The application of high frequency ultrasound waves to remove ammonia from simulated industrial wastewater

This article aims at applying the ultrasound technique in the field of clean technology to protect environment. The principle of ultrasound was conducted here to remove and recover ammonia from industrial wastewater. Three different concentrations of ammonia namely 5%, 15% and 25% (vol.%) were used to study the efficiency of removing ammonia from water. These concentrations are exactly similar to what may be found in wastewater resulting from strippers at petroleum refinery. High ultrasound frequency device with 2.4 and 1.7 MHz was conducted to study the effect of waves on the removal of ammonia. It was found that the ultrasound has the ability to remove ammonia with 5% concentration to meet the local standard of treated wastewater within less than 2 h for 0.080 L solution. It was also found that as the concentration of the ammonia increases the removing of ammonia within 2 h decreases, still the concentration of the ammonia meets the standard of the treated wastewater. The ability of the ultrasound to remove the ammonia failed to produce any mist when the height of the liquid solution increased, namely when the height reached (0.0337 m). This is equivalent to liquid volume of 0.150 L. It means that the device capacity to remove ammonia has certain limitations based on liquid heights. The best condition for ammonia removal was obtained at 5% concentration and 0.080 L liquid volume (equivalent to 0.0165 m).     

日光/Fenton法处理油田废水的机理

研究了日光/Fenton法对辽河油田采油废水处理效果,并分析了日光/Fenton法好于普通Fenton法的原因。辽河油田采油废水主要含有苯类和烷烃类化合物,日光/Fenton法对辽河油田采油废水处理效果与废水水层高度相关,水层高度升高,COD去除率降低,日光对本油田废水的穿透能力在1 m左右。废水水层高度为40 cm左右时,采油废水经日光/Fenton法处理后,COD由430降至63.2 mg·L-1。通过紫外可见光谱法、红外光谱法(FTIR)及X射线衍射法证明了利用日光/Fenton法处理辽河油田采油废水时体系中有聚铁生成,聚铁的形态与普通Fenton体系生成的聚铁基本相同。同时利用紫外光谱法研究了苯类及烷烃类的转化方式,结果表明： 烷烃类在日光/Fenton和Fenton体系中的转化方式基本相同;而苯类在日光/Fenton体系中的羟自由基作用下转化成具有光敏性的物质。芳香族中间产物的光敏性是日光/Fenton法比普通Fenton法高效的原因。     

3DEEM和PARAFAC的猪场废水DOM组成特征分析

猪场废水中物质组成与其潜在的环境效应密切相关,研究废水中有机物的组成特征将可为制订科学的资源管理措施提供理论依据。通过采集江西省余江县不同养殖规模(以年出栏量计)的吴杨高(WYG,2 000头)、成林牧业(CL,5 000头)、万谷(WG,20 000头)和正邦(ZB,24 000头)等猪场自然氧化塘内的养殖废水,运用三维荧光(3DEEM)和平行因子分析(PARAFAC)模型研究废水中可溶性有机物(DOM)组成及其荧光特性。结果表明,成林和吴杨高猪场废水中化学需氧量(COD)、全氮(TN)、氨氮(NH+₄)以及可溶性有机碳(DOC)浓度均显著高于万谷和正邦猪场。通过3DEEM和PARAFAC建模发现,猪场废水中可溶性有机物(DOM)主要有三个组分,其中包括两个类蛋白质组分(C1,C2)和一个类腐殖质组分(C3)。线性拟合结果表明,C1分别与C2,C3组分荧光强度间呈极显著正相关,表明不同组分间可能具有相同的物质来源或变化趋势。与养分浓度变化趋势一致,成林和吴杨高猪场DOM组分的荧光强度显著高于万谷和正邦。此外,C1和C2组分对猪场废水中DOM总的贡献率依次为成林(89.7%),吴杨高(87.9%),万谷(77.5%)和正邦(72.9%),而C3所占比例分别为成林(10.3%),吴杨高(12.1%),万谷(22.5%)和正邦(27.1%)。可见,废水中类蛋白质组分比例明显高于类腐殖质组分。与此同时,荧光指数(FI₃₇₀)和腐殖化指数(humification index, HIX)的变化趋势,整体表现为正邦和万谷猪场显著高于成林和吴杨高猪场。Pearson相关性分析表明,不同的荧光指数受环境指标的影响存在一定差异,COD与DOC浓度分别与DOM组分荧光强度间呈极显著相关性。综上,不同的规模化猪场废水中养分水平在一定程度上影响着DOM组成和荧光特性的形成。     

