钯/铁双金属对六氯乙烷的催化还原脱氯

用钯／铁双金属对水溶液中的六氯乙烷（HCE）进行催化还原脱氯，考察了各种因素对脱氯效果的影响。实验结果表明，在厌氧环境、饱和HCE溶液体积80mL、钯与铁质量比0．03％、钯／铁双金属质量3g、反应时间130min的条件下，脱氯率可达98．8％。采用气相色谱-质谱联用仪对HCE及其脱氯产物进行分析，结果表明，HCE的脱氯中间产物主要是四氯乙烯，四氯乙烯进一步脱氯的中间产物未检出。     

锌粉对1,2,4-三氯苯的脱氯性能

采用锌粉对1,2,4-三氯苯（1,2,4-TCB）进行了脱氯的研究。实验结果表明,在40mL质量浓度为22.94m g/L的1,2,4-TCB水溶液中加入1.0g锌粉,反应24h时,1,2,4-TCB的还原率可达94.6%;反应16h时,试样中的Cl-浓度约为1,2,4-TCB完全脱氯所得Cl-理论浓度的30%;锌粉还原1,2,4-TCB的反应能在较宽的pH范围内进行,弱碱性条件下的脱氯效果最好,1,2,4-TCB的还原率达70%。     

铁碳复合材料去除氯代有机物的研究进展

铁碳（Fe-C）复合材料可应用于污染场地中COCs的去除。综述了近年来Fe-C复合材料的制备方法（包括液相还原法、碳热还原法、水热碳化法、球磨法和绿色合成法），总结了几种常见碳材料载体（包括活性炭、生物炭、碳纳米管和石墨烯）的优缺点，梳理了Fe-C复合材料与COCs的相互作用机制（包括吸附、还原脱氯和刺激微生物脱氯），并对该领域未来的发展方向进行了展望，为Fe-C复合材料用于实际COCs污染场地的修复提供参考。     

零价铁、镍-铁和铜-铁双金属对四氯乙烯的脱氯性能研究

研究了零价铁、镍-铁和铜-铁双金属对四氯乙烯（PCE）的还原性脱氯性能。实验结果表明，零价铁、镍-铁和铜-铁双金属对PCE的脱氯反应符合准一级反应动力学方程；双金属对P（=E的脱氯反应速率高于零价铁，镍-铁双金属对PCE的脱氯反应速率常数是零价铁的2．486倍；镍-铁和铜-铁双金属可使PCE完全脱氯，零价铁在对PCE脱氯的过程中产生一定量的三氯乙烯；增加金属质量，可提高PCE的脱氯反应速率；金属颗粒越小，越有利于PCE脱氯反应。     

用含锌废催化剂制备纳米氧化锌

以含锌废催化剂为原料，经酸浸、除杂、锌粉置换、合成等工艺制得碱式碳酸锌，再经过滤、洗涤、干燥、煅烧制备纳米氧化锌。考察了酸浸工艺硫酸溶液含量和液固比（硫酸与含锌废催化剂的质量比）对锌浸出率的影响，以及煅烧温度对纳米氧化锌质量的影响。实验结果表明：在硫酸质量分数为30%、液固比为5的最佳酸浸工艺条件下，锌浸出率为92%；在最佳煅烧温度为400 ℃的条件下，氧化锌质量分数大于95%，比表面积大于50 m²/g；纳米氧化锌颗粒大小均匀，平均粒径小于50 nm。     

氟化物对酸浸取沸腾炉渣中铝的影响

采用酸浸取法、加入助溶剂浸取沸腾炉渣中的铝，考察了各种因素对铝浸出率的影响。实验结果表明：在球磨时间为30min、固液比（沸腾炉渣质量与酸体积之比）为1：7、硫酸浓度为4mol／L、浸取温度为107℃、浸取时间为120min的条件下，铝浸出率最高（为29．72％）；KF，NH4F，NaF，CaF2等作助溶剂可明显提高铝浸出率，且助溶剂为CaF：时的铝浸出率最高，CaF2与沸腾炉渣的质量比为0．08时的铝浸出率大于75％。     

活性污泥焚烧过程中镍的迁移分布特性

采用管式炉对污水厂活性污泥焚烧过程中Ni的迁移分布特性进行研究。实验结果表明：当污泥掺烧量（污泥质量与煤和污泥总质量的比）为25%时，Ni的挥发率（飞灰与气体中Ni质量的总和与污泥中Ni质量的比）几乎为零，且污泥与煤混合试样的综合燃烧效果最好；当污泥焚烧加入硫化物时，各种硫化物对Ni的残留率（炉渣中Ni的质量与污泥中Ni质量的比）提高能力大小顺序为Na₂S>S>Na₂SO₃>Na₂SO₄；当污泥焚烧加入氯化物时，促使Ni向烟气中迁移，且加入无机氯更易使Ni向烟气中迁移。     

