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The occurrence of 12 pharmaceuticals and personal care products (PPCPs) in two wastewater treatment plants in Beijing was studied monthly over the course of one year. The removal of PPCPs by three biological treatment processes including conventional activated sludge (CAS), biological nutrient removal (BNR), and membrane bioreactor (MBR) was compared during different seasons. Seasonal variations of PPCPs in the wastewater influent were discrepant, while in the wastewater effluent, most PPCPs had lower concentrations in the summer than in the winter. For the easily biodegradable PPCPs, the performance of MBR was demonstrated to be more stable than CAS or BNR especially during winter months. Diclofenac, trimethoprim, metoprolol, and gemfibrozil could be moderately removed by MBR, while their removal by CAS and BNR was much lower or even negligible. Nevertheless, no removal was achieved regardless of the season or the treatment processes for the recalcitrant PPCPs. Studies on the contribution of each tank of the MBR process to the total removal of four biodegradable PPCPs indicated the oxic tank was the most important unit, whereas membrane filtration made a negligible contribution to their elimination. 相似文献
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Municipal wastewater contains a mixture of minerals from different origins. Urine contributes 80% of the nitrogen (N) and 45% of the phosphate (P) load in wastewater. Effects of separate urine collection on BNR processes were evaluated by using a simulation model for an existing state-of-the-art biological nutrient removal process. It was found that increasing urine separation efficiency leads to lower nitrate effluent concentrations, while ammonium and phosphorus concentrations remain more or less the same. The improved nitrate effluent quality is most notable up to 50-60% urine separation. Urine separation allows primary sedimentation without an increase in the nitrate effluent concentration. Furthermore, urine separation increases the potential treatment capacity for raw and settled wastewater by 20% and 60%, respectively. Urine separation provides options for increasing the lifetime of existing treatment works. 相似文献
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不同激素处理8612葡萄果实膨大效果试验 总被引:3,自引:2,他引:1
8612葡萄是我国河北昌黎果树所用巨峰与郑州早红杂交得到的3倍体无核品种。1999年,西南农业大学园艺场引种试验,该品种在重庆地区表现早熟、红色、抗病、硬肉、丰产,推广前景很好。但由于8612自然无核,果实偏小成为阻碍大量推广该品种的重要原因,为解决此问题,本试验拟用植物生长调节剂GA3(赤霉素)和CPPU(吡效隆)进行浸 相似文献
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This study investigates the oxidation of pharmaceuticals during conventional ozonation and advanced oxidation processes (AOPs) applied in drinking water treatment. In a first step, second-order rate constants for the reactions of selected pharmaceuticals with ozone (k(O3)) and OH radicals (k(OH)) were determined in bench-scale experiments (in brackets apparent k(O3) at pH 7 and T = 20 degrees C): bezafibrate (590 +/- 50 M(-1) s(-1)), carbamazepine (approximately 3 x 10(5) M(-1) s(-1)), diazepam (0.75 +/- 0.15 M(-1) s(-1)), diclofenac (approximately 1 x 10(6) M(-1) s(-1)), 17alpha-ethinylestradiol (approximately 3 x 10(6) M(-1) s(-1)), ibuprofen (9.6 +/- 1.0 M(-1) s(-1)), iopromide (<0.8 M(-1) s(-1)), sulfamethoxazole (approximately 2.5 x 10(6) M(-1) s(-1)), and roxithromycin (approximately 7 x 10(4) M(-1) s(-1)). For five of the pharmaceuticals the apparent k(O3) at pH 7 was >5 x 10(4) M(-1) s(-1), indicating that these compounds are completely transformed during ozonation processes. Values for k(OH) ranged from 3.3 to 9.8 x 10(9) M(-1) s(-1). Compared to other important micropollutants such as MTBE and atrazine, the selected pharmaceuticals reacted about two to three times faster with OH radicals. In the second part of the study, oxidation kinetics of the selected pharmaceuticals were investigated in ozonation experiments performed in different natural waters. It could be shown that the second-order rate constants determined in pure aqueous solution could be applied to predict the behavior of pharmaceuticals dissolved in natural waters. Overall it can be concluded that ozonation and AOPs are promising processes for an efficient removal of pharmaceuticals in drinking waters. 相似文献
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Impact of treatment processes on the removal of perfluoroalkyl acids from the drinking water production chain 总被引:2,自引:0,他引:2
Eschauzier C Beerendonk E Scholte-Veenendaal P De Voogt P 《Environmental science & technology》2012,46(3):1708-1715
The behavior of polyfluoralkyl acids (PFAAs) from intake (raw source water) to finished drinking water was assessed by taking samples from influent and effluent of the several treatment steps used in a drinking water production chain. These consisted of intake, coagulation, rapid sand filtration, dune passage, aeration, rapid sand filtration, ozonation, pellet softening, granular activated carbon (GAC) filtration, slow sand filtration, and finished drinking water. In the intake water taken from the Lek canal (a tributary of the river Rhine), the most abundant PFAA were PFBA (perfluorobutanoic acid), PFBS (perfluorobutane sulfonate), PFOS (perfluorooctane sulfonate), and PFOA (perfluorooctanoic acid). During treatment, longer chain PFAA such as PFNA (perfluorononanoic acid) and PFOS were readily removed by the GAC treatment step and their GAC effluent concentrations were reduced to levels below the limits of quantitation (LOQ) (0.23 and 0.24 ng/L for PFOS and PFNA, respectively). However, more hydrophilic shorter chain PFAA (especially PFBA and PFBS) were not removed by GAC and their concentrations remained constant through treatment. A decreasing removal capacity of the GAC was observed with increasing carbon loading and with decreasing carbon chain length of the PFAAs. This study shows that none of the treatment steps, including softening processes, are effective for PFAA removal, except for GAC filtration. GAC can effectively remove certain PFAA from the drinking water cycle.The enrichment of branched PFOS and PFOA isomers relative to non branched isomers during GAC filtration was observed during treatment. The finished water contained 26 and 19 ng/L of PFBA and PFBS. Other PFAAs were present in concentrations below 4.2 ng/L The concentrations of PFAA observed in finished waters are no reason for concern for human health as margins to existing guidelines are sufficiently large. 相似文献
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目的 研究不同处理工艺对平阴玫瑰中总黄酮、芦丁、总多酚含量及抗氧化活性的影响。方法 对干花直接提取、干花超微粉碎提取以及鲜花冷冻干燥提取3种不同处理工艺的平阴玫瑰进行水提,采用分光光度法测定水提液中总黄酮、总多酚的含量,高效液相色谱法测定水提液中芦丁含量,并对3种不同处理工艺的水提液进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除、羟自由基清除以及超氧阴离子清除能力的研究。结果 3种不同工艺处理的玫瑰花总黄酮含量、芦丁含量、总多酚含量及抗氧化活性均为:鲜花冷冻干燥>干花超微粉碎>干花直接提取。结论 经冷冻干燥处理后的平阴玫瑰抗氧化性物质含量及抗氧化活性均有升高,为玫瑰花抗氧化应用提供依据。 相似文献
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Removal of pharmaceuticals in sewage treatment plants in Italy 总被引:11,自引:0,他引:11
Castiglioni S Bagnati R Fanelli R Pomati F Calamari D Zuccato E 《Environmental science & technology》2006,40(1):357-363
A listing of "priority pharmaceuticals" for human use in Italy resulted in the selection of 26 pharmaceuticals, belonging to 11 therapeutic classes. They were analyzed by liquid chromatography-tandem mass spectrometry, their occurrence was assessed in six sewage treatment plants (STPs), and the loads and the removal rates (RR) were studied. Total loads ranged from 1.5 to 4.5 g/day/1000 inhabitants in influents and 1.0 and 3.0 g/day/1000 inhabitants in effluents. Total RR in STPs were mostly lower than 40%. Pharmaceuticals could be divided into three groups according to their behavior in STPs: one group with RR higher in summer than in winter, one group with RR similar in summer and winter, and a last group not removed. Last, we studied the distribution and fate of residual pharmaceuticals in the surface waters receiving the effluents of the STPs and identified degradation and sorption as the major factors affecting attenuation. Ciprofloxacin, ofloxacin, sulfamethoxazole (antibiotics), atenolol (cardiovascular drug), ibuprofen (antiinflammatory), furosemide, hydrochlorothiazide (diuretics), ranitidine (gastrointestinal drug), and bezafibrate (lipid regulator) were the most abundant residual drugs, thus those of environmental concern. 相似文献
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Oladipupo Odunayo Olatunde Steffi Louisa Della Tan Soottawat Benjakul 《International Journal of Food Science & Technology》2021,56(4):1671-1681
Sedimentation process (GLE-S) or chloroform (GLE-Ch) were used for dechlorophyllisation of ethanolic guava leaf extract (EGLE). EGLE without chlorophyll removal (GLE-C) was served as control. Among all the extracts, GLE-S had the lowest chlorophyll a, chlorophyll b, and total chlorophyll contents (P < 0.05). Extraction yield was highest in GLE-C, followed by GLE-S and GLE-Ch, respectively. Total phenolic content and antioxidant properties were highest in GLE-S (P < 0.05). When Pacific white shrimp (PWS) was pre-treated with GLE-S at varying doses (0.5% and 1%), lipid oxidation products were monitored as compared to the control (CON) and those pre-treated with 1.25% sodium metabisulphite (SMS-1.25) during refrigerated storage (4°C) for 12 days. Lower lipid oxidation was recorded for PWS pre-treated with GLE-S, especially at 1%. Therefore, sedimentation process, a green method, showed promising efficacy for producing EGLE free of green colour with improved antioxidant properties. The extract effectively reduced lipid oxidation in PWS during refrigerated storage. 相似文献
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《食品与发酵工业》2015,(6):1-7
我国白酒通常采用甑桶一次蒸馏方式,不进行二次蒸馏。采用壶式蒸馏、常压蒸馏及减压蒸馏对浓香型原酒进行二次蒸馏,研究不同二次蒸馏方式对氨基甲酸乙酯(EC)去除率的影响。结果表明,采用适当的掐头去尾方法能够获得EC浓度较原酒低的二次蒸馏酒,EC大量存在于酒尾及残液中。壶式蒸馏时的EC相对去除率最高(92.76%),其次是减压蒸馏(89.55%)、常压蒸馏(81.46%)。慢火壶式蒸馏酒的EC浓度略低于快火,快、慢火壶式蒸馏对EC的去除无明显差异。二次蒸馏对不同EC浓度(233.33~1 162.94μg/L)的原酒均能达到较好的去除效果,EC相对去除率在89.91%~92.76%。壶式蒸馏过程中EC浓度随着酒精度的降低而呈现先下降后平稳再上升的趋势,二次蒸馏掐头去尾工艺能有效降低白酒中EC的含量。壶式蒸馏过程前期的EC主要来源于酒中本来存在的EC,而蒸馏过程后期的EC可能来自于氰化物等前体物质的转化。 相似文献
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To improve ammonium removal efficiency in wastewater treatment, a mixed culture of Alcaligenes faecalis no. 4 and its mutant L1, both of which have heterotrophic nitrification and aerobic denitrification abilities, was performed. In a batch culture, no. 4 has a higher denitrification ability than L1, but its ammonium removal rate was lower. In a mixed continuous culture in the ammonium loading range of 750 to 3500 mg-N/l/d, the average ammonium removal rate and the average denitrification ratio were 61 mg-N/l/h and 31%, respectively. In the mixed culture, the ammonium removal rate was twofold higher than that in a single culture of no. 4, the rate was similar to that in a single culture of L1, and the denitrification ratio was very high compared with that in the single culture of L1. 相似文献
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为了更好地掌握目前市场上使用较多的4种主要纺纱技术,以立达纱为例,对环锭纺、紧密纺、转杯纺和喷气纺的工作原理及纺纱工艺进行了归纳总结,对4种不同纱线的品质以及用途进行了比较和分析。 相似文献
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研究了大豆油、菜籽油、米糠油精炼过程中加工助剂对精炼油脂中铅含量的影响,并研究了利用吸附剂对铅超标油脂中铅的脱除效果。结果表明:在油脂精炼过程中,适量的食品级加工助剂的应用,可以有效脱除油脂中的铅,保证食用油脂中重金属铅的含量达到国家卫生标准的限量要求。但如果采用工业级的加工助剂或过量的加工助剂,精炼油脂中铅含量不仅不能降低,甚至可能升高,增大食用油安全的风险。对于铅含量超标的油脂样品,通过添加适量的吸附剂,可以将油脂中铅含量降低至符合国家卫生标准的限量要求。但随着油脂中铅含量超标幅度的增大,有效脱除油脂中的铅所需要的吸附剂用量也随之增加。活性白土对油脂中铅的脱除效果要好于活性炭。 相似文献
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Brandon Carter Larissa DiMarzo Joice Pranata David M. Barbano MaryAnne Drake 《Journal of dairy science》2021,104(7):7534-7543
Our research objective was to measure percent removal of whey protein from separated sweet whey using 0.1-µm uniform transmembrane pressure ceramic microfiltration (MF) membranes in a sequential batch 3-stage, 3× process at 50°C. Cheddar cheese whey was centrifugally separated to remove fat at 72°C and pasteurized (72°C for 15 s), cooled to 4°C, and held overnight. Separated whey (375 kg) was heated to 50°C with a plate heat exchanger and microfiltered using a pilot-scale ceramic 0.1-µm uniform transmembrane pressure MF system in bleed-and-feed mode at 50°C in a sequential batch 3-stage (2 diafiltration stages) process to produce a 3× MF retentate and MF permeate. Feed, retentate, and permeate samples were analyzed for total nitrogen, noncasein nitrogen, and nonprotein nitrogen using the Kjeldahl method. Sodium dodecyl sulfate-PAGE analysis was also performed on the whey feeds, retentates, and permeates from each stage. A flux of 54 kg/m2 per hour was achieved with 0.1-µm ceramic uniform transmembrane pressure microfiltration membranes at 50°C. About 85% of the total nitrogen in the whey feed passed though the membrane into the permeate. No passage of lactoferrin from the sweet whey feed of the MF into the MF permeate was detected. There was some passage of IgG, bovine serum albumen, glycomacropeptide, and casein proteolysis products into the permeate. β-Lactoglobulin was in higher concentration in the retentate than the permeate, indicating that it was partially blocked from passage through the ceramic MF membrane. 相似文献
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Role of biofilms in sorptive removal of steroidal hormones and 4-nonylphenol compounds from streams 总被引:1,自引:0,他引:1
Stream biofilms play an important role in geochemical processing of organic matter and nutrients, however, the significance of this matrix in sorbing trace organic contaminants is less understood. This study focused on the role of stream biofilms in sorbing steroidal hormones and 4-nonylphenol compounds from surface waters using biofilms colonized in situ on artificial substrata and subsequently transferred to the laboratory for controlled batch sorption experiments. Steroidal hormones and 4-nonylphenol compounds readily sorb to stream biofilms as indicated by organic matter partition coefficients (K(om), L kg(-1)) for 17β-estradiol (10(2.5-2.8) L kg(-1)), 17α-ethynylestradiol (10(2.5-2.9) L kg(-1)), 4-nonylphenol (10(3.4-4.6) L kg(-1)), 4-nonylphenolmonoethoxylate (10(3.5-4.0) L kg(-1)), and 4-nonylphenoldiethoxylate (10(3.9-4.3) L kg(-1)). Experiments using water quality differences to induce changes in the relative composition of periphyton and heterotrophic bacteria in the stream biofilm did not significantly affect the sorptive properties of the stream biofilm, providing additional evidence that stream biofilms will sorb trace organic compounds under of variety of environmental conditions. Because sorption of the target compounds to stream biofilms was linearly correlated with organic matter content, hydrophobic partition into organic matter appears to be the dominant mechanism. An analysis of 17β-estradiol and 4-nonylphenol hydrophobic partition into water, biofilm, sediment, and dissolved organic matter matrices at mass/volume ratios typical of smaller rivers showed that the relative importance of the stream biofilm as a sorptive matrix was comparable to bed sediments. Therefore, stream biofilms play a primary role in attenuating these compounds in surface waters. Because the stream biofilm represents the base of the stream ecosystem, accumulation of steroidal hormones and 4-nonylphenol compounds in the stream biofilm may be an exposure pathway for organisms in higher trophic levels. 相似文献