Endotoxin removal from water using microporous polyethylene chopped fibres as a new adsorbent

A new adsorbent, microporous polyethylene chopped fibre, was produced from a high density polyethylene. This can adsorb lipopolysaccharides (LPS) linearly up to 2 h, and showed the highest capacity to adsorb LPS when compared with two other polyethylene-based adsorbents and a polystyrene-based adsorbent. More than twice as much orange II and 4-nitroquinoline N oxide were adsorbed in the new adsorbent as was LPS. The adsorption isotherm of the new adsorbent for LPS was of Ln type, the correlation between adsorption and concentration of solute was proportional; whereas orange II and 4-nitroquinoline N oxide were of L type (greater adsorption than Ln type); tetrachloroethylene adsorption was of S type, less than Ln type. Adsorption of LPS to the new adsorbent increased when temperature rose, whereas adsorption of orange II and 4-nitroquinoline N oxide decreased. These data suggest that the binding of LPS to the new adsorbent is a hydrophobic interaction, whereas the binding of both orange II and 4-nitroquinoline N oxide is not. The new adsorbent has a greater potential for the removal of endotoxin from tap water than other commercially available adsorbents such as charcoal and Amberlite XAD-2.     

Endotoxin removal from water using microporous polyethylene chopped fibres as a new adsorbent.

A new adsorbent, microporous polyethylene chopped fibre, was produced from a high density polyethylene. This can adsorb lipopolysaccharides (LPS) linearly up to 2 h, and showed the highest capacity to adsorb LPS when compared with two other polyethylene-based adsorbents and a polystyrene-based adsorbent. More than twice as much orange II and 4-nitroquinoline N oxide were adsorbed in the new adsorbent as was LPS. The adsorption isotherm of the new adsorbent for LPS was of Ln type, the correlation between adsorption and concentration of solute was proportional; whereas orange II and 4-nitroquinoline N oxide were of L type (greater adsorption than Ln type); tetrachloroethylene adsorption was of S type, less than Ln type. Adsorption of LPS to the new adsorbent increased when temperature rose, whereas adsorption of orange II and 4-nitroquinoline N oxide decreased. These data suggest that the binding of LPS to the new adsorbent is a hydrophobic interaction, whereas the binding of both orange II and 4-nitroquinoline N oxide is not. The new adsorbent has a greater potential for the removal of endotoxin from tap water than other commercially available adsorbents such as charcoal and Amberlite XAD-2.     

锆改性壳聚糖-沸石-高岭土复合吸附剂的制备及饮水除氟应用

目的研制锆改性壳聚糖-沸石-高岭土复合吸附剂用于除去水中的氟离子。方法取0.60 g壳聚糖溶于36 ml的5%乙酸溶液,加入0.15 mol/L氧氯化锆溶液20.00 ml,用5%氨水调至p H 5.0,搅拌反应60 min,加入1.40 g人造沸石和0.50 g高岭土继续搅拌60 min,再用5%氨水调至p H 7.5,析出锆-壳聚糖-沸石-高岭土复合吸附剂,分别对5.24 mg/L含氟水进行静态除氟实验[复合吸附剂用量为1.5 g/L,p H 4~7(p H 5~6最佳),158 r/min振荡速度下于室温吸附120 min]和动态除氟实验[复合吸附剂2.00 g,p H 5~6(p H 6最佳),吸附剂粒径1~2 mm,水样以3~4 ml/min通过吸附柱]。结果静态除氟实验结果显示,复合吸附剂对氟的平衡吸附量为3.07 mg/g,出水氟浓度小于1.0 mg/L;动态除氟实验结果显示,过水量为1 800 ml,复合吸附剂对氟的吸附容量为2.71 mg/g。实验数据(30℃)符合Langmuir吸附等温线,最大吸附量为15.53mg/g。结论锆改性壳聚糖-沸石-高岭土复合吸附剂处理水样不会造成二次污染,用于静态除氟和动态除氟均可获得满意的效果。     

Antimicrobial antibodies in Danish slaughterhouse workers and greenhouse workers

Summary As a consequence of contact with animals and animal products slaughterhouse workers might be at risk of infection with pathogenic microorganisms. This hypothesis has been supported by some earlier studies. In this study 217 slaughtermen and a control group of 113 greenhouse workers were investigated for the prevalence of serum antibodies to Toxoplasma gondii, Campylobacter jejuni (IgA and IgG), Yersinia enterocolitica types 3 and 9, Yersinia pseudotuberculosis types I, II, III, IV, and V, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella typhimurium, and Borrelia burgdorferi. No significant differences were found concerning either frequency of positive tests or magnitude of titers. The prevalence of toxoplasma antibodies was remarkably high in both groups.     

High Efficiency Adsorption Removal of Arsenilic Acid and Arsenate(V) by Iron-Modified Corncob Biochar

It is crucial that a highly effective adsorbent can be used to simultaneously remove the composite pollution including both inorganic and organic arsenic from wastewater. In this work, the iron modified corncob biochar (MCCB), prepared via the co-precipitation of ferric chloride hexahydrate (FeCl₃?6H₂O) with sodium hydroxide (NaOH) on corncob biochar, was studied for the high efficiency removal of arsenilic acid (ASA) and arsenate [As(V)] in wastewater. X-ray diffraction, scanning electron microscopy, and fourier transform infrared spectroscopy were carried out to characterize the MCCB. At pH of 4.0–5.0, initial concentration of 10 mg/L ASA and 1 mg/L As(V), adsorbent dose of 0.4 g/L, the maximum adsorption capacities of ASA and As(V) were 49.20 and 4.89 mg/g, respectively. The adsorption performance of MCCB for ASA and As(V) was fitted well to the pseudo-second-order kinetic model. Results from this study indicate the promise of MCCB as an efficient, low-cost and environmentally friendly adsorbent for composite arsenic pollution.

     

Fenton试剂处理垃圾渗滤液技术进展的研究

介绍了垃圾渗滤液的危害及毒性,比较了用活性碳吸附、FeCl、絮凝、Fenton试剂中H2O2和FeSO4的不同比例处理垃圾渗滤液的工艺流程以及对COD处理效果的影响讨论了pH、温度、反应时间、Fenton试剂不同配比对处理效果的影响,得出用Fenton试剂处理垃圾渗滤液时,可把大分子的有机物氧化为小分子,从而降低了垃圾渗滤液的COD值,对分子量较小的有机物的去除率不高。     

Linking lysosomal biomarker and population responses in a field population of Aporrectodea caliginosa (Oligochaeta) exposed to the fungicide copper oxychloride

The effects of the fungicide copper oxychloride on a field population of the earthworm Aporrectodea caliginosa were investigated. Changes were monitored in earthworm numbers and biomass, copper concentrations in soil and earthworms, and neutral red retention times (NRRTs) of coelomocytes. The aim was to establish whether the cellular responses could be linked to changes at the population level. Results indicated that there was a significant (P<0.05) impact on worm density and biomass on the treated plots 6 months after spraying with the fungicide stopped. NRRTs of treated earthworms were significantly lower after one spraying when earthworms had elevated concentrations of copper in their body tissues. Six months after spraying stopped, copper levels in both soil and earthworm tissues declined significantly, but the earthworm numbers and biomass were still significantly lower in the treated plots. This indicated that the effects of the copper oxychloride exposure manifested at a much later stage at the population level, than on NRRT. We conclude that the decrease in NRRTs, which preceded the decrease in both earthworm biomass and numbers, may have predictive value as a biomarker of impending population changes.     

