污水排放预测的多因素灰色模型GM(1,N)及其应用

在分析污水排放数据处理的现状后,运用灰色系统理论,通过优化模型系数与背景取值,建立了多因素灰色GM(1,N)模型。该模型克服了现有GM(1,N)模型的不足,扩宽了GM(1,N)模型的应用范围．具有精度高、使用简便等特点。GM(1,2)计算实例表明,该模型简单实用,值得在污水排放预测中推广应用。     

Heavy metal pollution in surface sediment and mussel samples in the Gulf of Gemlik

Different sources of pollution in Karasu Creek were investigated to obtain the water quality and ratio of contamination in this region. To achieve the main objectives of the present study, water samples were collected from Karasu Creek, starting from flow pattern at the upstream site of Akkaya Dam to the end of the dam, crossing the place where the Creek drains into. Dissolved oxygen, electrical conductivity, temperature and maximum/minimum pH were measured systematically for 12 months in the stations, where the water samples were collected. Chemical analyses of the water samples were carried out by using Cadas 50 S brand UV spectrometer to find out the Pb, Fe, Cu, Zn, Ni, Cr, Cd, S, F and Cn concentrations. These concentration were determined in μg/lt as 80–850; 180–4,920; 10–6,100; 440–25,530; 130–2,400; 120–280; 20–150; 214,250–1,113,580; 1,560–4,270 and 40–690, respectively. To determine metal levels of the water samples, multivariate analyses (element coefficient correlation, coefficient correlation dendrogram, hierarchical cluster analysis dendrogram, model summary and ANOVA) were used. The analyses yielded highly accurate results. There were positive correlations between some elements and their possible sources were the same. The stations which resembled each other along the creek were divided into three groups. The water quality of the creek was low and had toxic qualities. Eutrophication developed in Akkaya Dam along the creek. The source of pollution was thought to be industrial and residential wastes. Absolute (0–100 m), short distance (100–500 m) and medium distance (500–2,000 m) conservation areas should be determined in pollution areas along Karasu Creek and they should be improved.     

Effect of vegetation change from native broadleaf forest to coniferous plantation on selected soil properties

The objective of this study was to examine the effects of vegetation change from a native broadleaf forest to a coniferous plantation on selected soil properties, including soil texture, pH, organic matter, total nitrogen (N), total phosphorus (P), exchangeable cations (Ca²⁺, K⁺, Na⁺), and cation exchange capacity (CEC). Results showed that the amount of clay particles, Ca²⁺, and K⁺ values significantly increased, whereas Na⁺, total N, and organic matter and soil pH values decreased on the treatment plot after vegetation change. Soil acidity also increased and soil textural group changed from moderately fine-textured soils (clay loam) to medium-textured soils (loam) under both control and treatment plots. Organic matter, total N, and Na⁺ values increased, whereas Ca²⁺ concentration decreased through time on the control plot. Soil pH, total P, K⁺, and CEC did not show significant changes through time on the control plot.     

Monitoring and measurement of microalgae using the first derivative of absorbance and comparison with chlorophyll extraction method

Monitoring of microalgae in water supplies and industrial applications are becoming increasingly important, yet there are few options available that are simple and accurate, and can provide real-time information. The present work illustrates a new method to determine the concentration of microalgae in water and wastewater using spectrophotometry and the first derivative of absorbance. Chlorella vulgaris was used as an indicator microalga, spiked in water samples representing a range of water qualities (distilled water, surface water, and wastewater), and correlations among C. vulgaris concentrations, absorbance, and the first derivative of absorbance measurements were investigated. In addition, detection limits were established and sensitivity analyses were carried out to determine the lowest C. vulgaris concentrations that can be confidently measured in different water matrices. Finally, the study compared the performance and detection limits of the spectrophotometry-based methods with the well-accepted chlorophyll extraction method. A strong linear relationship (R²?>?0.97) was found between C. vulgaris concentration and absorbance at 695 nm. Using the first derivative of absorbance improved C. vulgaris detection limits by reducing the effects of the background noise and interferences from other substances. The detection limits established using the first derivative method were 0.47, 0.56, and 1.96 mg TVS/L in distilled water, surface water, and wastewater, respectively. In comparison, the detection limits of the chlorophyll extraction method were found to be 19.6, 38.6, and 48.3 mg TVS/L in the same water matrices. These results indicate that first derivative of absorbance can be successfully used for monitoring of microalgae in surface waters and environmental samples as well as in bioreactors used for microalgae cultivation in industrial applications.     

