Development of low power non-thermal plasma jet and optimization of operational parameters for treating dyes and emerging contaminants

Non-thermal plasma has emerged as an effective treatment system against the latest class of highly recalcitrant and toxic environmental pollutants termed emerging contaminants(ECs).In the present work,a detailed experimental study is carried out to evaluate the efficacy of a non-thermal plasma jet with two dyes,Rd.B and Met.Blue,as model contaminants.The plasma jet provided a complete dye decoloration in 30 min with an applied voltage of 6.5 kV_(p-p).·OH,having the highest oxidation potential,acts as the main reactive species,which with direct action on contaminants also acts indirectly by getting converted into H_(2)O_(2)and O_(3).Further,the effect of critical operational parameters viz,sample pH,applied voltage(4.5–6.5 kV_(p-p)),conductivity(5–20 mS cm^(-1)),and sample distance on plasma treatment efficacy was also examined.Out of all the assessed parameters,the applied voltage and sample conductivity was found to be the most significant operating parameters.A high voltage and low conductivity favored the dye decoloration,while the pH effect was not that significant.To understand the influence of plasma discharge gas on treatment efficacy,all the experiments are conducted with argon and helium gases under the fixed geometrical configuration.Both the gases provided a similar dye decoloration efficiency.The DBD plasma system with complete dye removal also rendered maximum mineralization of 73%for Rd.B,and 60%for Met.Blue.Finally,the system's efficiency against the actual ECs(four pharmaceutical compounds,viz,metformin,atenolol,acetaminophen,and ranitidine)and microbial contaminant(E.coli)was also tested.The system showed effectivity in the complete removal of targeted pharmaceuticals and a log2.5 E.coli reduction.The present systematic characterization of dye degradation could be of interest to large communities working towards commercializing plasma treatment systems.

Non-thermal plasma enhances performances of biochar in wastewater treatment and energy storage applications

Surface functionalization or modification to introduce more oxygen-containing functional groups to biochar is an effective strategy for tuning the physicochemical properties and promoting follow-up applications.In this study,non-thermal plasma was applied for biochar surface carving before being used in contaminant removal and energy storage applications.The results showed that even a low dose of plasma exposure could introduce a high number density of oxygen-functional groups and enhance the hydrophilicity and metal affinity of the pristine biochar.The plasma-treated biochar enabled a faster metal-adsorption rate and a 40%higher maximum adsorption capacity of heavy metal ion Pb^(2+).Moreover,to add more functionality to biochar surface,biochar with and without plasma pre-treatment was activated by KOH at a temperature of 800℃.Using the same amount of KOH,the plasma treatment resulted in an activated carbon product with the larger BET surface area and pore volume.The performance of the treated activated carbon as a supercapacitor electrode was also substantially improved by>30%.This study may provide guidelines for enhancing the surface functionality and application performances of biochar using non-thermal-based techniques.

Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air

Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the

Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene （PP） films are modified by a dielectric barrier discharge （DBD） with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups.

Improving Hydrophobicity of Glass Surface Using Dielectric Barrier Discharge Treatment in Atmospheric Air

Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge （DBD） at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment, The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CHa and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly.

冷等离子体处理对棉秆无胶纤维板性能影响

以棉秆为原料,通过冷等离子体预处理纤维,采用干法纤维板生产工艺制备棉秆无胶纤维板。研究了处理时间对棉秆纤维表面自由基数量以及无胶纤维板性能的影响。研究结果表明:棉秆纤维经冷等离子体处理后表面相对自由基数量显著提高,用其制成的无胶纤维板强度有明显提高,但吸水率却有一定程度增加。随着处理时间的延长,纤维表面自由基数量增加不明显,板材强度变化亦不明显,因此,处理时间不宜过长。

