THE INVESTIGATION ON PHOTOCATALYTIC TREATMENT OF WASTE WATER CONTAINING PHENOL OVER ZnO

This paper adopts a medium pressure mercury lamp as light source and ZnO powder as catalyst to investigate the effect of radioactive wave length, component of phenol ZnO suspension and stirring method on phenol decomposition rate. The optimized conditions for the phenol decomposition are: (1) Radioactive wave length: 360～420 nm; (2)Phenol concentration in the suspension is less than 200 mg/l; (3)ZnO concentration is 3～8 g/l; (4)pH value is 5～7; (5)Reaction temperature is 25℃～40℃; (6)Agitation at atmosphere. Phenol can decompose in two ways: (1)Reacting with photogenerated cavity; (2)Reacting with ·OH radical.

Phenol Oxidation by Combined Cavitation Water Jet and Hydrogen Peroxide

The paper presents results of phenol oxidized under the conditions of high temperature created during collapse of cavitation bubbles.The degradation efficiency has been greatly improved by using cavitation water jets combined with H2O2 as demonstrated in laboratory tests.Various factors affecting phenol removal ratio were ex-amined and the degradation mechanism was revealed by high performance liquid chromatography(HPLC).The re-sults showed that 99.85% of phenol was mineralized when phenol concentration was 100 mg·L-1 with pH value of 3.0,H2O2 concentration of 300 mg·L-1,confining pressure of 0.5 MPa,and pumping pressure of 20 MPa.The in-termediate products after phenol oxidation were composed of catechol,hydroquinone and p-benzoquinone.Finally,phenol was degraded into maleic acid and acetic acid.Furthermore,a dynamic model of phenol oxidation via cavi-tation water jets combined with H2O2 has been developed.

STUDY ON APPLICATION OF AERATION BIOLOGICAL FLUID TANK TECHNOLGY IN NH_4^+-N WASTE WATER TREATMENT

This paper introduces an application of "Aeration biological fluid tank" technology (ABFT) for the treatment of waste water containing NH + 4 N and high concentrated organic chemicals. Highlights were focused on the effects of dissolved oxygen, pH, temperature and retention time on waste water biological treatment in order to find out a new approach in treatment of waste water containing high concentrated NH + 4 N.

Removal of phenol by activated alumina bed in pulsed high-voltage electric field

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe^2＋. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe^2＋ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.

In-situ route for the graphitized carbon/TiO composite photocatalysts with enhanced removal efficiency to emerging phenolic pollutants

TiO2 is the most photoactive material because of its superstrong photooxidizing ability,and TiO2 photocatalysis has been widely applied in sustainable water treatment and environmental remediation.However,poor sunlight or visible-light harvesting efficiency and fast recombination rate of the photogenerated charge carriers severely limit the practical applications of TiO2.To overcome these problems,the present work demonstrates a facile in-situ co-condensation method combined with hydrothermal treatment to prepare a series of graphitized carbon/TiO2 composite photocatalysts,and anatase TiO2 phase andp-p-conjugated polycyclic aromatic carbon structure are created simultaneously.As-prepared TiO2/C composites exhibit remarkably high visible-light photocatalytic activity in the degradation of aqueous emerging phenolic pollutants,acetaminophen(APAP)and methylparaben(MPB),and apparent rate constant of the TiO2/C composite with carbon doping level of 10.3%for APAP and MPB removal is 7.6 and 2.8 times higher than that of bare TiO2,and 6.2 and 2.6 times higher than that of Degussa P25 TiO2.Based on the results of photoelectrochemical experiments,indirect chemical probe measurements,and ESR spectroscopy,it is verified that doping TiO2 with graphitized carbon is responsible for this enhanced photocatalytic activity,which renders the improved visible-light harvesting ability,the accelerated separation of the photogenerated charge carriers,and enlarged BET surface areas.Through analyzing the intermediates yielded in the photodegradation process,the pathway of visible-light photocatalytic degradation of APAP and MPB over the TiO2/C composite is proposed.

Phenol Removal from Aqueous Solutions by Electrocoagulation Technology Using Iron Electrodes:Effect of Some Variables

The aim of this study was to determine the effect of electrocoagulation technology using iron electrodes on phenol removal in aqueous solutions. The removal of phenol was investigated in terms of various parameters, namely, current density, phenol and NaCl concentration, pH, and alginic acid concentration. The results showed that the removal efficiency of phenol increased with increasing the current density, pH and NaCl concentration, whereas it was inversely associated with initial concentration of phenol and alginic acid concentration. According to the results, electrocoagulation is a promising process for treatment of wastewater containing high concentration of phenol.

Promoting catalytic ozonation of phenol over graphene through nitrogenation and Co_3O_4 compositing

Catalytic ozonation is progressively becoming an attractive technique for quick water purification but efficient and stable catalysts remains elusive. Here we solvothermally synthesized highly-dispersed Co3O4 nanocrystals over microscale nitrogen-doping graphene （NG） nanosheets and tested it as a synthetic catalyst in the ozonation of phenol in aqueous solutions. Transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy were used to determine its morphology, crystallinity, elemental composition and molecular bonds, respectively. The comparative experiments confirmed the highest catalytic activity and oxidation degree （AOSC） of Co3O4/NG among four nanocomposites （G, NG, Co3O4/G, and Co3OJNG）. Co3O4/NG also has exhibited the highest degradation rate： complete conversion of a near-saturated concentration of phenol （941.1 mg/L） was achieved within 30 min under ambient conditions with only a small dosage of Co3O4/NG （50 mg/L） and ozone （4 mg/L, flow rate： 0.5 L/min）. It also resulted in 34.6% chemical oxygen demand （CODcr） and 24.2% total organic carbon （TOC） reduction. In this work, graphene nanosheets not only functioned as a support for Co3O4 nanocrystals but also functioned as a co-catalyst for the enhancement in phenol removal efficiency. The surface nitridation and Co3O4 modification treatment further improved the removal rate of the phenol pollutants and brought in the higher oxidation degree. Our finding may open new perspectives for pursuing exceptional activity for catalytic ozonation reaction.

膜分离技术在工业水处理中的应用

随着经济社会的发展,工业建设的规模不断扩大,对于低耗能高环保的技术的需求也在增大,而膜分离技术的出现能更好的满足这种需求。基于此,本文着重对膜分离技术在工业水处理中的应用进行研究,重点分析了膜分离技术的特点及工作原理,并在此基础上的分析了其在含酚废水和染料废水等的应用、在轻工废水中的应用、在含重金属废水的应用、在化学及石油工业废水中的处理,,希望对以后工业水处理中的膜分离技术应用能有所帮助。

炼焦过程产生的污染物分析

焦化厂是钢铁企业中对环境造成污染最严重的生产单元。在参阅有关文献的基础上,分析了焦化生产各个环节可能产生的污染。结果表明,备煤过程产生的煤尘、选煤废水、煤堆渗滤液,装煤过程产生的烟气,炭化室泄露的荒煤气,湿法熄焦产生的烟气、熄焦废水,荒煤气净化、焦油、粗苯精加工产生的烟气、焦化废水和固体废弃物等是焦化厂的主要污染源。炼焦过程产生的主要污染物为多环芳烃、酚类、氰化物、硫化物、重金属以及装煤、推焦过程产生的二噁英类等。其中炼焦炉周边、荒煤气净化车间、焦油和粗苯加工车间是焦化厂污染最严重的区域。

功率超声在有机废水处理中的应用

功率超声技术在有机污染物废水处理中应用是一种新型技术。本文介绍了功率超声技术在声化学法。

有机膨润土吸附苯酚的性能及其在水处理中的应用初探

分别用氯化十六烷基吡啶（ＣＰＣ）和溴化十六烷基三甲铵（ＣＴＭＡＢ）改性膨润土，试验了制备有机膨润土的适宜条件及其对吸附苯酚性能的影响。上述两种有机膨润土吸附水中苯酚很快能达到平衡。ｐＨ值为３─９时，有机膨润土处理苯酚的效果基本一致；ｐＨ＞１１时，有较高的去除率。ＣＰＣ－膨润土或ＣＴＭＡＢ－膨润土对苯酚的饱和吸附容量分别为１０３．５ｍｇ／ｇ和７５．０ｍｇ／ｇ。有机膨润土处理苯酚的效果比原土提高８倍以上。

阴-阳离子有机膨润土协同吸附作用及其机理研究

合成并研究了一系列阴-阳离子有机膨润土对水中苯酚、苯的吸附作用及其机理.结果表明,阴-阳离子有机膨润土对水中有机物具有协同吸附作用,其作用大小与改性时所用表面活性剂的种类、组成、配比及有机物本身的性质有关;对苯酚的吸附符合Langmuir和Freundlich吸附等温式,是分配作用(partition)和表面吸附(adsorption)共同作用的结果,分配作用的贡献率随改性时阴离子表面活性剂加入量的增大而增大;对水中苯的吸附以分配作用为主,分配系数大于原土及单阳离子有机膨润土,且与有机碳含量呈正相关.

污水处理生物技术的应用

针对环保要求日益严格,而水源污染却越演越烈的现象,选择性地综述了湿地工艺、固定化藻类和活性污泥等生物技术在污水处理中的应用实例及其在净化废水、减轻水体富营养化方面的显著作用。三项生物技术的共同特点是高效快速、低耗节能、简易实用、管理方便且能耐受高负荷污水的冲击。净化污水主要通过基质的过滤吸附、微生物的分解代谢、植物根系或藻类的吸收利用等理化和生物的协同作用。确保和提高污水净化效果的关键因素是:湿地系统———水力负荷与停留时间、有机污染物负荷、根系发达的植物种类;固定化藻类———载体的传导性能和孔径、被固定藻类的细胞粒径、密度和生长状态、藻类生长的最适pH和温度条件;活性污泥技术———单位体积内好气性微生物的浓度及其与其他活性生物的比例、活性污泥的循环速度与回用、系统中的溶氧浓度和好气条件。

我国水处理剂的研究与应用现状展望

论述了我国水处理剂的概况 ,着重介绍了絮凝剂的分类、应用和发展 ,并对我国水处理剂的产量、品种、质量等进行了分析 ,对其市场前景进行了展望。

沟戈登氏菌吸附Cu^(2+),Pb^(2+),Hg^(2+)的重金属抗性研究

用Cu2+,Pb2+和Hg2+3种离子对沟戈登氏菌诱导培养的结果表明,这些离子能促进提高培养后的沟戈登氏菌对Pb2+和Hg2+的吸附活性,但对Cu2+的吸附活性则不明显,甚至有一定的抵抗作用·培养基中加入5 72mg/L的Cu2+连续培养时,沟戈登氏菌对Hg2+的吸附率由39%上升至98%,对Cu2+的吸附率由51%下降至35%,这种差别使吸附过程具有选择性·在利用微生物吸附工业废水中的重金属离子时,选择性诱导培养是提高微生物吸附能力的有效方法·

壳聚糖及其衍生物在水处理中的应用新进展

天然高分子聚合物壳聚糖具有原料丰富、无毒、易于生物降解等优点,在水处理方面的应用日益广泛,不断有新方法和新技术产生。综述了近几年来壳聚糖及其衍生物在含重金属离子废水、染料废水、食品工业废水和含酚废水处理中的应用新进展。

特种活性炭处理含酚废水的实验研究

采用特种活性炭进行含酚废水的吸附处理试验，研究了特种活性炭吸附法处理含酚废水的反应机理和影响因素，并考察了活性炭用量、pH值、反应温度、反应时间等因素对含酚废水处理效果的影响。实验结果表明，对150mL焦化废水，在活性炭用量为10g、pH值为6．0—7．0、室温及反应时间为2h的条件下，含酚废水经过特种活性炭吸附处理后，出水酚浓度为0．296mg／L，水质指标满足《城镇污水处理厂污染物排放标准》中的排放标准。

有机粘土吸附处理水中苯酚的性能及应用

分别用溴化十六烷基三甲铵（ＣＴＭＡＢ）、氯化十六烷基吡啶（ＣＰＣ）和氯化十四烷基吡啶（ＴＰＣ）改性膨润土、沸石和硅藻土；探讨了制备有机粘土的适宜条件；研究了粘土类型、表面活性剂种类及其浓度对有机粘土吸附处理水中苯酚性能的影响。结果表明，有机粘土吸附处理苯酚的性能较相应的原土好得多。通过Ｘ－衍射分析等手段探讨了有机粘土的结构及其吸附机理。

焦化含酚废水在Ti／PbO_2电极上的氧化处理

通过对Ｔｉ／ＳｎＯ２＋Ｓｂ２Ｏ３＋ＭｎＯ２／ＮＯ２阳极在Ｈ２ＳＯ４中的使用寿命和电化学动力学参数的测试，并把该电极用于氧化处理焦化含酚废水，且和铅电极进行了比较研究，结果表明：Ｔｉ／ＳｎＯ２＋Ｓｂ２Ｏ３十ＭｎＯ２／ＰｂＯ２电极在Ｈ２ＳＯ４中具有较长的使用寿命，能使酚的转化率达到９５％并较Ｐｂ电极节电３３％，是一种优良的电化学催化剂。