井矿盐开发所致的辐射水平

本文报道了自贡市井矿盐开发所致的辐射水平。井矿盐开发的主要废弃物－卤泥中＾２３８Ｕ，＾２２６Ｒａ，＾２３２Ｔｈ的天然放射性核素比活度比四川省土壤中相应核素平均值高１－２个数量级，且造成卤泥堆积场和局部生产环境陆地γ辐射剂量率高出自贡市环境陆地γ辐射平均值的２．０－４８．３倍，最主超过１６５倍。部份卤泥和盐厂附近江河排放口底泥中天然放射性废物标准。     

AAS与ICP—AES间接测定天然水中硫酸盐

本文以ＳＯ４＾２－与过量Ｂａ＾２＋形成ＢａＳＯ４沉淀反应为基础，较详细地讨论了反应条件，从而拟定了用ＡＡＳ和ＩＣＰ－ＡＥＳ间接测定天然水中ＳＯ４＾２－的方法、确定了方法的精密度，ＡＡＳ法的ＲＳＤ％为１．５，ＩＣＰ－ＡＥＳ法为３．２， 两种方法对比分析的结果接近，误差为１．０％（相对）。用于天然水中ＳＯ４＾２－的测定，获得满意的结果。     

90Sr、137Cs在某种包气带土壤中的迁移研究

本文叙述了放射性废物中具有代表性的裂变核素^90Sr、^137Cs在某种包气带土壤中的迁移情况研究。使用小型土柱的氚水淋洗实验研究土壤水力学性质，最后进行大型土柱实验研究核素在该包气带土壤中的迁移，并对实验情况进行了数学模拟。用该土壤原状土进行小型土柱的氚水淋洗试验，测得了土壤的水力弥散度为0．32cm，土壤有效孔隙度为0．35。经过290天的大型柱迁移试验表明，土壤对^90Sr的阻滞系数为220．4，在模拟实际降雨量的情况下，^90Sr的平均迁移速度为0．63cm/y，^137Cs在大型柱试验中没有明显迁移。数值模拟^90Sr、^137Cs迁移，得出经过上述大型柱试验相同的条件下，^90Sr、^137Cs迁移的峰位置基本和大型柱试验结果相同。     

不同pH值、不同比例的添加剂对土壤吸附铯的影响

铯极易被粘土矿物和有机质吸附而且不易解吸,在示踪水土侵蚀、处置核废物方面有着积极的作用。不同的pH值、不同比例的添加剂都会影响土壤对核素铯的吸附,实验证明两种土壤对核素铯的吸附在pH=4～7时很大,pH=7时达到最大;四种添加剂粗沸石、人造沸石、Ca（OH）2、MnO2只有粗沸石的加入量与铯的吸附比成正相关关系,可以提高土壤对铯的吸附能力。     

成都市在气降尘放射性水平分析

本文介绍了成都市大气尘放射性水平的监测结果。发现除尘中除少量天然核素外，还尚存在以往大气层柱试验释放的裂变核素＾９０Ｓｒ和＾１３７Ｃｓ。     

宁夏沙湖自然保护区水生生物调查与分析

宁夏沙湖自然保护区位于平罗县，面积４２４７ｈｍ＾２，水面沼泽２７３２ｈｍ＾２。根据１９９９年７月对其进行了综合考察的统计结果，计有水生两栖类－大鲵１种，鱼类１６种，浮游植物８门２９科６１属（种）、浮游动物２９种、水生底栖无脊椎动物２９种。     

选择双波长光度法测定天然水中溶解氧

本文依据悬浮液对光的吸收行为研究ＤＯ与Ｍｎ＾２＋－Ｉ＾－－Ｈ＾＋反应液吸收光谱，发现在５２０－６００ｎｍ波长范围内其光谱与悬浊液光谱相平行，由此研究在此波长内任意选择双波长测定痕量锰的新方法，实验结果表明该方法灵敏度和精密度均较传统容量法高，计算曲线稳定性好，适合于天然水分析。     

