钻井废水可生化性研究及处理技术探索

钻井废水是油气井开采钻探过程中产生的废水，钻井废水成分复杂，有机物浓度高、色度高、悬浮物浓度高，水质变化大，排放点分散，不经处理排放会污染环境，破坏生态。随着石油工业的不断发展和国家环保法律法规的日益严格，钻井废水的治理也越来越受到重视。如何采用经济有效的方法处理废弃钻井液，对油气井开采业的可持续发展具有重要意义。本论文以遂宁磨153 井的钻井废水为主要研究对象，在对废水进行絮凝沉降预处理和生物法处理探索的基础上，针对钻井废水可生化性差的特点，采用水解酸化和Fenton 试剂改善钻井废水的可生化性，对反应过程进行了比较详细的考察，对可生化性改善的机理进行了探索。主要研究结论如下：1 用PFS 和PAC 配制的混合混凝剂对钻井废水COD 的去除效果比较显著，在最佳条件下COD 的去除率可达75%，且絮体沉降速度较快，出水pH 保持中性；2 水解酸化法处理钻井废水可显著改善废水的可生化性。经48 小时水解酸化处理，钻井废水的理论BOD5可提高约22 倍，表观BOD5/COD值由0.004 提高到0.034。用接触氧化反应器处理经水解酸化处理后的废水，处理效果比较稳定，COD平均去除率达35.5%；3 研究了Fenton反应中各影响因子对废水COD去除率、BOD5/COD的影响并分析其作用机制，确定了最佳条件：初始pH为4.0，H2O2/Fe2+(摩尔浓度比)为20，H2O2/COD（质量浓度比）为1，反应时间为2 个小时。此条件下，废水的COD去除率约为40%，BOD5/COD值从0.002～0.003 提高至0.15～0.2，可生化性得到很大提高。本论文的主要创新点在于：1 以成分复杂、水质变化大的气井钻井废水为研究对象，从理论BOD 和表观BOD 两方面对水解酸化过程中废水可生化性的变化进行了分析；2 对Fenton 试剂改善钻井废水可生化性的过程、主要影响因素进行了比较详细的考察。本论文的研究成果，可为生物法处理钻井废水的深入研究提供理论依据。Drilling wastewater is produced in the process of oil-gas well drilling,because of its complicated composition, high concentrate of organic compound andsuspended solid, high chroma, levity of water quality and decentralization ofdischarge point, it pollutes environment seriously if discharged without treatment.With the development of petroleum industry and the issuing of more strict laws forenvironmental protection, it has been paid more and more attention on drillingwastewater treatment. It is of great importance for the sustainable development ofoil-gas well drilling to treat drilling wastewater by economical and effective methods.In this paper, drilling wastewater of Mo No.153 well in Suining was studied asthe main object. On the basis of research on pre-treatment with flocculant andbiological treatment, and according to the character of poor biodegradability, thedrilling wastewater was treated by hydrolytic acidification and Fenton’s reagent toimprove its biodegradability. The process and mechanism of biodegradabilitychanging were investigated. The primary conclusions are:1 It is effective to treat drilling wastewater with mixing PFS and PAC asflocculant. The removal rates of COD came up to 75% under optimal conditions, thesedimentation rate of flocculation is rapid, and the pH value of treated water remainedneutral;2 The biodegradability of drilling wastewater was highly improved afterhydrolytic acidification process. The theoretic BOD5 of drilling wastewater increasedby 22 times and its detected BOD5/COD ratio increased from 0.004 to 0.034 afterhydrolytic acidification for 48 hours. The wastewater after hydrolytic acidificationwas treated by biological contact oxidation reactor. Stable treatment performance was achieved, and the average removal rates of COD came up to 35.5%;3 The effects of various affection factors on the removal efficiency of COD andBOD5/COD radio in treating drilling wastewater by Fenton’s reagent wereinvestigated and the mechanism was analyzed. The optimal conditions were: initialpH of solution was 4.0, the molar ratio of H2O2 and Fe2+ was 20, the concentrationratio of H2O2 and COD was 1 and the reaction time was 120 min. Under the aboveconditions, the removal efficiency was about 40% and the ratio of BOD5 and CODincreased from 0.002 ¡« 0.003 to 0.15 ¡« 0.2. The biodegradability of drillingwastewater was greatly improved.The innovations of this thesis are:1 The drilling wastewater was taken as the research object which hascomplicated composition and variational water quality, and the changes ofbiodegradability were analyzed from theoretic BOD and detected BOD aspects duringhydrolytic acidification process;2 The biodegradability changing process and primary affection factors of drillingwastewater treating by Fenton’s reagent were investigated.The results of this study could provide theoretic foundation for further researchon biological treatment of drilling wastewater.

Magnetic field configurations of radio jets in the double source of radio galaxy

As an improvement of resolution of observations, more and more radio galaxies with radiojets have been identified and many fine structures in the radio jets yielded. In the presentpaper, the two-dimensional magnetohydrodynamical theory is applied to the analysis of themagnetic field configurations in the radio jefs. Two-dimensional results not only are con-sistent theoretically, but also explain the fine structures of observations. One of the theo-retical models is discussed in detail, and is in good agreement as compared with the observedradio jets of NGC6251. The results of the present paper also show that the magneticfields in the radio jets are mainly longitudinal ones and associate with the double sources ofQSOs if the magnetic field of the central object is stronger; the fields in the radio jets aremainly transverse ones and associate with the double sources of radio galaxies if the fieldof the central object is weaker. The magnetic field has great influence on the morphol-ogy and dynamic process.

The magnetic jet theory of double source in radio galaxy

The two-dimensional accelerating theory about solar wind is applied to the study of theaccelerating process of jet beam in the radio galaxy. The flowing features are given with theanalytic method, and the basic flow is along the direction of the jet beam. The mechanism ofacceleration from subsonic to supersonic flow is discussed. At the same time, some fine struc-tures about the double sources in the radio galaxy are explained.

Fiber Dispersion and Nonlinearity Influences on Transmissions of AM and FM Data Modulation Signals in Radio-Over-Fiber System

Transmission properties of data amplitude modulation (AM) and frequency modulation (FM) in radio-over-fiber (RoF) system are studied numerically. The influences of fiber dispersion and nonlinearity on different microwave modulation schemes, including double side band (DSB), single side band (SSB) and optical carrier suppression (OCS), are investigated and compared. The power penalties at the base station (BS) and the eye opening penalties of the recovered data at the end users are both calculated and analyzed. Numerical simulation results reveal that the power penalty of FM can be drastically decreased due to the larger modulation depth it can achieve than that of AM. The local spectrum broadening around subcarrier microwave frequency of AM due to fiber nonlinearity can also be eliminated with FM. It is demonstrated for the first time that the eye openings of the FM recovered data can be controlled by its modulation depths and the coding formats. Negative voltage encoding format was used to further decrease the RF frequency thus increase the fluctuation period considering their inverse relationship.

Blue-violet luminescence double peak of In-doped films prepared by radio frequency sputtering

ZnO films doped with different contents of indium were prepared by radio frequency sputtering technique. The structural, optical and emission properties of the films were characterized at room temperature using XRD, XPS, UV-vis-NIR and PL techniques. Results showed that the indium was successfully incorporated into the c-axis preferred orientated ZnO films, and the In-doped ZnO films are of over 80% optical transparency in the visible range. Furthermore, a double peak of blue-violet emission with a constant energy interval (similar to 0.17 eV) was observed in the PL spectra of the samples with area ratio of indium chips to the Zn target larger than 2.0%. The blue peak comes from the electron transition from the Zn-i level to the top of the valence band and the violet peak from the In-Zn donor level to the V-Zn level, respectively.

Radio-resistance induced by nitric oxide to heavy ion irradiation in A172 human glioma cells

To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA72), were irradiated by C-12(6+) ions to 0, 1 or My. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G(2)/M stage arrest induced by the C-12(6+) ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.

Stiction and Anti-Stiction in Mems and Nems

Stiction in microelectromechanical systems (MEMS) has been a major failure mode ever since the advent of surface micromachining in the 80s of the last century due to large surface-area-to-volume ratio. Even now when solutions to this problem are emerging, such as self-assembled monolayer (SAM) and other measures, stiction remains one of the most catastrophic failure modes in MEMS. A review is presented in this paper on stiction and anti-stiction in MEMS and nanoelectromechanical systems (NEMS). First, some new experimental observations of stiction in radio frequency (RF) MEMS switch and micromachined accelerometers are presented. Second, some criteria for stiction of microstructures in MEMS and NEMS due to surface forces (such as capillary, electrostatic, van der Waals, Casimir forces, etc.) are reviewed. The influence of surface roughness and environmental conditions (relative humidity and temperature) on stiction are also discussed. As hydrophobic films, the self-assembled monolayers (SAMs) turn out able to prevent release-related stiction effectively. The anti-stiction of SAMs in MEMS is reviewed in the last part.

