植物纤维毯覆盖对干旱区尾矿砂水热分布的影响

覆盖会影响尾矿水、热分布,研究植物纤维毯覆盖对尾矿砂水热分布的影响,对微生物诱导碳酸钙沉淀(Microbial induced calcite precipitation,MICP)技术控制尾矿污染扩散过程中调控水热条件具有实际意义。于2022年夏季在中国科学院新疆生态与地理研究所莫索湾沙漠研究站,布设基于不同材料(黄麻、稻草、椰丝和棕榈)、不同规格(300 g·m^(-2)、500 g·m^(-2)、700 g·m^(-2)和900 g·m^(-2))的植物纤维毯覆盖于尾矿砂的田间模拟试验,通过测定尾矿砂温度、含水率与蒸发量变化,探究植物纤维毯覆盖对尾矿砂水热分布的影响。结果表明:(1)植物纤维毯覆盖能降低0~20 cm尾矿砂温度、减小日温差及日变化幅度,其中900 g·m^(-2)的稻草纤维毯(D9)降温作用最强,日变化幅度最小。(2)植物纤维毯覆盖能改善0~30 cm尾矿砂的保水性,减少水分蒸发损失。(3)植物纤维毯覆盖能抑制尾矿砂水分蒸发,试验结束时,相同规格下累积蒸发抑制效率除D9略大于900 g·m^(-2)的黄麻纤维毯(H9)外,均表现为:黄麻>稻草>棕榈>椰丝,且均随规格增大而增大,其中D9抑制蒸发效率高达71.3%。(4)植物纤维毯覆盖干旱区尾矿砂的最佳节水降温方案为D9。综上所述,植物纤维毯覆盖能有效节水降温,研究结果可为干旱区应用MICP技术控制尾矿污染扩散过程中调控水热条件提供理论支撑。

乳酸型钛酸酯偶联剂的合成和分析

本文合成了七种新的乳酸型钛酸酯偶联剂,研究了一种新的重量分析方法,可以同时测定钛、磷共存的有机物中钛和磷的含量。

额尔齐斯河流域典型尾矿库区周边土壤重金属污染评价

为了解额尔齐斯河流域典型尾矿库区周边土壤中8种重金属元素(Cr、Ni、Cu、Zn、Cd、Pb、Mn、As)的富集特征,采用调查分析方法,以额尔齐斯河流域土壤背景值和国家土壤环境Ⅱ级标准作为参比值,利用单因子污染指数(Contamination Factor,CF)、污染负荷指数(Pollution Load Index,PLI)、潜在生态风险指数(Potential Ecological Risk Index,RI)和生态风险预警指数(Ecological Risk Warning Index,I_(ER))对尾矿库区周边土壤重金属污染程度以及生态风险进行评价,旨在保护尾矿库区周边土壤环境安全,为土壤环境污染治理提供科学依据。结果表明,(1)尾矿库区周边土壤中Cr、Ni、Cu、Zn、Cd、Pb、Mn和As的含量平均值分别超出该区域土壤背景值的7.53、36.08、31.45、0.68、35.32、1.76、0.76和0.65倍。其中,Cd、Ni、Cu和Cr属于重度污染,Pb、Mn、Zn和As属于轻度污染。(2)尾矿库区周边土壤中重金属元素Ni、Cu和Zn主要来自于尾矿库区,Cr、Cd和Pb与交通运输以及矿业生产活动有关,As和Mn主要受土壤地球化学作用的控制。(3)以额尔齐斯河流域土壤背景作为参比值,研究区土壤PLI平均值为4.04,呈现重度污染,土壤RI平均值为1511.40,呈现很强生态风险态势;土壤IER平均值为115.02,属于重度预警水平。(4)基于国家土壤环境Ⅱ级标准,研究区内调查样点处于强度生态风险和很强生态风险的占比分别为18.52%、81.48%,处于重度预警水平的样点占比为100%。因此,从污染程度和恢复时间的角度来看,尾矿堆存都造成了巨大的环境足迹,急需针对尾矿库周边的土壤重金属污染采取修复措施。

