氯化镁微胶囊泡沫作用机理及阻化效果研究

针对现有硫化矿石自燃防治技术在应用中存在的不足,提出了采用氯化镁微胶囊泡沫防治硫化矿石自燃火灾的新思路。首先阐述了氯化镁微胶囊泡沫的特性与作用机理,然后通过实验,制备了微胶囊与微胶囊泡沫并以正交试验确定了制备微胶囊泡沫的最佳配方:微胶囊与水质量比为1∶5、ABS浓度为6 g/L、稳泡剂X浓度为6 g/L;最后采用对照实验,以温度与阻化率为优选依据,对氯化镁微胶囊泡沫、氯化镁溶液与水三者的阻化效果进行比较。结果表明在氯化镁微胶囊泡沫的作用下,硫化矿石堆的温度上升最慢,阻化率最高,达到81.6%,阻化效果优于其他两种阻化剂。     

Testing of chemical substances for environmental effects—an important task for the chemical industry

Recently the heterogeneous reactions are increasingly recognised as significant in polluted areas. In this work the reactions of gases with solid alkali‐halide crystals at temperatures 200K and 300K were examined by using a recently proposed thermodynamic model (Varotsos et al., 1988) which provides the interconnection of entropy and enthalpy for various processes with well known macroscopic properties of the bulk solid.     

On the role of solid NaCl in polluted marine urban areas

Last decade the reactions of gases at solid interfaces were increasingly recognized as significant in polluted marine troposphere and perhaps in remote areas as well. In this study the reactions of gases with solid NaCl at temperatures 200 K and 300 K were examined by using a recently proposed thermodynamical model (Varotsos et al., 1988) which provides the interconnection of entropy and enthalpy for various processes with well known macroscopic properties of the bulk solid.     

Preferential leaching of nitrate,chloride and phosphate in an Australian clay soil

This paper investigates leaching of water and nutrients (NO^‐ ₃, Cl^‐, PO^3‐ ₄) from the unsaturated layer in an Australian soil using a multisegment percolation system (MPS). Large undisturbed soil cores were collected from a clay‐based, basaltic plain, agricultural soil at Grassmere, 300 km west of Melbourne, Australia. Significant heterogeneity (or preferential flow) of effluent moisture and solutes was detected (one‐way ANO VA, p < 0.001). Fifty percent of the applied nitrate and chloride leached from the soil core within three days after initial application. Hundred percent of the applied nitrate and chloride leached from the soil core within 8 days after application. These results indicate little incorporation into the soil matrix, and possible denitrification or mineralisation. In contrast, after 18 days, less than 1 % of the total applied phosphates leached from the soil, indicating strong adsorption. Our experiments indicate considerable heterogeneity in water flow patterns and solute leaching on a small spatial scale. Very rapid transport of nitrate and chloride through the soil was evident, in comparison phosphate leaching was negligible. These results have important implications for the management of nutrient schedules in agricultural soils, particularly those located in the Western District of Victoria, Australia.     

Influence of marine alga against mercury-induced biochemical changes,structural destabilization,and genotoxicity in marine tiger fish,Therapon jarbua

This study elucidated the protective role of alga against mercury (Hg)-induced toxicity in marine fish. Bath immersion with mercury chloride (HgCl) [0.125 and 0.25?ppm] in combination with the algal extract (3?ppm) to Therapon jarbua offered a significant protection against Hg only induced disturbed liver function, damaged histoarchitecture, elevated oxidative stress, and DNA fragmentation of tissues. Mercury exposure decreased hepatic superoxide dismutase (SOD), catalase (CAT) activities, and the level of nonprotein-soluble thiol (NPSH, GSH), with a concomitant increase in thiobarbituric acid reactive substances (TBARS) in the gill, kidneys, liver, and blood. Algal supplementation diminished the rise in TBARS restoring CAT, SOD, and GSH levels to control. Reduced generation of free radicals may be correlated to protect DNA stability and morphology. This study indicates the ability of alga to ameliorate Hg-mediated injuries. In conclusion, Kappaphycus alvarezii extract did not show any toxicity and its safety is suggestive for using as a supplement in fish food.     

Mutagenic activity of transition‐metal complexes: Relation structure‐mutagenic and antibacterial activity for some Pd(II), Pt(II) and Rh(I) complexes†

The inhibitory and mutagenic action of some Pd(II), Pt(II) and Rh(I) complexes towards various bacterial strains has been evaluated, and some correlations have been found between the chemical behaviour of the complexes and their selective biological activity: most of the complexes cause only a DNA damage repaired by the excision repair system. Particularly, the Rh(I) complexes used in this work show selective antibacterial effects on defective but no effect on wild‐type strains.     

两性高分子螯合絮凝剂和氯化钙对羟基亚乙基二膦酸预镀铜废水的去除性能

以羟基亚乙基二膦酸(HEDP)预镀铜废水为处理对象,考察两性高分子螯合絮凝剂(ACPF)和CaCl2对其处理效果.结果表明,单独使用ACPF或CaCl2,用量大,残余Cu2+和COD浓度均不能达到电镀污染物排放标准(GB21900—2008);将ACPF和CaCl2配合使用,Ca2+可与HEDP螯合生成HEDP—Ca沉淀,促进ACPF与Cu2+螯合;且Ca2+还可与废水中的酒石酸根离子形成溶解度很小的结晶,促进絮体的形成和沉降.因此,处理药剂的用量明显降低,Cu2+和COD残余浓度均能达标.适宜的处理条件为:弱碱或碱性条件下,ACPF投加量为3.0 g.L-1,CaCl2投加量为2.0 g.L-1,Cu2+和COD的去除率分别达99.74%和97.5%,残余浓度分别为0.335和25.27 mg.L-1.     

阴极扩展电催化还原法对五氯苯酚的脱氯特性

以负载Pd催化剂的活性碳纤维作为扩展阴极,对吸附在活性碳纤维上的五氯苯酚进行了电催化还原脱氯研究.考察了电解质浓度、催化剂含量、电流密度等主要因素对还原脱氯效率的影响.结果表明,电解质浓度0.25 mol·L-1,温度40℃,电流密度25 mA·cm-2,催化剂Pd的含量5%,反应4 h,五氯苯酚的降解率可达到94.3%.通过中间产物的分析对电催化还原脱氯反应机理进行了初步探讨.     

Equilibrium,kinetics and thermodynamics of hexavalent chromium biosorption on pristine and zinc chloride activated Senna siamea seed pods

Hexavalent chromium contamination in water is an issue of huge concern due to its use at a high scale, toxicity and non-biodegradability. Biosorption is a cost effective and unconventional strategy for the elimination of Cr(VI). Here, a novel biosorbent Senna siamea seed pod biomass and its chemically activated form have been investigated for the elimination of hexavalent chromium from aqueous solution. The biosorbent was characterized by using BET, FTIR, FESEM-EDX and TGA techniques. Parameters controlling the biosorption process were optimized as pH 2.0, temperature 30°C, initial Cr(VI) concentration 500?mg/L, biosorbent dose 0.5?g/L. Optimized contact time was 210 and 180 min for pristine biomass and activated carbon, respectively. Langmuir isotherm correlated well with experimental data revealing that the biosorption occurred in monolayer pattern. Maximum biosorption capacity calculated by Langmuir biosorption isotherm was 119.18 and 139.86?mg/g for S. siamea pristine biomass and activated carbon, respectively. Pseudo-second order kinetic model correlated well with experimental data. Thermodynamic studies suggested that the biosorption process occurs in a non-spontaneous, stable and endothermic manner. These interesting findings on Cr(VI) biosorption by S. siamea seed pod biomass and S. siamea zinc chloride activated carbon vouches for its potential application as an unconventional biosorbent.     

Broadening of appropriate demulsifier dosage range for latex-containing wastewater by sulfate addition

Investigation of demulsification of polybutadiene latex (PBL) wastewater by polyaluminum chloride (PAC) indicated that there was an appropriate dosage range for latex removal. The demulsification mechanism of PAC was adsorption-charge neutralization and its appropriate dosage range was controlled by zeta potential. When the zeta potential of the mixture was between -15 and 15 mV after adding PAC, the demulsification effect was good. Decreasing the latex concentration in chemical oxygen demand (COD) from 8.0 g/L to 0.2 g/L made the appropriate PAC dosage range narrower and caused the maximum latex removal efficiency to decrease from 95% to 37%. Therefore, more accurate PAC dosage control is required. Moreover, adding 50 mg/L sulfate broadened the appropriate PAC dosage range, resulting in an increase in maximum latex removal efficiency from 37% to 91% for wastewater of 0.2 g COD/L. The addition of sulfate will favor more flexible PAC dosage control in demulsification of PBL wastewater.

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