Preparation and application of pharmaceutical wastewater treatment by praseodymium doped SnO_2/Ti electrocatalytic electrode

Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment; the micrograph and the structure were characterized by SEM and XRD. Mixture uniform design was used in the optimization of the electrolytic conditions; mathematical model was established according to the rate of wiping COD off, which revealed the relationship between the current intensity, time of electrolysis, the amount of doped Pr, and the ratio of area （SnOJTi：Al）. On the basis of the analysis of the empirical model, the optimized parameters had been obtained; the rate of wiping COD off was up to 94.9%, it decreased from 392 to 20 mg/L. Experimental results showed that the electrocatalytic performance of the electrode doped with Pr was superior for the treatment of pharmaceutical wastewater.

Treatment of pharmaceutical wastewater containing recalcitrant compounds in a Fenton-coagulation process

The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB （upflow anaerobic sludge bed） and a SBR （sequencing batch reactor） process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry （GC-MS）, mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton＇s reaction was conducted at pH=3.0, H2O2CODOcr=0.27, H2O2/Fe^2＋=3：1 and 30 min of reaction time, and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units, meeting the secondary standard of GB8978-1996 for industrial wastewater.

Membrane Separation Technology on Pharmaceutical Wastewater by Using MBR (Membrane Bioreactor)

This study demonstrated the feasibility of implementing of MBR in pharmaceutical wastewater independently, and concluded different applications of MBR in industries. Membrane bioreactor (MBR) technology was a new wastewater treatment technology with a combination of membrane separation technology and biological treatment technology, which had unique advantages on pharmaceutical wastewater treatment. The modified membrane rector design provided a significantly lower concentration of NH3-N, Phosphorous, Total Nitrogen and COD around the membranes, and subsequently a more sustainable membrane performance due to much lower overall fouling rates. In this paper, the classification and structure of biological waste water treatment by using MBR technology were summed up along with some examples of MBR in industrial wastewater treatment, which was emphatically analyzed and discussed. Finally, the prospect of MBR in industrial wastewater treatment was described. The industrial wastewater was a high-strength wastewater which had characteristics of complicated constituents, high organics concentration, highly toxic.

Growth properties of mixed liquor suspended solids in SMBR for pharmaceutical wastewater treatment

This paper presents the performance results of a 366-day pilot-scale submerged membrane bioreactor (SMBR) for treating high-strength pharmaceutical wastewater. The study focuses on the growth properties of mixed liquor suspended solids (MLSS) in SMBR operated at high volumetric loading rates. The influences of MLSS on COD removal,sludge yield,oxygen utilization rates and sludge viscosity are studied. Results show that the bioreactor can be operated at higher volumetric loading rate with a low sludge yield. VSS/SS and observed sludge yield coefficient (Yo) present a decreasing trend with the decrease of hydraulic retention time (HRT) . Sludge oxygen utilization rate decreases with the increase of mixed liquor volatile suspended solids (MLVSS) . A mathematical model between sludge viscosity and MLSS is developed.

Application of an immobilized microbial consortium for the treatment of pharmaceutical wastewater: Batch-wise and continuous studies

In the present investigation,a microbial consortium consisting of four bacterial strains was selected for the treatment of pharmaceutical industry wa stewater.The consortium was immobilized on a natural support matrixLuffa and used for the treatment of real-time pharmaceutical wastewater in batch and continuous processes.The batch process was carried out to optimize the culture conditions and monitor the enzymatic activity.An array of enzymes such as alcohol dehydrogenase,aldehyde dehydrogenase,monooxygenase,catechol 2,3-dioxygenase and hydroquinol 1,2-dioxygenase were produced by the consortium.The kinetics of the degradation in the batch process was analyzed and it was noted to be a first-order reaction.For the continuous study,an aerobic fixed-film bioreactor(AFFBR) was utilized for a period of 61 days with variable hydraulic retention time(HRT) and organic loading rate(OLR).The immobilized microbes treated the wastewater by reducing the COD,phenolic contaminants and suspended solids.The OLR ranged between(0.56±0.05) kg COD·m^(-3) d^(-1) to 3.35 kg COD·m^(-3)·d^(-1) and the system achieved an average reduction of 96.8% of COD,92.6% of phenolic compounds and 95.2% of suspended solids.Kinetics of the continuous process was interpreted by three different models,where the modified Stover Kincannon model and the Grau second-order model proved to be best fit for the degradation reaction with the constant for saturation value,k_(L) being 95.12 g·L^(-1)·d^(-1).the constant for maximum utilization of the substrate U_(max) being 90.01 g·L^(-1) d^(-1) and substrate removal constant KY was1.074 d^(-1) for both the models.GC-MS analysis confirmed that most of the organic contaminants were degraded into innocuous metabolite s.

Experimental study on micro-electrolysis technology for pharmaceutical wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removng chromaticity and COD and improving the biodegradability of pharmaceutical wastewater.The results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of phamaceutical wastewater.Lower initial pH could be advantageous to the removal of chromaticity .A retention time of 30 minutes was recommended for the process design of micro-electrolysis.

Effects of Influencing Factors on Fenton Oxidation of Antibiotic Pharmaceutical Wastewater by a Statistical Design Approach

A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The significance of five operational factors including the mass ratio of H2O2/COD (g/g), the mole ratio of H2O2/Fe2+ (mol/mol), initial pH, oxidation temperature T, and reaction time t were evaluated statistically by Box-Behnken design (BBD). It was found that the five parameters were all significant to the COD removal efficiency by t-test, as well as the interactions between mass ratio/reaction time and oxidation temperature/reaction. The optimal COD removal efficiency (89.50%) was achieved when the mass ratio of H2O2/COD and the mole ratio of H2O2/Fe2+ were 3.00 and 5.00 respectively, with pH value of 3.68 at 298K for 72min reaction. A quadratic regression model with 0.9907 regression coefficient (R2) was developed which had good agreement to the experimental data.

Treatment of Wastewater from Pharmaceutical Intermittent Production by Fe/C-Fenton-Hydrolysis Acidification-A/O Process

The design and running effect of treatment of wastewater from pharmaceutical intermittent production by iron-carbon（Fe/C）-Fentonhydrolysis acidification-anoxic/aerobic（A/O）process were introduced.The results of continuous operation showed that when the flow rate of the influent wastewater was 300 m^3/d,after the influent high-concentration wastewater（CODCrand NH4＋-N concentration were 35 000 and 1 000 mg/L,respectively）and medium-concentration wastewater（CODCrand NH4＋-N concentration were 1 500 and 100 mg/L,respectively）were treated by the process,CODCrand NH4＋-N concentration in the effluent decreased to 360-410 and 20-25 mg/L,respectively,and the quality of the effluent could meet the Grade III standard of Integrated Wastewater Discharge Standard（GB 8978-1996）.The combined process was proved to be an effective method to treat wastewater from pharmaceutical intermittent production,and its operation was stable.

Life cycle assessment of homogeneous Fenton process as pretreatment for refractory pharmaceutical wastewater

The applicability of the life cycle assessment(LCA)to the Fenton process should be considered not only at the laboratory-scale but also at the full-scale.In this study,the LCA process was applied to evaluate the homo-geneous Fenton process for the treatment of high salinity pharmaceutical wastewater.The potential environmental impacts were calculated using Simapro software implemen-ting the CML 2001 methodology with normalization factors of 1995 world.Foreground data obtained directly from the full-scale wastewater treatment plant and labora-tory were used to conduct a life cycle inventory analysis,ensuring highly accurate results.By normalized results,the Fenton process reveals sensitive indicators,primarily toxi-city indicators(human toxicity,freshwater aquatic toxicity,and marine aquatic toxicity),as well as acidification and eutrophication impacts,contributed by hydrogen peroxide and iron sludge incineration,respectively.Overall,hydrogen peroxide and iron sludge incineration contribute significantly,accounting for at least 78%of these indicators.In sludge treatment phase,treatment of iron mud and infrastructure of hazardous waste incineration plants were the key contributors of environmental impacts,adding up to more than 95%.This study suggests the need to develop efficient oxidation processes and effective iron sludge treatment methods to reduce resource utilization and improve environmental benefits.

Stability and Removal of Commonly Used Drugs in Environmental Water and Wastewater

Introduction:Pharmaceuticals are regarded as emerging contaminants in the environment.In recent years,their destiny and removal have piqued people’s interest.Methods:Examine how well conventional wastewater treatment facilities and cutting-edge technologies(ultrafiltration and reverse osmosis)can remove specific pharmaceutical compounds from water,with a focus on the compounds'environmental status,their origin,deterioration,metabolites,and the capacities of these facilities.Results and discussion:the ability and efficacy of sophisticated treatment technologies such as membrane separation,adsorption,and AOPs(Advanced Oxidation Processes)in eliminating chosen commonly used drugs from water are explored.Batch adsorption experiments were integrated with appropriate adsorption isotherms and appropriate kinetic models to predict the final extent of pollutant removal by this method.Continuous filtration mode was also investigated.Combining filtration(using AC(Activated Carbon)and micelle-clay granule complexes)with AOPs improves the economy of treating wastewater,which contains recalcitrant PhACs(Pharmaceutical Compounds).

Micro-electrolysis technology for industrial wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

Efficient photocatalysis of tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater using AgCl/ZnO/g-C_(3)N_(4) composite under visible light: Process and mechanisms

AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy(SEM), UV-visible light absorption spectrum(UV–Vis DRS), X-ray diffractometer(XRD), Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C_(3)N_(4)significantly increase electron-hole transfer and separation compared to pure ZnO and g-C_(3)N_(4). Thus, AgCl/ZnO/g-C_(3)N_(4)could exhibit superior photocatalytic activity during TC-HCl assays(over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide(H_(2)O_(2)) and superoxide radical(·O_(2)) contributed more than holes(h+) and hydroxyl radicals(·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer(LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/gC_(3)N_(4)against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand(COD) and total organic carbon(TOC) respectively. AgCl/ZnO/g-C_(3)N_(4)can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.

Assessment of Ozone or Not-Treated Wastewater Ecotoxicity Using Mechanism-Based and Zebrafish Embryo Bioassays

Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more adapted tests. The present work aimed to add the recording of several sub-lethal endpoints in exposed zebrafish embryo-larval stages in order to increase the sensitivity of residual toxicity evaluation of WWTP effluents using a semi-quantitative method (iFET score). This approach was complemented with the genotoxicity assessment on the exposed embryos, a sub-acute hazard particularly relevant to evaluate a potential chronic toxicity risk of low and multi-contaminated environmental matrices. Additionally, endocrine activities of effluents were quantified using human reporter cell lines. This test battery was applied to the assessment of the residual toxicity of five biological treatment effluents, further treated or not using various ozonation treatments intended to improve pharmaceutical compounds removal. Acute toxicity towards zebrafish embryos was very low. However, iFET score approach proposed was able to reveal residual toxicity through the presence of developmental abnormalities in all samples tested. Additionally, a low residual genotoxicity was measured in embryos exposed to two of the WWTP effluents when all excepted one exhibited a residual endocrine activity potential in the ng/L range providing complementary information on the occurrence of endocrine active chemicals and their reduction by different processes. To sum up, such a simplified and ecologically relevant test battery was found sensitive enough to characterize and differentiate various residual effluent’s ecotoxicity at contaminant levels of environmental concern.

Co掺杂Mn_(2)O_(3)复合材料的构筑及活化过氧单硫酸盐降解医药废水

废水中的抗生素对人类健康与生态安全构成了重大威胁,通过活化过氧单硫酸盐(PMS)产生活性氧物种是处理抗生素废水的有效手段。然而,由于电子迁移效率不足,实现高效的PMS活化仍然具有挑战性。在此,Co掺杂的Mn_(2)O_(3)催化剂(Co5-Mn_(2)O_(3))通过简单的一步煅烧法得到,以氧氟沙星(OFX)为目标污染物,考察了Co5-Mn_(2)O_(3)/PMS体系的降解性能,在15 min内OFX去除率达到了95%,相比于原始Mn_(2)O_(3)提升了12.3倍,同时Co5-Mn_(2)O_(3)/PMS体系对多种污染物(环丙沙星、磺胺甲恶唑、四环素、罗丹明B和甲基橙)均表现出良好的降解性能,体现了实际应用的潜力。X射线光电子能谱证实,Co掺杂引起了催化剂表面重构与电子迁移实现了Mn^(4+)-O-Co^(2+)活性位点的形成。猝灭实验分析,富电子Co位点与缺电子的Mn位点可以有效地活化PMS生成硫酸根自由基与单线态氧从而实现OFX的高效去除。这项工作为控制催化功能提供了一种活性位点的结构调控方法,为自由基与非自由基耦合降解提供新视角。

基于氧化应激生物标志物的抗生素制药废水生态风险评价

近年来我国制药产业发展迅速,由此产生了大量的制药废水。制药废水尤其是抗生素制药废水的排放,对水环境造成了潜在威胁。以石家庄市某制药厂达标排放的抗生素制药废水为研究对象,将斑马鱼暴露于不同浓度的抗生素制药废水中(体积分数为10%、40%、70%),分别于第3、6、9、12、15天测定斑马鱼肌肉组织中活性氧自由基(ROS)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽(GSH)、丙二醛(MDA)和磷酸化组蛋白H2AX(γ-H2AX)6项氧化应激生物标志物的活性或含量,并基于生物标志物测定结果计算基于改进的综合生物标志物响应指数(IBR v2)以评价其生态风险。结果表明:抗生素制药废水的胁迫使斑马鱼肌肉组织产生了氧化应激反应,但不同实验组之间的响应时间存在差异,暴露第6天时,70%实验组的ROS含量、CAT活性、GSH含量、MDA含量和γ-H2AX含量均较对照组发生了显著的变化(p<0.001),响应时间早于10%和40%实验组,表明高浓度抗生素制药废水胁迫能够快速诱导斑马鱼产生氧化应激反应;基于6项肌肉组织氧化应激生物标志物的IBR v2值计算结果显示,达标排放的抗生素制药废水仍具有较高的环境风险,且高浓度的制药废水产生的生态风险更加快速和持久。本研究可为抗生素制药废水生态风险评价和相关排放标准的制定和完善提供参考。

高盐废水厌氧生物处理的强化方法研究

通过厌氧消化瓶小试实验和厌氧中试装置实验相结合的研究方法,驯化培养耐盐厌氧菌实现制药高盐废水的有机物质降解能力提升和氯离子浓度有效降低。首先,通过厌氧小试针对COD≈2500 mg/L,ρ(Cl^(-))≈10000 mg/L的高盐制药废水选取五种外源投加物展开实验,每种投加物设置六个不同投加量平行试验组,实验结果表明,外源投加相容性溶质,可增强厌氧耐盐菌在高盐环境下的活性,投加2 mmol/L甜菜碱对厌氧耐盐菌活性提升效果最佳,COD去除率较空白组提升约8%,达到60.83%,氯离子去除率为8.63%,实现了对厌氧处理高盐废水的有效强化。其次,利用多点回流式两相厌氧深度反应器处理ρ(Cl^(-))≈10000 mg/L的实际制药废水,在20 t/d的中试处理规模下,有效运行75天,厌氧处理效果良好,在稳定运行状态下废水COD去除率达到60%左右,氯离子吸附截留去除率为10%。

电芬顿耦合工艺氧化降解制药废水研究进展

电芬顿工艺通过Fe^(2+)和H_(2)O_(2)的反应生成活性高、氧化能力强的羟基自由基(·OH)降解制药废水中的有机污染物。通过介绍三维电极耦合电芬顿技术、臭氧耦合电芬顿技术、光耦合电芬顿技术、超声耦合电芬顿技术、微生物耦合电芬顿技术的原理和近年来的研究进展,探讨了各种耦合工艺的氧化效果,最后展望了电芬顿耦合工艺的不足与发展方向。

光催化技术在水处理中的应用研究进展

光催化技术应用于水处理领域,既可以提高水质安全,也可以缓解全球水资源短缺问题,是一项具有广泛应用前景的技术。该文介绍了光催化技术的机理及常见光催化剂的特点,重点综述了光催化技术在饮用水中的除臭、消毒,在染料废水含油废水制药废水催化还原重金属离子养殖废水焦化废水方面的应用。自由基途径与非自由基途径在该技术中发挥重要作用,在光催化材料中,TiO_(2)､金属-有机框架(MOFs)基光催化材料及其类似材料(如MIL系列､ZIFs系列等)可产生更多的•OH;TiO_(2)､g-C_(3)N_(4)基光催化材料可产生更多的•O_(2)^(–)和e^(–);CdS､TiO_(2)､g-C_(3)N_(4)基光催化材料可产生更多的h^(+)。最后对光催化技术的机理､光催化材料、水处理方向及实际应用进行了总结与展望。

三维电极电Fenton处理阿奇霉素制药废水研究

以钛涂钌铱电极(RuO_(2)-IrO_(2)/Ti)为阳极,石墨为阴极,活性炭为粒子电极构建三维电极电Fenton体系,研究三维电极电Fenton处理阿奇霉素制药废水的影响因素,系统性考察活性炭粒子电极类型及投加量对处理效果的影响,并通过改变极板间距、pH、曝气强度、电解电压、反应时间等因素,确定最佳反应条件。进一步通过正交实验比较各因素影响程度大小,优化三维电极电Fenton处理阿奇霉素制药废水实验条件。结果表明,以3 mm柱碳作为粒子电极,当其投加质量浓度为100 g/L时,最佳工艺条件为pH=3、电解电压15 V、曝气强度1.0 L/min、极板间距7 cm、反应时间2 h。此条件下,废水COD平均去除率为72.28%,B/C由初始的0.086上升至0.312,处理效果达最优。此外,各因素对于三维电极电Fenton处理阿奇霉素制药废水效果的影响程度为pH>曝气强度>电解电压>反应时间>极板间距。