湿法处理工业废渣热力学分析

根据冶金，煤炭及无机化工工业类废渣的物理化学性质，通过Ｍ＾ｎ＋ ｅ－Ｈ２Ｏ系和Ｍ＾ｎ＋ｅ－Ｆ＾－Ｈ２Ｏ系热力学平衡图，对废渣中硅，铝，铁及钙镁等主要矿物的溶出热力学行为进行了分析。     

低中放处置场环境影响评价中~(90)Sr分配系数的选取

放射性固体废物处置的基本安全目标是保护人类和环境免受电离辐射的有害影响。开展放射性固体废物处置场环境影响评价可以量化对人体健康和环境潜在影响。放射性核素分配系数是反映放射性核素在处置场周边土壤介质中迁移的关键参数,对环境影响评价结果的影响显著。不同核素分配系数试验测量方法的实验周期、经济成本以及结果精确度等方面差别很大。从工程角度考虑,如测量结果相差不大,则应优先选择实验周期短、费用低的方法进行分配系数测量。~(90)Sr是拟近地表处置的放射性固体废物中具有代表性的裂变核素之一。采用静态实验和动态实验方法对~(90)Sr在我国北方几种典型土壤(砂土、粘土和黄土)包气带中的迁移进行了研究,分析了不同试验方法测量得到的~(90)Sr分配系数的差异。结果表明:对~(90)Sr的吸附能力,粘土最强,黄土次之,砂土最弱;对于低中放处置场地下水核素迁移模拟,~(90)Sr在粘土和黄土中采用平衡吸附模式或非平衡吸附模式模拟结果差别不大;而采用非平衡模式模拟砂土中~(90)Sr的迁移更为恰当;在低中放处置场环境影响评价中,对于砂土介质,~(90)Sr分配系数的测量应优先选择动态实验法,对于黄土和粘土则可采用静态吸附法。     

五氯酚对环境污染及居居健康影响研究

中国长期以来使用五氯酚的盐茶灭血吸虫的中间宿主－－钉螺，为评价它对环境的污染及居民健康危害，1990－1993年在我省开展了五氯酚环境污染及对民民健康影响研究，在研究区采集环境样品（空气，不体，土壤及底泥，蔬菜，肉，蛋，鱼等）共173份，生物材料（人血，尿）共457份，分析一氯酚浓度，结果表明，在五氯酚使用区，环境中PCP浓度稍高于对照区，而生物材料尿，血中PCP浓度明显高于对照区，全血胆碱脂酶活性用药区明显低于对照区，编译学分析有显著差异（P＜0．001），证实了长期低剂量使用可造成环境及生物蓄积。     

屯绿陈茶有效成分提取及茶多酚提纯工艺研究

探讨了从陈茶中提取有效成分和茶多酚的提纯工艺。采用不同物料比、浸提温度、浸提时间的正交实验,通过热水煮提从茶叶中获取水溶性物质。结果表明,当料液比为1：20、90℃、120min时,测得的水提取物固化物量最多可达31％;茶叶水提物固化物、水配比为13：400时与乙酸乙酯萃取茶多酚的得率达23％,茶多糖从总量中提取的得率达2．5％。屯绿陈茶有效成分保留效果良好,具有较好的综合利用价值。     

池州悬钩子的食用价值与茶多酚含量研究

研究了池州市悬钩子属植物的食用价值与其中茶多酚(TP)的含量,目的是为了综合利用悬钩子属植物,促进其全面开发,提高经济效益.用正交实验法确定了提取TP的最佳实验条件,用分光光度法测定其含量.从分析结果看,悬钩子属植物中含有一定量的TP.因此,在开发悬钩子属植物果实作为第三代水果资源时,从其茎叶中提取TP具有一定的经济价值,这对促进悬钩子资源的开发与利用是很有意义的.     

Removal of Pb(II) ions from aqueous solution using activated tea waste: Adsorption on a fixed-bed column

An inexpensive and effective adsorbent was developed from waste tea leaves for the dynamic uptake of Pb(II). Characterization of the adsorbents showed a clear change between physico-chemical properties of activated tea waste and simply tea waste. The purpose of this work was to evaluate the potential of activated tea waste in continuous flow removal of Pb(II) ions from synthetic aqueous effluents. The performance of the system was evaluated to assess the effect of various process variables, viz., of bed height, hydraulic loading rate and initial feed concentration on breakthrough time and adsorption capacity. The shape of the breakthrough curves was determined for the adsorption of Pb(II) by varying different operating parameters like hydraulic loading rate (2.3–9.17 m³/h m²), bed height (0.3–0.5 m) and feed concentration (2–10 mg/l). An attempt has also been made to model the data generated from column studies using the empirical relationship based on the Bohart–Adams model. There was an acceptable degree of agreement between the data for breakthrough time calculated from the Bohart–Adams model and the present experimental study with average absolute deviation of less than 5.0%. The activated tea waste in this study showed very good promise as compared with the other adsorbents available in the literature. The adsorbent could be suitable for repeated use (for more than four cycles) without noticeable loss of capacity.     

Streamside Forest Buffer Width Needed to Protect Stream Water Quality,Habitat, and Organisms: A Literature Review

This literature review addresses how wide a streamside forest buffer needs to be to protect water quality, habitat, and biota for small streams (≤~100 km² or ~5th order watershed) with a focus on eight functions: (1) subsurface nitrate removal varied inversely with subsurface water flux and for sites with water flux >50 l/m/day (~40% avg base flow to Chesapeake Bay) median removal efficiency was 55% (26‐64%) for buffers <40 m wide and 89% (27‐99%) for buffers >40 m wide; (2) sediment trapping was ~65 and ~85% for a 10‐ and 30‐m buffer, respectively, based on streamside field or experimentally loaded sites; (3) stream channel width was significantly wider when bordered by ~25‐m buffer (relative to no forest) with no additional widening for buffers ≥25 m; (4) channel meandering and bank erosion were lower in forest but more studies are needed to determine the effect of buffer width; (5) temperature remained within 2°C of levels in a fully forested watershed with a buffer ≥20 m but full protection against thermal change requires buffers ≥30 m; (6) large woody debris (LWD) has been poorly studied but we infer a buffer width equal to the height of mature streamside trees (~30 m) can provide natural input levels; (7, 8) macroinvertebrate and fish communities, and their instream habitat, remain near a natural or semi‐natural state when buffered by ≥30 m of forest. Overall, buffers ≥30 m wide are needed to protect the physical, chemical, and biological integrity of small streams.     

长江上游及川江水系水环境中~(239)Pu的水平和分布情况

~(239)Pu是一种极毒的放射性核素,水环境,尤其是江河环境中~(239)Pu的水平与分析情况,目前在国内还未见有系统的报道,本文通过对长江的一些江段及川江水系水环境中~(239)Pu水平的分析,探讨了其分布情况及规律;并初步分析了目前长江水域中~(239)Pu的主要来源;得出了研究江段水底沉积物中~(239)Pu的沉积规律。     

软锰矿与氧化亚铁硫杆菌吸收SO2过程中的影响因素

研究了低浓度软锰矿浆与氧化亚铁硫杆菌(Thiobacillus ferrooxidans,简称 T.f)联合吸收SO2过程中软锰矿浆浓度、T.f菌液量、O2体积分数、气体流量以及SO2进口浓度对硫酸根生成的影响.研究表明:在该体系中,生成的硫酸根浓度随着软锰矿浆浓度、T.f菌液量、O2体积分数以及气体流量的增加而增大;随着进口SO2浓度的增加,硫酸根的生成呈现先增加后减少的趋势.     

Potential health hazard of drinking water in restaurants and tea stalls

Potable and equitable drinking water (DW) is a fundamental human right and essential for human health. This study is conducted to assess the groundwater and jar water quality of the roadside restaurants and tea stalls used for drinking by the local people around the Gazipur City area in Bangladesh. Water samples from 173 restaurants and tea stalls are collected. The physico-chemical and biological parameters are analyzed according to the guidelines and standards. The results illustrate that the color, EC, and Mn of 41%, 80%, and 62% of the samples, respectively, exceed the WHO and Environmental Conservation Rules (ECR) standards. In addition, E. coli and total coliform exceeding the threshold standards are found in 47% and 64% of the water samples, respectively. The contamination of DW by fecal coliforms is confirmed and supported by prior studies, which indicates that the DW supplied in restaurants and tea stalls are unsafe because of the possible presence of pathogens. These may cause potential health hazards to consumers from various water-borne diseases. Poor sanitation, unhygienic practices, and improper disposal of wastewater are responsible for the microbial contamination of DW. So, the authorities in charge of these places should take the right regulatory steps, such as regular sanitation inspections, DW quality monitoring, hand-washing practices, and better sanitation in these places.     

