Stimulation of Heavy Metal Adsorption Process by Using a Strong Magnetic Field

The adsorption process is one of the most important techniques of water and wastewater treatment technology. Therefore, there are many methods allowing to improve the effectiveness of these processes based mainly on the chemical modification of adsorbents. However, they are always associated with the necessity of introducing an additional wastes or sewage to the environment. That is why a purpose of the presented was to investigate an innovative and noninvasive adsorption supporting method based on the using of a static magnetic field. The results showed that in the adsorption process of equimolar copper, nickel, and cadmium mixture, a presence of the magnetic field may increase the effectiveness of the process, with respect to copper by more than 40% and a summary molar removal was increased about 11%. However, the effectiveness of the analyzed modification depends largely on the heavy metal equilibrium concentration, and when it increases, a beneficial effect of magnetic field significantly decreases. Nevertheless, due to the fact that heavy metal adsorption processes are very important part of environmental engineering technologies, it can be assumed that further work on magnetic modification of these processes can allow for a significant improvement of many water and wastewater purification plants.

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Photocatalytic Degradation of Chlorophenol Compounds using Poly Aromatic Star Copolymer

This study investigated the encapsulation and photocatalysis of chlorophenol compounds in water using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The chloride ions generated during photocatalytic process were identified and quantified. 2,4,6-Trichlorophenol, pentachlorophenol, and 2,4-dichlorophenol were satisfactorily decomposed in the photoreactor using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer, with removal efficiencies of 2,454, 498, and 760 mg/g of porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The half-life times reached around 30 min, with the exception of that for 2,4-dichlorophenol. The star polymer-impregnated porphyrin is a promising photocatalyst for the removal of chlorophenols.     

Effect of Environmental Factors on Estrogenic Compounds Adsorption by MIP

In this study, the effects of environmental factors, including humic acid (HA), pH, ionic strength, and the coexistence of competing estrogenic compounds, on the adsorption of four typical estrogenic compounds, estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and bisphenol A (BPA), were studied by molecularly imprinted polymer (MIP). The adsorption capacities of MIP for E2 were 116.3, 118.5, 127.0, and 109.0 µmol/g at HA concentrations of 0, 5, 15, and 20 mg/L in total organic carbon, respectively, while the corresponding adsorption capacities of nontemplate imprinted polymer (NIP) for E2 were 98.1, 109.4, 113.8, and 98.0 µmol/g. This implied that no significant trend could be found with the increasing HA concentrations. Furthermore, the selective adsorption capacity, represented by the difference in adsorption capacities between MIP and NIP, was not affected significantly. Similar observations were noted for E1, EE2, and BPA in the presence of HA. Ionic strength did not exert a considerable influence on the adsorption capacities of MIP and NIP for E1, E2, and BPA. However, at 0 mM of NaCl, EE2 adsorption capacities of MIP and NIP were 124.7 and 111.7 µmol/g, respectively, while the corresponding adsorption capacities were 144.7 and 138.2 µmol/g at 10 mM of NaCl due to the increased hydrophobic interactions. Nevertheless, the selective adsorption capacity was not significantly affected by the range of ionic strength tested in this study. The study demonstrated that there was no significant effect of pH on the adsorption capacity of both MIP and NIP from pH 3.1 to 9 and that no considerable effect of pH on selective adsorption capacity of MIP could be established. However, the adsorption capacities of MIP and NIP for E2 at pH 9 were 95.1 and 82.9 µmol/g, while at pH 11, the adsorption capacities were 12.1 and 5.9 µmol/g correspondingly. This means that adsorption capacity and selective adsorption capacity were influenced significantly due to the ionization of target compounds. A similar trend was observed for E1, EE2, and BPA. The study on the effect of the coexistence of competing estrogenic compounds demonstrated that selective adsorption capacities of MIP can be influenced. Differences between MIP and NIP for E1, E1, EE2, and BPA under competing conditions were 8.8, 6.8, 10.2, and 4.2 µmol/g, respectively, while the corresponding differences were 12.6, 18.2, 13.0, and 9.8 µmol/g, respectively, when adsorbed individually.     