Water quality and heavy metal monitoring in water and sediment samples of the Küçükçekmece Lagoon, Turkey (2002–2003)

Physical and chemical parameters have been analyzed in water samples from a brackish water lagoon, Küçükçekmece, located on the western outskirts of Istanbul. Samples were collected every two months for a year from nine sampling stations. Of the parameters measured, temperature, pH, salinity, nitrate and phosphate showed changes when compared with the previously published data. The lagoon was found eutrophic as it was reported previously. Sulphate and COD levels were higher when compared with the standards established by the Turkish Water Pollution and Control Regulation. Additionally, concentrations of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in water and bottom sediments were measured and compared with the standards established by the Turkish Water Pollution and Control Regulation and with the previously published data. The results were analysed statistically with respect to location and any relationships between the concentration of the elements in corresponding water and sediment samples were examined. Principal Component Analysis of water samples allowed us to discriminate three areas affected mainly by heavy metal contamination, possibly due to industrial, commercial and/or urban activities. Generally, the concentrations of the heavy metals were higher at stations near the three estuaries, suggesting a direct influence of the three creeks on the pollution of the Küçükçekmece Lagoon. Although elevated levels of Cd were recorded in several water samples, it was not detected in sediment. On the other hand, a particularly high level of Cr pollution was recorded most of the water and sediment samples.     

Toxic metal (Pb, Cd, As and Hg) and organochlorine residue levels in hake (Merluccius merluccius) from the Marmara Sea, Turkey

Toxic metals (Pb, Cd, As and Hg) and organochlorine residue levels were measured in hake (Merluccius merluccius) from the Marmara Sea. Biota samples were collected by a trawling cruise of the R/V ARAR in August and December 2009. The concentrations of toxic metals varied between Pb, 3.23-14.4; Cd, <0.01-2.14; Hg, 0.01-0.18 and As, 0.01-0.21 [Formula: see text]g g(-1) dry wt. Pb levels in the Marmara Sea were found to be higher than the critical limits set by the both Turkish Ministry of Environment for Aquatic Products (1 μg g(-1) wet wt.) and European countries (2.0 μg g(-1), UNEP 1985). In contrast, As and Hg levels were found to be lower than the critical limits for two periods. Cd contents of fish from the Marmara Sea were also comparable to or slightly lower than contents of fish from the Southern Black Sea Shelf. The results of organochlorine residues ranged between total HCH, <0.05 and 99 ng g(-1); endrin, <0.001 and 381 ng g(-1); alpha-endosulphan, <0.05 and 90 ng g(-1); beta-endosulphan, <0.05 and 15.3 ng g(-1); o,p DDE, 3.5 and 52.4 ng g(-1); p,p DDE, 7.4 and 139 ng g(-1); o,p DDD, 1.5 and 90.2 ng g(-1) and p,p DDD, 2.7 and 86 ng g(-1) wet weight. The rivers for the distribution of organochlorine levels in the Marmara Sea ordered from highest to lowest as Dil R. > Susurluk R. > Biga R. > G?nen R. The high levels of o,p and p,p DDE, and o,p and p,p DDD compounds, which are metabolites of DDT, indicate its illegal use. Toxic metal and organochlorine residue levels of fish are significantly higher than levels from the Mediterranean Sea.     

Radiological hazard assessment of natural gross radioactivity in some cosmetic products

Many kinds of cosmetic products were analyzed to determine gross radioactivity. In this study, gross alpha/beta radioactivity concentrations in 51 cosmetic samples were determined. The examined cosmetic products consist of blusher, eye shadow, lipstick, nail polish, shampoo, hand cream, cellulite cream, baby powder, soap, and toothpaste. The gross alpha–beta activity concentrations were measured with a nuclear spectroscopic system which contains gas-flow proportional counters. The highest gross alpha/beta activity concentrations were found in eye shadow samples of 1.621Bq g^?1 for alpha and 6.471Bq g^?1 for beta. The total effective doses due to gross radioactivity for skin were calculated. Although the effective dose of eye shadow samples had the highest value, the effective doses due to gross radioactivity concentrations in this study were found to be lower than the radiological limits given by the authorities.     

Determination of T‐2 toxin in grain and grain products by HPLC and TLC

Abstract

The purpose of this study was to investigate the T‐2 toxin contaminated grain and grain products consumed especially by Turkish population. The T‐2 toxin was detected using the high performance liquid chromatography (HPLC) with UV detector at 208 nm and the identify of T‐2 was further confirmed by thin layer chromatography (TLC). The recovery was 91 ±4.24% for corn flour fortified with the known amount of T‐2 toxin (1 ppm). The detection limits of T‐2 toxin for the HPLC and the TLC were 25 ng and 50 ng, respectively. A total of 30 commercially available grain and grain product samples were analyzed. Two corn flour samples were found to contain detectable levels of T‐2 toxin at a level of 1.60 ppm and 4.08 ppm.     

声发射技术在湘西金矿深井安全开采中的应用

笔者介绍了岩体声发射监测技术及其基本技术参数 ,描述了井下采矿环境下识别岩体声发射信号的频谱特征 ,并进一步介绍了岩体声发射监测技术在湘西金矿深井开采中的应用情况。声发射安全监测技术应用表明 ,声发射事件率及其增长幅度直接反映了顶板稳定性的变化情况 :当岩音频度在 1 0次 /分以下时 ,采场顶板处于稳定 ;但达 1 6次 /分以上时 ,采场顶板就有冒落的可能性 ,应该采取预防措施。该技术安全监测预报结果为深井的安全生产、避免灾害事故的发生提供了决策依据