Preparation of a permanent magnetic hypercrosslinked resin and assessment of its ability to remove organic micropollutants from drinking water

A rapid and effective method based on a novel permanent magnetic hypercrosslinked resin W150 was proposed for the removal of organic micropollutants in drinking water. W150 was prepared by suspension and post-crosslinking reaction and found to possess a high specific surface area of 1149.7 m²·g^-1, a small particle size of 50 μm to 100 μm, and a saturation magnetization as high as 8 emu·g^-1. W150 was used to eliminate nitrofurazone (NFZ) and oxytetracycline (OTC) from drinking water compared with commercial adsorbents XAD-4 and F400D. The adsorption kinetics of NFZ and OTC onto the three adsorbents well fitted the pseudo-second-order equation (r>0.972), and the adsorption isotherms were all well described by the Freundlich equation (r>0.851). Results showed that the reduction in adsorbent size and the enlargement in sorbent pores both accelerated adsorption. Moreover, the effect of particle size on adsorption was more significant than that of pore width. Given that the smallest particle size and the highest specific surface area were possessed by W150, it had the fastest adsorption kinetics and largest adsorption capacity for NFZ (180 mg·g^-1) and OTC (200 mg·g^-1). For the adsorbents with dominant micropores, the sorption of large-sized adsorbates decreased because of the inaccessible micropores. The solution pH and ionic strength also influenced adsorption.     

Ammonia removal from low-strength municipal wastewater by powdered resin combined with simultaneous recovery as struvite

• Powdered resin was employed for ammonia recovery from municipal wastewater. • Powdered resin achievedefficient ammonia removal under various working conditions. • Co-existing cations indicated competitive adsorption of ammonia. • Ammonia was recoveredby two-stage crystallization coupled with ion exchange. Low-strength municipal wastewater is considered to be a recoverable nutrient resource with economic and environmental benefits. Thus, various technologies for nutrient removal and recovery have been developed. In this paper, powdered ion exchange resin was employed for ammonia removal and recovery from imitated low-strength municipal wastewater. The effects of various working conditions (powdered resin dosage, initial concentration, and pH value) were studied in batch experiments to investigate the feasibility of the approach and to achieve performance optimization. The maximum adsorption capacity determined by the Langmuir model was 44.39 mg/g, which is comparable to traditional ion exchange resin. Further, the effects of co-existing cations (Ca²⁺, Mg²⁺, K⁺) were studied. Based on the above experiments, recovery of ammonia as struvite was successfully achieved by a proposed two-stage crystallization process coupled with a powdered resin ion exchange process. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) results revealed that struvite crystals were successfully gained in alkaline conditions (pH= 10). This research demonstrates that a powdered resin and two-stage crystallization process provide an innovative and promising means for highly efficient and easy recovery from low-strength municipal wastewater.     

Decomposition reactions of epoxy resin and polyetheretherketone resin in sub- and supercritical water

Epoxy resin and polyetheretherketone (PEEK) resin were decomposed into their monomers such as phenol, cresols, and their analogues by thermal treatment in sub- and supercritical water in a 10-ml tubing bomb reactor. The addition of basic compounds such as Na₂CO₃ was effective in promoting the decomposition reaction of the resins. In the reaction of epoxy resin, the yield of identified products reached 10% for the reaction at 703K over 1h. In the reaction of PEEK resin, the total yield of phenol and dibenzofuran reached 88% for the reaction at 703K over 3h. Chemical participation of water in the decomposition reaction was confirmed by the reaction of dinaphthylether.     

XDA-1型大孔吸附树脂对水中氯仿的吸附性能

研究了XDA-1型大孔吸附树脂对用自来水配制的低浓度溶液中氯仿的动态吸附能力,以及浓度、流速、温度和pH等因素对吸附过程的影响.结果显示,采用XDA-1大孔树脂吸附水中的氯仿,其吸附效率可达99%以上,泄漏点前的吸附量为160mg/ml.采用热空气热解吸方式回收氯仿,回收率达85%,为含氯仿工业废水的处理提出一种新的处理工艺.     

高浓度ABS树脂生产污水治理技术

ABS树脂生产装置中的污水处理一直是影响化工装置环保的一大难题。一方面,其废水水质差,悬浮物含量高,且多为细微颗粒,难以从水中分离,进入生化系统也难以去除;另一方面,污水中溶解性胶乳较多、粘性大,且为间歇式排放,对污水处理系统冲击较大。大庆石化总厂采取完善生产工艺操作过程、采用高效净水剂、对处理设备进行改进及对生产全过程进行污染控制等措施,并分阶段、分单元、分步骤地对污染源进行处理。采取这些措施后使ABS树脂生产中的废水得到了有效治理,处理后的ABS污水中CODcr含量在1000mg/L以下,悬浮物含量在500mg/L以下,石油类物质含量在30mg/L以下。处理装置的能耗、物耗也大幅度降低。     

离子交换树脂再生水回用的实验研究

在油田稠油注蒸汽所需的离子交换树脂系统中,再生盐水仅能一次性使用,外排盐水会对水体、耕地和环境产生不良的影响。对离子交换树脂再生盐水回用工艺进行了实验研究。实验结果表明:当HJ-1与HJ-3、HJ-4、HJ-5联合使用时,再生盐水中镁离子的浓度可大幅度地降低。几种药剂对再生盐水中钙离子的去除作用效果各不相同,HJ-4对钙的处理效果明显优于HJ-3与HJ-5。现场实验表明:采用复配药剂处理含盐废水,可以实现含盐废水的回用。目前该处理工艺已在某些油田应用,取得了良好的运行效果。     

聚苯乙烯树脂溶剂型可剥防锈塑料的研制

本实验通过对比实验方法,研制了一种具有优良耐腐蚀性能与机械性能的聚苯乙烯树脂溶剂型可剥防锈塑料,该产品采用废弃泡沫为主要成膜物质,即解决了白色垃圾问题,实现了废物利用,又解决了钢铁件的防锈问题。对该产品进行性能测试,所得到的产品膜层光亮、韧性好,易于涂施、流平性好。     

大孔弱碱性树脂对2,4-二硝基苯酚吸附性能的研究

研究了2,4-二硝基苯酚在D301大孔弱碱树脂上的吸附性能。结果表明:在283～313K和研究的浓度范围内,吸附行为符合Freundlich和Langmuir等温式,D301树脂对2,4-二硝基苯酚的平衡吸附容量为235.9mg/g,动态吸附容量为121.3mg/g。用质量分数为10%的氢氧化钠溶液作脱附剂,温度333K,体积为6BV(床体积)时,脱附率为89.2%,树脂脱附再生后可反复使用,并回收2,4-二硝基苯酚。     

［omim］［PF6］萃淋树脂的制备及对萘吸附机制的研究

将离子液体[omim][PF6]以液膜的形式固定在大孔吸附树脂上,制备萃淋树脂,研究其对水相中萘的吸附及影响因素.结果表明,离子液体[omim][PF6]萃取萘的过程,萘主要分配在[omim]+的疏水饱和碳链上;树脂和离子液体质量比为10∶1和20∶1的萃淋树脂,[omim][PF6]在水相中的溶解明显小于2∶1和5∶1的萃淋树脂;不同质量比萃淋树脂对萘的饱和吸附量大小为10∶1萃淋树脂>20∶1萃淋树脂>树脂,对吸附等温线的拟合结果表明,树脂对萘的吸附更符合Freundlich吸附等温式,而萃淋树脂对萘的吸附则更符合Langmuir吸附等温式.不同温度萃淋树脂对萘的饱和吸附量大小为:20℃>15℃>25℃,随着pH的升高饱和吸附量下降,随着无机盐浓度的提高饱和吸附量均有提高;正交实验确定的最佳条件为:温度=30℃、pH=3、NaCl浓度=2 000 mg.L-1,其中pH值是最主要的影响因素.     

PBT树脂生产过程中主要危险有害因素分析及对策

分析了PBT树脂生产过程中的主要危险有害因素有火灾爆炸、机械伤害、中毒及灼烫等,提出了相应的预防对策。