结皮量与含水率对尾矿风蚀影响的风洞模拟研究

尾矿风蚀是影响周边环境空气质量和人体健康的重要因素。以喀拉通克铜镍矿加乌尔尾矿库尾矿为研究对象,通过风洞试验,对不同风速、含水率和结皮量条件下的尾矿风蚀率、风蚀颗粒释放特征进行研究。结果表明:尾矿风蚀率、风蚀颗粒量及其碰撞能量随着试验风速的增加而增加,随着尾矿含水率和结皮量的增加而减小。首次出现颗粒碰撞的风速随着尾矿含水率和结皮量的增加而增加。尾矿风蚀颗粒主要分布在3 cm高度内,占总风蚀颗粒的50%以上。在结皮不被吹破的情况下,结皮的抗风蚀效果要优于含水率。因此,结皮抗风蚀效果与风速和结皮量有关,10 m/s以下风速任何结皮量均能有效抗风蚀,12 m/s需25 g以上结皮量,14 m/s需50 g以上结皮量;而含水率在任何试验风速下需达到2.72%以上才有较好的抗风蚀效果。

承德市水质部分化学指标的测定及分析

以化学滴定法和仪器分析法对承德市自来水、地表水、河流水以及实验室蒸馏水分别取样分析,分析测定水样的酸碱度、电导率、水的总硬度、Ca(Ⅱ)、Mg(Ⅱ)、Pb(Ⅱ)、Fe(Ⅱ)、Mn(Ⅱ)、等含量以及化学需氧量(COD)等部分化学指标,由此说明承德自来水、地表水、河流水的水质情况。检验结果表明承德地区饮用水和非饮用水的部分化学指标基本都能达到国家相应的标准。承德多山多矿,故所有水体总硬度和钙离子含量都偏高。生活饮用水全部符合国家饮用水标准,河流水质除了铅含量高一些以外其他指标也相当不错,可以用于正常的农业工业等其他方面。

塔里木沙漠公路防护林土壤环境因子的根际效应

选取塔里木沙漠公路防护林不同定植年限下3种灌木的根际和非根际土,比较研究了土壤物理、化学、生物因子的根际效应。结果表明:(1)除全氮和全磷外,20种土壤因子在3灌木根际土间差异极显著;(2)根际土的容重、全盐含量、有机质含量、全氮含量、速效氮磷钾含量、微生物代谢活性、脂肪酸含量和DNA片段多样性、微生物生物量碳氮磷和6种酶活性在不同年限林地间的差异极显著;(3)全氮含量、速效氮磷钾含量、微生物代谢活性、DNA片段多样性、微生物量碳和磷、纤维素酶和磷酸酶活性在不同树种与年限的交互效应上差异极显著;(4)微生物生物量碳氮磷的根际效应大小为柽柳>沙拐枣>梭梭,而不同树种各土壤养分因子和酶活性的根际效应大小并不一致。可见,几种荒漠灌木的定植促进了土壤养分转化,加速了沙漠防护林土壤的发育进程。

Evaluation of soil fertility of the shelter-forest land along the Tarim Desert Highway

To study the changes of soil fertility of the shelter-forest land along the Tarim Desert Highway, soils from the forest land were collected at the layers of 0―10 cm, 10―20 cm, 20―30 cm. Different soil fertility parameters were measured, and quantitative evaluation of soil fertility was performed by the soil integrated fertility index (IFI). The main results show that the construction of the shelter forest along the Tarim Desert Highway improved the soil physical structure, increased soil porosity and enhanced wa- ter-holding capacity. With the increase of plantation time of the shelter forest, soil microbial biomass C, N, P and the activities of six types of enzyme were enhanced, which promoted the accumulation and transformation of soil nutrients of the forest land. Consequently, the soil nutrients in 12-year-old forest land were much higher than in the newer ones and drifting sand. However, soil salt content of the older forest land was higher owing to the drip-irrigation with salt water. Through the comprehensive evalua- tion, we found that soil fertility index in the forest land was enhanced with the forest age, and it had close correlations with the growth indices of the forest trees. In summary, construction of the shelterforest along the Tarim Desert Highway accelerated the improvement of aeolian soil in the forest land, and the soil fertility improved year by year. We conclude that the forest trees grow normally under the stress of the present drip-irrigation with salt water.

Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway

In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%―80% and 87.45%―99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed.