Dust deposition in a sub-tropical opencast coalmine area, India

This paper provides baseline information about the total annual dust fall, and its constituents and seasonal variation, from a sub-tropical opencast coalmine area in Bina, India. Dust samples were collected monthly for 2 years (June 2002-May 2004) from five sampling sites in the region and analyzed in the laboratory for water-soluble and -insoluble matter. Water-insoluble components constituted the major fraction of the total annual dust fall. Two-way ANOVA indicated significant variations in dust fall at different sites, over the months and in their interactions. The dust deposition rate was highest during summer (March-June), followed by winter (November-February) and lowest in the rainy season (July-October). Maximum dust fall was observed near the coal handling plant (at site 2) followed by the receiving pit of the coal handling plant (site 3), near the main sub-station (site 4), Jawahar colony (site 1) and Gharasari village (site 5). An inverse and significant relation was observed between dust fall and precipitation. Our studies have shown that the main residential areas are experiencing higher levels of dust fall which makes them unsuitable for living. We suggest that residential areas should be moved farther away from the mining area in the opposite direction of prevalent winds.     

STREAMFLOW MEASUREMENT USING SALT DILUTION IN TUNDRA STREAMS,NORTHWEST TERRITORIES,CANADA1

ABSTRACT: With the recent increased exploration and mining activity in the Northwest Territories, there has been growing interest in streamflows. However, streamflow monitoring in Canada's north is limited, especially in the central Northwest Territories where the exploration activity is concentrated. To complicate matters, the standard approach of measuring discharge with current meters or weirs is often inadequate or prohibitively expensive, as many streams in the region are shallow, braided and rocky. In response, alternative techniques such as salt dilution can be used. A salt tracer's competence in turbulent and rocky channels makes it ideal for discharge measurements in these situations. This paper summarizes the work performed by Indian and Northern Affairs Canada and Canamera Geological Ltd. staff in determining the stream discharge of a lake outlet using a potassium chloride (KC1) tracer. A variety of streamflow measurement methods were performed and compared to determine the viability and rigor of the dilution method. Results suggest the dilution method compares favorably to other measurement techniques both in accuracy and operational ease.     

WATER QUALITY OF AN INTENSWE AGRICULTURAL WATERSHED IN QUEBEC1

ABSTRACT: . Under a watershed based approach being examined by the Quebec Ministry of Agriculture to accelerate the adoption of conservation practices, a study on the impacts of agricultural practices on the St. Esprit watershed was initiated in the fall of 1993. The water quality of this 26 km² intensive agricultural watershed was studied over an 18 month period. Water samples taken at the outlet of the watershed were analyzed for nitrate, phosphate, suspended sediment, and atrazine. Water quality data were analyzed to establish seasonal trends in pollutant concentration and load in the watercourse. Spring snowmelt was identified as a significant period of pollutant material export. All pollutant materials displayed seasonal variability in the export process. Peak pollutant concentrations were associated with high flow events. Mean observed pollutant concentrations did not exceed drinking water quality standards.     

德阳市主要农作物生产潜力

本文在简述了农业生产潜力定量测度方法的基础上,计算和分析了德阳市主要作物生产潜力。得出光能利用率低是造成该区作物产量不高的主要原因,各种作物中水稻生产力、生产潜力最大,不同种植制度中水旱轮作生产力、生产潜力最大     

浅谈环境成本

本文论述了环境的资源观、价值观以及环境的商品性,介绍了环境成本概念,分析了环境成本确认、环境成本的核算。     

水中砷的原子荧光光谱测定结果的不确定度评定

目的 对原子荧光光谱法测定水中砷含量的不确定度来源及其对测量不确定度的影响进行分析。方法 利用相对标准不确定度进行测量不确定度的评定。过程采用直观的因果图,建立有效的数学模型,利用相对标准不确定度分量进行测量不确定度评定,并在砷含量为1．7μg/L的水样测定中,获得其相对标准不确定度为3．4％,有效自由度为25。结论 原子荧光光谱法对水中砷浓度测量不确定度影响因素中,工作曲线拟合产生的不确定度较大。     

