膜分离技术处理石墨烯生产废酸的试验研究

作为一种新型分离技术,膜分离技术广泛应用于处理工业废水。为考察耐酸纳滤膜技术对石墨烯行业生产废酸的处理效果,试验分别采用国产膜元件和进口膜元件对废酸进行处理。结果表明,两种膜元件对锰离子的截留率较高,截留率为88%~97%;两种膜元件对钾离子的截留率差异较大,进口膜元件截留率大于50%,国产膜元件大于20%;运行过程中,国产膜元件的运行压力约为进口膜元件的一半。运行结果表明,膜分离技术用于处理石墨烯行业废酸,工艺可行。

对利用铁矾和废酸浸出硫酸锰的研究

研究了利用钛白粉生产的副产品铁矾FeSO4.7H2O和废酸代替两矿加酸法中的硫铁矿和浓硫酸来浸渍低品位的软锰矿生产硫酸锰,通过正交试验确定了最优生产条件:铁矾用量50g,温度95℃,时间3h,废酸用量90ml。该方案锰的浸出率达到98.12%,大于按原始两矿加酸法工艺生产的浸出率96%。

Process Development and Design of Chlorine Dioxide Production Based on Hydrogen Peroxide

This paper presents a process development and design of chlorine dioxide production based on hydrogen peroxide. The process is characterized by cleaner production, high efficiency, and waste minimization. Optimization of process conditions, selection of equipment, and experiment of recycle of waste acid are carried out. The process design is realized in consideration of several aspects such as operation, material, equipment design and safety. An industrialized process flowsheet is developed according to experiment. A pilot testing is carried out to confirm the lab results. Process design of chlorine dioxide production based on hydrogen peroxide is realized.

Extraction of Theanine from Waste Liquid of Tea Polyphenol Production in Aqueous Two-phase Systems with Cationic and Anionic Surfactants

Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactanttwo-phase system （ASTP） with cationic surfactant （CTAB） and anionic surfactant （SDS）. Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant. The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP. Theanine concentration in the bottom phase increases with increasing concentration of theanine, whereas the Partition coefficient and extraction rate only change a littlewhen the concentration of theanine is above 0.2 g.L-＇. With the increase of SDS concentration, the phase ratio and the partition coefficient decrease, while the extraction efficiency of theanine increases and the concentration of theanine changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio. The temperature has a notable ef- fect on the concentration of theanine in the bottom phase, partition coefficient and extraction rate of theanine. The increase of waste liquid decreases the phase ratio, increases the concentration and extraction rate of theanine in the bottom ohase, since the orotein and the saccharide enter the bottom nhase with theanine.

THEATMENT OF WASTEWATER FROM PRODUCTION PROCESS OF 2,3-ACID

Wastewater from production process of 2,3-acid was treated by adsorption usingmacroporous resin NDA-708. After only one-step treatment by resin adsorption, removalefficiency of three kinds of naphthalene chemicals was above 99%, removal efficiency ofCODcr was above 96% Under proper operating condition, desorption efficiency wasaround 100%. The running records of the industrial facility showed that the naphthlenechemicals in desorption effluent could be reused without obvious influence on the qualityOf the product.

Ferulic Acid in Paper Mulberry and Its Wastewater from Pulps Production

Wastewater from paper mulberry （Broussonetia papyrifera） pulps production was subjected to biological activities evaluations and phenolics characterization. The EtOAc extract was found to be the best antioxidant （IC50 = 0.4408 mg/mL） and tyrosinase inhibitor （IC50 = 1.6340 mg/mL） comparing to vitamin C （1C50 = 0.0011 mg/mL） and kojic acid （IC50 = 0.0244 mg/mL）, respectively, and the highest ferulic acid content （4.450 ±0.0077 ppm）. This fraction was further column chromatographed and antioxidant activity was archived （IC50 = 0.075 mg/mL） as well as tyrosinase inhibitory effect （IC50 = 0.042 mg/mL） in addition to ferulic acid （45.310 ± 0.0115 ppm）. Ferulic acid in paper mulberry was compared. Reflux with H2O gave the highest ferulic acid content （37.848 ± 1.2470 ppm） followed by a mixture of MeOH and H2O （2.002 ± 0.0370 ppm） and MeOH （1.185 ± 0.0320 ppm）, respectively. The reflux H2O was partitioned with EtOAc that extracted most of ferulic acid （256.678 ± 0.3760 ppm） and left less in the aqueous layer （9.408 ± 0.2820 ppm）.

A Combined System for Biological Removal of Nitrogen and Carbon from Nylon-6 Production Wastewater

A combined system consisting of hydrolysis acidification, denitrification and nitrification reactors was used to remove carbon and nitrogen from the nylon - 6 production wastewater, which was characterized by good biodegradability and high nitrogen concentration. The influences of Chemical Oxygen Demand （COD） in the influent, recirculation ratio, Hydraulic Residence Time （HRT） and Dissolved Oxygen （DO） concentration on the system performances were investigated. From results it could be seen that good performances have been achieved during the overall experiments periods, and COD, Total Nitrogen （TN）, NH^＋ -N and Suspended Solids （SS） in the effluent were 53, 16, 2 and 24 mg· L^-1, respectively, which has satisfied the first standard of wastewater discharge established by Environmental Protection Agency （EPA） of China. Furthermore, results showed that operation factors, viz. COD in the influent, recirculation ratio, HRT and DO concentration, all had important influences on the system performances.

TREATMENT OF SORBIC ACID MANUFACTURING WASTEWATER BY HYPERCROSSLINKED POLYMERIC ADSORBENT (NDA-150)

The treatment of sorbic acid manufacturing wastewater by NDA-150 resin was investigated. The experiments show that this process is suitable for the treatment of sorbic acid manufacturing wastewater. About 98% sorbic acid and 50% CODcr were removed under optimal operating conditions, and 70% of sorbic acid in sorbic acid manufacturing wastewater was reclaimed. This process makes it possible to recover valuable materials from the wastewater and to improve the quality of effluent water.