上海市杨树浦水厂新旧取水口水质比较

上海市杨树浦水厂,是上海市也是我国最早建成的自来水厂。它为上海的发展繁荣辛勤地工作,服务了106年。现仍在继续昼夜不停地服务,肩负着四化建设的重任。自60年代以来,由於黄浦江的污染日趋严重,杨树浦水厂取水口的水质,每况愈下。为此,市政府决定於1987年将其取水口上移到临江地区。从而使水质有所改善。但由於黄浦江的污染尚未得到根治,临江取水口的水质仍有波动。因此,取水口上移后,杨树浦水厂供水水质改善的程度如何,仍为各方所关注。为此,该厂曾作过许多检测工作。对上移前后的新、旧取水口的水质,进行了比较。本刊特请该厂乐林生厂长就此撰文,予以介绍。

Preliminary Study on the Extraction of Crude Toxin of Rhizoctonia solani and Its Activity

[ Objective] This study was to investigate the pathogenic mechanism of rice sheath blight pathogen （ Rhizoctonia solani） and the bioactive components of toxin. [ Method ] Rice sheath blight pathogen was cultured in the improved Richared medium; the culture filtrate was centrifuged and sterilized, then treated by activated carbon adsorption chromatography, distilled with methanol or water, and all were next concentrated, yielding the crude extracts of culture solution, crude extracts of methanol and crude extracts of water; the activities of these three extracts were determined, [ Result] The three extracts were russet pastes; activity determination showed that they had remarkable inhibitory effects on the growth of rice radicle and plantule, as well as the growth of four-foliage-young seedlings. They could also generate toxic effects on abscisic foliages and spots similar to the symptoms of sheath blight pathogen. [ Conclusion] Bioactive components of rice sheath blight pathogen toxin may be composed of various ingredients.

Determination of Fe, Cu, and Zn in Water Samples by Microcolumn Packed with Multiwalled Carbon Nanotubes as a Solid Phase Extraction Adsorbent Using ICP-MS

The heavy metals determination in tap water samples using microcolumn packed with multiwalled carbon nanotubes （MWNTs） as a solid-phase extraction adsorbent before to their determination by inductively coupled plasma mass spectrometry （ICP-MS） has been studied. Standard addition method was applied for the calibration using aqueous solutions. The metals ions absorption were achieved by multiwalled carbon nanotubes （MWNTs） at pH 8.0, and then these retained metals on MWNTs column were eluted by 1.0 mol.L^-1 HNO3. The analytical parameters for the determination ofFe, Cu, and Zn in tap water samples which have been investigated previously were applied. Fifteen tap water samples were collected from different locations of Riyadh metropolitan area and then determined the concentration ofFe, Cu, and Zn by ICP-MS after preconcentration with MWNTs. The concentration range for Fe, Cu, and Zn measured （μg/L） in water samples are 23.37-137.91, 2.12-121.36, and 14.43-202.47 respectively. The level of Fe exceeded the limits set by WHO and SASO for drinking water.

Cloud-point extraction and preconcentration of bisphenol A from water samples

A novel cloud-point extraction （CPE） was successfully used in preconcentration of biphenol A （BPA） from aqueous solutions. Majority of BPA is extracted into the surfactant-rich phase. The parameters affecting the CPE such as concentration of surfactant and electrolyte, equilibration temperature and time and pH of sample solution were investigated. The samples were analyzed by high-performance liquid chromatography with ultraviolet detection. Under the optimized conditions, preconcentration of 10 mL sample gives a preconcentration factor of 11. The limit of detection （LOD） and limit of quantification （LOQ） are 0.1 μg/L and 0.33 μg/L, respectively. The linear range of the proposed method is 0.2-20 μg/L with correlation coefficients greater than 0.998 7 and the spiking recove6es are 97.96%-100.42%. The interference factor was tested and the extraction mechanism was also investigated. Thus, the developed CPE has proven to be an efficient, green, rapid and inexpensive approach for extraction and preconcentration of BPA from water samples.

Study on Extraction and Conversion Annatto （Bixa orellana L.） Color into Norbixin to Prepare Food Grade Water-Soluble Norbixin Powder

Response surface methodology was used in this research to optimize the technical parameters of the extraction and conversion color compound in armatto seeds into norbixin. Parameters affected the extraction efficiency and norbixin recovery yield were solvent concentration, rate of solvent/seed, incubation time, and incubation temperature. The optimization results including： concentration of ethanol is 51.82°; concentration of NaOH is 0.52 M; ratio of solvent/seed is 7.1/1; incubation time is 33.12 minutes, incubation temperature is 58.6℃, and the rate of 36% HCl/color solution is 0.5/5 （v/v）.

A Rapid Extraction Procedure for the Determination of Strontium-90 in Water Samples

A beta spectrometric method for the rapid determination of strontium-90 （90Sr） in water samples was developed and tested. 90Sr is extracted directly from the water samples by means of a scintillator cocktail, containing the crown ether dicyclohexano-18-crown-6 as an extracting agent （STRONEX）. Minimal clean-up is necessary when other beta nuclides are present, such as barium-140. These nuclides are eliminated by a barium chromate scavenge, prior to the extraction step. The method presented here allows for the investigation of at least 12 water samples a day and is therefore a suitable tool for emergency analysis.

Supercritical extraction to obtain vetiver （Vetiveria zizanioides L. Nash） extracts from roots cultivated hydroponically

We determined the global yield and composition of extracts from vetiver roots cultivated hydroponically. We extracted roots of two varieties collected at different times after planting. The extracts were obtained by supercritical fluid extraction （SFE）; we also estimated manufacturing costs. Constituents were quantified by gas-chromatography/time ionization detection （GC-FID）. Results demonstrated the efficacy of a hydroponic system in producing vctiver with a high root extract content. The largest yield was obtained from roots collected on days 132 and 92 after planting from varieties National （1.41%） and Bourbon （1.28%）, respectively. The major compounds present in the extract were khusimoi, isovalencenol, alpha-vetivone and beta-vetivone. To determine the economic viability of producing these extracts, manufacturing costs were estimated using a simplified methodology. The manufacturing costs were US$ 22.26/kg and US$ 24.26/kg for varieties national and Bourbon, respectively.

Gasification of Bio-waste and Biomass Products through Exposure to HD and LD Supercritical Water

Biomass as a sustainable and renewable energy source is starting to gain momentum, especially as more economical energy extraction methods prevail. SCWBG （supercritical water biomass gasification） is one of the more promising methods to extract energy from biomass in a gaseous form due to its lower temperature and simpler setup. In this work, two biomass and two bio-waste samples are gasified in SCW （supercritical water） under two temperatures （hence water densities）. As temperature increases and water density decreases, combustible gas yields tend to increase due to changes in reaction pathways and reaction rates. An analytical comparison is also made between the four different types of biomass in terms of the combustible gases produced and hence the energy value. As a result of this analysis beet skin produces the most methane and corn silage yields the most hydrogen. The two bio-waste samples （straw and beet skin） are found to have the highest HHV （higher heating values）.

Mesoporous Silica Nanoparticles for the Analytical Extraction of Triphenyltin from Water

A rapid, precise, sensitive and simple method has been developed for the extraction and determination of TPT （triphenyltin）, DPT （diphenyltin） and MPT （monophenyltin） in seawater samples. The procedure is based on the use of the dual functionalization of mesoporous silica with diol and Cl6 alkane groups for the collection of TPT and its derivatives, DPT and MPT, from seawater samples, followed by ethylation of the target matrices using sodium tetraethylborate （NaBEt4） and quantification by gas chromatography with pulsed flame photometric detection. The modified extraction method replaces conventional solid- and liquid-phase extraction with solid dispersion of silica nanoparticles. The partitioning of the analyte between a carefully size-selected silica nanoparticles （solid phase） and a liquid phase occurs as the solid moves through the sample as a colloidal sol. By tailoring the size of the particles to approximately 250 nm in diameter, they can be easily dispersed in aqueous solution, without the need for any mechanical or hand shaking and the solid can then be readily recovered, together with the analytes, by simple filtration or centrifugation. Recoveries of TPT, DPT and MPT chloride spiked matrices rang from 87.3±1.1 to 98.1±1.3 in seawater samples （n = I 1 samples）. The limit of detection obtained was typically in the range of 0.1-3 ng Sn/L. The proposed method shows excellent linearity in the range of 0.5-2 ng Sn/L and good repeatability （RSD 〈 5% at 0.02 ng TPT （as Sn）/L）. The method performance is demonstrated with real seawater samples.