Protein-induced alterations in murine hepatic α-aminoadipate δ-semialdehyde synthase activity are mediated posttranslationally

The molecular mechanisms responsible for alterations in lysine α-ketoglutarate reductase (LKR) activity are unknown. Therefore, the aim of these studies was to discern the mechanism(s) responsible for induction of hepatic LKR activity in rodents fed excess dietary protein. Four studies were conducted that used 84 mice. Mice were fed either a high-protein (50% casein) or adequate-protein (20% casein) diet in powder form in study 1 and a high-protein (46% casein) or adequate-protein (21% casein) diet in pellet form in the remaining studies. No significant differences in weight gain between the mice fed the different diets were detected. As expected, mice fed high-protein diets had a greater (P < .05) LKR activity in all 4 experiments. Mice fed high- and adequate-protein diets for 8 days showed no difference (P > .1) in α-aminoadipate δ-semialdehyde synthase (AASS) mRNA in experiment 1. However, after pooling the data from the remaining 3 experiments, mice receiving the high-protein diet had greater (P < .05) AASS mRNA compared to mice fed the adequate protein diet. In this investigation, no differences (P > .1) in AASS protein abundance were detected. The results are consistent with a mechanism in which posttranslational regulation is responsible for hepatic induction of LKR activity in mice fed high-protein diets.     

Biosorptive removal of Ni(Ii) from wastewater and industrial effluent

The objective of the present work was to investigate the removal of Ni(II) by the fresh biomass (FBM) and chemically treated leached biomass (LBM) of Calotropis procera. The scope of the work included screening of the biosorbents for their metal uptake potential, batch equilibrium, column mode removal studies and kinetic studies at varying pH (2-6), contact time, biosorbent dosages (1-25 g/L) and initial metal ion concentration (5-500 mg/L). The development of batch kinetic model and determination of order, desorption studies, column studies were investigated. It was observed that pH had marked effect on the Ni(II) uptake. Langmuir and Freundlich models were used to correlate equilibrium data on sorption of Ni(II) metallic ion by using both FBM and LBM at 28 degrees C and pH 3 and different coefficients were calculated. It was found that both biomasses were statistically significant fit for Freundlich model. The biomass was successfully used for removal nickel from synthetic and industrial effluents and the technique appears industrially applicable and viable.     

Influence of EDTA and chemical species on arsenic accumulation in Spirodela polyrhiza L. (duckweed)

The influence of ethylenediaminetetraacetic acid (EDTA) and chemical species on arsenic accumulation in aquatic floating macrophyte Spirodela polyrhiza L. (duckweed) was investigated. The uptake of inorganic arsenic species (arsenate; As(V) and arsenite; As(III)) into the plant tissue and their adsorption on iron plaque of plant surfaces were significantly (p<0.05) higher than those of organic species (monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA)). The addition of EDTA to the culture media increased the uptake of As(V) and As(III) into the plant tissue though the MMAA and DMAA uptake were not affected. About 4–6% of the inorganic arsenic species were desorbed or mobilized from iron plaque by EDTA. Desorption of organic arsenic species was not affected by EDTA addition because the co-precipitation occurs only with inorganic species. Phosphate uptake was not affected by EDTA though its concentration in citrate-bicarbonate-EDTA (CBE)-extract was much higher than that of plant tissue. Iron uptake into the plant increased significantly (p>0.05) by EDTA addition to the culture media while its concentration in CBE-extract decreased significantly (p<0.05). The As(inorganic)/Fe ratios in plant were higher than those of CBE-extract which indicate the increased uptake of these arsenic species into the plant relative to the iron. The lower As(organic)/Fe ratios in plant and on CBE-extract suggest the reduction of accumulation of these arsenic species relative to the iron.     

<Emphasis Type="Italic">Azadirachata indicum</Emphasis> (Neem): An Effective Biosorbent for the Removal of Lead (II) from Aqueous Solutions

Laboratory batch experiments with Azadirachata indicum indicated that this population had an excellent ability to bind lead (II) from its aqueous solution. The experiments carried out examined pH, biomass quantity, time of contact, and temperature dependency. Under optimum conditions, the removal of lead (II) was found to be around 95%. Column experiments were performed to examine the binding of lead (II) to silica-immobilized biomass under flow conditions. During this, a slight decrease in the pH of the effluents was also observed, implying an ion-exchange mechanism for metal binding.     

Determination of phosphine by adsorption sampling with modified silica gel and colorimetry of phosphate

A method for determining phosphine was developed using adsorption sampling followed by colorimetric measurement. Two types of adsorbent used in this study were prepared from silica gel by impregnation with potassium permanganate (1% w/w) or (mercury(II) chloride and sodium chloride) (0.2 + 0.2% w/w). Each adsorbent (150 mg) packed in a glass tube had the capacity to adsorb 0.3 ppm of phosphine in 3 l of test gas passing through at a rate of 300 ml/min without breakthrough. The adsorbed phosphine was desorbed into solutions as phosphate and the recovered phosphate was determined by ICP-AES or by one of two kinds of colorimetric methods for phosphate based on the molybdenum blue method, i.e., the colorimetric method following JIS K 0102 and that following the NIOSH Manual of analytical method, No. S 332. When 0.01 ppm of phosphine in 3 l of test gas was adsorbed on the potassium permanganate adsorbent and determined by the JIS method, 93.8% of the phosphine was recovered as phosphate with a CV of 12.9% (n = 3). This method was applicable to field surveys of phosphine in workplaces. The other method with the mercury(II) chloride adsorbent followed by the NIOSH method resulted in lower recovery of phosphate in low phosphine concentration range. ICP-AES was less sensitive than the colorimetries. The effect of coexistent arsenite or silicate on the colorimetry of phosphate was assessed.     

The Effects of Tannery Wastewater on the Development of Different Plant Species and Chromium Accumulation in <Emphasis Type="Italic">Phragmites australis</Emphasis>

Toxicity tests were performed to assess the effect of tannery wastewater with different treatment levels on two wetland plants, Phragmites australis and Typha latifolia, which are frequently used in constructed wetlands (CWs) for water treatment, and thus deepen the knowledge on their capacity to withstand the application of industrial wastewater. Trifolium pratense, a plant generally used as an indicator in toxicity tests, was included as a control. End points measured were germination percentage, shoot length, root elongation, and biomass growth of the plants. When tannery effluent, with a low treatment level, was supplied to the wetland plants germination occurred even at effluent concentrations of 100%, whereas germination of T. pratense was completely inhibited, almost invariably, at effluent concentration of 50%. Higher germination levels were achieved when the plants were exposed to effluent originating from the outlet of constructed wetland pilot units, allowing germination of all tested plants, indicating a significant decrease in its toxicity level. Experiments conducted with the same plants using different growing substrata as the germination matrix, namely expanded clay aggregates (Filtralite MR 3-8 and Filtralite NR 3-8) and two types of sand (fine gravel and standard sand) have shown that higher germination levels were achieved in standard sand and that P. australis was the plant species showing higher germination in all cases, reinforcing the robustness of this plant to environmental stress. The phytoextraction potential of P. australis, was evaluated by subjecting the plant to tannery wastewater supplemented with 50 and 150 mg Cr/L. After 6 weeks of exposure, levels up to 4825, 883, and 627 mg Cr/kg were found in the rhizome, shoot, and leaves, respectively, although phytotoxic signs in the plant were evident. This plant might not be considered a chromium hyperacumulator, but the potential to extract and accumulate this metal on its rhizomes is high.     

Effects of EDTA on Lead Uptake by <Emphasis Type="Italic">Typha orientalis Presl</Emphasis>: A New Lead-Accumulating Species in Southern China

A series of field investigations have been conducted at Yongzhou Pb/Zn/Cu mine tailings, Hunan Province, southern China. The specific aim was to search for new lead accumulators with fast growth rate and large biomass. The results of tissue analyses identified Typha orientalis Presl has a strong accumulation of lead. The average lead concentrations in the leaves and roots are 619 and 1,233 mg/kg, respectively. The growth and Pb content of the plant were also studied by hydroponic culture with different concentrations of Pb(NO(3))(2). Growth of the plant was not affected by Pb up to 300 mg/L. The Pb concentrations in the leaves and roots increased with increasing of Pb level in the modified Hoagland's nutrient solution. The maximum concentrations of Pb in the leaves and roots were 16,190 and 64,405 mg/kg, respectively. The study also demonstrated that EDTA not only increased the amount of Pb taken up by plants but also speeded up the metal translocation from roots to leaves.     

