稻—金鱼共栖生态系统的水质理化性质分析

稻田养金鱼能显著提高稻田溶氧水平,其日变化规律与水温呈正相关关系,在14-16时达到最高值,凌晨5时左右稻田溶氧值达到最低值;水中NH4+ 浓度较对照组要高;S2-的浓度两者均在18点时最低, 凌晨4点时时最高,但稻一金鱼处理组比对照组S2-浓度稍低;pH值与水温呈正相关关系,在14:00左右pH 值最高,在凌晨06:00最低,稻一金鱼处理组pH值比对照组稍为降低。

北方某大型水库水质理化性质研究

从水库多年平均水质理化性质、代表性监测点水质指标、有机污染物等方面系统分析研究了北方某大型水库的水质状况。在系统分析水温、pH、营养盐、重金属及有毒物质等多年平均基本理化性质及水质综合评价的基础上,对水库代表性监测点进行了水质指标和有机污染物状况分析,提出了建议。

难沉降煤泥水组成及特点的研究

以山东某选煤厂的难沉降煤泥水为研究对象，利用现代分析测试手段，分析难沉降煤泥水的水质特性、矿物组成、粒度组成、表面电性等。结果表明导致煤泥水难沉降的主要原因是煤泥水中粘土矿物含量较高，泥化现象严重，颗粒粒度小，表面带有很强的负电荷，具有胶体稳定特性，从而导致其难以沉降。

Sorption and Fractionation of a Peat Derived Humic Acid by Kaolinite, Montmorillonite, and Goethite

Sorption of humic acid （HA） on mineral surfaces has a profound interest regarding the fate of hydrophobic organic contaminants （HOCs） and carbon sequestration in soils. The objective of our study is to determine the fractionation behavior of HA upon sorption on mineral surfaces with varying surface properties. HA was coated sequentially on kaolinite （1：1 clay）, montmorillonite （2：1 clay）, and goethite （iron oxide） for four times. The unadsorbed HA fractions were characterized by elemental analysis, diffuse reflectance infrared Fourier transform spectroscopy （DRIFT）, and solid state 13C nuclear magnetic resonance spectroscopy （NMR）. The mineral-HA complexes were characterized by DRIFT. Polarity index [（N＋O）/C] revealed higher polarity of the unadsorbed HA fractions after coating on kaolinite, reflecting that relatively higher polarity fractions of HA remain unadsorbed. Sorption of aiiphatic alcohol fraction along with carbohydrate was prominent on kaolinite surface. DRIFT results of the unadsorbed HA fractions indicated more sorption of aiiphatic moieties on both kaolinite and montmorillonite. DRIFT results of the unadsorbed HA fractions after sorption on kaolinite and goethite showed the sorption of the proteinaceons fractions of HA. The HA fractions obtained after coating on goethite showed significant sorption of carboxylic moieties. The results mentioned above comply reasonably well with the DRIFT spectra of the minerai-HA complexes. ^13C NMR results showed higher sorption of anomeric C on kaolinite surface. Higher sorption of paraffinic fraction waS observed on montmorillonite. NMR data inferred the sorption of carboxylic moieties on goethite surface. Overall, this study showed that aliphatic moieties of HA preferentially sorbed on kaolinite and montmorillonite, while carboxylic functional groups play a significant role in sorption of HA on goethite. The sorbed fractions of HA may modify the mineral surface properties, and thus, the interaction with organic contaminants.

Fish Protein Recovered Using pH Shifting Method and Its Physicochemical Properties

The solubility of meat protein of croaker and jack mackerel was significantly affected by pH shifting. The protein yield of alkali-aided processing is higher than those of conventional and acid-aided processing. The addition of sarcoplasmic protein increases the breaking force and deformation value. The breaking force of recovered protein gel from alkali-aided processing is decreased by the addition of NaCI. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） revealed that fish protein of alkali is similar to that at pH7.0. Alkali-aided processing for recovering fish protein is a valuable method for increasing the utilization of frozen and pelagic fishes and for making kamaboko products.

Influence of nitrogen hetero-substitution on the electrochemical performance of coal-based activated carbons measured in non-aqueous electrolyte

Nitrogen-containing carbons were prepared by modification of activated carbons.The modified carbons were used as electrode materials with improved electrochemical performance.Precursor anthracite was activated by KOH(KOH:anthracite= 1:1), modified by melamine or urea and then treated at 1173 K to obtain the modified carbons.The porous structure, the chemical composition and the electrochemical characteristics of the carbons were investigated by nitrogen sorption, XPS and electrochemical methods respectively.Electrochemical experiments were performed in an organic electrolytic solution of 1 M(C2H5)4NBF4/PC.The samples modified by the different methods showed differences in chemical composition that introduced varying degrees of electrochemical performance enhancement.The presence of nitrogen enhanced the electron donor properties and the surface wettability of the activated carbons:this ensured a sufficient utilization of the exposed surface for charge storage.

Effects of Oyster Shell Soil Amendmenton Fruit Auality and Soil Chemical Properties in Greenhouse Tomato Acidic Soils

[Objective]The aim was to explore the feasibility of applying oyster shell soil amendment for tomato production in order to determine proper quantity of the soil conditional.[Method]Field tests were performed to research effects of the soil conditioner on tomato yield,quality and soil p H.[Result]The results showed that tomato yield increased in the treatment groups with oyster shell soil amendment.The group SC50 increased the most by 16.5%than the control group.Based on normal fertilization,tomato growth was promoted by the soil amendment,and per tomato weight and lycopene content both improved during peak-fruiting period.Besides,soil p H value was enhanced by the soil amendment also.[Conclusion]It can be concluded that the effect was the best when soil conditioner was applied at 750 kg/hm2.

Effects of Composted and Thermally Dried Sewage Sludges on Soil and Soil Humic Acid Properties

The effect of annual additions of composted sewage sludge (CS) and thermally dried sewage sludge (TS) at 80 t ha-1 on soil chemical properties was investigated for three years in a field experiment under semiarid conditions. Humic acids (HAs) isolated by conventional procedures from CS, TS, and unamended (SO) and sludge amended soils were analysed for elemental (C, H, N, S and O) and acidic functional groups (carboxylic and phenolic) and by ultraviolet-visible, Fourier transform infrared and fluorescence spectroscopies. With respect to CS, TS had similar pH and total P and K contents, larger dry matter, total organic C, total N and C/N ratio and smaller ash content and electrical conductivity. Amendment with both CS and TS induced a number of modifications in soil properties, including an increase of pH, electrical conductivity, total organic C, total N, and available P. The CS-HA had greater O, total acidity, carboxyl, and phenolic OH group contents and smaller C and H contents than TS-HA. The CS-HA and TS-HA had larger N and S contents, smaller C, O and acidic functional group contents, and lower aromatic polycondensation and humification degrees than SO-HA. Amended soil-HAs showed C, H, N and S contents larger than SO-HA, suggesting that sludge HAs were partially incorporated into soil HAs. These effects were more evident with increasing number of sludge applications.

A modified Hoek-Brown failure criterion considering the damage to reservoir bank slope rocks under water saturation-dehydration circulation

After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturation- dehydration circulation （WSDC）. To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers （1, 5, 10, 15, and 20） of simulated WSDC cycles. Based on the curves derived from these tests, a modified Hock- Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hock-Brown failure criterion is useful. Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion.

Pond Water Quality and Cyclops Population in Dracunculiasis Endemic Areas of Ogun State, Nigeria

This study investigated the association between Cyclops population and physico-chemical properties of pond water in villages selected from Odeda and Obafemi-Owode areas of Ogun State, Nigeria. Epidemiological data on guinea worm were collected from Global 2000 South-West Zonal Office. Two villages were selected from each of Odeda and Obafemi-Owode LGAs while one village was sampled from Abeokuta North LGA as control. Physico-chemical analysis and microscopic examination of pond water utilized for domestic purpose in the selected villages were conducted. Mean values of 6.78±0.10, 33.00±0.14℃, 1.09＋0.80 mg/L and 1.30±0.25 mg/L were recorded for pH, temperature, DO and nitrate respectively while control had 7.30±0.14, 36.30±14℃2, 2.72±0.14 mg/L and 5.80±0.57 mg/L. These values with the exception of DO and nitrate were within WHO standard but vary significantly （P〈0.05） between the villages. The results further showed that BOD, COD and acidity were positively correlated with Cyclops population during the rainy and dry seasons while temperature, nitrate, pH, and alkalinity have negative correlation coefficients （r=-0.81, -0.91） with Cyclops population during the two seasons. Regression analysis showed that nitrate, BOD and acidity levels explained 67.7 percent, 50.4 percent and 44.5 percent of Cyclops population in the ponds. Guinea worm eradication in endemic rural areas should incorporate ecological strategy.

武义县饮用水源水质理化和微生物状况调查分析

目的探讨分析武义县饮用水源水质理化和微生物状况。方法随机选取武义县21份居民家用末梢水,水样采集工作严格依据《生活饮用水标准检验方法水样的采集与保存》进行。每个监测点采集生活饮用水水样1份,所有水样于3 h内检测。每份水样检测理化项目22项,其中感官性状和一般化学指标13项、水质毒理指标8项、消毒剂使用情况1项。每份水样进行微生物检测,包括菌落总数和总大肠菌群。结果21份饮用水样本中,pH值、臭和味、耗氧量、溶解性总固体、肉眼可见物、色度、氨氮、锰、铁和硫酸盐合格率均为100%;浑浊度合格率为95.23%,总硬度合格率为95.23%,氯化物合格率为95.23%。21份饮用水样本中,镉、铅、砷、硒、三氯甲烷和氟化物合格率为100.00%;硝酸盐合格率为85.71%,四氯化碳和游离余氯合格率为95.23%。21份生活饮用水中,总大肠菌群检测合格样品18份,合格率为85.71%;菌落总数检测合格样本18份,合格率为85.71%。结论武义县水源水质饮用水理化项目和微生物状况检测合格率良好,但仍存在一定安全风险,需加强生活饮用水的监督和检测改进工作。

Effect of SHAKTI and KUBOTA power tillers on physical properties of soil and rice yield under Sawah production system in Nigeria

The use of the power tillers （walking tractors） are increasingly popular in Nigeria among farmers adopting Sawah rice production technology. This study compares the effects of two types of power tillers on physical properties of soil and rice yield. because soil properties determine to a large extents rice yield. Data on soil properties and rice yield were collected and subjected to t-test statistics. The results show that, significant differences exit for all the physical properties of soils rice yields from fields where the two power tiller were used with yields from rice field where SHAKTI was used was higher than KUBOTA. It is important that farmers using these models of power tillers for rice production should not only focus on the purchase cost of these power tillers but their overall efficiency in order to achieve the desired high level of yield.

Spatial impact of organic matters from point sources on stream water quality

To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.

Solute Transportin Sand Columns as Affected by Effluent Surface Tension

Transport of nonreactive solutes in soils is principally controlled by soil properties, such as particle-size distribution and pore geometry. Surface tension of soil water yields capillary forces that bind the water in the soil pores. Changes in soil water surface tension by contaminants may affect flow of soil water due to decreased capillary forces, caused by lowered soil water surface tension. This study aimed at assessing solute transport in sand columns as affected by effluent surface tension. Miscible displacement （MD） tests were conducted on sand columns repacked with sands sieved from 2.0, 1.0, 0.5 and 0.25 mm screens. The MD tests were conducted with 0.05 M bromide solutions prepared using water with surface tension adjusted to 72.8, 64, 53.5 and 42 dyne/cm2. Obtained breakthrough curves were modeled with the convection-dispersion equation （CDE） model. Coefficient of hydrodynamic dispersion and pore-water velocity responded inconsistently across decreased particle-sizes and water surface tensions and this was attributed to non-uniform effect of lowered effluent surface tension on solute transport in different pore-size distribution.

Research on pore microstructure features for dredger fill based on mercury intrusion method

The material composition and microstructure have a comprehensive influence on geological engineering properties of dredger fill.The porosity of the dredger fill is an important characteristic of microscopic structure.Taken dredger fill from Binhai New Area in Tianjin as research object,the distribution trend of pore is obtained by granularmetric analysis,mineral composition analysis and mercury intrusion method.By discussing the variation regulation of dredger fill in two different kinds of processing methods,certain theoretical basis is provided for evaluating the engineering geological properties of dredger fill.It can be concluded from the test results that after drainage treatment,the porosity decreased and the structure unit changed from the relatively loose state to aggregate state.In certain depth range,the consolidation effect of dredger fill with drainage treatment is better than that without drainage treatment.

Assessing seawater quality with a variable fuzzy recognition model

With the rapid development of the marine economy industry, human exploitation of marine resources is increasing, which is contributing to the growing trend of eutrophication and frequent occurrence of red tide. Accordingly, investigations of seawater quality have attracted a great deal of attention. This study was conducted to construct a seawater environmental quality assessment model based on the variable fuzzy recognition model. The uncertainty and ambiguity of the seawater quality assessment were then considered, combining the monitoring values of evaluation indicators with the standard values of seawater quality. Laizhou Bay was subsequently selected for a case study. In this study, the correct variable model for different parameters was obtained according to the linear and nonlinear features of evaluation objects. Application of the variable fuzzy recognition model for Laizhou Bay, water quality evaluation and comparison with performance obtained using other approaches revealed that the generated model is more reliable than traditional methods, can more reasonably determine the water quality of various samples, and is more suitable for evaluation of a multi-index, multi-level, nonlinear marine environment system; accordingly, the generated model will be an effective tool for seawater quality evaluation.

Study of Changes in Physiochemical Properties of Soil by the Addition of Cement

The effect of cement on physiochemical properties of three types of soils i.e garden soil, agricultural soil and roadside soil was investigated. The ordinary Portland cement was used. The amount of cement added to soil samples, as dry mass percentage was 20%. The results of analysis showed that the addition of cement is capable of bringing about changes in physiochemical properties of soil. The electrical conductivity and organic matter content in three soils get decreased by the addition of cement. While the pH, bulk density and water holding capacity of soils after the addition of cement gets increased. The soil found most suitable to be treated with cement was roadside soil. It was concluded that cement can be used to change the physiochemical properties of soil and this technique has great utility in improving the quality of problematic soils.

Clonal performance of Scirpus yagara in multiple levels of substrate heterogeneity and submergence

Aims Environmental heterogeneity affects the performance of clonal aquatic plants.Few researchers integrated two aspects of heterogeneity into the study of clonal plant ecology.The aims of the present study are to(i)test whether different substrate heterogeneity and submergence exert similar effects on plant performance and(ii)explore the foraging behaviour.Methods In this study,Scirpus yagara was subjected to multiple levels of substrate heterogeneity and submergence.Substrate treatments included one homogeneous substrate and three heterogeneous substrates(two-patch,four-patch and eight-patch).Water level treatments included 0,10 and 30 cm.Traits including ramet number,generation number,leaf number,bulb number,ramet height,culm length,rhizome length,clonal radius,spacer length,spacer thickness,total biomass,biomass of bulbs and biomass per bulb were measured.Important Findings Deeper water levels significantly reduced variables associated with growth such as ramet number,generation number,leaf number and bulb number,while substrate patchiness induced significant variations in traits such as spacer length and spacer thickness.Significant interactive effects of the two factors were found for ramet number,leaf number and spacer length.Scirpus yagara showed colonization towards the lake sediment patch in two-patch and four-patch substrates,and more structures were placed in the lake sediment patch.Especially for the two-patch substrate,all structures occupied the lake sediment patch.Two-sided intrusion was observed in the eight-patch substrate,which induced an even allocation of structures in different patches.The foraging behaviour was correlated with the patch size.

Effect of Vegetation Succession on Organic Carbon,Carbon of Humus Acids and Dissolved Organic Carbon in Soils of Copper Mine Tailings Sites

Carbon of humus acids(HSAC) and dissolved organic carbon(DOC) are the most active forms of soil organic carbon(SOC) and play an important role in global carbon recycling. We investigated the concentrations of HSAC,water-soluble organic carbon(WSOC),hot water-extractable organic carbon(HWOC) and SOC in soils under different vegetation types of four copper mine tailings sites with differing vegetation succession time periods in Tongling,China. The concentrations of HSAC,WSOC,HWOC and SOC increased with vegetation succession. WSOC concentration increased with the accumulation of SOC in the tailings,and a linearly positive correlation existed between the concentrations of HSAC and SOC in the tailings. However,the percentages of HSAC and DOC in the SOC decreased during vegetation succession. The rate of SOC accumulation was higher when the succession time was longer than 20 years,whereas the speeds of soil organic matter(SOM) decomposition and humification were slow,and the concentrations of HSAC and DOC increased slowly in the tailings. The percentage of carbon of humic acid(HAC) in HSAC increased with vegetation succession,and the values of humification index(HI),HAC/carbon of fulvic acid,also increased with the accumulation of HSAC and SOC in soils of the tailings sites. However,the HI value in the each of the tailings was less than 0.50. The humification rate of SOM was lower than the accumulation rate of SOM,and the level of soil fertility was still very low in the tailings even after 40 years of natural restoration.