超声辐照降解水中亚硝基二丙胺和亚硝基二丁胺的动力学研究

采用超声辐照技术,研究了其降解水中痕量亚硝基二丙胺（NDPA）和亚硝基二丁胺（NDBA）混合物的性能。结果表明,在中性条件下,最佳功率和频率分别为100 W和600 k Hz时,超声辐照可在60 min内降解99%以上的NDPA和NDBA混合液（质量浓度为0.10 mg/L）。NDPA和NDBA的降解反应均符合伪一级反应动力学模型,速率常数kapp受超声频率、功率和溶液初始浓度的影响。     

Naproxen removal from water by chlorination and biofilm processes

Naproxen is an anti-inflammatory pharmaceutical that has been detected in natural and engineered aquatic environments. The primary aim of this research was to study chemical transformations of naproxen following chlorine oxidation, which is common in water and wastewater treatment systems. Synthetic waters containing elevated concentrations of naproxen were oxidized by free chlorine at naproxen:chlorine molar ratios of 0.02-3:1 and pH values of 5-9. The formation of naproxen products was dependent on pH, chlorine dosage and contact time. This study demonstrates that naproxen readily reacts with free chlorine and forms disinfection products. The formation of specific reaction products can vary depending on the characteristics of the water or wastewater and treatment operating conditions. More research is needed to identify intermediate and chemical reaction end products and to understand the reaction kinetics of naproxen chlorination for a range of water and wastewater treatment conditions. A secondary aim of this research was to study effects of naproxen and its chlorination products on biofilm processes, which are common in water and wastewater treatment systems and natural aquatic environments. A bioreactor was fed a naproxen solution and then fed a solution at the same naproxen concentration following contact with free chlorine. Results indicate that naproxen was not degraded biologically for the conditions of this study. In contrast, the naproxen solution containing products of chlorination caused an adverse response by discharging biomass from the bioreactor. Results therefore demonstrate that naproxen products of chlorination can adversely affect a biofilm process, which potentially can impact the performance of biofilm processes in natural and engineered aquatic environments. More research is needed to study naproxen chlorination reactions at low concentrations and in complex matrices, and to understand the toxicological relevance of naproxen and its products of chlorination in natural and engineered aquatic environments.     

Dissipation of insecticides in a Mediterranean soil in the presence of wastewater and surfactant solutions. A kinetic model approach

The simultaneous disappearance of four organophosphorous insecticides in a Mediterranean calcareous soil was evaluated in the presence of surfactant solutions and municipal wastewater. A cationic, an anionic and a non-ionic surfactant were used at a low (0.75 mg L⁻¹) and at a high (twice the critical micelle concentration) concentration level. The cationic surfactant was also studied at a higher concentration. Dissipation in control soil was rapid for malathion (half-life 4 days), intermediate for dimethoate and methidathion (ca. 6 days) and slow for diazinon (29 days). Wastewater did either not modify (diazinon, dimethoate and methidathion) or slightly enhance (malathion) insecticide decay. The increase in concentration of the non-ionic surfactant Tween 80 resulted in enhanced dissipation rates for all the pesticides except diazinon. The addition of the anionic surfactant did not show a clear trend. At the highest cationic surfactant concentration a reduction of pesticide disappearance occurred linked with a reduced availability, since the insecticides were retained on the surfactant-modified soil (final residual concentration of 85% for diazinon and ≈55% for methidathion and dimethoate). Soil microbial activity, estimated by measuring dehydrogenase activity, was low in wastewater- and surfactant-treated soil at the high levels. Fitting of the experimental data to commonly used mathematical models was poor and alternatives were looked for.     

Factors which facilitate waste water treatment by aquatic weeds – the mechanism of the weeds’ purifying action

Aquatic weeds such as water hyacinth, salvinia, pistia, and lemna have proved to be powerful bioagents which significantly purify wastewater lying under them. Even the performance of conventional oxidation ponds can be greatly enhanced by the simple expedient of introducing one of these aquatic weeds. Weeds absorb certain pollutants. But the contribution of absorption to the overall treatment is only one among several contributory factors. This paper examines the factors responsible for the water‐purifying ability of the weeds.     

Removal of the surfactant sodium dodecylbenzenesulphonate from water by simultaneous use of ozone and powdered activated carbon: comparison with systems based on O3 and O3/H2O2

A study was conducted on the efficacy of the system based on the simultaneous use of ozone and powdered activated carbon (PAC) in removing sodium dodecylbenzenesulphonate (SDBS) from drinking waters and on the influence of operational parameters (PAC dose, ozone dose and presence of radical scavengers [HCO3-]) on this process. Results obtained showed that low doses of PAC during SDBS ozonation markedly increased the rate of SDBS removal from the medium. These results are due to the combined effect of two processes: (i) SDBS adsorption on the activated carbon surface and (ii) transformation of the dissolved ozone into .OH radicals. At higher ozone and PAC doses, there was a higher rate of SDBS removal from the medium. The presence of HCO3- in the medium reduced the SDBS removal rate of the O3/PAC system. This finding confirms that the presence of PAC during SDBS ozonation favours ozone transformation into .OH radicals. Comparison of the O3/PAC system with systems based on the use of O3 or O3/H2O2 showed that the efficacy of the O3/PAC system to remove SDBS is much greater than that of the traditional oxidation methods. Thus, in the first 5 min of treatment (usual hydraulic retention time), the percentage of SDBS removed was 18% and 30% for the O3 and O3/H2O2 systems, respectively, compared with 70% for the O3/PAC system. SDBS ozonation in surface waters intended for human consumption demonstrated that the O3/PAC approach is the most efficacious of the studied systems, considerably increasing the SDBS removal rate and also reducing the concentration of dissolved organic carbon. Therefore, the results of this study show that the system based on O3/PAC is a highly attractive option for the treatment of drinking water.     

BIM技术在上海泰和污水处理厂工程中的应用

地下式污水处理厂可实现地下“治”污,地上“造”绿,逐渐成为城市中心城区污水厂的主要建设形式。泰和污水处理厂作为上海市中心城区规模最大、标准最高的全地下污水厂,其与环境相容的集约化设计、高效节能降耗、自动化控制提升等方面面临着一系列挑战。本工程将BIM技术作为工程管理及提升的重要手段,探索并形成适用于地下式污水厂的BIM技术应用框架,通过BIM技术应用实现高品质设计、建设以外,还开展了多种BIM+智慧化创新运维应用,为日后超大规模地下式智慧化污水厂的建设提供借鉴作用。     

Degradation of H-acid and its derivative in aqueous solution by ionising radiation

The mechanism of high-energy radiation induced degradation of H-acid (4-amino-5-hydroxynaphthalene-2,7-disulphonic acid, (I)) and its derivative, 4-hydroxynaphthalene-2,7-disulphonic acid (II) (central parts of a large number of azo dyes), was investigated in aqueous solutions. These compounds can be efficiently destroyed by the (*)OH and hydrated electron intermediates produced during water radiolysis. As the first step of degradation mainly cyclohexadienyl-type radicals form, however, with I H-atom elimination from the NH(2) group is also observed yielding anilino-type radicals. Both the cyclohexadienyl and the anilino-type radicals decay on the millisecond timescale. In the (*)OH reactions as stable products hydroxylated molecules and quinone-type compounds form. These molecules by further decomposition of the ring structure transform to open chain molecules. In the case of hydrated electron, the primarily formed products have absorption spectra shifted to the low-wavelength region indicating the destruction of at least one of the aromatic rings.     

Occurrence of selected surfactants in untreated and treated sewage

Several surfactants were monitored in treated and untreated sewage in nine municipal wastewater treatment plants (WWTPs) in western Austria. The nine sampled WWTPs cover a wide variety referring to size and applied treatment technology. The investigation focused on linear alkylbenzene sulphonate (LAS), quaternary ammonia compounds (QAC), nonylphenol (NP), octylphenol (OP), nonylphenolmono- (NP(1)EO) and -diethoxylates (NP(2)EO). Whereas LAS, NP, OP and NP(1,2)EO were analysed separately in the liquid phase and in the solid phase, the QACs were measured in the total sample. Total influent concentrations of LAS varied between 2.4 mg l(-1) up to 6.7 mg l(-1) whereas total effluent concentrations were in the lower microg l(-1) range (11-50 microg l(-1)). Whichever the type of treatment, a clear removal during treatment was observed. Solid liquid distribution coefficients K(d) were calculated for untreated sewage. The calculated K(d) values varied between 1300 and 3900 l kg(-1). OP was of minor importance with total influent concentrations below 1microg l(-1). NP and NP(1,2)EO were present in all analysed influents in concentrations between 1 and 35microg l(-1). Effluent concentrations were notably lower than the measured influent concentrations. K(d) values for NP varied between 500 and 6600 l kg(-1), for NP(1)EO between 800 and 2700 l kg(-1) and for NP(2)EO between 100 and 1800 l kg(-1). From the QACs several alkyl benzyl (BAC), dialkyl (DDAC) and trialkyl (ATAC) ammonium chlorides with varying alkyl chain lengths were analysed. Highest total concentrations in the influents to the WWTPs were observed for the BAC-C12 and the ATAC-C16 homologues. Effluent concentrations were notably lower compared to influent concentrations, indicating removal by adsorption and/or biodegradation. The influence of the removal by adsorption increased with increasing alkyl chain length.     

Removal of perfluorooctane sulfonate from wastewater by anion exchange resins: Effects of resin properties and solution chemistry

Perfluorooctane sulfonate (PFOS) is a new persistent organic pollutant of substantial environmental concern, and its removal from industrial wastewater is critical to eliminate its release into water environment. In this paper, six anion exchange resins with different polymer matrix, porosity, and functional group were evaluated for PFOS removal from simulated wastewater. Resin matrix displayed significant effect on the sorption kinetics and capacity of PFOS, and the polyacrylic resins including IRA67 and IRA958 exhibited faster sorption and higher sorption capacity for PFOS than the polystyrene resins due to the hydrophilic matrix. Sorption isotherms illustrated that the sorption capacity of PFOS on IRA67 and IRA958 was up to 4-5 mmol/g, and the amount of PFOS sorbed on the resins was more than chloride released from resins, indicating that other interactions besides anion exchange were involved in the sorption. Solution pH had little impact on the sorption of PFOS on IRA958, but displayed significant effect on IRA67 at pH above 10 due to the deprotonation of amine groups. The coexisting sulfate and hexavalent chromium in wastewater interfered with the sorption of PFOS because of their competitive sorption on the exchange sites. The spent resins were successfully regenerated using the mixture of NaCl and methanol solution. This work provided an understanding of sorption behavior and mechanism of PFOS on different anion exchange resins, and should result in more effective applications of ion exchange for PFOS removal from industrial wastewater.     

Degradation of nonylphenolic surfactants in activated sludge batch tests

The fate of nonylphenol polyethoxylate surfactants in the activated sludge wastewater treatment process is a concern due to the formation of estrogenic nonlyphenols on degradation and due to the large amounts discharged to the aquatic environment through sewage treatment works. Batch tests using activated sludge from a Husmann apparatus were used to determine the effects of these compounds physico-chemical properties and biological sludge characteristics on biodegradation. Degradation of nonylphenol polyethoxylates with up to 12 ethoxy groups was observed in unacclimated sludge with a concomitant production of nonylphenol and short chain nonylphenol polyethoxylate compounds. Degradation was determined to be a biotic process involving intracellular enzyme activity, which resulted in sludge age being an influential parameter. With increasing sludge age there is an increase in mixed liquor solids concentration in activated sludge which results in greater bacterial numbers and the potential for greater species diversity which therefore increases compound degradation. However, increased degradation of long chain compounds resulted in an accumulation of shorter chain compounds and nonylphenol, which are more resistant to degradation.     

Degradation of endocrine disrupting bisphenol A by 254 nm irradiation in different water matrices and effect on yeast cells

The photodegradation of bisphenol A (BPA) in pure water, surface water and wastewater effluents was studied. The effect of different hydrogen peroxide concentrations on degradation was investigated. The rate of BPA photolysis in the presence of hydrogen peroxide was lower in wastewater effluent than in purified water.

Phenol, 1,4-dihydroxylbenzene and 1,4-benzoquinone were identified by means of HPLC as intermediate products of the photodegradation of bisphenol A.

In addition, the disappearance of the estrogenic activity of bisphenol A during irradiation was shown by the YES test. Based upon the YES test results, there was a strong decrease of estrogenic activity of parent compound after 120 min irradiation in the presence of hydrogen peroxide.     