Self-consistent kinetic modeling of low-pressure inductively coupled radio-frequency discharges

An efficient method for solving the spatially inhomogeneous Boltzmann equation in a two-term approximation for low-pressure inductively coupled plasmas has been developed. The electron distribution function (EDF), a function of total electron energy and two spatial coordinates, is found self-consistently with the static space-charge potential which is computed from a 2D fluid model, and the rf electric field profile which is calculated from the Maxwell equations. The EDF and the spatial distributions of the electron density, potential, temperature, ionization rate, and the inductive electric field are calculated and discussed. (C) 1996 American Institute of Physics.

Numerical Simulation of Heat Transfer and Kinetics in the Bulk Growth of Silicon Carbide

The growth process of 2-inch silicon carbide (SiC) single crystals by the physical vapor transport method (or modified Lely method) has been modeled and simulated. The comprehensive process model incorporates the calculations of radio frequency (RF) induction heating, heat and mass transfer and growth kinetics. The transport equations for electromagnetic field, heat transfer, and species transport are solved using a finite volume-based numerical scheme called MASTRAPP (Multizone Adaptive Scheme for Transport and Phase Change Process). Temperature distribution for a 2-inch growth system is calculated, and the effects of induction heating frequency and current on the temperature distribution and growth rate are investigated. The predicted results have been compared with the experimental data.

Photoionization of H atoms in few-cycle laser pulses

Photoionization of hydrogen atoms in few-cycle laser pulses is studied numerically. The total ionization probability, the. instantaneous ionization probability; and the partial ionization probabilities in a pair of opposite directions are obtained. The partial ionization probabilities are not always equal to each other which is termed as inversion asymmetry. The variation of asymmetry degree with the CE phase, the pulse duration and the pulse intensity is studied. It is found that the pulse intensity affects the asymmetry degree in many aspects. Firstly, the asymmetry is more distinct at higher intensities than that at lower intensities when the pulse duration exceeds 4 cycles; secondly, the maximal asymmetry in lower intensities varies with the CE phase visibly while at higher intensities riot; thirdly, the partial ionization probabilities equal to each other for some special CE phases. For lower pulse intensities, the corresponding value of CE phase is always 0.5 pi and 1.5 pi, while for higher pulse intensities, the corresponding value varies with the pulse intensity. Similar phenomena were observed in a recent experiment using few-cycle radio-frequency (RF) pulses.

Trapping of neutral atoms with a radio-frequency field

Based on the dressed-atom approach, we discuss a two-dimensional (2D) radio-frequency trap for neutral atoms, in which the trap potential derives from the magnetic-dipole transition among the hyperfine Zeeman sublevels. By adjusting the detuning of the radiation from resonance, the trapping states will be changed predominantly from the bare states Of m(FgF) > 0 to other states of m(FgF) < 0, where m(F) and g(F) are the quantum numbers of Zeeman sublevels and the Lande factor, respectively. This character contrasts finely with that, of a static magnetic, trap that can only trap or guide the states of m(FgF) > 0. In comparison to the optical field, the radio-frequency trap eliminates the spontaneous emission heating of the atoms. Unlike other oscillating traps reported in the e literature, the configuration of the radio-frequency trap is suitable for realization of a miniature magnetic guide.

Surface planar ion chip for linear radio-frequency Paul traps

We propose a surface planar ion chip which forms a linear radio frequency Paul ion trap. The electrodes reside in the two planes of a chip, and the trap axis is located above the chip surface. Its electric field and potential distribution are similar to the standard linear radio frequency Paul ion trap. This ion trap geometry may be greatly meaningful for quantum information processing.

A radio frequency field guide using field induced adiabatic potential

We study the behaviour of atoms in a field with both static magnetic field and radio frequency (rf) magnetic field. We calculate the adiabatic potential of atoms numerically beyond the usually rotating wave approximation, and it is pointed that there is a great difference between using these two methods. We find the preconditions when RWA is valid. In the extreme of static field almost parallel to rf field, we reach an analytic formula. Finally, we apply this method to Rb-87 and propose a guide based on an rf field on atom chip.