Copper Availability and Accumulation by Portulaca Oleracea Linn. Stem Cutting

The Cu accumulation capacity of stem cuttings of Portulaca oleracea was assessed in two different soils, alfisol and vertisol, which differ from each other mainly due to their clay content~— several fold lower in the former than in the latter. The DTPA extractable concentration of Cu in soil and the level of its accumulation in stem cuttings were, therefore, greater in alfisol than in vertisol. In the mixed soils, the DTPA extractable as well as plant accumulated levels of Cu decreased with an increase in the proportion of vertisol. With an increase in the soil available and plant accumulated Cu, a decrease has been observed in the ability of stem cuttings to regenerate leaves and roots. As a consequence biomass reduction has been observed with an increase in the concentration of Cu in the soil and plant body. In view of comparatively low availability of Cu in vertisol, regeneration of stem cuttings occurred up to a concentration of 1600 $μ gofCu/gofsoil, whereasinalfisolitoccurredonlyupto200μ g of Cu/g of soil. The results of the present study showed that P. oleracea stem cutting is an accumulator of Cu and the availability of Cu in soils could be manipulated through addition of clay since the plant available concentration of Cu is less in the soil (vertisol) with high clay content.     

烷基多糖苷季铵盐改性粘土治理赤潮研究

研究了新型表面活性剂烷基多糖苷季铵盐在2种粘土高岭土和膨润土上的吸附行为,发现其在2种粘土上的吸附符合Langmuir吸附等温线,并且吸附速率很快,在1～2min之内就能够达到吸附平衡,经红外分析发现其可以对粘土进行有效改性.在此基础上,还研究了烷基多糖苷季铵盐对东海原甲藻、强壮前沟藻、锥状斯氏藻生长的影响以及2种有机改性粘土对赤潮藻的去除情况和絮凝动力学.结果表明,烷基多糖苷季铵盐用量分别为0～0.4 mg/L、0～0.5 mg/L、0～0.8 mg/L时,对上述3种藻的生长只是抑制作用;当浓度为0.6～1.2 mg/L、0.75～1.5 mg/L、1.2～2.4 mg/L时,就会阻碍上述3种藻的生长,并且3d之后能够使其几乎全部死亡.用其改性粘土后,在与原土相同的用量条件下可将对赤潮藻的去除率从20%左右提高到90%以上,大大降低了有效去除赤潮藻的粘土用量.其沉降动力学研究表明,粘土的种类、用量以及改性剂的用量都是影响体系沉降速率的重要因素,在实际应用中可以根据不同的情况而改变其中的某个因素以达到提高沉降速率的效果.     

吉米奇表面活性剂改性粘土治理赤潮研究

为了证明吉米奇类表面活性剂三烷基聚氧乙烯基三季铵盐（TPQAC）对粘土改性的有效性,利用UV-1100紫外可见分光光度计对其在2种粘土高岭土和膨润土上的吸附行为进行了研究,发现其在2 min内基本可以达到吸附平衡,吸附模式较好的符合双表面Langmuir吸附等温线,吸附量大,经红外分析发现其可以对粘土进行有效改性.作为一种改性粘土在用于赤潮治理之前,有必要对改性剂本身对赤潮藻的灭杀作用以及改性粘土对赤潮藻的去除效果进行研究,为此选择了3种常见的赤潮藻进行了灭杀实验,并对不同比例的改性粘土对赤潮藻的去除情况进行了比较,结果表明,TPQAC用量在2 mg/L时24 h内几乎可以100%的灭杀赤潮藻,粘土与改性剂比例为14左右时对赤潮藻的去除效果最好.同时为了弄清TPQAC在治理赤潮的实际应用中对养殖生物可能造成的危害,选用了黑褐新糠虾为代表性养殖生物,对其48 h急性毒性情况进行了研究,并且室内模拟研究了改性粘土在去除赤潮藻的过程中可能对养殖生物造成的影响,实验发现粘土改性剂对黑褐新糠虾48 h半致死浓度为16.7 mg/L,改性粘土在去除赤潮藻的同时没有对养殖生物造成明显的毒害作用.     

尾矿代粘土在干法回转窑水泥生产中的应用研究

为获取尾矿在干法回转窑水泥生产应用的技术参数,在对尾矿和粘土特性进行分析的基础上,在2500t·d-1的新型干法回转窑生产线上进行了浙江诸暨铜尾矿替代粘土配料的应用试验研究.试验采用循序渐进的方法,诸暨铜尾矿按质量分数为1%、2%、3%、5%依次在生产原料中掺配,对试验熟料样品进行了化学成分分析和矿物组成X射线衍射(XRD)分析.试验结果表明,掺铜尾矿生产得到的熟料化学组成和游离氧化钙(f-CaO)含量正常,熟料烧成情况良好;与掺粘土熟料相比,掺铜尾矿熟料矿物组成结构有所调整,早强和高强矿物含量有所增加.熟料物性检测表明,掺铜尾矿生产得到的熟料的各项性能指标均满足技术要求,熟料各龄期强度指标与掺粘土熟料相比略有提高.掺铜尾矿配料与粘土配料主要生产运行指标统计分析表明,试验过程在干法回转窑生产运行稳定的情况下,掺铜尾矿配料较粘土配料,其熟料平均日产量提高10.07%,熟料标煤耗降低8.29%.     

凹凸棒石对水中3,4-二氯苯胺的吸附

研究了凹凸棒石对水中3,4-二氯苯胺(3,4-DCA)的吸附行为,对不同温度下(298K,303K,313K)的数据分别用Langmuir,Freundlich和Redlich-Peterson模式进行拟合,并用假一级方程和假二级方程描述凹凸棒石对3,4-DCA的吸附动力学过程,结果表明:吸附作用受pH值影响明显,在pH=4.O时,吸附量最大;凹凸棒石的吸附能力随着温度的升高而降低;Redlich-Peterson方程更适合描述3,4-DCA在凹凸棒石上的吸附行为;Gibbs自由能(△G0)、熵变(△S0)和焓变(△H0)值均小于零,说明此吸附过程是自发进行的、放热的物理吸附过程;假二级方程更适用于描述凹凸棒石对3,4-DCA的吸附动力学过程,     

用炼油厂废白土制备有机膨润土的研究(I)──废白土的提纯

对炼油厂废白土的脱蜡脱油工艺及脱蜡脱油后度白土的湿法提纯工艺进行了实验研究,并用阳离子交换容量（CEC）和吸蓝量（M．B．）来表征提纯废白土的活性和蒙脱石含量,找到了废白土提纯的最佳工艺条件,为进一步利用提纯废白土合成有机膨润土提供了合格的原料     

粉煤灰结合施肥对土壤微生物和酶活性的效应

在以前对粉煤灰改良石灰性土壤对其理化性质和养分效应研究的基础上,分析了小麦不同生育期土壤中微生物数量和几种重要的土壤酶的活性,旨在探讨石灰性褐土施用粉煤灰配合有机肥对土壤环境生物质量的效应。结果表明,每公顷施用粉煤灰150t以上显著提高了土壤中各种微生物的数量,对土壤酶活性也有显著的作用,尤其是对小麦灌浆期脲酶的活性有显著的促进作用。因此,施用粉煤灰可以改善土壤的生物活性,从而达到保护和治理土壤环境的效果。     

润滑油废白土的热解处理

以润滑油废白土为原料,利用电热解法,研究了热解终温、加热速率和CaO添加量对热解产物的影响。实验结果表明:热解终温对热解产物的影响最为显著。随着热解终温的升高,不凝气产量和产油率均迅速增加。当热解终温达到600℃时,其增加的速率逐渐缓慢增大。当控制热解终温为800℃、加热速率为16℃/min、CaO添加量为0.5%时,富氢气体产量为189.2 L/kg,气体中主要成分为H2和CH4,其含量分别为27.97%和41.64%;热解残渣含油率和重金属溶出物均低于标准规定值,热解油产率为10.98%,回收率为38.94%,其主要成分为汽油、柴油和重油3部分组成,分别含19.13%、31.35%和49.52%。     

Fenuron sorption on homoionic natural and modified smectites

Abstract

The adsorption isotherms of fenuron (l, l‐dimethyl‐3‐phenylurea) on three smectites (SWy and SAz montmorillonites and SH hectorite) differing in their layer charge (SH<SWy<SAz) and saturated with several inorganic and organic cations were determined. The isotherms and sorption parameters from Freundlich equation indicate low adsorptivity on inorganic clays, but medium sorption in organoclays (OCls). Fenuron adsorption on homoionic smectites increases with decreasing layer charge and hydratation power of the inorganic exchangeable cation (except Fe³⁺), indicating that fenuron adsorbs as neutral molecule on uncharged siloxane surface by hydrophobic bonding, with some contribution of polar bond (fenuron C=O group and water associated to exchangeable cation). In the case of Fe³⁺‐saturated smectite fenuron protonation, provided by the interlayer acidic environment, promotes further sorption of fenuron as cationic form. The sorption on organoclays is enhanced via hydrophobic interaction with organocations, which is favoured for high layer charge and basal spacing and organocation saturation close to CEC. Quaternary alkylamonium is more efficient in high layer charge smectite, whereas primary alkylammonium is more efficient in medium charge smectite. The low values of the maximum sorption obtained with homoionic inorganic and organic smectites (100 and 5000 μmol/Kg) represent one fenuron molecule for each 2000–200 exchange sites and indicate that fenuron sorption is mainly associated to the outer exchange sites. This low adsorptivity of fenuron, as consequence of its high water affinity (high water solubility) would suggest high mobility of fenuron in natural soil and water systems.     

Influence of Substrate on Bioaccumulation of 14C-Paraquat in Compost Worms Eisenia foetida

Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl- ¹⁴C] paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 μg paraquat g^?1 substrate. The action of the worms did not influence the loss of ¹⁴C from the substrates, as the ¹⁴C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.