漆酶对活性艳蓝染料废水脱色

用白腐真菌漆酶对活性艳蓝X-BR和活性艳蓝K-NR 2种活性染料进行脱色实验。研究了pH、温度、染料浓度和酶活力对脱色率的影响。结果表明,漆酶脱色的适宜条件为:反应温度45℃,pH 6～7,适宜染料浓度为50 mg/L,酶浓度5 U/mL,反应1 h两种染料脱色率可达到75%;通过正交实验确定2种染料的最佳脱色组合分别为:反应温度55℃、pH7、活性艳蓝X-BR浓度50 mg/L、酶浓度5 U/mL和反应温度55℃、pH 6、活性艳蓝K-NR浓度50 mg/L、酶浓度5 U/mL。在所得最优条件下反应1 h,活性艳蓝X-BR和活性艳蓝K-NR的脱色率分别为74.2%和78.6%;反应2 h,脱色率分别为78%和79.5%。     

灵芝漆酶对直接蓝86的催化脱色性能

利用灵芝菌Ganoderma lucidum U-281漆酶对直接蓝86进行酶促氧化脱色,并对其降解机理进行了探讨。结果表明,染料-漆酶共反应体系在20～50℃及pH小于5.0范围内,直接蓝86均可脱色50%以上;漆酶对直接蓝86具有宽泛的浓度适应性,对300 mg/L的该染料仍具有耐受性。最优脱色工艺参数为温度40℃、pH 5.0、染料初始浓度200 mg/L、漆酶用量1 U/mL。在优化条件下,直接蓝863 h的脱色率达到54.54%,48 h脱色率达到91.54%。紫外-可见吸收光谱分析表明,漆酶的酶促氧化导致染料的分子结构产生了变化,是造成直接蓝86脱色的主要发生机制。     

漆酶/HBT介质系统对靛蓝染料及废水脱色的初步研究

以云芝(Trametes versicolor)1126发酵所得漆酶粗酶液与1-羟基苯并三唑(HBT)组成的漆酶/HBT介质系统对靛蓝染料进行脱色实验,分别考察了温度、转速、pH和HBT与漆酶的加入量等条件对靛蓝染料脱色的影响.最终确定的优化脱色条件为:温度60℃,转速200r/min, pH4.5, 100mL靛蓝染料"溶液"中粗酶液和HBT溶液分别加入2mL.以上述脱色条件对靛蓝印染废水进行脱色实验,反应80min,脱色率可达90.1%.     

漆酶对活性黑KN-B和直接大红染料的脱色性能

利用白腐真菌漆酶对活性黑KN-B和直接大红2种偶氮染料进行脱色实验。考察反应时间、加酶量、pH值、染料浓度、温度对脱色率的影响，研究了ABTS介体以及金属离子存在下的脱色效果，并分析了漆酶脱色的动力学性能以及其对偶氮染料的降解规律。结果表明，活性黑KN-B和直接大红脱色适宜条件为：反应时间为30 min，加酶量8 U/mL，pH=7，染料浓度分别为50 mg/L和80 mg/L，温度40~45℃。ABTS介体对酶促偶氮染料脱色没有明显促进作用。Fe²⁺对漆酶脱色有较强的抑制作用；Cu²⁺对漆酶催化活性黑KN-B促进作用较大，对直接大红影响较小。漆酶对2种染料的脱色反应符合米氏方程，其催化活性黑KN-B和直接大红染料的K_m值分别为114.81 mg/L，317.5 mg/L，v_max值分别为6.57 mg/（L·min）和26.0 mg/（L·min）。     

Ganoderma sp.SYBC L48漆酶酶学性质及其对酸性红1的脱色性能

对灵芝菌Ganoderma sp. SYBC L48漆酶进行了纯化和酶学性质分析,并利用该漆酶对偶氮染料酸性红1进行脱色处理;考察了脱色体系中各因素对脱色效率的影响;采用小麦种子和水稻种子对酶处理后的染料进行了毒性测试。结果表明,以ABTS为底物时,该酶的最适pH为2.5,最适温度为60℃,在pH5～9和20～60℃具有良好的稳定性,Co2+、Cr~(3+)和Fe~(3+)离子对酶活性有较强的抑制作用。在染料浓度100 mg·L-1,酶浓度0.5 U·mL-1,介体HOBT浓度0.25 mmol·L-1,pH为4,50℃的条件下反应30 min后,该漆酶对酸性红1的脱色率可达90.3%;1 mmol·L-1的Cr~(3+)、Cu~(2+)、Al~(3+)和Ni~(2+)存在下,漆酶仍能催化酸性红1脱色;脱色后染料的植物毒性下降。上述结果表明该漆酶在纺织废水处理中具有一定的应用前景。     

固定化青霉X5对孔雀石绿的脱色研究

采用植物载体玉米芯对青霉X5进行固定化.利用正交实验,确定了固定化最优操作条件为:菌量0.4 g/L,载体大小为1/2×π×12×1 cm3,载体个数为10,摇床转速为100 r/min.同时考察了各种因素如温度、pH、碳源浓度和盐浓度等对染料脱色的影响,结果表明,在温度为30℃、pH 4.0、碳源浓度为10 g/L条件下,以100 r/min的摇速培养,脱色效果最佳,脱色率达96.1%.重复脱色实验表明,固定化青霉X5经过4次重复利用后,固定化细胞的结构仍良好,脱色率仍在90%以上.脱色平衡时间为360 min.     