工业污水消毒脱色的紫外-可见吸收光谱分析

研究紫外-可见吸收光谱用于工业污水色度表征的替代方法,并用以比较消毒剂对污水的脱色效果。结果表明,对于色度组成变化较大的工业污水,应使用可见吸收光谱(350～600 nm)而非紫外吸收光谱表征色度。可见吸收光谱的特征值与污水的真色值相关性良好。三种消毒剂中臭氧和二氧化氯的脱色性能好于氯,但二氧化氯自身色度对脱色有负面影响。可见吸收光谱特征值能有效反映消毒处理后污水色度的变化。     

废水处理过程中荧光测量系统研究

针对废水处理过程中厌氧反应器过程中产生的荧光类物质荧光特性和废水处理过程之间的关系,采用荧光光谱技术构建一个在线测量废水处理过程中厌氧反应状态的荧光检测平台,并为废水处理过程中的参数控制提供有效的、可信的和稳定的技术依据,在一定程度上可提高废水处理的效率.结果表明:本系统采用荧光光谱技术,对废水处理过程中厌氧反应器检测...     

Treatment of petroleum refinery wastewater by ultrasound-dispersed nanoscale zero-valent iron particles

Petroleum refineries release wastewater, which is rich in organic pollutants and cannot be treated easily. This study presents the treatment of petroleum refinery wastewater using nanoscale zero valent iron (NZVI) in the presence of ultrasonication. NZVI characteristics were analyzed using SEM and XRD. The influence of NZVI dosage and initial pH on % chemical oxygen demand (COD) reduction was studied. From the results, it can be inferred that a dosage of 0.15 g/l and an initial pH are optimum for the effective degradation of effluents. The degradation data were found to follow first order kinetics. The results indicate that using NZVI in combination with ultrasonication is an efficient method for the treatment of petroleum refinery wastewater.     

Elemental analysis of trace elements in fly ash sample of Yata?an thermal power plants using EDXRF

Fly ash samples collected by means of an electrostatic precipitator from the lignite-fired Yata?an Power Plants of the located in Turkey was analysed using X-ray fluorescence technique. Five trace elements, namely Nd, Ba, Sr, Mo and As were quantified using XRF. These concentration values can be helpful in developing a environmental pollution abatement approach for various applications of fly ash such as cement manufacture, wastewater treatment, lightweight contraction aggregate, ceramic production, and secondary source in recovery of valuable elements. Present results compared with results of the Kemerkoy thermal power plants [?ahin Y, Karabulut A, Budak G. A practical method for the analysis of overlepped peaks in energy dispersive X-ray spectra. Appl Spectrosc Rev 1996;31:333-45].     

城市污水的三维荧光指纹特征

传统表征有机物含量的水质参量如化学需氧量(COD)和生化需氧量(BOD)等只能表示总量,无法展示有机物成分.荧光光谱可以作为一种新型的水质表示方法,它像指纹一样与水样一一对应,被称为水质荧光指纹.采用三维荧光光谱(EEM)技术研究了城市污水荧光指纹特征,结果表明城市污水具有4个典型荧光区,各区的荧光中心、强度以及1区荧光中心λex=280 nm,λem=340 nm与2区荧光中心λex=225 nm,λem=340 nm的荧光强度的比值可以作为城市污水的主要荧光指纹特征.荧光指纹包含了大量污染物信息,通过与城市污水中典型污染物质的荧光光谱的比对,初步确定了各荧光区可能的荧光信号来源.荧光指纹法可表示有机物类型和含量,可作为化学需氧量和生化需氧量等参量的有益补充.     

食品工业清洁生产测评技术与方法研究--废水中氨氮含量的测定

对肉类加工废水中的氨氮(NH3-N)含量的测评技术和方法进行了研究.采用纳氏试剂分光光度法测定了不同废水中的NH3-N含量.结果表明,屠宰和熟食加工产生的废水、熟食加工产生废水和混合废水经处理后的水样中氨氮含量分别为255mg/L、8.24mg/L、和13.4mg/L,平均回收率为93.0%,平均相对标准偏差为2.19%.所得数据可靠、准确,其方法快速、可行.探讨的测评废水中氨氮的方法,将为企业实施内部监测提供依据,为我国制定清洁生产测评标准提供参考.     

Removal of dinitrotoluenes in wastewater by sono-activated persulfate

Oxidative degradation of dinitrotoluenes (DNTs) in wastewater was performed using persulfate anions combined with ultrasonic irradiation, wherein a synergistic effect is observed. The batch-wise experiments were carried out to elucidate the influence of various operating parameters on sono-activated persulfate oxidation, including ultrasonic power intensity, persulfate anion concentration, reaction temperature and acidity of wastewater. It is noteworthy that the nitrotoluene contaminants could be almost completely eliminated by virtue of sono-activated persulfate oxidation, wherein sulfate radicals serve as principal oxidants, of which amounts are significantly enhanced via addition of sodium sulfate. Based on the results given by gas chromatograph-mass spectrometer (GC-MS), it is postulated that the methyl group of DNTs preliminarily underwent oxidation pathway into dinitrobenzoic acid, followed by decarboxylation to form 1,3-dinitrobenzene (DNB). In sum, the sono-activated persulfate oxidation is a promising method for treatment of nitrotoluenes in wastewater.     

Matrix-Assisted Photochemical Vapor Generation for the Direct Determination of Mercury in Domestic Wastewater by Atomic Fluorescence Spectrometry

In this article, matrix-assisted photochemical vapor generation is proposed for the direct determination of mercury in domestic wastewater by atomic fluorescence spectrometry. With the ultraviolet light irradiation, the matrix (low-molecular-weight organic compounds) in domestic wastewater samples can produce reducing species. These reducing species could reduce mercury from mercury (II) to elemental mercury, subsequently swept by argon to atomic fluorescence spectrometry for detection. The effects of several factors, such as material of the photoreaction coil, ultraviolet light wavelength, ultraviolet light irradiation time, and flow rate of carrier gas, were investigated. Under the optimized condition, a limit of detection of 0.1 µg L^?1 was obtained. The standard addition method was used for the spiked mercury domestic wastewater sample analysis, with a relative standard deviation (n = 11, at 20 µg L^?1) of 4.8%, and recovery test results ranged from 81% to 110%. The proposed method was applied to analyze two certified reference materials and four domestic wastewater samples, with analytical results in good agreement with certified values or those obtained by ICP-MS. Interferences from common transition metals and alkaline metals as well as alkaline earth metals were also investigated. This is a simple, reagent-free, cost-effective, green method for mercury determination in domestic wastewater.     

某半合成青霉素制药废水的水质指纹特性

近年来,地表水中时有抗生素检出,且浓度较高,因此加强抗生素废水的监管势在必行。三维荧光技术快速、简便且灵敏度高,可以反映有机物组成,其光谱被称为水质指纹。选取某典型半合成青霉素制药废水进行水质指纹特性研究。该废水共有4个主要水纹峰,分别位于激发波长/发射波长为360/445,255/445,275/305和230/300 nm附近。在一定浓度范围内,各峰强度与污染物浓度呈现良好的线性关系。该废水的两个峰275/305和230/300 nm可能源于产品中间体左旋对羟基苯甘氨酸邓钾盐、产品阿莫西林和水解产物左旋对羟基苯甘氨酸等。pH对水质指纹有明显影响,这显示出某些荧光污染物可能具有酸碱基团。水质指纹能够用于该种抗生素制药废水的监测。     

Decomposition of nitrotoluenes in wastewater by sonoelectrochemical and sonoelectro-Fenton oxidation

