蒸发/芬顿/生化/工艺处理塑胶化工废水

浙江某企业主要从事PVC塑胶板带生产及液体钙钡锌稳定剂复配项目,采用了“隔油+蒸发+二级芬顿+生化+臭氧”核心工艺处理该塑胶化工生产废水并达到相应排放标准。该生产废水主要有包括钙锌热稳定剂、钡锌热稳定剂、钾锌热稳定剂生产过程中产生的废水,废水含有高难度难降解的COD、石油类、SS等特征污染因子,处理水量为10 m³/d。运行结果表明,该工艺对废水具有良好的治理效果,经过处理,其中主要污染物COD_Cr≤300 mg/L,最后出水水质满足纳管要求。     

混凝/气浮/水解/接触氧化工艺处理食品加工废水

采用隔油和格栅作为预处理单元去除废水中部分悬浮物和动植物油,以混凝/气浮/水解酸化/接触氧化为核心工艺处理该食品加工废水。该废水含有COD、氨氮、ss、动植物油等特征污染因子,处理水量为400 m~3/d。介绍了该废水处理工程的工艺流程、主要设计参数及设备配置。实际运行结果表明,该工艺对该废水具有良好的去除效果,出水水质完全满足当地污水处理厂的纳管标准,可为同类废水处理工程的设计和运行提供借鉴。     

瓮福集团实施50万吨/年氨氮废水深度处理项目

正瓮福(集团)有限责任公司近期计划在贵州省福泉市马场坪工业园区实施50万吨/年氨氮废水深度处理项目。该项目工程总投资2700万元,分两期建设。其中一期投资650万元,新建一套15万吨/年氨氮废水处理系统,使企业生产线来的废水经脱盐浓缩、电渗析处理后与生产线母液水一并进入公司现有系统消化。含氨氮蒸发冷凝液废水经脱盐浓     

氮肥企业污水A/A/O处理工艺研究

氮肥企业生产过程中排放大量的高浓度氨氮废水,给周围地区的水环境带来不利影响。A/A/O污水处理工艺是国内先进的生物脱氮工艺,其将传统的活性污泥、生物硝化工艺结合起来,能更有效地去除水中的氨氮、磷、BOD、COD及SS等污染物。采用A/A/O工艺处理了某氮肥企业氨氮含量较高的生活及化验废水、煤气水处理装置废水、低温甲醇洗废水、甲醇精馏废水、硝铵废水等。处理结果表明,该工艺能够有效降解废水中的COD和氨氮,使废水中的各项污染物指标达标排放。     

3.5万t/a糊树脂项目废水处理运行总结

采用加药澄清和中和混凝沉淀组合式工艺形式对3.5万t/a糊树脂项目有机废水进行了有效的处理,通过有机废水处理装置运行得出:p H值6.8-8.3,悬浮物105.0 mg/L,BOD5115.2 mg/L,CODcr 156.0 mg/L。出水各项指标均优于综合废水处理装置的进水水质指标。说明该组合式工艺法处理糊树脂有机废水是可行的,回收有机废水中的糊树脂为360 t/a,对发展循环经济具有良好的社会效益,经济效益和生态效益。     

某400万t/a煤制油项目废水分盐工程设计探讨

介绍了中国五环工程有限公司建设的某400 t/a煤制油项目废水分盐工程的设计,阐述了工艺流程和关键技术应用,分析了该工程的经济效益,并对矿井水及煤化工废水膜法和热法分盐技术进行了技术经济对比。     

CeO_2/TiO_2/海泡石复合体处理甲醛废水

采用水解法制备CeO_2/TiO_2/海泡石复合光催化剂,研究了该复合光催化剂催化降解废水中甲醛的性能,并分别研究了废水pH值、催化剂用量、光照时间和甲醛浓度等对CeO_2/TiO_2/海泡石光催化降解甲醛的影响,设计正交试验,确定了降解甲醛废水的最佳条件.     

金属加工生产废水的预处理/水解酸化/MBR/RO处理工艺

金属加工废水主要来自酸洗作业、轧制挤压作业、除油作业等工段,其中包括含酸废水、含碱废水及废乳化液。该生产废水存在水量随生产情况变化,污染成分浓度变化大的特点。设计采用预处理/水解酸化/MBR/RO组合工艺处理生产废水,处理规模为360 m3/d。结果表明该工艺处理效果稳定,MBR膜系统出水水质同时满足《污水综合排放标准》(GB 8978—1996)一级标准和《城市污水再生利用城市杂用水水质》(GB/T 18920—2002)中关于绿化用水标准。MBR膜系统出水经RO后用于生产回用。     

微电解/Fenton氧化/水解酸化/生物接触氧化处理制药废水

某制药厂废水处理工程,采用微电解/Fenton氧化/水解酸化/生物接触氧化组合工艺处理制药废水,根据实际运行情况分析,该工艺对制药废水有良好的处理效果,耐冲击负荷强、运行稳定,该工程从2016年6月运行至今出水水质达到GB8978-1996《污水综合排放标准》中的三级标准.     

HSRO?技术在脱硫废水零排放中的设计及应用

介绍了HSRO^?(高盐反渗透)的技术特点。内蒙古境内某火力发电厂脱硫废水零排放一期项目工程工艺流程膜浓缩工段成功设计并应用了HSRO装置,该装置运行稳定可靠,整体回收率高于90%,最终反渗透产水可作为生产用水直接回用。该技术不仅在脱硫废水领域成功得到了工程验证,也为高矿化度矿井水、煤化工浓盐水等浓盐水领域工艺选择提供了参考。     

Preparation and properties of poly(Nε,Nε-dicarboxymethyl-l-lysine)

A new ampholytic homopolypeptide, $\text{poly}\text{(N}{}^{\mathrm{\epsilon }}\text{,N}{}^{\mathrm{\epsilon }}\text{-}\text{dicarboxy-methyl-}\text{l}\text{-lysine}\text{)}$, which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO₄ and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu²⁺ and Ca²⁺, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu²⁺ complex near 240 nm. Dependence of the peak intensity on pH at various q values ($\text{q =}\text{[}\text{Cu}{}^{\mathrm{2+}}\text{]}\text{[}\text{residue}\text{]}$) indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu²⁺ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu²⁺ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu²⁺-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation.     

Wet Milling of Fe/Al/Al2O3 and Fe2O3/Al/Al2O3 Powder Mixtures

Wet milling of Al₂O₃-aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al₂O₃ and Fe₂O₃/Al/Al₂O₃ powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe₂O₃/Al/Al₂O₃ powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al₂O₃ powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8.     

Participation of lewis base on vinyl chloride polymerization with Al(C2H5)3CCl4 catalyst system

The polymerization of vinyl chloride has been investigated using an $\text{Al}\text{(}\text{C}{}_2\text{H}{}_5\text{)}{}_3\text{CCl}{}_4$ catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed.     

Sintering of Si3N4-Y2O3-Al2O3

Sintering kinetics of the system Si₃N4-Y2O₃-Al₂O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si₃N₄ were studied with additions of 4 to 17 wt% Y₂O₃ and 4 wt% A1₂O₃. Sintering occurs by a liquid-phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X-ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β ' -Si₃N₄ and glass or β '-Si₃N₄, α '-Si₃N₄, and glass. The compositions and amounts of the residual glassy phases are estimated.     

Synthesis and Characterization of Ti0.33Ta0.33Nb0.33C and Ti0.33Ta0.33Nb0.33CxN1-x Whiskers

Ta_0.33Ti_0.33Nb_0.33C and Ta_0.33Ti_0.33Nb_0.33C _x N_{1− x} whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N₂. The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO₂, Ta₂O₅, Nb₂O₅, C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl₂( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature.