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181.
This paper presents a fully automated method for determining ten primary amines in wastewater at ng/L levels. The method is based on simultaneous derivatization with pentafluorobenzaldehyde (PFBAY) and headspace solid-phase microextraction (HS-SPME) followed by gas chromatography coupled to ion trap tandem mass spectrometry (GC–IT-MS–MS). The influence of main factors on the efficiency of derivatization and of HS-SPME is described in detail and optimized by a central composite design. For all species, the highest enrichment factors were achieved using a 85 μm polyacrylate (PA) fiber exposed in the headspace of stirred water samples (750 rpm) at pH 12, containing 360 g/L of NaCl, at 40 °C for 15 min. Under optimized conditions, the proposed method achieved detection limits ranging from 10 to 100 ng/L (except for cyclohexylamine). The optimized method was then used to determine the presence of primary amines in various types of wastewater samples, such as influent and effluent wastewater from municipal and industrial wastewater treatment plants (WWTPs) and a potable water treatment plant. Although the analysis of these samples revealed the presence of up to 1500 μg/L of certain primary amines in influent industrial wastewater, the concentration of these compounds in the effluent and in municipal and potable water was substantially lower, at low μg/L levels. The new derivatization–HS-SPME–GC–IT-MS–MS method is suitable for the fast, reliable and inexpensive determination of primary amines in wastewater in an automated procedure. 相似文献
182.
Singh OV 《Applied biochemistry and biotechnology》2006,135(1):43-57
Aspergillus niger ORS-4.410, a mutant of A. niger ORS-4, was generated by repeated ultraviolet (UV) irradiation. Analysis of the UV treatment dose on wild-type (WT) A. niger ORS-4, conidial survival, and frequency of mutation showed that the maximum frequency of positive mutants (25.5%) was obtained
with a 57% conidial survival rate after the second stage of UV irradiation. The level of glucose oxidase (GOX) production
from mutant A. niger ORS-4.410 thus obtained was 149% higher than that for WT strain A. niger ORS-4 under liquid culture conditions using hexacyanoferrate (HCF)-treated sugarcane molasses (TM) as a cheaper carbohydrate
source. When subcultured monthly for 24 mo, the mutant strain had consistent levels of GOX production (2.62±0.51 U/mL). Mutant
A. niger ORS-4.410 was markedly different from the parent strain morphologically and was found to grow abundantly on sugarcane molasses.
The mutant strain showed 3.43-fold increases in GOX levels (2.62±0.51 U/mL) using HCF-TM compared with the crude form of cane
molasses (0.762±0.158 U/mL).
The results reported herein were obtained while the author was working at the Department of Biotechnology, Indian Institute
of Technology, Roorkee-247667, India. 相似文献
183.
Abstract River pollution creates negative externalities to downstream water users. In this paper, we analyze how voluntary joint action of water users can improve pollution abatement when optimal treatment cannot be enforced. We model a transboundary pollution game with a unidirectional pollutant flow. Players are identical except for their location along the river. We find that, surprisingly, the location of coalition members has no impact on coalition stability. Location does, however, affect overall welfare. The more upstream the members of the coalition are, the higher is the overall welfare because the positive externalities of cleaning accrue to a larger number of downstream water users. 相似文献
184.
185.
《Arabian Journal of Chemistry》2022,15(12):104315
The green and high-value recycling of shrimp shell and straw remains a worldwide problem. This study aimed to investigate the potential utilization of a fermentation broth (FB) which contains shrimp shell and straw as a new source for preparation of biodegradable films. Aureobasidium pullulans and Photobacterium sp. LYM-1 were used in the fermentation. The cellulase activity was 115.92 U/mL and chitinase activity was 17.89 U/mL in FB. The polysaccharides concentration in FB was 1.05 mg/mL after 7 days of fermentation. An eco-friendly PVA-reinforced FB biodegradable film (FBBF) was successfully prepared and the effect of different plasticizers and surfactants on the mechanical, structural, and impermeability properties of the film was determined. The formation of new bonds between PVA and FB was proved by FTIR spectroscopy. The FBBF containing 0.25 % (w/v) glycerol and 0.01 % (v/v) tween-20 showed better strength properties. Elongation and water-swelling properties were highly improved by adding 0.2 % (m/v) citric acid. According to FE-SEM images, the smooth and tight surface of citric acid added FBBF was observed. Interestingly, the FBBF film showed good heat/moisture capacity, antifungal, and degradation properties. This report reveals a new green, and high-value recycling of straw and shrimp shell by the co-fermentation with A. pullulans and Photobacterium sp. LYM-1. It is also a novel way for the preparation of biodegradable film. 相似文献
186.
聚丙烯加热改性制备大孔吸附树脂的工艺及其应用 总被引:4,自引:0,他引:4
This article reported the preparation of macro porous resin by heating polyproplyene and improving its property. The result showed that macro porous resin with good quality and big soil adsorption rote can be prepared when the ration of polypmplyene to soybean salad oil is 1 : 2, the highest heating temperture is 250℃, time of homothermal agitation is 20min and the rote of cooling is 2℃/min.The resin can effectively adsorb waste grease in restaurant wastewater. After removing grease, wastewater is treated with cogulant deposition. CODcr descend to 83mg/l from 790mg/l, which can reach the national discharge standards. 相似文献
187.
碳纳米管/SnO2复合电极的制备及其电催化性能研究 总被引:4,自引:0,他引:4
采用液相沉积法制备碳纳米管(CNTs)/SnO2复合材料, 并制备成电极, 分别与石墨/SnO2及活性炭/SnO2复合电极比较, 考察电催化降解有机废水的性能. 由于CNTs高的比表面积及优良的导电性能, 结合SnO2良好的催化活性, CNTs/SnO2复合电极电催化降解有机废水性能优越. 研究发现, CNTs的预处理情况、SnO2负载量以及煅烧温度对复合电极的电催化性能有重要影响. 当功能化CNTs负载40% SnO2, 煅烧温度600 ℃时, 所得CNTs/SnO2复合电极电催化降解有机废水的能力是纯CNTs电极的2倍. 最后, 初步探讨了CNTs/SnO2复合电极电催化降解有机废水的机理. 相似文献
188.
Timoth Mkilima Kulyash Meiramkulova Ubaidulayeva Nurbala Amanbek Zandybay Mansur Khusainov Nurgul Nurmukhanbetova Lyazzat Tastanova Toghan Mashan Abdilda Meirbekov 《Molecules (Basel, Switzerland)》2021,26(22)
Textile industry production processes generate one of the most highly polluted wastewaters in the world. Unfortunately, the field is also challenged by the availability of relatively cheap and highly effective technologies for wastewater purification. The application of natural zeolite as a depth filter offers an alternative and potential approach for textile wastewater treatment. The performance of a depth filter treatment system can be deeply affected by the column depth and the characteristics of the wastewater to be treated. Regrettably, the information on the potential of these filter materials for the purification of textile wastewater is still scarce. Therefore, this study investigated the potential applicability of natural zeolite in terms of column depth for the treatment of textile wastewater. From the analysis results, it was observed that the filtration efficiencies were relatively low (6.1 to 13.7%) for some parameters such as total dissolved solids, electrical conductivity, chemical oxygen demand, and sodium chloride when the wastewater samples were subjected to the 0.5 m column depth. Relatively high efficiency of 82 and 93.8% was observed from color and total suspended solids, respectively, when the wastewater samples were subjected to the 0.5 m column depth. Generally, the 0.75 m column depth achieved removal efficiencies ranging from 52.3% to 97.5%, whereas the 1 m column depth achieved removal efficiencies ranging from 86.9% to 99.4%. The highest removal efficiency was achieved with a combination of total suspended solids and 1 m column depth (99.4%). In summary, the treatment approach was observed to be highly effective for the removal of total suspended solids, with a 93.8% removal efficiency when the wastewater was subjected to the 0.5 m column depth, 97.5% for 0.75 m column depth, and 99.4% for 1 m column depth. Moreover, up to 218.233 mg of color per g of the filter material was captured. The results derived in this study provide useful information towards the potential applicability of natural zeolite in the textile wastewater treatment field. 相似文献
189.
190.