Oxidative degradation of dinitrotoluene (DNT) and 2,4,6-trinitrotoluene (TNT) in wastewater was conducted using electrochemical and electro-Fenton processes respectively, combined with ultrasonic irradiation, wherein a synergistic effect is observed. Experiments were carried out to elucidate the influence of various operating variables on the sonoelectrolytic behavior, such as electrode potential, sonoelectrolytic temperature, acidity of wastewater, oxygen dosage, and dosage of ferrous ions. It deserves to note that the nitrotoluene contaminants could be completely decomposed by sonoelectro-Fenton method, wherein hydrogen peroxide was in situ generated from cathodic reduction of oxygen, supplied partially by anodic oxidation of water. During the sonoelectrolytic process, in spite of existence of degassing phenomenon, the high yield of hydrogen peroxide was produced due to the significantly enhanced mass transfer rate of oxygen toward the cathode, caused by ultrasonic irradiation. Because higher removal efficiency of DNTs and TNT obtained at ambient conditions, it is believed that the sonoelectrolytic method is potentially applied to dispose wastewater from toluene nitration processes.     

利用衰减全反射傅里叶红外光谱(ATR-FTIR)技术快速筛选可降解苯酚菌株

苯酚是一种重要的化工原料并广泛存在于工业废水中,随着各国对苯酚生物毒性的认识,排放标准日益提高。生物法作为一种高效、 低成本、 不易二次污染的方法常用于含酚的废水处理。但是可降解苯酚的微生物筛选却是一个复杂繁琐的过程。衰减全反射傅里叶红外光谱(attenuated total reflection Fourier transform infrared,ATR-FTIR)技术是一种高效、 快捷、 高指纹特性的物理检测技术,主成分分析联用最小偏二乘法(principal component analysis-partial least squares,PCA-PLS)是一种有效提取特征指纹峰并建立模型的方法,该实验联合ATR-FTIR检测技术和PCA-PLS统计方法建立苯酚浓度与吸光度模型,可以快速检测固体培养基中底物浓度。实验建立模型判定系数可以达到99.5%,预测集的判定系数可以到达99.4%,说明模型具有较高的拟合性和推广性。通过模型可以预测出菌株降解后固体培养基底物浓度,筛选出可降解苯酚功能微生物,传统的液体培养并采用气相色谱检测残留苯酚浓度筛选出的结果与ATR-FTIR方法筛选出结果进行对比发现,得到相同的筛选结果。结果表明ATR-FTIR联合PCA-PLS建立高拟合度模型,可以快速检测固体培养基底物浓度,从而达到快速筛选可降解苯酚菌的目的,这种方法可以应用到其他有特征指纹峰的底物中,ATR-FTIR是一种可以广泛应用到功能微生物筛选的快速检测方法。     

相关向量机在污水硝氮检测中的应用

针对地表水质的复杂性以及紫外光谱数据维数高、谱带重叠严重的特点,提出将相关向量机算法应用于硝氮的连续紫外光谱分析,实现了对实际污水硝氮的快速准确无污染检测。首先介绍了相关向量机算法原理,然后在分析制药污水紫外吸收光谱的基础上选取230～245 nm紫外吸光度数据用于建模,应用多元线性回归、偏最小二乘方法、经典支持向量机方法(SVM)和相关向量机方法分别建立硝氮回归模型并比较分析模型性能。实验结果表明：相关向量机模型预测更准确,模型更稀疏,预测速度快,检测结果的相对满量程误差控制在4.5%以内,适用于对复杂组成成分的实际污水硝氮的有效快速检测。     

电镀废水中Cr（Ⅵ）的次甲基蓝分光光度法研究

在H2SO4溶液中,以次甲基蓝（MB）为显色剂,利用铬（Ⅵ）与次甲基蓝（MB）在水浴加热条件的显色反应,建立了一种测定电镀废水中微量铬（Ⅵ）的新光度法。反应产物的最大吸收波长为573nm,摩尔吸光系数为1.40×10^4L·mol^-1·cm^-1,检出限为2.4×10^-7g·mL^-1,铬（Ⅵ）含量在10—50μg/25mL范围内有良好的线性关系,相关系数为0.9991,用于测定电镀废水中的微量铬（Ⅵ）,加标回收率为97.5%—104.5%,相对标准偏差≤0.46%。     

Use of hydrodynamic cavitation in (waste)water treatment

The use of acoustic cavitation for water and wastewater treatment (cleaning) is a well known procedure. Yet, the use of hydrodynamic cavitation as a sole technique or in combination with other techniques such as ultrasound has only recently been suggested and employed.In the first part of this paper a general overview of techniques that employ hydrodynamic cavitation for cleaning of water and wastewater is presented.In the second part of the paper the focus is on our own most recent work using hydrodynamic cavitation for removal of pharmaceuticals (clofibric acid, ibuprofen, ketoprofen, naproxen, diclofenac, carbamazepine), toxic cyanobacteria (Microcystis aeruginosa), green microalgae (Chlorella vulgaris), bacteria (Legionella pneumophila) and viruses (Rotavirus) from water and wastewater.As will be shown, hydrodynamic cavitation, like acoustic, can manifest itself in many different forms each having its own distinctive properties and mechanisms. This was until now neglected, which eventually led to poor performance of the technique. We will show that a different type of hydrodynamic cavitation (different removal mechanism) is required for successful removal of different pollutants.The path to use hydrodynamic cavitation as a routine water cleaning method is still long, but recent results have already shown great potential for optimisation, which could lead to a low energy tool for water and wastewater cleaning.     

Critical evaluation of screening techniques for emerging environmental contaminants based on accurate mass measurements with time-of-flight mass spectrometry

Emerging contaminants from wastewater effluent samples were analysed, using posttarget and nontarget analysis techniques. The samples were analysed with an ultra performance liquid chromatograph-time-of-flight mass spectrometer (UPLC-TOF-MS), and the resulting data were processed with commercial deconvolution software. The method works well for posttarget analysis with prior information about the retention times of the compounds of interest. With positive polarity, 63 of 66 compounds and with negative polarity, 18 of 20 compounds were correctly identified in a spiked sample, while two compounds of a total of 88 fell out of the mass range. Furthermore, a four-stage process for identification was developed for the posttarget analysis lacking the retention time data. In the process, the number of candidate compounds was reduced by using the accurate mass of selected compounds in two steps (stages 1 and 2), structure-property relationships (stage 3) and isotope patterns of the analytes (stage 4). The process developed was validated by analysing wastewater samples spiked with 88 compounds. This procedure can be used to gain a preliminary indication of the presence of certain analytes in the samples. Nontarget analysis was tested by applying a theoretical mass spectra library for a wastewater sample spiked with six pharmaceuticals. The results showed a high number of false identifications. In addition, manual processing of the data was considered laborious and ineffective. Finally, the posttarget analysis was applied to a real wastewater sample. The analysis revealed the presence of six compounds that were afterwards confirmed with standard compounds as being correct. Three psycholeptics (nordiazepam, oxazepam and temazepam) could be tentatively identified, using the identification process developed. Posttarget analysis with UPLC-TOF-MS proved to be a promising method for analysing wastewater samples, while we concluded that the software for nontarget analysis will need improvement before it can be used in environmental analytical work with LC-TOF-MS systems.     

激光诱导荧光水体污染遥测数据定量分析方法

在紫外光的激发下,污染水体中的溶解有机物(DOM)会产生特定的荧光光谱,因此利用激光诱导荧光(LIF)可对水体中的溶解有机物的含量进行定量分析,从而可估计出水体富营养化的程度。提出了一种用于对水质遥测数据进行定量分析的方法,这是一种基于遗传算法(GA)的光谱分离算法。首先确定拉曼散射信号和溶解有机物的荧光在404nm波段的信号强度,然后再利用拉曼散射信号对DOM荧光光谱进行归一化处理。根据浓度校准曲线可得到水体中的溶解有机物的浓度。     

超声-生物法在废水处理中的研究进展

超声-生物法作为一种新的污染治理工艺，正日益受到人们的重视。本文介绍了声解机理及主要的影响因素，综述了超声-生物法(厌氧、好氧及厌氧加好氧)在废水处理中的研究进展。