Equilibrium and kinetics studies on removal of arsenite by iron oxide coated activated alumina

Arsenic in drinking water is causing much concern because of its toxicity. It occurs in water naturally as As(III) and As(V). Of these As (III) is more toxic. Adsorption on activated alumina has been one of the most commonly used methods for As (V) removal from drinking water. But it is not very effective for As (III). Activated alumina was modified by coating it with Iron oxide to make it suitable for As (III) adsorption. Iron oxide coated activated alumina was tested for its effectiveness as an adsorbent for As (III). The As (III) adsorption was strongly dependent on pH and a maximum removal of 98% was observed at a pH of 12. The adsorption process followed a first order kinetics. The equilibrium was attained after 8 hours. The kinetic study was carried out with different initial As (III) concentration. It was observed that time taken to attain equilibrium was independent of initial concentration but percentage removal decreased with increasing initial concentration. The adsorption isotherms were fitted well to both Langmuir and Freundlich equation.     

Activated carbons for medical applications. In vitro microparticle characterization and solute adsorption.

Activated carbon is a high surface area adsorbent. Its ability to adsorb nitrogenous metabolic wastes and exogenous poisons from blood has been well documented. Polymeric coatings on activated carbon enhance its biotolerability and make it feasible for use in hemoperfusion devices. The only drawback seems to be the presence of microparticles on the carbon surface. These particles may become emboli during hemoperfusion. This paper describes a series of in vitro tests used to evaluate many commercially available granular and pelletized activated carbons. The tests were as follows: 1) creatinine adsorption capacity and kinetics, 2) initial cleanliness, 3) washability, 4) attrition resistance, and 5) carbon particle surface morphologymone grade of activated carbon has been chosen for hemoperfusion studies on the basis of the above evaluations; The nature of the microparticles and the approach used to remove them from this carbon is described.     

Identification and Chemical Enhancement of Two Ornamental Plants for Phytoremediation

With an increase in the contamination of urban areas, more and more attention has been paid to the role of ornamental plants in remedying contaminated soils. Thus, cadmium (Cd) tolerance and accumulation characteristics of Calendula officinalis and Althaea rosea as ornamental plants under the concentration gradient experiment with single Cd, as well as the effect of ethylenegluatarotriacetic acid (EGTA) and sodium dodecyl sulfate (SDS) on their Cd phytoremediation capacity under the chemically enhanced experiment was further investigated. It was showed that they had strong tolerance and accumulation capacity of Cd under single Cd treatments, thus they had great potential to be used for Cd contaminated soil remediation. Furthermore, under chemically enhanced treatments, the great efficiency was found through applying EGTA and SDS, they could not only increase the dry biomass of the plants, but also promote the Cd accumulation in shoots and roots. Particularly, Althaea rosea can be regarded as a potential Cd-hyperaccumulator through applying chemical agents. In conclusion, the two ornamental plants are promising to be used for phytoremediation.     

Potentially human pathogenic vibrios in marine and fresh bathing waters related to environmental conditions and disease outcome

In 2009, four bathing sites in The Netherlands were monitored for potentially human pathogenic Vibrio species to observe possible associations with environmental conditions and health complaints. Three slightly different enrichment procedures were used to isolate Vibrio species with different growth requirements. Waters were generally positive for Vibrio from May until October; median Vibrio concentrations ranged from 4 to 383 MPN per litre (maximum 10⁵ MPN per litre). Isolated Vibrio species included V. alginolyticus (50.6%) and V. parahaemolyticus (8.5%) from bathing sites with salinities ranging between 2.8 and 3.5% and V. cholerae non-O1/O139 (6.9%) from sites with salinities ranging between 0.007 and 0.08%. Although more samples were positive for Vibrio at elevated water temperatures, a quantitative relation between Vibrio numbers in water samples and the water temperature was not observed which may be explained by maximum water temperatures of 21 °C. Active surveillance yielded one case of a recreational water related Vibrio infection. V. cholerae non-O1/O139 was cultured from the patient's wound and the implicated recreational water; PFGE profiles of the water and patient isolates were not identical. The number of patients that contract a Vibrio infection through exposure to Dutch recreational waters seems low, but may be underestimated. The common occurrence of Vibrio species in these waters stresses the need for providing information on Vibrio to risk groups to prevent infections.     