Sorption interactions between imazaquin and a humic acid extracted from a typical Brazilian oxisol

Soil sorption of most hydrophobic organic compounds (e.g., nonpolar pesticides) is directly related to soil organic matter (SOM) content. Humic substances are the major SOM components, containing carboxylic, phenolic, amine, quinone, and other functional groups, and specific structural configurations. In this paper, sorption interactions between imazaquin (2-[4,5-dydro-4-methyl-4-(1-methylethyl)-5-oxo-1H- imidazol-2-yl]-3-quinoline-carboxylic acid) herbicide (IM) and a humic acid (HA) extracted from a typical Brazilian Oxisol were studied with electron paramagnetic resonance (EPR) and Fourier-transform infrared (FTIR) spectroscopic techniques. A polarographic technique was used to quantify sorption. The IM amount sorbed on the HA was much higher than that on the whole soil within the pH range studied, emphasizing the prominent role played by SOM on IM sorption. Moreover, IM sorption increased as the soil-solution pH decreased. This enhancement in sorption was attributed to the hydrophobic affinity of the herbicide by the HA and to the electrostatic interaction between the protonated quinoline group of IM and the negative sites of the HA. Hydrophobic regions in the HA's interior at low pH (< 5.0) were recently demonstrated by an EPR detectable spin-label molecule. The FTIR and EPR spectroscopy and polarography data indicated weak interaction between IM and the soil and its HA, involving hydrogen bonding, proton transfer, and cation exchange (at low pH), and mainly hydrophobic interactions. However, no strong reaction mechanism, such as charge transfer, was involved. In addition, this research suggested that soil amendment with organic material might increase magnitude of IM sorption, consequently avoiding leaching and carryover problems usually found for mobile and persistent herbicides such as imazaquin.     

Historical and Future Stream Temperature Change Predicted by a Lidar‐Based Assessment of Riparian Condition and Channel Width

Riparian forests attenuate solar radiation, thereby mediating an important component of the thermal budget of streams. Here, we investigate the relationship between riparian degradation, stream temperature, and channel width in the Chehalis River Basin, Washington State. We used lidar data to measure canopy opening angle, the angle formed between the channel center and trees on both banks; we assumed historical tree heights and calculated the change in canopy angle relative to historical conditions. We then developed an empirical relationship between canopy angle and water temperature using existing data, and simulated temperatures between 2002 and 2080 by combining a tree growth model with climate change scenarios from the NorWeST regional prediction. The greatest change between historical and current conditions (~7°C) occurred in developed portions of the river network, with the highest values of change predicted at channel widths less than ~40 m. Tree growth lessened climate change increases in maximum temperature and the length of river exceeding biologically critical thresholds by ~50%–60%. Moreover, the maximum temperature of channels with bankfull widths less than ~50 m remained similar to current conditions, despite climate change increases. Our findings are consistent with a possible role for the riparian landscape in explaining the low sensitivity of stream temperatures to air temperatures observed in some small mountain streams.     

四川原煤及其废渣与制品放射性的测试分析

本文介绍了四川原煤及其废渣与制品的γ辐射剂量率、附加γ辐射人均年有效剂量量。同时,用低本底Ge(Li)多道γ能谱仪测定了原煤、矸粉与矸砖,煤渣与煤渣砖、粉煤灰及粘土砖等样品中的天然放射性核素~(238)U,~(232)Th,~(226)Ra,~(40)K的比活度。经比较和研究,找出了这些物质的放射性水平及它们彼此之间的规律。