Enhanced degradation of reactive brilliant red X-3B by photocatalysis integrated with micro-electrolysis

Environmental Science and Pollution Research - The microwave electrodeless lamp UV photocatalysis (MWUV) integrated with iron carbon micro-electrolysis (ME) was applied to degrade reactive...     

Efficient removal of nitrogen and phosphorus in aqueous solutions using modified water treatment residuals–sodium alginate beads

Environmental Science and Pollution Research - A high-performance sorbent, modified water treatment residuals–sodium alginate beads (WTR-SA beads), was prepared through a series of salt and...     

Red mud-modified biochar reduces soil arsenic availability and changes bacterial composition

Environmental Chemistry Letters - Worldwide arsenic (As) contamination in soils induces pollution of surface and ground waters, reduces crop quality and yield, and threatens human health....     

黄土丘陵沟壑区不同土地利用类型对坡地产流、产沙的影响

于甘肃省安家沟流域选择设计15个径流小区,通过对径流小区1986-1999年的水文监测资料进行年尺度上的方差分析、多重比较和相关分析,研究不同土地利用类型对坡地产流、产沙的影响,同时分析年降雨量与坡地单位面积年产流、产沙量的相关关系.结果表明,相同坡度等级下5种土地利用类型坡地的单位面积年产流量之间及单位面积年产沙量之间都存在显著差异,大小顺序均表现为:坡耕地>人工草地>乔木林地>自然草地>灌木林地;在研究的坡度(10°～20°)范围内,同一土地利用类型、不同坡度径流小区的单位面积年产流量差异不显著,坡耕地和人工草地的单位面积年产沙量差异显著;年降雨量分别与坡地单位面积年产流量、产沙量无显著相关性.     

Cl-BDE-208和BDE-209诱导LINE-1基因低甲基化和ESR1基因高甲基化

十溴联苯醚(BDE-209)是使用最多的一种多溴阻燃剂,由于具有高亲脂性和低挥发性,容易蓄积在生物体内,在人体血清、母乳、肝脏等组织中均有检出;其环境脱溴产物九溴一氯联苯醚(Cl-BDE-208)也在血清样品和环境样品中被频频检出,而目前对这种化合物的毒理学研究,特别是对人体早期健康效应的研究较少。为了评估Cl-BDE-208和BDE-209的早期健康效应,以人乳腺癌细胞MCF-7为模型,环境相关浓度(0.375~3μmol·L-1)为暴露浓度,检测Cl-BDE-208和BDE-209对重复序列LINE-1、全基因组DNA甲基化(GDM)和雌激素受体基因(包括ESR1和ESR2)甲基化水平的改变。结果表明,Cl-BDE-208和BDE-209都可能通过降低DNA甲基化转移酶(DNMTs)活性而诱导了LINE-1和GDM的低甲基化,8-羟基脱氧鸟苷(8-OHd G)水平的升高可能参与了BDE-209引起的低甲基化过程;同时通过促进雌激素受体α(ESR1)基因的高甲基化而显著下调了ESR1基因的表达,而对雌激素受体β(ESR2)基因甲基化水平并没有显著影响。Cl-BDE-208和BDE-209都可能通过改变DNA甲基化水平而影响人体的早期健康效应,同时ESR1基因的高甲基化可能是Cl-BDE-208和BDE-209引起内分泌毒性的机制之一。     

珠江主干和东江河流表层沉积物中有机磷酸酯阻燃剂/增塑剂分布

有机磷酸酯阻燃剂/增塑剂(organophosphate esters,OPs)用量大、环境分布广泛、毒理效应显著,已成为环境领域关注热点。采用超声辅助提取结合固相萃取技术和气相色谱-质谱分析,研究珠江主干和东江河流表层样品中7种常见OPs含量水平与分布特征。结果表明,研究区域沉积物中OPs分布广泛,珠江主干∑7OPs范围为78.9~577 ng·g~(-1),主要污染物为磷酸三(丁氧基乙基)酯(TBEP),其次为磷酸三丁酯(TBP)和磷酸三(2-氯)乙酯(TCEP),均值分别为84.6 ng·g~(-1)、55.6 ng·g~(-1)和27.8 ng·g~(-1);东江河段沉积物中∑7OPs含量范围为24.0~293 ng·g~(-1),以磷酸三甲苯酯(TTP)、磷酸三苯酯(TPh P)和TBEP为主要污染物,平均浓度分别为55.6 ng·g~(-1)、32.7 ng·g~(-1)和17.5 ng·g~(-1)。以上结果揭示了珠江和东江沉积物中有机磷阻燃剂/增塑剂的浓度和分布是明显不同的,可能与不同来源的点源排放有关。     

ZnCl_2/CuCl_2复合活化剂制备污泥活性炭及其分形研究

以污水处理厂剩余污泥为原料,以氯化锌和氯化铜为复合活化剂,采用低温炭化及中温活化方法制备了污泥活性炭。经正交优化得到最佳制备条件为:活化温度为534℃,活化时间为60 min,ZnCl2浓度为3.0 mol/L,CuCl2浓度为0.3 mol/L,碘吸附值达到534.0 mg/g。所得污泥活性炭含有大量微孔,同时也含有部分中孔和大孔,BET比表面积为784.89 m2/g,Langmuir比表面积为1 053.69 m2/g;利用污泥活性炭吸附制药废水,实验结果符合Freundlich方程,由此建立的分形吸附模型证明制备的污泥活性炭具有分形特征,其分形维数越高,则粗糙度越大,碘吸附值越高。     

Chemical Tracking and Marine Environmental Impact of Ocean Disposal of Calcium Carbonate Residue in the North Yellow Sea

The objective of this study is to determine the sedimentation rate and dispersion area of calcium carbonate residue dumped at sea and the impact to marine environment of dumping by a laboratory simulation experiment; chemical tracking in the field with the help of acoustic and optical tracking; and a comparative study of baseline conditions and marine environmental impact after dumping. Turbidity, pH and phosphate are selected as the chemical tracers to be monitored.

Results show that in the dumping area of 15 square miles with water depth of 50 m, if 217 t calcium carbonate residue is dumped (spot dumping) in the presence of a pycnocline with a current velocity of 60 cm/s (close to the maximum) the maximum dispersion distance of the calcium carbonate residue plume front is less than 2100 m; the dispersion area is less than 0.56 km²; and the maximum dispersion time is about 60 min when the turbidity and pH in the whole dispersion area return to background level. Therefore, the ocean disposal of calcium carbonate residue is feasible.     

日本青鳉(Oryzias latipes)胚胎和卵黄期仔鱼对镉的 敏感性

物理化学方法对镉的监测忽略了其生物可利用性,生物监测可以有效地弥补这种不足。本研究测试了日本青鳉(Ory-zias latipes)胚胎和卵黄期仔鱼对镉的敏感性。结果表明:日本青鳉胚胎和卵黄期仔鱼的蛋白含量对镉表现出较高的敏感性,卵黄期仔鱼的蛋白含量在4μg·L-1的氯化镉暴露后就出现显著降低;氯化镉对卵黄期仔鱼脊柱畸形的EC50低于国家地表水环境质量标准规定的Ⅱ类水标准;脊柱畸形率与镉浓度之间存在的线性关系,可为定量监测镉污染提供理论依据;脊柱畸形可以在48h之内被4μg·L-1的氯化镉极显著地诱导,因此这种潜在的生物监测模型很有希望应用到水环境污染的快速预警中。通过对国内主要水体中镉污染水平的分析发现,卵黄期仔鱼的蛋白含量变化和脊柱畸形率对部分水体的镉污染可以实现生物监测。因此,利用日本青鳉胚胎和卵黄期仔鱼对低水平镉污染的高度敏感性,能够建立起1种简易廉价并且有效的水环境中低水平镉污染的生物监测模型。     

A compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe,South America,South Africa and China: separating fads from facts

Mercury is transported globally in the atmosphere mostly in gaseous elemental form (GEM, \( {\text{Hg}}_{\text{gas}}^{0} \) ), but still few worldwide studies taking into account different and contrasted environmental settings are available in a single publication. This work presents and discusses data from Argentina, Bolivia, Bosnia and Herzegovina, Brazil, Chile, China, Croatia, Finland, Italy, Russia, South Africa, Spain, Slovenia and Venezuela. We classified the information in four groups: (1) mining districts where this contaminant poses or has posed a risk for human populations and/or ecosystems; (2) cities, where the concentration of atmospheric mercury could be higher than normal due to the burning of fossil fuels and industrial activities; (3) areas with natural emissions from volcanoes; and (4) pristine areas where no anthropogenic influence was apparent. All the surveys were performed using portable LUMEX RA-915 series atomic absorption spectrometers. The results for cities fall within a low GEM concentration range that rarely exceeds 30 ng m^?3, that is, 6.6 times lower than the restrictive ATSDR threshold (200 ng m^?3) for chronic exposure to this pollutant. We also observed this behavior in the former mercury mining districts, where few data were above 200 ng m^?3. We noted that high concentrations of GEM are localized phenomena that fade away in short distances. However, this does not imply that they do not pose a risk for those working in close proximity to the source. This is the case of the artisanal gold miners that heat the Au–Hg amalgam to vaporize mercury. In this respect, while GEM can be truly regarded as a hazard, because of possible physical–chemical transformations into other species, it is only under these localized conditions, implying exposure to high GEM concentrations, which it becomes a direct risk for humans.