郫县灰潮田有效硅含量和小麦施硅效应初探

通过同田对比试验，本文对郫县水稻土小麦施用硅肥进行了初步研究．结果表明，小麦施硅获得了增产效果；施硅对小麦穗粒数、株高和基部节间体积等具有生长效应；郫县水稻土有效硅含量为１２７±３９ｍｇ·ｋｇ－１（ｎ＝１２），变异较大，与土壤粘粒（＜０．００１ｍｍ）呈极显著正相关（ｒ＝０．７９）；发育于第四系岷江灰色冲积母质的郫县水稻上，粘粘含量普遍较低，因此，郫县小麦施硅具有较大增产潜力．     

小口径弹用密封材料贮存寿命预测

采用美国军用手册，ASTM的方法和数据，以最少的试验和费用，快速地预测硅橡胶贮存寿命。预测结果可以作为评估该弹用密封材料自然长贮寿命的依据。     

施用钢渣对水稻土硅素肥力的影响

施用钢渣种植水稻的盆栽试验结果表明,与对照相比,施用钢渣使土壤pH升高,土壤水溶态硅和无定形硅的含量下降,活性硅及有效硅含量上升,水稻植株含硅量增加.除水溶态硅外,上述影响均随钢渣用量增加或粒度变细而增强.     

底泥中重金属毒性的室内孔隙水分析技术

根据孔隙水中重金属的浓度可以判定底泥中重金属的毒性但获得真正的底泥孔隙水十分困难。本文提供了一套简便易行的室内原状孔隙水取样技术，将碳化硅砂芯埋入底泥，添加表层水并静置９０ｄ，通过渗滤获得孔隙水，测定孔隙水中重的浓度，所得结果与微生态系统暴露试验中生物指示的重金属的毒性大小相吻合，与生物积累重金属的浓度显著正相关。     

不同晶型纳米TiO_2在斑马鱼体内的富集与清除

为探讨纳米材料的慢性生物效应以及材料结构对生物富集的影响,开展了A-TiO2(锐钛型纳米TiO2)和R-TiO2(金红石型纳米TiO2)在斑马鱼(Danio rerio)体内的长期富集和清除试验.采用半静态暴露试验,试验周期为46 d(暴露阶段28 d,清除阶段18 d),每种晶型设置2个处理组(ρ分别为4.0和10.0 mg/L),测定各时间点斑马鱼体内不同晶型纳米TiO2含量(以w计);以暴露阶段的BAF(生物富集系数)以及清除阶段的排出速率常数、总量清除率为终点,比较斑马鱼对2种晶型纳米TiO2的富集、清除的异同.结果表明:在暴露阶段,A-TiO2在斑马鱼体内的富集量显著高于R-TiO2,10.0 mg/L处理组斑马鱼体内富集量均显著高于4.0 mg/L处理组;4.0和10.0 mg/L的A-TiO2处理组的BAF分别为76.7和105.4 L/kg,略高于R-TiO2(41.6和36.1 L/kg),二者在斑马鱼体内均不具有生物蓄积性.在清除阶段,斑马鱼体内的2种晶型的纳米TiO2均可被排出,清除阶段的清除率为88.0%~100%;斑马鱼体内2种晶型纳米TiO2富集量的下降均符合一阶指数衰减方程,排出速率常数在0.26~1.01 d-1之间.     

Leaching-induced migration and compositional form change of Cu,Zn, and Cd from sludge to loess

Land utilization of sewage sludge has become one of the major issues in environmental mitigation in China. This is particularly important in the Loess Plateau of Northwest China. Sludge enriched with organic matter and nutrients might effectively help to resolve the problems of silty loess soils as evidenced by porosity defect, structural alterations and absence of fertility. After sludge flows into the loess, irrigation water contains heavy metals that leach and migrate into sludge and consequently related human health risks may occur that raise concerns; and this situation needs to be rectified. The characteristics of the vertical migration and composition form change of Cu, Zn, and Cd from composted sludge to loess, and corresponding influencing factors, were investigated by performing a soil column simulation test under the leaching treatment of a one-year irrigation water capacity. Results demonstrated that: (1) composted sludge significantly improved loess fertility, and irrigation leaching transported only a small quantity of organic matter in sludge in the plough layer; (2) although some of the Cu, Zn, and Cd in composted sludge migrated to and concentrated in the middle and upper layers of the soil column during leaching, these metals were mostly retained in the plough layer; and (3) after the leaching treatment of the one-year irrigation water capacity, the compositions of Cu, Zn, and Cd (particularly Cu and Zn) in both plough layer and loess began to stabilize with low concentrations in the exudate. These findings confirmed the applicability of composted sludge in loess regions. This study provided a new insight into the sludge reuse in alkaline soils in arid and semi-arid region.     

贵州百花湖消落区土壤磷赋存形态初步研究

应用磷形态标准测试程序(SMT)对百花湖(水库)消落区土壤磷赋存形态进行了分级测定,分析了各形态磷之间与样品理化性质如有机质、pH、总氮和含水率的相关性。结果表明,百花湖消落区1区全磷含量平均为1239.9mg/kg,2区为1097.4mg/kg,3区为1041.5mg/kg;各形态磷中有机磷占全磷的百分比1区为58.7%,2区为55.1%,3区降至54.7%;消落带土壤中的磷以有机磷为主,无机磷为辅。铁铝结合态磷则是无机磷的主要组分,其中1区为77.1%,2区为66.7%,3区为61.4%;全磷、有机磷和铁铝结合态磷含量的总体变化趋势为1区>2区>3区;而钙结合态磷含量却呈现出3区>2区>1区。有机磷与全磷显著性相关,是土壤中磷素增加的主要因素;无机磷与铁铝结合态磷和钙结合态磷显著性相关,二者的增加和减少对无机磷的含量具有显著影响;全磷与有机质、酸碱性显著相关;有机磷与有机质,钙结合态磷与酸碱性之间均呈现出显著性相关,表明土壤的有机质和酸碱性影响磷的含量和分布。     

不同性质硅肥影响土壤生物有效态镉砷的主要因素

为研究硅肥影响土壤中生物有效态镉(Cd)和砷(As)的主要因素,选择不同性质的3种碱性硅肥[Na₂SiO₃、 CaSiO₃与ASSF (pH 9～11)]和一种弱酸偏中性可溶硅肥(NSSF,pH 5～6)并通过添加不同用量硅肥(25～800 mg·kg^-1,以Si计)开展室内土盆试验,淹水共育21 d后对土壤基本理化性质进行检测,同时利用薄膜扩散梯度(DGT)提取土壤生物有效态Cd和As.结果表明,不同性质硅肥施用对土壤基本理化性质的影响差异显著,具体来说：3种碱性硅肥均显著提升土壤pH值(P<0.05),其中Na₂SiO₃提升土壤pH能力最强;而NSSF的施用则显著降低土壤pH值但提升了土壤Eh值(P<0.05),每单位质量(mg) Si添加量的NSSF可使土壤pH下降0.001 7个单位;在Si添加量达到400 mg·kg^-1后,3种碱性硅肥和NSSF土壤pH和Eh变化都趋于平缓. 4种不同性质硅肥提升土壤有效硅含量能...