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羟基磷灰石对成都平原水稻土中重金属的钝化效果研究 总被引:1,自引:0,他引:1
本研究选取成都平原典型农田系统受Cd和Zn复合污染土壤为研究对象,采用淋溶试验和老化试验,探索添加羟基磷灰石对土壤中重金属生物有效性以及形态分布的影响,羟基磷灰石添加比例(w/w)设置为0%(CK)、1%(P1)、3%(P3)和5%(P5)。结果表明:①添加羟基磷灰石能够明显降低土壤中Cd和Zn淋失量,P1、P3和P5与CK的Cd累积淋失量(110 μg)相比,降低比例分别为82.7%、92.7%、90.7%,P1、P3和P5与CK的Zn累积淋失量(9.30 mg)相比,降低比例分别为94.8%、97.1%、94.6%;②添加羟基磷灰石能够显著提高土壤pH,P1、P3和P5的pH分别比CK升高了0.30、0.53、0.95个pH单位;③添加羟基磷灰石能够显著降低土壤有效态Cd和Zn(0.025 mol HCl),相较于CK,P1、P3和P5的有效态Cd含量分别降低了59.0%、94.7%、98.7%,有效态Zn含量分别降低了18.6%、49.6%、87.6%;④添加羟基磷灰石能够显著降低土壤可交换态和碳酸盐结合态Cd和Zn含量,增加土壤中残渣态Cd和Zn含量,从而促进Cd和Zn向非活性态转化。本研究结果表明羟基磷灰石在成都平原区典型农田系统耕地Cd和Zn污染的修复中有较大的应用潜力。 相似文献
114.
以福建省长汀县为研究区域,基于遥感和GIS技术的支持,对研究区2000年、2009年、2016年的土地利用结构及分形动态进行分析。研究表明:经过多年的治理工作,长汀县的土地覆被情况有了很大的改善,林地面积不断增加,裸地面积持续减少。各土地利用斑块形态具有明显的分形特征,2000?—?2009年,耕地、建设用地分维值呈增加趋势,空间形态趋于不规则;林地、裸地和水域分维值减少,空间形态趋于规则。2009?—?2016年,耕地、裸地和水域斑块分维值呈上升趋势,空间形态趋于不规则;而林地和建设用地斑块分维值趋于下降,空间形态趋于规则。总体上土地利用分维值仍有增大的趋向,土地斑块的稳定度趋于下降。土地利用的复杂性和稳定性受到人为因素影响强烈,合理协调人地关系,避免治理成效出现反复,仍然是水土流失区治理的关键。 相似文献
115.
延长缺氧水力停留时间对A-AAO工艺氮磷去除影响的研究 总被引:1,自引:0,他引:1
相比传统厌氧-缺氧-好氧(简称AAO)脱氮除磷工艺,改良AAO工艺(定义为A-AAO)增加了回流污泥的硝酸盐反硝化区并对进水多点分配,氮磷去除能力得到显著提高。为进一步优化A-AAO的除污染能力,本研究以A-AAO工艺后2部分缺氧和好氧段(AO段)为对象,研究AO段水力停留时间改变对A-AAO工艺脱氮除磷的影响。试验采用两套小试规模A-AAO工艺(定义为1#和2#反应器)开展研究,1#反应器缺氧段及好氧段停留时间分别为5.5 h和10 h,2#反应器缺氧段及好氧段停留时间分别为2.5 h和13 h。研究结果表明:总停留时间不变,缩短好氧停留时间而延长缺氧停留时间有助于氮磷的去除。1#和2#反应器总氮和总磷平均去除率分别为61.36%、57.08%和85.72%、82.0%。 相似文献
116.
根据2013年8月对辽东湾海域拖网采集的127个生物体样品石油烃含量测试结果,结合历史调查数据,分析该海区生物体内石油烃含量水平、分布特征和变化趋势,评估生物体石油烃污染程度.结果表明:调查海区生物体内石油烃含量为2.76~41.81 mg·kg-1,平均为12.19mg·kg-1;整体石油烃含量具有软体腹足纲甲壳动物蟹类软体头足甲壳动物虾类鱼类,内脏组织高于肌肉组织的特点;生物体内石油烃含量与沉积物中石油烃含量存在显著相关性,与水体石油烃含量不存在明显相关性;年际变化趋势分析显示2012年软体类和甲壳类生物体石油烃含量高于2007年和2013年,表明调查海域2012年以前存在明显的石油烃输入;与国内其他海域相比,调查海域生物体石油烃含量较高. 相似文献
117.
Pengjun Xu Bu Tao Zhiqiang Ye Hu Zhao Yue Ren Ting Zhang Yeru Huang Jiping Chen 《环境科学学报(英文版)》2016,28(10):102-111
The concentrations of 16 priority polycyclic aromatic hydrocarbons(PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste(EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments.The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources,but the PAHs in the sediments were derived from both combustion and petroleum sources. 相似文献
118.
The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2+and Zn2+in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients(above 0.99 for both metal ions) and insignificant lack of fit(p = 0.0838 and 0.0782 for Pb2+and Zn2+, respectively). Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation(between –NH2,-CN and metal ions) and ion-exchange(between –COOH and metal ions). The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions. 相似文献
119.
以TI公司的CC2530ZigBee芯片为核心单元,采用ZigBee无线通信协议,设计了一种实用、安全、可靠的煤矿瓦斯无线监测系统。设计具有移动性强、数据传输稳定和成本低等优点。 相似文献
120.
Qinxue Wen Zhiqiang Chen Ye Zhao Huichao Zhang Yujie Feng 《Journal of Polymers and the Environment》2011,19(1):125-132
Efficient and reliable removal of polyacrylamide (PAM), which are present in oil extraction waste water, is critically important to prevent toxic discharges to receiving waters. In the present study, two PAM degrading bacterial strains, namely HWBI and HWBIII, were isolated from the activated sludge and soil in an oil field. Two sequencing batch reactors (SBRs) were bioaugmented with either HWBI or HWBIII and the performance of each bacteria for enhancing PAM removal was compared. The effects of bioaugmentation on the performance of the SBRs with different exogenous strains after a single inoculation were investigated under long term operation. Results showed that for the SBR augmented with HWBI, 70% of PAM was removed at the end of the first operation cycle, and the removal remained at approximately 70% in the following eight cycles after a single inoculation. For the SBR augmented with HWBIII, only 45% of the PAM was removed in the first cycle after the inoculation, and PAM removal decreased to 30% after eight cycles. Terminal restriction fragment length polymorphism (T-RFLP), a molecular screening technique, was applied to track the supplemented bacterial strains and to evaluate the effects of bioaugmentation on the microbial communities and to investigate the optimal bioaugmentation strategy. 相似文献