益气除湿解毒汤治疗宫颈HPV感染的临床研究

目的探讨益气除湿解毒汤治疗宫颈人乳头瘤病毒(HPV)感染的临床疗效。方法将2010年2月-2014年1月间在我院中医妇科门诊就诊符合中医带下病气虚湿热、湿毒蕴结证170例生殖道高危型人乳头瘤病毒(HR-HPV)阳性感染患者,依据宫颈病变"三阶梯"式诊断程序(细胞学筛查-阴道镜检查-组织病理学检查)结果分成3组,分别为A:HR-HPV,新柏氏液基细胞学检测(TCT)阴性;B:HR-HPV,宫颈上皮内瘤变Ⅰ级(CINⅠ);C:HR-HPV CINⅡⅢ;A、B、C3组分别设治疗组A1、B1、C1和对照组A2、B2、C2。A1、B1两治疗组口服益气除湿解毒汤结合阴道塞复方沙棘籽油栓。C1治疗组在宫颈环形电切术(Leep术)后口服益气除湿解毒汤结合阴道塞复方沙棘籽油栓。A2、B2组均自愿接受无治疗而采取随访观察,C2组行Leep术后随访。结果治疗组A1、B1治疗前与治疗3个疗程后的证候积分,经比较P<0.01;A1、B1比较,P<0.05。3组的HPV转阴率,治疗组与对照组比较,P<0.05。结论益气除湿解毒汤可治疗HPV感染,疗效较好。

微等离子体射频技术结合透皮给药系统治疗增生性瘢痕

目的:观察微等离子体射频技术(Fractional micro-plasma radio frequency technology)联合透皮给药系统导入曲安奈德治疗外伤、烧伤等增生性瘢痕的疗效。方法:选取笔者科室2012年11月以来收治的增生性瘢痕患者100例,随机分为观察组和对照组,每组50例。观察组采用微等离子体射频技术联合透皮给药系统治疗;对照组单纯应用微等离子体射频技术治疗。观察两组患者治疗效果及不良反应情况。结果:观察组有效率明显高于对照组,在大面积瘢痕进行透皮给药治疗时,在一定药物总剂量下可增加治疗面积,缩短治疗时间。结论:微等离子体射频技术联合透皮给药技术,易于操作,创伤小,痛苦少,恢复期短,安全性高且副作用小,为微创治疗瘢痕的方法之一。

鼻内镜下低温等离子射频消融术微创治疗腺样体肥大

目的探讨鼻内镜下低温等离子射频消融术治疗腺样体肥大的可行性和优点。方法对29例并发分泌性中耳炎、慢性鼻窦炎及阻塞性睡眠呼吸暂停低通气综合征的腺样体肥大患儿,在鼻内镜辅助下采取低温等离子射频消融术治疗腺样体肥大,再辅以相应手术和药物治疗后观察其转归情况。结果随访3～12个月,7例(11耳)分泌性中耳炎和18例阻塞性睡眠呼吸暂停低通气综合征均痊愈,3例慢性鼻窦炎痊愈,1例基本痊愈。无腺样体残留及并发症发生。结论鼻内镜下低温等离子射频消融术治疗腺样体肥大,具有直视下进行、病变切除彻底、疗效明显、安全性高、创伤小及并发症少等优点,是一种安全、有效、微创的理想腺样体切除术式。(中国眼耳鼻喉科杂志,2006,6:162～163)

ⅠB2和ⅡA2期子宫颈癌术前近距离放疗联合同步化疗的近期疗效及安全性

目的探讨ⅠB2和ⅡA2期子宫颈癌术前近距离放疗联合同步化疗的近期疗效及安全性。方法收集120例ⅠB2和ⅡA2期子宫颈癌患者,按照随机数字表法均分为放疗联合化疗组、化疗组和放疗组。放疗联合化疗组行术前近距离放疗(行腔内后装放疗,192Ir为放射源,5~9 Gy/次,2~3次,总剂量10~27 Gy。)联合同步化疗[顺铂(250~350 mg/m2)联合紫杉醇(130~170 mg/m2)的新辅助化疗,全身静脉化疗2 d后,通过微量泵持续静脉注入化疗],化疗组仅行新辅助化疗,放疗组仅行术前近距离放疗。比较三组近期疗效、临床症状改善情况以及治疗后不良反应情况。结果放疗联合化疗组近期总有效率为90.0%,高于化疗组的70.0%和放疗组的65.0%,组间比较差异具有统计学意义(P<0.05)。三组治疗后阴道排液和出血均有明显改善,组间比较差异无统计学意义(P>0.05)。治疗后,放疗联合化疗组Ⅰ~Ⅱ级骨髓抑制和消化道反应发生率分别为20.0%(8/40)和40.0%(16/40),化疗组为5.0%(2/40)和22.5%(9/40),放疗组为5.0%(2/40)和20.0%(8/40),组间比较差异均具有统计学意义(均P<0.05)。三组均无Ⅲ~Ⅳ级不良反应发生。结论术前近距离放疗联合同步化疗治疗ⅠB2和ⅡA2期子宫颈癌患者能有效改善临床症状,近期疗效较好,安全性较高。

