化,其絮凝-过滤工艺需要根据地勘报告进行设计,考虑泥浆脱水过程中的最不利情况.提出了絮凝-过滤工艺未来的优化及发展方向.