Iron availability of a fortified processed wheat cereal: a comparison of fourteen iron forms using an in vitro digestion/human colonic adenocarcinoma (CaCo-2) cell model

In this three-phase study we first compared the availability of fourteen Fe forms in a wheat-based ready-to-eat breakfast cereal using an in vitro digestion/human colonic adenocarcinoma (CaCo-2) cell model. We then investigated the effect of milk and/or coffee on those fortified cereals found in phase 1 to show promising increases in Fe availability. The Fe forms assessed in phase 1 were reduced (control), carbonyl, electrolytic, FePO(4), FeSO(4), FeCO(3), Na(2)FeEDTA, Ferrochel (Albion Laboratories, Clearfield, UT, USA; ferrous bis-glycinate), encapsulated ferrous fumarate, FeSO(4), ferrous lactate and Biofer (LipoTech, Britwell Salome, Oxfordshire; FeSO(4)), SQM (Sea-Questra-Min Iron; Quali Tech, Chaska, MN, USA; polysaccharide-complexed FeSO(4)) and Sun Active (Taiyo Kagaku, Yokkaichi, Japan). All these forms increased Fe uptake compared with the unfortified cereal. Relative to the control, the following increases in Fe availability were observed: electrolytic, 52 %; ferrous fumarate, 30-35 %; Sun Active, 78 %; Ferrochel, 125 %; Na(2)FeEDTA, 291 %. Recent human studies have shown similar data with regard to Ferrochel, FeSO4 and Na(2)FeEDTA, with the latter being more bioavailable. Our phase-2 studies indicated that the addition of milk to FeSO(4)-fortified cereal increased Fe availability, but this availability was markedly decreased by the addition of coffee to the digest. Conversely, a loss in availability from Na(2)FeEDTA was observed with the addition of milk; however, the addition of coffee did not markedly affect Fe availability from this form. In phase-3 studies we observed increased Fe availability upon the addition of milk to cereals containing Ferrochel, FeSO(4), Sun Active, a mixture of reduced Fe and Na(2)FeEDTA or reduced Fe. For these forms we did not assess the behaviour after the addition of coffee. In conclusion, when considering possible fortificants for optimizing Fe bioavailability within a foodstuff, it is of paramount importance to consider the interaction between the fortified foodstuffs and other components of the meal (such as milk and coffee with a breakfast).     

Extraction and Analysis Methods for the Determination of Pyrethroid Insecticides in Surface Water,Sediments and Biological Tissues at Environmentally Relevant Concentrations

The aim of this study was to develop and validate chemical methods for measuring pyrethroid insecticides at environmentally relevant concentrations in different matrices. The analytes included six synthetic pyrethroids with the highest agricultural and commercial structural uses in California: bifenthrin, cyfluthrin, cypermethrin, esfenvalerate/fenvalerate, lambda-cyhalothrin, permethrin, and their corresponding stereoisomers, which includes enantiomers, diastereomers and racemic mixtures. Fortified water samples were extracted for analysis of synthetic pyrethroids using liquid-liquid extraction, while fortified sediment and fish tissue samples were extracted using pressurized fluid extraction followed by gel permeation chromatography (GPC) to remove matrix interferences. A florisil column was used for additional cleanup and fractionation of sediment and tissue extracts. Extracts were analyzed using dual column high resolution gas chromatography with electron capture detection (GC/ECD) and confirmation was obtained with gas chromatography mass spectrometry using a quadrupole ion trap detector in MS-MS mode. Method detection limits (MDLs) have been established for water (1-3 ng/L), sediment (0.5-4 ng/g dry weight) and tissue (1-3 ng/g fresh weight). Mean percent recoveries of fortified blanks and samples ranged from 75 to 115% with relative standard deviation (RSD) values less than 20% for all target compounds.