类Fenton反应对偶氮染料橙黄Ⅱ的脱色研究

以橙黄Ⅱ染料溶液为研究对象,通过正交实验确定了Fe-NTA/H2O2构成的类Fenton反应中各影响因子的最佳操作条件为:[H2O2]=20 mmol/L,[Fe-NTA]=2.5 mmol/L,pH=3.同时考察了反应时间、溶液pH值、H2O2浓度、Fe-NTA浓度对脱色效率的影响.实验表明脱色反应在30 min内基本完成,类Fenton试剂能在较宽的pH范围内保持较好的脱色效果,而且在pH=6时,类Fenton试剂比传统Fenton试剂的脱色效率提高约75%.增加双氧水浓度可以提高橙黄Ⅱ溶液脱色率,但超过20 mmol/L后效果提高不明显.在0.5～2.5 mmol/L的范围内,Fe-NTA浓度对脱色效果的影响不显著.     

应用漆酶SUKALacc脱色处理纺织染料

印染废水中含有大量的剩余染料,对生态环境构成了巨大威胁.漆酶能够氧化多种纺织染料使其脱色,在印染废水处理领域具有潜在的应用性.为了开发基于酶技术的印染废水处理工艺,利用商业化的漆酶制剂SUKALaccTM对5种常见纺织染料的脱色能力进行了测试,结果显示,SUKALaccTM对于这些测试的染料均具有脱色效果,脱色效率为14.85％～ 85.97％;此外,还考察了酶制剂浓度、染料浓度、温度和pH等因素对脱色效率的影响,确定了最优的反应条件;利用斜生栅藻(Scenedesmus obliquus)和大型溞(Daphnia magna)分别对酶处理后的染料毒性进行了测试,结果表明,酶制剂处理后的染料毒性减弱.这些实验结果为漆酶制剂实际应用于印染废水处理奠定了坚实基础.     

偶氮染料脱色菌Lysinibacillus sp.FS1的脱色性能

从佛山某工业园印染废水处理厂曝气池中,经梯度驯化筛选出一株对多种染料具有较强脱色能力的菌株FS1,通过16S r DNA基因序列分析初步鉴定为Lysinibacillus sp.,研究了该菌株在不同营养条件(氮源、碳源、碳源浓度),不同培养条件(p H、温度、供氧条件),不同染料(甲基橙、亚甲基蓝、中性红、酸性红B)和染料浓度下的脱色性能。结果表明,该菌株的最佳脱色条件:温度30~40℃,p H 7~9,氯化铵1 g/L,葡萄糖2 g/L的厌氧条件下培养脱色效果最好,10 h时对酸性红B脱色率可达98.73%左右,且脱色过程符合一级反应动力学方程:-ln(At/A0)=0.0588t-0.0448。该菌株可降解多种染料,脱色率均随污染强度的升高先增大后减小,对高浓度染料和混合染料也表现出很好的脱色效果,是一株高效广谱的染料降解菌,具有处理印染废水的开发应用价值。     

染料废水的脱色研究

模拟中温(35℃左右)厌氧消化条件,以葡萄糖为共基质,对模拟染料废水的厌氧生物脱色进行了研究.结果表明对可溶性的活性染料处理效果,脱色率和COD去除率可分别达到90%和70%左右.特别是对红、紫、橙三色染料处理效果好,如活性红KD-8B、活性艳兰KGL、活性金黄MG、活性红紫KN-2R、活性艳橙KGN等.当染料浓度在1.0 g/L以下,都没有抑制;脱色在22 h就可达90%的脱色率;污泥负荷在2～4 g/L时,处理效果最佳.实验亦证实,在厌氧处理过程中,染料分子结构发生了明显的变化.     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos national laboratory and the doses to humans from the consumption of muscle and bone

Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for ³H, ⁹⁰Sr, ¹³⁷Cs, ^totU, ²³⁸Pu, ^239,240Pu, and ²⁴¹Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of ⁹⁰Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g^‐1 [126E‐02 Bq kg^‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g^‐1 [518E‐02 Bq kg^‐1]). The differences in ⁹⁰Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y^‐1 (1.0 ± 1.0 μSv y^‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y^‐1 (1000 μSv y^‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.     

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of ³H, ¹³⁷Cs, ⁹⁰Sr, ^totU, ²³⁸Pu, ^{239, 240}Pu, and²⁴¹ Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of ³H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.     

Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils

Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg^?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg^?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of ¹⁴C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative ¹⁴CO₂ was less than 1.5% of applied ¹⁴C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.     

Biochemical interaction of six op delayed neurotoxicants with several neurotargets

Abstract

Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with ³H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia.