处理高砷浓度工业废水的化学沉淀法

简要介绍了国内近年来以化学沉淀法处理高浓度砷工业废水的试验研究及工业应用状况,讨论了化学沉淀法除砷工艺中的关键性工序,指出所得含砷沉淀物组成复杂(含砷、铁和钙离子等)及稳定性不够理想.为了适应目前环境保护的严格要求以及尽可能对废物进行资源化处理,认为对于砷和重金属浓度高、规模大的废水,应重视综合治理回收工艺研究.     

Industrial Plant for Olive Mill Wastewater from Two-Phase Treatment by Chemical Oxidation

Olive-oil production generates high and variable amounts of wastewaters from the olives and olive-oil washing (OMW), resulting to great environmental impact. These waters are normally stored in large holding ponds for evaporation during the summer. The present study examines the chemical-oxidation process using ferric chloride catalyst for the activation of H2O2 (Fenton reaction). Tests have been made on an industrial scale. The final average value of chemical oxygen demand (COD) was close to 371?mg?O2?L?1 (%CODremoval = 86%, CODinitial = 2684?mg?O2?L?1), and the water produced can be used for irrigation or can be discharged directly into the municipal wastewater system for tertiary treatment.     

有色金属冶炼企业高砷废水处理工艺

为处理有色金属冶炼厂高砷废水,选择先硫化-化学沉淀-聚合共沉淀工艺,分别考察了硫化钠加入量、添加剂加入量、终点pH,澄清剂加入量等因素的影响,取得了废水处理的最佳条件,结果,处理后废水100%达国家排放标准。     

Engineering Aspects of the Integration of Chemical and Biological Oxidation: Simple Mechanistic Models for the Oxidation Treatment

Oxidation processes can oxidize biorecalcitrant compounds into biodegradable intermediates, which in turn can be treated less expensively by a subsequent biological process. To design such a two-step (chemical+biological) process to treat poorly characterized wastewaters, it is useful to model the time evolution of characteristic global variables, chemical oxygen demand (COD) and biochemical oxygen demand (BOD), in order to develop a useful treatment strategy based upon these classical variables. We consider two simple model reaction networks, requiring three- and five-rate constants, respectively. The first model, proposed recently, involves conversion of a nonbiodegradable species, C, into a single biodegradable intermediate S. Here, biodegradable compounds are immediate kinetic products of oxidation. In general, it is not probable that a single recalcitrant compound undergoes a single-step reaction to CO2. However, when working with complex undefined wastewaters streams, single-step reactions may be used to simplify. The second new model corresponds to a lag time in BOD formation due to the necessity of multiple partial oxidations to reach a first biodegradable intermediate. The second network includes two intermediates, I and S, which are, respectively, nonbiodegradable and biodegradable. We then compare model behavior with an unfortunately sparse literature on BOD and COD values versus time in chemical reactors, and demonstrate the convenience of the first model, and the occasional necessity of the second, which reflects the presence of early intermediates which are nonbiodegradable.     

Biological and Abiotic Color Reduction of Paper Mill Effluents during Anaerobic Composting

Biological and abiotic sorptions as well as kinetic experiments were performed to elucidate the mechanism by which color was being removed from paper mill effluents using anaerobic composting. Experiments were performed using pulp mill upset tank wastewater (color = 5,500?PCU) and E stage filtrate (color = 10,300?PCU). Color removal experiments using active and gamma sterilized compost showed that the color removal capacity for both wastewaters was nine times higher when using active compost than for those reactors using gamma sterilized compost. Final decolorization for pulp mill upset tank and E stage filtrate was 91 and 83%, respectively, while only 33% decolorization was achieved with gamma sterilized compost. Kinetic tests also showed higher color degradation rates when using active compost compared to sterilized compost. Additional experiments demonstrated that biological color removal appears to be robust with respect to pH and is largely unaffected by pH over a range from pH 5 to 10, typical values for the effluents in paper mills. The effect of aging in sorption were tested and results showed that virgin compost could establish a microbial population in less than 50 days which resulted in a compost with sorption capacity similar to the aged compost.     

热连轧含油污泥离心处理方法的研究

本钢１７００ｍｍ热连轧油膜轴承机械漏油严重，含油污泥原工艺无法处理。结合现场实际，通过试验探索离心处理含油污泥的可行性，以期连轧污泥中油、水、泥三相分离，提高供水水质及热连轧板卷的质量。     

Systematic Approach for Quick Quality Assessment of Ink Effluents for Treatment and Discharge

A characterization study on synthetic wastewaters containing various commercially available ink-jet inks was conducted. Analysis of this resulted in the identification of seven high-risk noncompliance parameters, namely, chemical oxygen demand (COD), biochemical oxygen demand at 5 days (BOD5), total dissolved solids (TDS), phenols, copper, iron, and sulphate concentrations. Of these, COD reduction was found to be the most stringent treatment criterion based on the industry-accepted standard Fenton’s oxidation reaction for treatment. TDS and COD were also proposed as critical parameters for the initial assessment of the quality of untreated ink effluents. To provide for rapid and robust indications of the TDS and COD of the untreated ink effluents, a correlation for TDS as a function of conductivity and turbidity was obtained. Furthermore, a deterministic approach based on Beer’s law of absorbance additivity was developed for determining COD of mixtures of ink effluents using absorbance measurements at 210, 436, 525, and 620 nm. These were validated successfully against experimental data. Based on an in-depth analysis of the compositions of ink effluents, a list of simple and rapid on-site water quality parameters was proposed for monitoring the quality of the treated ink wastewater. This consisted of measurements of UV-absorbance at 210 nm, conductivity, pH, turbidity, and color. Based on the discharge limits imposed by a particular country, one can then develop a range of values for these quality parameters in order to meet the discharge regulations of that country. The Singapore context was used as a case study to illustrate this approach. In addition, it was found that the copper content in the cyan ink effluents was substantially reduced by more than 96% along with the standard Fenton’s reaction. Through the course of investigating the Fenton’s oxidation reaction, it was found that measurements of oxidation-reduction potential and/or temperature are suitable indicators of the progress of the reaction.     