微生物絮凝剂在棉浆废水处理中的应用

为了微生物絮凝剂在棉浆废水中的絮凝率最大化,将絮凝菌株筛选并发酵后对絮凝体系中的各影响条件进行优化。结果表明,从新疆达坂城盐湖采集的5个土壤样品中筛选到一株高活性絮凝剂产生菌XN-2,经初步鉴定为类芽孢杆菌,通过测定其对高岭土悬浊液的絮凝率为90%。最佳絮凝条件为:pH 9.0(原水p H值)、废水温度20℃、在文章所述实验条件下,絮凝剂投加量为4m L、2%Ca Cl23.5m L。

Degradation of Aniline Wastewater Using Dielectric Barrier Discharges at Atmospheric Pressure

Aniline is a toxic water pollutant detected in drinking water and surface water, and this chemical is harmful to both human and aquatic life. A dielectric barrier discharge （DBD） reactor was designed in this study to investigate the treatment of aniline in aqueous solution. Discharge characteristics were assessed by measuring voltage and current waveforms, capturing light emission images, and obtaining optical emission spectra. The effects of several parameters were analyzed, including treatment distance, discharge power, DBD treatment time, initial pH of aniline solutions, and addition of sodium carbonate and hydrogen peroxide to the treatment. Aniline degradation increased with increasing discharge power. Under the same conditions, higher degradation was obtained at a treatment distance of 0 mm than at other treatment distances. At a discharge power of 21.5 W, 84.32% of aniline was removed after 10 rain of DBD treatment. Initial pH significantly influenced aniline degradation. Adding a certain dosage of sodium carbonate and hydrogen peroxide to the wastewater can accelerate the degradation rate of aniline. Possible degradation pathways of aniline by DBD plasmas were proposed based on the analytical data of GC/MS and TOC.

低温等离子体在废气处理中的应用

目前对异味恶臭废气的常用处理方法存在运转费用高、设备及运行管理要求高、占地面积大、净化效率不高、极易产生二次污染、易受污染物浓度及温度影响等缺点。低温等离子体降解污染物是利用高能电子、自由基等活性粒子与废气中的污染物作用,使污染物分子在极短的时间内发生分解,以达到降解污染物的目的。通过山东某制药公司废气处理项目应用实例,显示出低温等离子体处理废气的效果和经济效益的优势。

Catalytic decomposition performance for O_3 and NO_2 in humid indoor air on a MnO_x/Al_2O_3 catalyst modified by a cost-effective chemical grafting method

Processes based on non-thermal plasma（NTP） for indoor air treatment inevitably lead to the formation of toxic by-products such as ozone（O3） and nitrogen oxides（NOx）. Adding a step of heterogeneous catalysis in series with NTP could allow for the decomposition of the by-products. Therefore, different catalysts were developed based on transition metal oxides, such as NiOx, CoOxand MnOxwith different weight percentage 1, 5 and 10 wt.%,deposited on a γ-Al2O3 support. The O3 removal efficiency（ORE） and the NOxremoval efficiency（NRE） were very encouraging in dry air： about 65% and 80%, respectively, by using2 g 5 wt.% MnOx/Al2O3 catalyst under the experimental conditions. However, strongly negative effects of relative humidity（RH） on the catalytic decomposition performance were observed. To overcome this limitation, the catalyst surface was modified to make it hydrophobic using a cost-effective chemical grafting method. This treatment consisted in impregnating the 5 wt.% MnOx/Al2O3 catalyst with different trichloro（alkyl）silanes（TCAS）.The effects of different linker lengths and amounts of TCAS for the hydrophobicity and the decomposition performance of surface-modified catalysts under humid conditions were investigated. Our results show that the surface-modified catalyst with the shortest linker and 0.25 mmol/gcatof modifying agent represents the best catalytic decomposition performance for O3. Its ORE is 41% at 60% RH, which is twice that of the non-modified catalyst.