多氯苯催化加氢脱氯

在微反应色谱和熔盐换热固定床反应装置上，用Ｐｔ／Ａｌ２Ｏ３催化剂进行多氯苯加氢脱氯反应的试验研究，考察了温度，液体空速，压力，氢料摩尔反应条件对多氯苯催化氢解脱氯的影响，结果表明，在适宜反应条件下，多氯苯脱氯率为５０％，氯苯和二氯苯收率在４０％以上。     

NDA-66树脂对邻苯二甲酸的吸附及脱附性能

研究了NDA-66新型超高交联树脂对邻苯二甲酸的吸附及脱附性能。实验结果表明：静态吸附过程中，在初始邻苯二甲酸质量浓度1 000 mg/L、溶液pH=2.0、吸附时间600 min的条件下，吸附量可达190 mg/g；动态吸附过程中，处理11吸附床层体积倍数（BV）的邻苯二甲酸溶液，当溶液流量为1.5 BV/h时，吸附率可达100%；动态脱附过程中，在w（NaOH）= 6%、脱附温度328 K的最佳脱附条件下，脱附率可达99%以上。     

从废弃镍氢电池负极板中回收稀土金属

通过废弃镍氢电池负极板在稀硫酸中的浸出实验，考察了稀硫酸浓度、稀硫酸体积与废弃镍氢电池负极板质量比（液固比）、浸出时间、搅拌转速等因素对稀土金属（RE）浸出率的影响。通过正交实验确定的最佳浸出条件：稀硫酸浓度为2．5mol／L，液固比为10，浸出时间为60min，搅拌转速为800r／min。在此条件下，RE浸出率为92．50％。基于RE的硫酸盐和无水硫酸钠生成RE复盐沉淀的原理，向稀硫酸浸出废弃镍氢电池负极板后得到的硫酸盐溶液中加入无水硫酸钠，得到RE复盐沉淀，通过正交实验确定的最佳沉淀条件为：溶液pH为2．0，无水硫酸钠与浸出液中RE^3＋的摩尔比为4，反应温度为60℃。在此条件下，RE回收率为94．6％。用X射线衍射仪对RE复盐进行了表征。     

Relation between mechanochemical dechlorination rate of polyvinyl chloride and mill power consumption

A sample of polyvinyl chloride (PVC) powder was milled with CaO powder in a planetary mill for various mill operational parameters. The milled product consisted of dechlorinated hydrocarbon and water-soluble CaOHCl. The dechlorination rate of PVC was determined by the concentration of Cl⁻ ions measured in solution after dispersing the milled product in water. To evaluate the power consumption during PVC dechlorination, the mill power consumption was measured during each experimental run. In addition, media motion during planetary milling was simulated using the discrete element method (DEM), enabling calculation of the mill power consumption. The power consumption calculated by the DEM simulation compared well with the power consumption measured experimentally. The dechlorination rate correlated well with the specific mill power consumption, regardless of the sample weight. The dechlorination rate of PVC when milled with oyster shells (CaCO₃) was observed to be faster than that of the PVC/CaO system, and oyster shells could be used as a reactant for the treatment of PVC wastes. This work should be useful for the design of a reactor for the dechlorination of PVC. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Effect of additives on dechlorination of PVC by mechanochemical treatment

Polyvinyl chloride (–CH₂–CHCl–) _n (PVC) was ground with a powdered inorganic material (CaO, CaCO₃, SiO₂, Al₂O₃, or slag) in a planetary ball mill under atmospheric conditions to investigate the effect of additions on its dechlorination. The grinding causes a dehydrochlorinating reaction, forming a mixture of partially dechlorinated PVC and inorganic chloride, depending on the grinding time. The dechlorination increases as the grinding progresses, and is improved with increasing amounts of additives. The most effective additive is a mixture of CaO, SiO₂, and Al₂O₃, which has the same constituent components as blast furnace slag. CaO, a mixture of CaO, SiO₂, and blast furnace slag, are also effective, but CaCO₃ is the least effective additive tired. Received: August 3, 2000 / Accepted: September 21, 2000     

Mechanochemical dechlorination of polyvinyl chloride with calcium sulfates

Polyvinyl chloride (PVC) was milled with hydrated or unhydrated calcium sulfates (CaSO₄·2H₂O or CaSO₄) in air by using a planetary mill to investigate mechanochemical dechlorination behavior. The milling process resulted in size reduction and in the breaking of bonds leading to mechanically induced solid state reaction, forming CaCl₂ and dechlorinated hydrocarbon with C=C double bonds in the product. Washing the milled mixtures with water at room temperature allowed removal of the chloride formed during milling, and more than 95% of the chlorine in PVC was removed from a mixture milled for 4 h. This process could offer a potential route for the handling and disposal of both PVC and gypsum wastes. H₂S gas was generated during milling; more H₂S was released from the unhydrated sample than from the hydrated sample.     