Degradation of organolead species in aqueous solutions by electron beam irradiation

Electron beam irradiation of aqueous solutions containing different lead compounds (Pb(2+), (CH(3))(3)Pb(+), (C(2)H(5))(3)Pb(+)) was carried out. Formate and hydrogen peroxide were used as radical scavengers to elucidate the influence of the different species generated by water radiolysis. The precipitation of Pb(2+), only observed in the presence of formate, was attributed to COO(*-) but the nature of the precipitate is still unclear. Organolead compounds were shown to be efficiently degraded, probably converted into Pb(2+), using doses around 4 kGy. In the absence of scavengers, the degradation occurred according to the alkyl group stability. Both trialkyllead compounds were shown to be degraded by HO(*). On the contrary, the contribution of hydrogen atoms (H(*)) was shown to be highly dependent on the nature of the alkyl group, i.e. negligible for (C(2)H(5))(3)Pb(+) and more important for (CH(3))(3)Pb(+).     

Synergistic effect of the sequential use of UV irradiation and chlorine to disinfect reclaimed water

The effectiveness of UV and chlorination, used individually and sequentially, was investigated in killing pathogenic microorganisms and inhibiting the formation of disinfection by-products in two different municipal wastewaters for the source water of reclaimed water, which were from a microfilter (W1) and membrane bioreactor (W2) respectively. Heterotrophic plate count (HPC), total bacteria count (TBC), and total coliform (TC) were selected to evaluate the efficiency of different disinfection processes. UV inactivation of the three bacteria followed first-order kinetics in W1 wastewater, but in W2 wastewater, the UV dose-response curve trailed beyond approximately 10 mJ/cm² UV. The higher number of particles in the W2 might have protected the bacteria against UV damage, as UV light alone was not effective in killing HPC in W2 wastewater with higher turbidity. However, chlorine was more effective in W2 than in W1 for the three bacteria inactivation owing to the greater formation of inorganic and organic chloramines in W1 wastewater. Complete inactivation of HPC in W1 wastewater required a chlorine dose higher than 5.5 mg/L, whereas 4.5 mg/L chlorine gave the equivalent result in W2 wastewater. In contrast, sequential UV and chlorine treatment produced a synergistic effect in both wastewater systems and was the most effective option for complete removal of all three bacteria. UV disinfection lowered the required chlorine dose in W1, but not in W2, because of the higher chlorine consumption in W2 wastewater. However, UV irradiation decreased total trihalomethane formation during chlorination in both wastewaters.     

Degradation of the antibiotic amoxicillin by photo-Fenton process--chemical and toxicological assessment

The influence of iron species on amoxicillin (AMX) degradation, intermediate products generated and toxicity during the photo-Fenton process using a solar simulator were evaluated in this work. The AMX degradation was favored in the presence of the potassium ferrioxalate complex (FeOx) when compared to FeSO₄. Total oxidation of AMX in the presence of FeOx was obtained after 5 min, while 15 min were necessary using FeSO₄. The results obtained with Daphnia magna biossays showed that the toxicity decreased from 65 to 5% after 90 min of irradiation in the presence of FeSO₄. However, it increased again to a maximum of 100% after 150 min, what indicates the generation of more toxic intermediates than AMX, reaching 45% after 240 min. However, using FeOx, the inhibition of mobility varied between 100 and 70% during treatment, probably due to the presence of oxalate, which is toxic to the neonates. After 240 min, between 73 and 81% TOC removal was observed. Different pathways of AMX degradation were suggested including the opening of the four-membered β-lactamic ring and further oxidations of the methyl group to aldehyde and/or hydroxylation of the benzoic ring, generating other intermediates after bound cleavage between different atoms and further oxidation to carboxylates such acetate, oxalate and propionate, besides the generation of nitrate and ammonium.     

Degradation of antibiotics in water by non-thermal plasma treatment

The decomposition of three β-lactam antibiotics (amoxicillin, oxacillin and ampicillin) in aqueous solution was investigated using a dielectric barrier discharge (DBD) in coaxial configuration. Solutions of concentration 100 mg/L were made to flow as a film over the surface of the inner electrode of the plasma reactor, so the discharge was generated at the gas-liquid interface. The electrical discharge was operated in pulsed regime, at room temperature and atmospheric pressure, in oxygen. Amoxicillin was degraded after 10 min plasma treatment, while the other two antibiotics required about 30 min for decomposition. The evolution of the degradation process was continuously followed using liquid chromatography-mass spectrometry (LC-MS), total organic carbon (TOC) and chemical oxygen demand (COD) analyses.     

Degradation of phenol using tyrosinase immobilized on siliceous supports

The degradation of phenol by tyrosinase immobilized on chemically modified sodium aluminosilicate (NaA), calcium aluminosilicate (CaA), and silica gel was studied. Phenol conversion by immobilized tyrosinase ranged between approximately 15% and 60%, depending upon the initial phenol concentration, pH, and enzyme loading. Tyrosinase immobilized on CaA and on NaA could be re-used repeatedly without any decrease in performance. However, in studies at pH 8.0, significant enzyme inhibition was observed, since phenol conversion was rapid for approximately 20 min, then reached a plateau. The inhibition was reversible; activity was restored upon placing the immobilized enzyme in fresh substrate. Reducing the pH to 6.8 from 8.0 led to higher conversion of phenol, and decreased the inhibition of the immobilized enzyme.     

Disinfection of Legionella pneumophila by ultrasonic treatment with TiO2

An ultrasonic treatment system, using a TiO₂ photocatalyst, was used to disinfect Legionella pneumophila. A kinetic study of the process indicates that TiO₂ significantly improves the disinfection process. The concentrations of viable cells were reduced to 6% of the initial concentrations in the presence of 0.2 g/ml TiO₂ after a 30 min of treatment period, while only an 18% reduction was observed in the absence of TiO₂. The potency of the disinfection could be enhanced, to some extent, by increasing the amount of TiO₂ used. Cell concentrations were decreased by an order of 3 within 30 min of treatment in the presence of 1.0 g/ml TiO₂. The disinfection power in the presence of TiO₂ versus Al₂O₃ was also compared and the findings showed that TiO₂ induced a higher cell killing. No significant effect of initial cell concentration on the disinfection was found in the range of 10²-10⁷ CFU/ml after a 30 min of treatment period. The mechanism of cell killing was investigated by examining the effects of OH radical scavengers such as ascorbic acid, histidine and glutathione. The disinfection power was reduced in samples that contained these radical scavengers, thus indicating the importance of OH radicals.     

Degradation of the emerging contaminant ibuprofen in water by photo-Fenton

In this study the degradation of the worldwide Non-Steroidal Anti-Inflammatory Drug (NSAID) ibuprofen (IBP) by photo-Fenton reaction by use of solar artificial irradiation was carried out. Non-photocatalytic experiments (complex formation, photolysis and UV/Vis-H₂O₂ oxidation) were executed to evaluate the isolated effects and additional differentiated degradation pathways of IBP. The solar photolysis cleavage of H₂O₂ generates hydroxylated-IBP byproducts without mineralization. Fenton reaction, however promotes hydroxylation with a 10% contamination in form of a mineralization. In contrast photo-Fenton in addition promotes the decarboxylation of IBP and its total depletion is observed. In absence of H₂O₂ a decrease of IBP was observed in the Fe(II)/UV-Vis process due to the complex formation between iron and the IBP-carboxylic moiety. The degradation pathway can be described as an interconnected and successive principal decarboxylation and hydroxylation steps. TOC depletion of 40% was observed in photo-Fenton degradation. The iron-IBP binding was the key-point of the decarboxylation pathway. Both decarboxylation and hydroxylation mechanisms, as individual or parallel process are responsible for IBP removal in Fenton and photo-Fenton systems. An increase in the biodegradability of the final effluent after photo-Fenton treatment was observed. Final BOD₅ of 25 mg L⁻¹ was reached in contrast to the initial BOD₅ shown by the untreated IBP solution (BOD₅ < 1 mg L⁻¹). The increase in the biodegradability of the photo-Fenton degradation byproducts opens the possibility for a complete remediation with a final post-biological treatment.     

Degradation of phenolic compounds in water by non-thermal plasma treatment

A stainless-steel hollow needle type anode was used in the reactor to treat industrial wastewater by gas-liquid phase of non-thermal plasma by corona discharge. The results showed that the short electrode gap, 1 cm, has a higher plasma energy density which improves the removal of the phenolic derivatives, reaching 100% after about 60 min. The H₂O₂ concentration was higher in the discharge system when the content of oxygen was increased. The efficiency of the phenol removal by chemical oxygen demand was only 10?C31% after 60 minutes. The identified intermediates were catechol, hydroquinone, 1,4-benzoquinone, 2-nitrophenol, 1,2-benzenedicarboxylic acid, diphenylmethanone, 2-methyl-hydroquinone, 2-methyl-1,4-bezoquinone, and trace amounts of organic.