化学水处理站存在的问题及改进

1引言通化钢铁公司热电厂化学水处理站是90年代初设计及施工的,投入运行以来存在各种问题。当时设计制水能力为200t/h,仅能满足当时生产要求。随着公司的发展,除盐水需求量逐步加大,水质不能达到要求,运行成本高等问题明显突出来。为此对化学水处理站进行了认真的分析与研究,找出原有水处理工艺中存在的问题,通过一系列的技术改造措施,提高制水量和水质,降低了成本。2水站现运行中存在的问题原水处理系统工艺流程见图1。图1原水处理系统工艺流程图因原水处理系统中离子交换器采用的是固定床逆流再生方式,因此原系统中的阳、阴离子交换器正常…     

铜箔轧机带材表面的除油方法

阐述了铜箔轧机除油的重要性,并根据调试经验介绍了几种比较有效的除油方法及其特点。     

定径机机架加工及检测方法探析

文章介绍了定径机机架的加工工艺及采用加工中心机床和常规百分表相结合对机架进行检测的方法。机架的成功加工为下一步制作其它型号的机架提供了依据,且具有较好的市场发展前景。     

Chemical Oxidation of Iron Sulfide Minerals for Metals Recovery

A greal deal of effort has been directed towards the development of economically and technically feasible processes for the chemical oxidation of iron sulfides. Such processes applied commercially or under active development, including roasting, and sulfate-, nitrate-, chloride- and alkaline-based aqueous oxidation processes, are outlined in this paper.     

球磨机中空轴漏浆处理措施的改进设计

针对球磨机运行过程中出现的中空轴漏浆现象,分析了漏浆形成的原因和对设备造成的危害性,讨论了传统的漏浆处理措施设计,同时提出了镶套式维修新思路,并试验应用于球磨机端盖上。实践证明,采用镶套式维修方法处理后的球磨机进料端盖运行稳定安全,有效地延长了进料端盖的使用寿命,取得良好效果。     

酚醛树脂生产过程中高浓度含酚废水处理工艺的研究

通过实验，研究了高浓度含酚废水的处理方法：首先，通过催化沉降，除掉废水中水溶性小分子树脂；然后，通过选用特定的复合萃取剂，在适当的工艺条件下(萃取时间、搅拌速度、废水pH值、剂水比等)达到最佳的处理效果，从而确定出废水处理的最佳工艺方案。     

Development of an Apparatus for pH-Isolated Electrokinetic In Situ Chemical Oxidation

An apparatus was designed, manufactured, and implemented to isolate pH during electrokinetic in situ chemical oxidation (EK-ISCO). H+ and OH- electromigration were used to determine the adequacy of the designed apparatus for pH isolation. A series of pH-isolation and normal-mode (no pH-isolation) experiments were undertaken and compared. It was found that pH isolation was achieved when the electrode reservoirs were separated by porous media combined with the purging of the electrode reservoir fluid. The electromigration retardation factor of H+ and OH- was calculated for the porous media using the observed pH breakthrough times. The retardation factor for H+ was also calculated by considering mass flux data. The retardation factors for H+ and OH- were found to be 28.3 and 95, respectively, when using the breakthrough time. The retardation factor for H+ was calculated to be 36.7 using the mass flux data.     

粗轧机系统的谐波治理

本文通过对粗轧机的系统分析,找出解决系统高次谐波的处理办法,实施后系统的高次谐波含量达到了国家电网要求,同时也达到了节能降耗的作用。     

冷轧酸性废水处理系统优化

新钢冷轧生产线酸性废水处理系统在运行过程中存在处理效果不理想、检修时间受限、p H值调节不准等问题,根据这些问题产生的原因采取相应措施后取得了较好的效果。同时指出了水处理系统在设计时应注意的问题,并提出了水处理是集药剂管理、设施设备管理于一体的观点。     

化学法处理混合电镀废水及药剂选择

通过热动力学分析、理论计算和实验,确定在碱性条件下用NaClO作氧化剂,Na₂S和FeSO₄作还原剂处理混合电镀废水的工艺流程,并通过计算和实验确定了Na₂S与FeSO₄的最佳药剂比:Na₂S为80%~90%,FeSO₄为10%~20%.Na₂S+FeSO₄比单独使用FeSO₄少产生60%~70%的污泥.该工艺在实际工程运行过程中效果良好.     

单机架可逆冷轧机轧制规程优化设计

以唐钢冷轧薄板厂1 800 mm单机架可逆冷轧机的2级轧制规程为研究对象,在分析轧制负荷分配对冷轧带钢板形精度影响的基础上,系统研究了冷轧轧制模型,应用最优化方法编制了轧制规程设计程序并付诸工程实践。