The toxicity of cadmium ion (Cd2+) to phycocyanin: an in vitro spectroscopic study

Environmental Science and Pollution Research - The pollution of heavy metals is a severer problem for the ecosystems in waters. The toxicity of Cd2+ on phycocyanin (PC) is studied in molecular...     

Evaluation of combined developmental neurological toxicity of di (n-butyl) phthalates and lead using immature mice

Environmental Science and Pollution Research - In this study, the immature mice were taken to assess the potential neurological toxicity of lead (Pb) and di (n-butyl) phthalates (DBP) combination...     

Effects of intercropping with floricultural accumulator plants on cadmium accumulation in grapevine

Environmental Science and Pollution Research - Grapevine (Vitis vinifera L.) intercropping with floricultural cadmium (Cd) accumulator plants (Helianthus annuus L., Cosmos sulphureus Cav., Cosmos...     

Numerical model of aerobic bioreactor landfill considering aerobic-anaerobic condition and bio-stable zone development

Environmental Science and Pollution Research - Aeration by airflow technology is a reliable method to accelerate waste biodegradation and stabilization and hence shorten the aftercare period of a...     

制备ZnO/CdS/Au异质结用于可见光催化降解低浓度甲醛

采用水热法和化学浴沉积法制备了ZnO/CdS/Au异质结光催化剂,用于可见光下室温去除低浓度甲醛。通过XRD、SEM、TEM、XPS、UV、PL、PEC、EIS等手段对ZnO/CdS/Au异质结光催化剂的光学性能、光电性能进行表征。结果表明,Au负载的ZnO/CdS纳米棒组成的微米花状结构中,异质结和金属等离子体效应能拓宽光谱吸收范围,抑制半导体缺陷发光,促进光吸收以及光生电子空穴的分离和迁移;所制备的ZnO/CdS/Au异质结光催化剂对甲醛的去除具有优异性能,室温下2 h即可将反应舱内低质量浓度甲醛(1.25 mg·m⁻³)降至0.025 mg·m⁻³以下,且经过8次重复使用后催化剂活性没有明显下降。此外,影响甲醛去除的因素,如催化剂种类、光照波长、甲醛初始质量浓度、相对湿度也进行了研究和探讨。该研究结果对低浓度甲醛的室温去除具有理论指导意义。     

Fractionation of fulvic acids: characteristics and complexation with copper

Two fulvic acid samples isolated from Suwannee river (International Humic Substance Society) and Feeitsuey reservoir were subjected to gel filtration chromatography (GFC) for molecular size fractionation. The GFC-eluted samples were separated into three groups corresponding to the molecular weight ranges: < 220, 220-1000, and 1000-4000. Fluorescence quenching techniques were employed for determining the conditional stability coefficient and kinetic parameters of copper complexation with the three fractions of fulvic acids. Experimental conditions were pH 6, 5 x 10(-5)m total copper and 5 mg C litre(-1) of fulvic acids. The conditional stability coefficients of the fulvic acid fractions were in the order of 0.9-3.3 x 10(5)m(-1), and the forward and reverse rate constants were in the order of 6.9-12.4 x 10(3)m(-1) s(-1) and 3.5-8.0 x 10(-2) s(-1). Information could be useful in modelling copper transport in the hydrosphere.     

Environmental contamination of mercury from Hg-mining areas in Wuchuan, northeastern Guizhou, China

Total Hg and methyl-Hg were evaluated in mine wastes, soils, water, and vegetations from the Wuchuan Hg-mining areas, Guizhou, China. Mine wastes contain high total Hg concentrations, ranging from 79 to 710 microg g(-1), and methyl-Hg from 0.32 to 3.9 ng g(-1). Total Hg in soil samples range from 0.33 to 320 microg g(-1) and methyl-Hg from 0.69 to 20 ng g(-1). Vegetations present a high average total Hg concentration of 260 ng g(-1), which greatly exceeds the maximum Hg concentration of 20 ng g(-1) recommended by the Chinese National Standard Agency for food sources. The rice samples contain elevated methyl-Hg concentrations, ranging from 4.2 to 18 ng g(-1). Stream water collected from Hg-mining areas is also contaminated, containing Hg as high as 360 ng l(-1), and methyl-Hg reaches up to 5.7 ng l(-1). Data indicate heavy Hg-contaminations and significant conversion of methyl-Hg in the study areas.     

Methods for the preparation of a biodesulfurization biocatalyst using Rhodococcus sp

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.     

Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons

This study selected biosolids from a petrochemical waste-water treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl2) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl2-immersed biosolids pyrolyzed at 500 degrees C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high.