荞麦不同器官总黄酮含量的日变化研究

研究荞麦初花期不同器官总黄酮含量的日变化趋势、最佳取样时间和取样部位,为养麦的综合开发利用提供理论依据.对4份来自不同地区的甜荞和苦养不同器官的总黄酮含量进行了日变化研究.结果表明,一天中同一品种不同器官中的黄酮含量均表现为花>叶>茎>根,且花和叶中的含量显著大于茎和根,不同品种各器官中总黄酮含量的日变化差异较大.     

The effect of Oja-titun market effluent on the chemical quality of receiving OPA reservoir in Ile-Ife, Nigeria

The effect of market effluent from the Oja-titun market in Ile-Ife, Nigeria on the chemical quality of the Opa Reservoir located 3.5 km downstream was investigated between February and November 2000. Water samples were collected in February, May, August and November from 16 sites, four along each of the market drainage channels (MDC), market stream, tributary stream and the Opa River and Reservoir. The peak level of each variable-biochemical oxygen demand, temperature, total alkalinity, Na(+), K(+), Ca(2+), Mg(2+), PO(4)(3+), SO(4)(2+), Cl(-), NO(3)(-), Pb and Zn-occurred at the MDC, and decreased significantly downstream, except pH, conductivity and dissolved oxygen, which increased. Seasonal fluctuation in most variables was pronounced. Generally, there were high values in the early dry and dry seasons and low values in the rainy and early rainy seasons. Comparison of the reservoir water with international limitation standards for drinking water supply showed that the quality of the reservoir water was very low and that treatment required to achieve minimum limitation standards for drinking water would be both intensive and expensive. The study concluded that the stream borne effluent from the market impacts significantly on the chemical quality of the reservoir water although other tributaries within the Reservoir's catchment are other possible sources of pollutants in the reservoir.     

RUNOFF,EROSION, AND SOLUTES IN THE LOWER TRUCKEE RIVER,NEVADA, DURING 19691

The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates in Pyramid Lake. During the 1969 water year, flow about 9 miles upstream from the mouth (974,000 acre-ft) was almost four times the long-term average, due mainly to heavy winter rains and spring snowmelt. A short period of low-altitude rainfall produced the highest concentrations of suspended sediment, whereas a much longer subsequent period of snowmelt yielded a much greater total quantity of material. The upper 90 percent of the basin yielded about 260 acre-feet (630,000 tons) of sediment at the Nixon gage, whereas an estimated 2,800 acre-feet (6.8 million tons) was contributed by erosion of about 200 acres of river bank below the gage. Solute content at the gage ranged from 80 to 450 mg/l, dominated by calcium, sodium, and bicarbonate, plus silica in the most dilute snowmelt and chloride in the most concentrated low flows. Solute load totaled about 130,000 tons, of which the principal constituents in Pyramid Lake-sodium plus equivalent bicarbonate and chloride-amounted to almost 40,000 tons. The total solute load during a year of average flow may be 45,000-55,000 tons, including 18,000-22,000 tons of principal lake constituents.     

高含氯水样高锰酸盐指数测定新方法

在高锰酸盐指数的测定中,干扰最为严重且难以消除的是氯离子(Cl-)的影响。高浓度氯离子的干扰会导致测定结果偏差大,无法界定高锰酸盐指数是否达标。对高含氯水样高锰酸盐指数测定新方法(改进的高锰酸盐指数法)的实验研究结果表明,在采用标准高锰酸钾法对高含氯水样进行的高锰酸盐指数测定中,利用稀释方法,在碱性条件下用硫酸锰作催化剂,可以避免氯离子的干扰,提高了高锰酸钾对有机物的氧化率,能真实地反映水样中有机物的污染程度。