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以冷砂黄泥和矿子黄泥为研究对象,猪粪沼渣为有机物料,分别添加0%、5%、7.5%和10%质量分数的蒙脱石,采用室内培养试验研究了蒙脱石对施有机物料土壤pH、磷形态和有效性的影响.结果表明,有机物料对两种土壤pH无显著影响,而蒙脱石使土壤pH显著提高.施加有机物料使两种土壤铝结合态磷(Al-P)含量和分布比例提高,铁结合态磷(Fe-P)含量培养后期提高、比例略有下降,闭蓄态磷(O-P)含量无明显变化、比例下降.有机物料对冷砂黄泥中钙结合态磷(Ca-P)的含量无明显影响、比例下降,却使矿子黄泥Ca-P含量和比例提高.在施加有机物料基础上添加蒙脱石后,冷砂黄泥Al-P和O-P含量和比例下降,Fe-P含量无明显变化、比例下降,Ca-P含量和比例大幅度提高;矿子黄泥Fe-P和O-P含量和比例下降,Al-P含量无明显变化、比例下降,Ca-P含量和比例大幅度提高.培养过程中,有机物料使冷砂黄泥和矿子黄泥有效磷含量分别提高了17.9%~38.0%和17.1%~33.7%,土壤磷的活化系数也显著提高,添加蒙脱石后使两种土壤有效磷含量分别降低8.8%~35.5%和1.1%~11.6%.相关分析结果表明,蒙脱石通过提高pH和Ca-P含量、降低Al-P含量降低冷砂黄泥磷的有效性,通过提高pH、降低Fe-P含量降低矿子黄泥磷的有效性,对冷砂黄泥磷有效性的影响较矿子黄泥大. 相似文献
334.
An organo-montmorillonite-supported nanoscale zero-valent iron material(M-NZVI) was synthesized to degrade decabromodiphenyl ether(BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmorillonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30–90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased. 相似文献
335.
Qiushi Shen Qilin Zhou Jingge Shang Shiguang Shao Lei Zhang Chengxin Fan 《环境科学学报(英文版)》2014,26(2):281-288
Organic matter-induced black blooms(hypoxia and an offensive odor) are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration(close to 0 mg/L), low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe2+and∑S2-were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column. 相似文献
336.
Xiuying Zhao Xinming Wang Xiang Ding Quanfu He Zhou Zhang Tengyu Liu Xiaoxin Fu Bo Gao Yunpeng Wang Yanli Zhang Xuejiao Deng Dui Wu 《环境科学学报(英文版)》2014,26(1):110-121
Organic acids as important constituents of organic aerosols not only influence the aerosols' hygroscopic property, but also enhance the formation of new particles and secondary organic aerosols. This study reported organic acids including C14–C32fatty acids, C4–C9dicarboxylic acids and aromatic acids in PM2.5collected during winter 2009 at six typical urban, suburban and rural sites in the Pearl River Delta region. Averaged concentrations of C14–C32fatty acids, aromatic acids and C4– C9 dicarboxylic acids were 157, 72.5 and 50.7 ng/m3, respectively. They totally accounted for 1.7% of measured organic carbon. C20–C32fatty acids mainly deriving from higher plant wax showed the highest concentration at the upwind rural site with more vegetation around, while C14–C18fatty acids were more abundant at urban and suburban sites, and dicarboxylic acids and aromatic acids except 1,4-phthalic acid peaked at the downwind rural site. Succinic and azelaic acid were the most abundant among C4–C9dicarboxylic acids, and 1,2-phthalic and 1,4-phthalic acid were dominant aromatic acids. Dicarboxylic acids and aromatic acids exhibited significant mutual correlations except for 1,4-phthalic acid, which was probably primarily emitted from combustion of solid wastes containing polyethylene terephthalate plastics. Spatial patterns and correlations with typical source tracers suggested that C14–C32fatty acids were mainly primary while dicarboxylic and aromatic acids were largely secondary. Principal component analysis resolved six sources including biomass burning, natural higher plant wax, two mixed anthropogenic and two secondary sources; further multiple linear regression revealed their contributions to individual organic acids. It turned out that more than 70% of C14–C18fatty acids were attributed to anthropogenic sources, about 50%–85% of the C20–C32fatty acids were attributed to natural sources, 80%–95% of dicarboxylic acids and 1,2-phthalic acid were secondary in contrast with that 81% of 1,4-phthalic acid was primary. 相似文献
337.
Higher concentrations of Hg can be emitted from coal pyrolysis or gasification than from coal combustion, especially elemental Hg. Highly efficient Hg removal technology from coal-derived fuel gas is thus of great importance. Based on the very excellent Hg removal ability of Pd and the high adsorption abilities of activated carbon(AC) for H2 S and Hg, a series of Pd/AC sorbents was prepared by using pore volume impregnation, and their performance in capturing Hg and H2 S from coal-derived fuel gas was investigated using a laboratory-scale fixed-bed reactor. The effects of loading amount, reaction temperature and reaction atmosphere on Hg removal from coal-derived fuel gas were studied. The sorbents were characterized by N2 adsorption, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The results indicated that the efficiency of Hg removal increased with the increasing of Pd loading amount, but the effective utilization rate of the active component Pd decreased significantly at the same time. High temperature had a negative influence on the Hg removal. The efficiency of Hg removal in the N2-H2S-H2-CO-Hg atmosphere(simulated coal gas) was higher than that in N2-H2S-Hg and N2-Hg atmospheres, which showed that H2 and CO, with their reducing capacity, could benefit promote the removal of Hg. The XPS results suggested that there were two different ways of capturing Hg over sorbents in N2-H2S-Hg and N2-Hg atmospheres. 相似文献
338.
Arsenic in the environment is attracting increasing attention due to its chronic health effects. Although arsenite(As(III)) is generally more mobile and more toxic than arsenate(As(V)), reducing As(V) to As(III) may still be a means for decontamination, because As(III) can be removed from solution by precipitation with sulfide or by adsorption or complexation with other metal sulfides. The performance of As(V) bio-reduction under autohydrogenotrophic conditions was investigated with batch experiments. The results showed that As(V) reduction was a biochemical process while both acclimated sludge and hydrogen were essential. Most of the reduced arsenic remained in a soluble form, although 20% was removed with no addition of sulfate, while 82% was removed when sulfate was reduced to sulfide. The results demonstrated that the reduced arsenic was re-sequestered in the precipitates, probably as arsenic sulfides. Kinetic analysis showed that pseudo first-order kinetics described the bio-reduction process better than pseudo second-order. In particular, the influences of pH and temperature on As(V) reduction by acclimated sludge under autohydrogenotrophic conditions and total soluble As removal were examined. The reduction process was highly sensitive to both pH and temperature, with the optimum ranges of pH 6.5–7.0 and 30–40°C respectively. Furthermore, Arrhenius modeling results for the temperature effect indicated that the As(V) reduction trend was systematic. Total soluble As removal was consistent with the trend of As(V) reduction. 相似文献
339.
餐厨及厨余垃圾是有机垃圾的一种,餐厨垃圾是指餐饮服务单位在食品加工、饮食服务、单位供餐活动中产生的食物残渣、残液和废弃油脂等废弃物。厨余垃圾是指,家庭中产生的易腐食物垃圾,主要包括剩菜、剩饭、菜帮菜叶、瓜果皮核废弃食物等。餐厨及厨余垃圾含有大量的有机质,如果将它们能就地处理变成有机肥,既可省下用作填埋场的土地,还能节约运输它们的车辆和能源,防止滋生蚊蝇和细菌。不仅保护了环境,还滋养了土地。 相似文献
340.