2种典型耕作方式影响下的蔗田土壤孔隙结构及其水分运动特性

为了明确农业生产过程中耕作方式对田间土壤孔隙结构及土壤水分运动特性的影响,以广西农地蔗田为研究对象,基于土壤切片技术分析研究免耕和垄耕2种典型耕作方式蔗田的田间土壤孔隙结构特征,并结合土柱模拟入渗试验,探究土壤孔隙结构对土壤水分运动的影响,进一步揭示孔隙结构与土壤水分运动特性之间的相互作用关系。结果表明：随着土层深度的增加,免耕蔗田孔隙形态以聚集的团块状分布为主,垄耕蔗田孔隙形态以条状分布为主。与免耕蔗田相比,垄耕蔗田的土壤总孔隙度和>2.5 mm孔径的孔隙度分别增加32.5%和21.9%。垄耕蔗田在局部土层深度范围内显著增加上下土层孔隙的变异度(p<0.05),显著降低土壤孔隙的连通性(平均邻近指数为0.448)(p<0.05),土壤孔隙形态相对规则(平均成圆率为0.335)。对于土壤水分运动特性,免耕蔗田总体的土壤饱和导水率和质量流率显著高于垄耕蔗田(p<0.05),初始含水率显著低于垄耕蔗田(p<0.05),质量流率随时间变化强度相对较大,提高水流入渗能力。垄耕降低土壤孔隙结构连通性,使水分蓄存在表层土壤中,一定程度上可降低土壤水分的入渗现象,改变蔗...     

干旱地区喷洒水利用系数的田间试验研究

为了科学地评价喷灌在干旱地区的适宜性,在内蒙古包头春小麦生育期内对喷洒水利用系数进行了监测,结果指出,通过选择适宜的灌溉时间,喷洒水利用系数可以达到0.85以上。对影响喷洒水利用系数的环境因素进行分析后得出,风速的影响最大,相对湿度次之,气温的影响很小;在此基础上建立了喷洒水利用系数与上述3因子之间的回归模型。为了估算整个灌溉季节的喷洒水利用系数,对所研究地区1991～2001年灌溉季节(4～9月份)内的日平均风速进行了统计分析,发现不大于3m/s的日数占灌溉季节总日数的90%以上,因此,选择日平均风速不大于3m/s的时间灌溉可以满足作物的需水要求,这种情况下,整个灌溉季节的喷洒水利用系数可以达到0.83。由此可见,在条件与包头类似的干旱地区,从提高水的利用率的角度出发,发展喷灌也是适宜的     

不同开垦年限白浆土磷素吸附特征

选取开垦0,1,10,20,30年白浆土为研究对象,采用室内培养方法,以Langmuir方程研究白浆土磷素吸附特征,并分析Langmuir方程特征参数.结果表明:在外源磷浓度为0～50 mg/L时,随平衡液浓度增加,不同开垦年限白浆土磷素吸附量显著增加;不同开垦年限白浆土间磷素吸附量存在明显差异,开垦30年明显低于其他开垦年限,开垦10年显著高于其他开垦年限土壤.长期耕作施肥可显著降低白浆土磷素吸附亲和力常数(k)、最大缓冲容量(MBC)、标准需磷量(SPR).其中又以开垦30年土壤的k、MBC、SPR值最低.施肥对最大吸附量(Xm)的影响不显著.     

磁场对土壤呼吸强度的影响

本文研究了磁场对棕壤和草甸土的土壤呼吸强度的影响。研究发现,磁场对土壤的呼吸强度有明显的影响。但是在磁场强度50mT、100mT、300mT、500mT和700mT范围内,随着磁场强度的增加其影响效果大小变化没有规律性,对于一定的土壤类型存在一个较适宜的磁场强度范围。棕壤在300mT场强下处理,其土壤呼吸强度增加幅度最大;在300mT磁场处理后1～7天内土壤呼吸强度升高。相对含水量70%的草甸土湿土样经过5个场强处理后,土壤呼吸强度均显著增加,其中经500mT场强后土壤呼吸强度增加幅度最大;土壤水分对土壤呼吸强度的磁处理效应有一定的影响。     

宽地膜覆盖条件下土壤温度场特征

宽地膜覆盖对土壤温度有明显的正效应。通过对新疆奎屯地区某地宽地膜覆盖条件下地温场动态的分析，可知膜间、膜边、膜中和揭膜4种处理下的土壤表层5 cm处的温度（以下称表层土温）都可拟合为时间的正弦函数；温度的日变化特征可以用8：00，16：00，20：00 三个时刻来简要表征；种植季节内表层土壤最高温度、表层土温最大变幅及平均表层土温的最大值均发生在膜中，其后依次为膜边、膜间与揭膜；膜中、露地和膜间的不同深度地温在一日内和种植季节内均有一个变化过程；一日内地温变幅与深度关系可拟合成指数函数。     

水溶性有机高分子对红壤磷吸附特征的影响

本试验采用连续振荡法,初步研究了水溶性有机高分子材料聚乙烯醇、聚丙烯酰胺和聚乙二醇对磷在红壤中吸附过程的影响,并对该过程拟合出方程。结果表明:在聚乙烯醇、聚丙烯酰胺和聚乙二醇作用下土壤磷吸附动力学以幂函数方程为最优方程,且方程参数与单施磷酸二氢钙的处理方程参数有显著差异性。有机高分子能显著提高磷在红壤中的吸附和土壤pH,但材料之间的土壤吸附量无差异显著性,需进一步研究。     

磁处理棕壤对磷吸附-解吸特性的影响

探讨了磁处理棕壤对磷吸附-解吸的影响,结果表明:外加磁场处理棕壤后磷的吸附量降低,促进了磷的解吸。棕壤不同粒级磁化后(0.002~0.005mm除外)吸附量基本都减少,而<0.002mm粒级和0.005~0.01mm粒级对吸附量减少起主要作用。     

酸性条件下可变电荷土壤对铜吸附动力学特征

用自行设计的动力学装置,研究了酸性条件下Cu在可变电荷土壤表面的反应动力学吸附特征。结果表明,在酸性条件下,Cu吸附过程分为快反应和慢反应。从一级动力学方程拟合的参数可知,3种土壤的最大吸附量依次为砖红壤〉赤红壤〉红壤,Cu最大吸附量随酸度增加显著下降;用Elovich方程和抛物线扩散方程常数b值,解释离子的表观扩散速率,3种土壤的b值依次为砖红壤〉赤红壤〉红壤,且随酸度的增大而降低。从相关系数的比较看,Elovich方程在描述Cu的吸附数据比一级动力学方程和抛物线扩散方程要差。在Cu吸附过程中,pH为5．5和4．3时,红壤和赤红壤流出液中有质子释放,质子的释放可能涉及铜离子的水解;而砖红壤在pH为5．5有质子的释放,pH4-3时有质子的消耗。当原液pH为3.3和3．8时,都存在质子的消耗。3种土壤H＋的消耗过程有较大的区别,砖红壤上快速消耗H＋鱼-远远大于红壤和赤红壤。反应初期,H＋质子的消耗是快速反应,主要包括土壤交换阳离子的缓冲作用、土壤表面的质子化及硫酸根专性吸附释放的羟基中和H＋质子;而以后的反应中,H＋质子对矿物的溶解是一缓慢过程。     

Novel Magnetic Nanocarbon and Its Adsorption of Hg and Pb from Water

Lead and mercury are two of the most toxic heavy metals in environments. Mesosilicate-templated magnetic nanocarbons with ascorbic acid as carbon precursor were developed through nanocasting processes. The nanocarbon showed effective magnetic separation and the maximum adsorption capacity of 80.6 and 66.3 mg/g for Hg and Pb, respectively. Langmuir model well described adsorption processes of both Hg and Pb from water. Magnetic nanocarbon could be easily separated and incinerated, reducing the volume requiring the disposal. This study indicates that mesosilicate-templated nanocarbons with easy disposal potentials may be good candidates for cleansing Hg and Pb from contaminated water.     

宽地膜覆盖条件下土壤温度场特征

宽地膜覆盖对土壤温度有明显的正效应。通过对新疆奎屯地区某地宽地膜覆盖条件下地温场动态的分析，可知膜间、膜边、膜中和揭膜4种处理下的土壤表层5cm处的温度（以下称表层土温）都可以拟合为时间的正弦函数；温度的日变化特征可以用8：00，16：00，20：00三个时刻来简要表征；种植季节内表层土壤最高温度、表层土温最大变幅及平均表层土温的最大值均发生在膜中，其后依次为膜边，膜间与揭膜；膜中、露地和膜间的不同深度地温在一日内和种植季节内均有一个变化过程；一日内地温度变幅与深度关系可拟合成指数函数。     

不同田间工程措施条件下降水入渗规律的数值模拟

采用数值模拟方法针对北京市主要土壤类型研究了不同工程措施（免耕、深松、免耕覆盖、深松覆盖）条件下的降水入渗问题。在研究过程中,考虑了雨滴打击下地表密实问题,即考虑地表密实的降雨入渗问题。地表密实使土壤入渗能力降低,覆盖可以避免表层土壤密实保持土壤入渗能力。深松可使土壤入渗能力提高,在该实验条件下１２０ｍｉｎ入渗量裸地和覆盖分别可以增加入渗１．７９ｃｍ和２．２８ｃｍ;适宜的松土深度裸地为１５～２０ｃｍ,覆盖为３０ｃｍ。提高降水入渗的田间工程措施为深松覆盖,松土深度３０ｃｍ。     

磁场对棕壤脲酶活性的影响

通过对棕壤风干土样和相对含水量70%的湿土样进行磁场处理研究发现,对棕壤风干土脲酶活性抑制作用最大的处理为500mT5分钟,对棕壤湿土脲酶活性抑制作用最大的处理为100mT10分钟。土壤湿度对棕壤脲酶活性的磁致效应大小有一定影响;无论是对于风干土或是湿土,500mT场强10分钟处理对棕壤脲酶活性的抑制作用时间最长,磁处理42天后抑制效果仍然显著。     

土壤—植物系统的磁生物效应及其微观机制研究进展

在综合前人研究的基础上 ,结合自己的研究成果 ,系统地阐述了磁处理 (如磁场、磁化水、磁改良剂等 )对土壤微生物、酶活性以及种子萌发和植物生长的影响 ,并对土壤—植物系统磁生物效应的共同特点和微观机制进行了探讨     

小麦种子磁化机磁场参数的探讨

用磁化机对小麦干种子进行不同强度的磁化处理,大田试验发现:适宜的磁场强度可使小麦产量有较大的增加,旱地中最大增产幅度可达18.5％,同时还发现种子磁化后,其光合强度、呼吸强度以及酶的活性都增强了。用计算机对试验结果进行了曲线回归、方差分析及多重比较,得出了小麦种子磁化机的最佳磁场及其调节范围。     

Comparison of Polycyclic Aromatic Compounds and Heavy Metals Contents in Sewage Sludges from Industrialized and Non-Industrialized Region

The total contents of PAHs, organic polar fractions and 14 major hydrocarbons containing 3–6 aromatic rings as well as heavy metal contents were determined in sewage sludges from highly industrialized (Upper Silesia), agricultural and recreational regions of Poland. Sludges from the industrial region showed markedly increased concentrations of all the organic micropollutants and 2–10 times higher levels of the following heavy metals: Pb, Cd, Cr, Cu, Fe, Zn, Ni, Mn and Co. The levels, however, did not exceed the Polish as well as European Economic Community limit values, which renders all the sludges applicable to land and some of them suitable for utilization on agricultural soils.     

杭州湾典型潮滩湿地植物带沉积物磷吸附特征

利用磷酸盐吸附动力学和等温吸附实验,研究了杭州湾潮滩湿地沉积物磷素吸附特征,并分析了不同植被类型及其沉积物理化性质对磷吸附的影响。结果表明,不同沉积物磷的吸附与释放过程均包括快速吸附(0~1 h)、慢速吸附(1~16 h)和平衡(16~72 h)3个阶段,不同植物没有明显影响这一趋势。改进的Langmuir模型拟合表明,沉积物最大吸附容量(Qmax)在154.5~436.2 mg/kg间,生长植物的沉积物Qmax明显高于光滩沉积物。沉积物自带可解吸磷(NAP)较少,在1.853~4.777 mg/kg间,NAP在不同类型沉积物的分布趋势与Qmax值相似。4种植被类型沉积物EPC0值低于潮汐水体中磷酸盐浓度,扮演着"汇"的角色,EPC0在不同沉积物间差异较小。相关性分析显示,杭州湾潮滩沉积物Qmax和NAP受有机质、颗粒组成和总无机磷含量影响,其中Qmax还受电导率影响,而研究区EPC0与沉积物理化性质不存在显著相关性。植物可以通过影响沉积物的物理化学参数,从而影响磷的吸附过程。