Deplasticization and dechlorination of flexible polyvinyl chloride in NaOH solution by microwave heating

This study investigated the deplasticization and dechlorination of flexible polyvinyl chloride (PVC) containing 59.2% PVC, 29.7% dioctyl phthalate (DOP), and approximately 12% stabilizers. Flexible PVC was treated with NaOH solutions at concentrations in the range 2–16 mol/l and heated by microwaves to temperatures between 100° and 250°C for 0–120 min. DOP was extracted from flexible PVC into the NaOH solution as a phthalic acid salt; the remaining PVC was subsequently dechlorinated by increasing the temperature. On internal heating using microwaves, the plasticizer was 100% extracted during processing at 150°C for 30 min, whereas the chlorides were 100% removed during processing at 235°C for 30 min; the residue was converted into hydrocarbon compounds. The maximum weight loss ratio was 71% compared to the pretreatment state. It was also found that 100% deplasticization and dechlorination was possible using 8 mol/l NaOH solution, which is almost half the concentration employed when using conventional external heating systems.     

Upgrading of poly(vinyl chloride) by chemical modifications using sodium sulfide

The recycling of poly(vinyl chloride) (PVC) is one of the most important issues in the treatment of waste plastics. To improve PVC recycling, it is necessary to develop new recycling techniques, including new techniques for the dechlorination of chlorine-containing polymers. It has been established that wet dechlorination of PVC in NaOH/ethylene glycol solution is more effective than dry dechlorination. In this study, the wet process was used, and the chemical modification of PVC by nucleophilic substitution was considered for upgrading waste PVC. Chlorine was substituted in solution by several nucleophilic reagents, thus changing the properties of PVC. The reaction of PVC in Na2S/ethylene glycol solution at 170°C resulted in the formation of a mixture comprising 32% elimination and 26% substitution products. The scanning electron microscopy/energy dispersive X-ray spectroscopy mappings and elementary analysis of PVC indicated that this chlorine-substitution process led to cross-linking by sulfur.     

The variability in nutrient composition of Anaerobic Digestate granules produced from high shear granulation

This study investigates the production of organic fertilizer using Anaerobic Digestate (as a nutrient source) and limestone powder as the raw materials. A two-level factorial experimental design was used to determine the influence of process variables on the nutrient homogeneity within the granules. Increasing the liquid-to-solid ratio during granulation resulted in increased granule nutrient homogeneity. Increasing the processing time and the impeller speed were also found to increase the nutrient homogeneity. In terms of nutrients release into deionized water, the granules effectively released both potassium and phosphate into solution.     

电炉炼锡废渣制备白炭黑

以电炉炼锡废渣为原料,经过酸浸处理去除Fe元素后,再用沉淀法制备白炭黑。探索了制备白炭黑的最佳工艺条件。分别采用XRD、FTIR、SEM及粒度分析等技术表征了白炭黑产品的物相、形貌、粒径及其分布。实验结果表明,制备白炭黑的最佳工艺条件为:Na OH溶液浓度8 mol/L、固液比1∶10(干燥废渣质量与Na OH溶液体积比,g/m L)、搅拌速率300 r/min、反应温度90℃、反应时间6 h。在最佳工艺条件下制备的白炭黑产品中Si O2质量分数达92.8%。表征结果显示,所制备的白炭黑产品是由近似球形的颗粒聚集而成的无定形非晶体水合二氧化硅,粒径为95~200 nm的颗粒约占87.5%。     

湿法脱硫石灰石制浆系统的比选

石灰石制浆系统被广泛应用于燃煤电厂石灰石／石膏湿法烟气脱硫系统中。对典型的湿磨制浆和石灰石粉制浆系统从工艺流程特点、设备组成、技术经济等方面进行详细的分析比较。考虑到1000MW机组工程石灰石耗量较大，从电厂长期运行角度考虑，推荐采用技术成熟、运行经济的石灰石湿磨制浆方案，同时要加强湿磨制浆系统的日常维护和管理：     

Studies on the dechlorination and oil-production technology of waste plastics

 Recycle technology for waste plastics containing polyvinyl chloride (PVC) has been developed in the Hokkaido National Industrial Research Institute for the production of solid and liquid fuel, and has established a recycling process which includes a dechlorination process for PVC plastics, and a two-stage catalytic pyrolysis process for plastics using zeolite catalysts. The dechlorination equipment consists of a two-axis screw extruder with a heating element, which can remove chlorine up to 99.9 wt. % from PVC containing plastics as hydrogen chloride. The product had about 44 000 kJ/kg calorific value and was fed into the next oil production process, although it could also be used as a solid fuel. Natural and synthetic zeolite were used as catalysts for the two-stage catalytic process, which produced a light oil with a boiling point which was between those of kerosene and gasoline. The yield of this oil reached 82 wt. %. The chemical type was analyzed using liquid chromatography, and was found to have many aromatic compounds. These technologies make it possible to produce a nonpolluting, high-calorie solid fuel and a liquid fuel very efficiently. Received: July 19, 2000 / Accepted: September 21, 2000