含砷废水净化剂的制备及其应用研究

本文描述了用黄铁矿和还原铁粉或其代用品为原料制备含砷废水净化剂－硫化亚铁的新方法，获得了制备的最佳条件，探讨了其在含砷废水处理中的应用条件和影响因素，结果表明，该净化剂的生产及其处理含砷废水的工艺简单，经济高效，具有良好的开发应用前景。     

Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket reactors

Calcium carbonate often precipitates in anaerobic reactors treating wastewater with high calcium content. The aim of this paper is to study the effect of wastewater composition on calcium carbonate precipitation in upflow anaerobic sludge blanket (UASB) reactors. Two laboratory-scale UASB reactors were operated with calcium-containing influents using acetate and carbohydrate as substrate, respectively. There was an obvious accumulation of inorganic precipitate observed in the biogranules. Observations via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) showed that the acclimated biogranules in the two reactors differed in microstructure. Calcium carbonate was found to have precipitated on the surface of acetate-degrading biogranules, but precipitated at the core of the carbohydrate-degrading biogranules. The results indicated that substrates had significant influence on the location of calcium carbonate precipitation in anaerobic granular sludge, which was expected due to the different methanogens distribution and pH gradient within the granular sludge degrading various substrates. Moreover, the location of calcium carbonate precipitation substantially affected the specific methanogenic activity (SMA) of the granular sludge. The SMA of the acetate-degrading biogranules dropped from $ 1.96 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} $ 1.96 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} to $ 0.61 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} $ 0.61 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} after 180-d of operation in the reactor. However, the SMA of the carbohydrate-degrading biogranules was not adversely affected by calcium carbonate precipitation.     

WASP水质模型在辽河干流污染减排模拟中的应用

运用WASP模型对辽河流域实施水质改善方案后水质的变化进行模拟,以辽河干流铁岭段水质指标COD为例,结合流域污染削减目标寻求合理的减排任务分配方案。结果袁明：根据不同季节灵活地分配减排任务,辽河干漉铁岭段年削减COD1．74—2．49万吨可使其水质状况得到明显改善,迭到减排耳标。     

丹江口水库水位抬高面临的挑战及其对策

移民与生态环境问题是丹江口水库水位抬高所面临的主要问题。移民问题是水位抬高首当其冲需要解决的难题,存在政策法规、移民资金、安置措施、脱贫致富等问题,需要以市场为导向,综合考虑诸多因素,制定可行的移民规划,确保移民的稳定和发展。生态环境问题是非常艰巨的问题,水土流失严重、污染源与污染总量日益增加、水质下降、支流库湾富营养化进程加剧等问题将困扰水库的运行与管理,后靠移民的生产生活也在一定程度上对生态环境产生影响;建议成立专门的监管机构,全方位开展水源地保护工作,确保水库水质安全和南水北调中线工程战略目标的实现。     

Germination of Deyeuxia angustifolia as affected by soil type, burial depth, water depth and oxygen level

Deyeuxia angustifolia is a dominant species in the Sanjiang Plain, the largest freshwater marsh wetland in China. However, this species has declined because of great environment changes. In the effects of sea-level rise and greenhouse gas, magnitude and frequency of flood and rate of deposit in wetland increased greatly. Thus, in this paper, effects of soil environment (soil type, burial depth, water depth and oxygen concentration) on seed germination of D. angustifolia were investigated. Both soil type and burial depth affected seedling emergence. Seedlings emerged through 1-, 2-, 4-mm sand, and at 1-and 2-mm mud. Regardless of soil, seedling emergence time increased and emergence percentage decreased with increasing burial depth. For example, seedlings started to emerge on the 4th day and the final emergence percentage was 30% when covered with1-mm mud, whereas the initial emergence time was on the 6th day and the final emergence percentage was only 8% when covered with 2-mm mud. At the same burial depth, emergence percentage was higher in sand than in mud. Increasing water depth inhibited seed germination. Germination percentage in 2-cm water level (20%) was 1.2 times higher than that in 12-cm water level (9%). Oxygen concentration also affected germination. In the 21% oxygen concentration, germination was started on the 2nd day and the germination percentage was 36%, while seed started to germinate on the 4th day and the germination percentage was only 3% at the 7% oxygen concentration. These data indicate that seed germination of D. angustifolia was highly sensitive to soil type, burial depth, water depth, oxygen concentration, and these responses may be an explicit indication of maladjustment to environment changes, and an important reason accounting for the decline of this species in the Sanjiang Plain.     

堆肥对重金属污染土壤Cu、Cd形态变化的影响

通过盆栽茼蒿试验研究了不同堆肥用量对重金属Cu、Cd污染土壤根际土和非根际土中Cu、Cd形态变化的影响.结果表明,随着堆肥用量的增加,非根际土和根际土交换态(含水溶态)Cu含量显著增加,最大值是对照的6.0倍;;有机结合态Cu含量在非根际土中显著升高,而在根际土中则先显著升高后降低,两者最大值是对照处理的1.1倍;;非根际土中无机结合态Cu含量先降低后升高;;非根际土和根际土残渣态Cu含量都先显著增加后基本不变.随着堆肥用量增加,非根际土中交换态(含水溶态)Cd含量显著降低,有机结合态和残渣态Cd含量显著升高,无机结合态Cd含量变化不明显;;根际土中,交换态(含水溶态)Cd含量先降低后升高,有机结合态Cd含量显著上升,无机结合态和残渣态Cd先上升后下降.因此,供试堆肥可作为修复剂减弱Cd的危害,但长期施用会造成Cu的累积,应慎重考虑.     

富锰渣高炉煤气布袋除尘的实践

富锰渣高炉煤气具有含尘量多、含水量大、温度高且变幅广等特点。国内大都采用湿式除尘,其缺点是会造成水污染。这里采取一系列综合措施,有效地控制了水分和温度,使组合式布袋除尘得到成功应用,消除了水污染,保护了生态环境。      

基于GF-1 WFV影像和BP神经网络的太湖叶绿素a反演

叶绿素a浓度是可直接遥感反演的重要水质参数之一,常用来评价湖泊水体的富营养化程度.太湖是典型的二类水体,光学性质复杂,应用一类水体线性反演模式拟合较为片面且难以找到最佳拟合模型.BP神经网络模型具有模拟复杂非线性问题的功能.为研究高分一号卫星16m多光谱相机WFV4结合BP神经网络进行太湖叶绿素a浓度监测的可行性,实验利用GF-1 WFV4影像和实时的地面采样数据,建立了BP神经网络模型,同时采用波段比值经验模型进行对比.经精度检验,BP神经网络模型预测值与实测值之间的可决系数R2高达0.9680,而波段比值模型的R2为0.9541,且均方根误差RMSE由波段比值模型的18.7915降低为BP神经网络模型的7.6068,平均相对误差e也由波段比值模型的19.16%降低为BP神经网络模型的6.75%.结果证明,GF-1 WFV4影像应用BP神经网络模型反演太湖叶绿素a浓度较波段比值模型精度有所提高.将经过水体掩膜的GF-1 WFV4影像用于训练好的BP神经网络反演太湖叶绿素a浓度分布,结果显示,叶绿素a高浓度区集中分布在湖心区北部、竺山湾、梅梁湾区域,与之前的研究一致.本文研究结果验证了采用BP神经网络模型对GF-1 WFV4影像进行太湖叶绿素a浓度反演的可行性.     

2006—2012年广东省机动车尾气排放特征及变化规律

利用广东省年鉴及实地调查资料,基于COPERT Ⅳ模型计算并分析了2006─2012年广东省珠三角和非珠三角地区的机动车尾气排放清单. 结果表明:研究地区2006─2012年机动车保有量上升,国Ⅲ、国Ⅳ车辆所占比例提高,其中珠三角地区优化程度大于非珠三角地区;2006─2012年2个地区污染物(CO、VOC、NO_x、PM_2.5)排放因子均有降低,降幅在24.54%~57.89%之间. 机动车污染物排放量上升趋势及贡献特征地区性差异明显,2006─2012年非珠三角地区CO、VOC排放量分别上升了37.20%、26.93%,增幅高于珠三角地区,而珠三角地区2012年的NO_x、PM_2.5排放量增幅(分别为21.65%、14.60%)高于非珠三角地区. 轻型客车是2个地区CO和VOC的主要贡献车型,贡献率均达46.96%以上,并且处于上升状态,但珠三角地区增幅小于非珠三角地区;重型客车和重型货车是2个地区NO_x、PM_2.5的主要来源,贡献率均在40.78%以上.      

Fe-C-H_2O_2协同催化氧化处理印染废水

用Fe-C-H2O2协同催化氧化体系对印染工业废水的降解脱色处理进行了研究。对影响印染废水降解的几种因素如铁屑/碳粒质量比、双氧水的质量分数、废水pH等进行考察。试验结果表明,对于色度为650度和ρ（COD）为468mg·L-1的印染废水,在废水pH=4.8的情况下,当铁屑/碳粒质量比为25∶1、H2O2用量为150mg·L-1、催化反应30min时,印染废水的脱色率达98%以上,CODCr去除率可达78%。与Fe-C微电解法相比,Fe-C-H2O2协同催化氧化方法对印染废水的脱色能力和去除COD,表现出了更好的处理效果。