Effects of humic acid-modified magnetic Fe3O4/MgAl-layered double hydroxide on the plant growth, soil enzyme activity, and metal availability.

The synthesis of a humic acid-layered double hydroxide (HA-LDH) hybrid was purposed for the remediation of contaminated soils in mining area. The hybrid was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscope and energy dispersive spectrometer. In order to investigate the effect of HA-LDH on the mine soil, greenhouse experiments of Artemisia ordosica were carried out under different concentrations of amendments (0, 1%, 3%, 5%, 7%). The plant growth, metal availability, and soil enzyme activities were studied to determine the effects of HA-LDH. The mine soil with 5% HA-LDH was the optimum proportion, and the growth of Artemisia ordosica was in good status. The HA-LDH and Artemisia ordosica could effectively decrease the bioavailability of heavy metals (such as Pb, Cr, Ni, Cd, Zn, and As) in the mine soil, and improve the enzyme activities of ß-glucosidase, urease, and phosphatase. The HA-LDH with magnetism could be easily separated. The characteristics and reusability of HA-LDH could be well maintained after five cycles of remediation. Consequently, the HA-LDH is promising for the remediation of contaminated soils in mining area.

Contextual modulation of the red-attractiveness effect: Differences in affiliation and competitive settings.

Color is not just about aesthetics but also communicates specific information and has important implications for psychological functioning. It has been shown that the color red enhances perceived attractiveness when evaluating the opposite sex, which we call the red-attractiveness effect. However, few studies have attached importance to the social context in which attractiveness ratings are made, which means that the red-attractiveness effect is rarely explained by analyzing the role of social context. We conducted two experiments to test the red-attractiveness effect in Chinese culture and the influence of context (affiliation or competitive) on the red-attractiveness effect. Experiment 1 (160 Chinese college students, 80 males) showed that the opposite-sex target in red, compared to white, was rated more attractive, and the red-attractiveness effect was applicable to Chinese culture. Experiment 2 (480 Chinese college students, 240 males) found that perceived attractiveness was strengthened in the affiliation context and weakened in the competitive context, that is, the main effect of context was significant. We did not find any significant effect of the color red in either context, that is, the color main effect was not significant. However, the results indicate that red can enhance perceived attractiveness when evaluating the opposite sex. This study demonstrates that the red attractiveness effect may exist in different cultural backgrounds and contexts.

Humic acid coupled with coal gasification slag for enhancing the remediation of Cd-contaminated soil under alternated light/dark cycle.

In this study, the synthesis of a coal gasification slag-humic acid (SA) hybrid was purposed for the remediation of cadmium (Cd)-contaminated soil. In order to investigate the effect of SA on the Cd-contaminated soil and plant growth, a series of experiments were carried out under different illumination condition. The results showed that the SA has some the photocatalytic activity, and adding 10 wt% of SA to the soil could obviously improve the soil fertility and decrease the mobility of Cd in the soil under alternated light/dark cycle (12L/12D); the content of the residual fraction in the SA-amended soil reached 69.5%, and the Cd decreasing rates for the leaf, stem, and root of Artemisia ordosica were near 100%, 91.3%, and 75.3%, respectively. Characterizations of amendments suggested that the synergistic effect of precipitation and surface complexation played a major role in the remediation of Cd-contaminated soil.

Effects of sewage sludge modified by coal gasification slag and electron beam irradiation on the growth of Alhagi sparsifolia Shap. and transfer of heavy metals.

A greenhouse experiment was performed to investigate the feasibility of sewage sludge modified by coal gasification slag pretreatment and electron beam irradiation in soil application for cultivation of Alhagi sparsifolia Shap . The results showed that modified sewage sludge had an active effect on the growth of Alhagi sparsifolia Shap . The sandy soil and modified sludge at the volume ratio of 2:1 were optimal, and the growth potential of Alhagi sparsifolia Shap . was highest. In the sandy soil, the values of bioconcentration factor of most heavy metals were below 1.0 except for Zn and Cu. The average bioconcentration factor values of heavy metals in Alhagi sparsifolia Shap . decreased in a sequence of Zn>Cu>Ni> Mn>Co>Pb>Cr>Fe>V>Cd>Mo for all treatments. Alhagi sparsifolia Shap . could decrease the eco-toxicity and bioavailability of Ni, Fe, and Mo in all mixed soil, and Alhagi sparsifolia Shap . could reduce the eco-toxicity and bioavailability of all heavy metals discussed in this study (except for Mn) in the mixed soil of SS:MSS = 2:1.

Cobalt-60 gamma-ray irradiation pretreatment and sludge protein for enhancing enzymatic saccharification of hybrid poplar sawdust.

In order to improve the enzymatic saccharification of hybrid poplar sawdust, gamma irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein were investigated. The cellulose crystallinity index were significantly decreased after irradiation pretreatment, and adding sludge protein improved enzyme activity and increased the reducing sugar yield. The conditions of irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein were systematically examined. The maximum reducing sugar yield was 519mg/g under an irradiation dose of 300kGy, a sludge protein dosage of 2mg/mL, an enzymatic hydrolysis temperature of 45°C, an enzymatic hydrolysis time of 84h, and a 90FPU/g enzyme loading. This work indicated that the combined method of gamma irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein was a promising potential for the saccharification of hybrid poplar sawdust.