造纸废水处理工程设计实例

采用"前物化-厌氧-好氧"组合工艺处理高浓度废纸造纸废水,同时以芬顿高级氧化工艺进行深度处理,进一步提高废水处理效率。经过系统处理,废水CODCr从进水5200 mg/L左右降至80 mg/L以下,SS从进水1700 mg/L左右降至30 mg/L以下,处理效率均达到98%,排放水质完全达到《制浆造纸工业水污染物排放标准》GB 3544-2008表2标准。通过长时间实际运行表明,该系统处理的出水水质稳定,处理效率高。     

A/O/BAF工艺处理日化厂废水回用工程实例

采用"厌氧——接触氧化——曝气生物滤池"组合工艺处理日用化工废水。废水CODcr从进水1000 mg/L左右降到50 mg/L以下,BOD5从进水400 mg/L左右降到10 mg/L以下,处理效率均达到了95%以上,出水水质达到《城市再生利用水回用标准》GB/T 18920-2002。通过工程的长期实际运行表明,高效的厌氧系统和曝气生物滤池深度处理系统是该工艺处理稳定的关键。     

色织布废水处理工程设计实例

采用"前物化-水解酸化-好氧"组合工艺处理色织布废水,同时以氧化塘-臭氧高级氧化工艺进行深度处理,进一步提高废水处理效率。经过系统处理,综合废水CODcr从进水2350 mg/L左右降至50 mg/L以下,色度从进水3500度左右降至50度以下,处理效率均达到97%处理后排放水质达到越南排放标准(QCVN40:2011/BTNMT)A标准。本工程为越南的中资企业所有,出水监测系统实时在线,监管严格,但项目投产运行至今,没有出现超标的现象,长时间实际运行表明,该系统处理的出水水质稳定,处理效率高。     

组合工艺处理高浓度日用化工废水

采用"厌氧-接触氧化-臭氧-曝气生物滤池"组合工艺处理高浓度日用化工废水.废水中CODCr从进水5000 mg/L降到出水＜80 mg/L,BOD5从进水1100 mg/L降到出水＜20 mg/L,处理效率＞98%,排放水质达到广州市污水排放一级标准(DB 4437-1990).废水处理站的长期实际运行结果表明,高效的厌氧处理和臭氧-曝气生物滤池深度处理系统是该工艺处理高浓度废水稳定达标的关键.     

某化工制药废水处理“零排放”工程实例研究

采用反渗透工艺对某化工制药废水进行"零排放"研究。在MBR出水COD为120mg/L,SS为70mg/L,电导率3 000μs/cm条件下,经过反渗透系统后废水COD降至10 mg/L,色度去除率为99%,电导率≤10μs/cm,出水水质达到了GB 19923-2005《再生水工业用水水质》标准。同时,工艺产生浓水可用于冲渣,其他产水可满足车间用水要求,最大限度地利用了化工制药废水,实现了废水的"零排放"与节能减排。     

丁腈手套生产废水处理工程实例

为确保某医疗手套生产企业废水站出水TN稳定达标，从运行的经济性角度考虑，对生产废水进行分质分流处理，高浓度废水先采用混凝气浮-高效脱氮工艺进行预处理，再与低浓度废水混合后进行A/O生化处理。详细介绍了废水处理工艺流程及设计参数。运行结果表明，废水中TN质量浓度从420 mg/L降至约30 mg/L，总锌质量浓度从14 mg/L降至0.56 mg/L，出水水质均能稳定达到GB 27632—2011《橡胶制品工业污染物排放标准》表2中的间接排放标准。     

焦化废水深度处理回用及新鲜水系统重复利用技改

根据山焦外排废水的水质特点,实施了生化出水深度处理回用和新鲜水系统重复利用改造两个项目。生化出水深度处理采用"树脂吸附+脱盐"工艺,处理后出水COD≤30 mg/L、氨氮≤5 mg/L、硬度5μmol/L、电导率10μs/cm,用作锅炉补水;新鲜水系统重复利用的改造采用低压蒸汽喷射制冷技术,将第二回收车间初冷器退水水温从32℃降至16℃后,循环利用。焦化废水深度处理回用项目的实施,具有较好的环境效益和经济利益。     

化妆品生产废水处理工程设计与调试实例

采用“水解酸化-接触氧化”组合工艺处理高浓度日用化工废水，同时以曝气生物滤池工艺进行深度处理，进一步提高废水处理效率。经过系统处理，废水CODcr从进水4000mg／L左右降为80mg／L以下，BOD5从进水1100mg／L左右降为20mg／L以下，处理效率均达到98％，排放水质完全达到广州市污水排放一级标准（DB4437-90）。通过工程的长期实际运行表明，该系统处理的出水水质稳定，处理效率高。     

A2/O工艺处理焦化废水

简述了生物脱氮工艺处理焦化废水的基本原理、工艺流程和主要控制要求,介绍了某企业采用该工艺处理焦化废水的调试运行过程和结果,可使废水中氨氮从150mg/L～250mg/L降至15mg/L以下,并且出水中COD基本维持在100mg/L左右,达到了《污水综合排放标准》(GB8978-1996)的二级标准。     

UASB/SBR/脱氮/Fenton组合工艺处理垃圾渗滤液实例

该文采用UASB/SBR/脱氮/Fenton组合工艺处理垃圾渗滤液。结果表明废水CODCr从1 140 mg/L左右降至100 mg/L以下,去除率达到91%;氨氮从430 mg/L左右降至25 mg/L以下,去除率达到94%。排放水质完全达到《生活垃圾填埋场污染物控制标准》(GB 16889—2008)中规定的排放标准。     

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.