Abstract: Portland cement can be used as soil stabilizer, but poses some problems such as dust pollution, consumption of fossil energy and relatively large amounts of calcium-rich raw materials. Enzyme as a soil enzymatic stabilizer is a natural organic compound and promising material to reduce the application of Portland cement. Perma-Zyme is one type of enzyme. The results of the study showed that soil type and curing method significantly affected the effectiveness of the treatments with Perma-Zyme and Composite Portland cement. Under the air-dry conditions, the unconfined compressive strengths of soils stabilized with Composite Portland cement were lower than those treated with Perma-Zyme at each age. In sealed glass containers, the unconfined compressive strengths of soils treated with Composite Portland cement were higher than those treated with Perma-Zyme. These results indicate that after compaction, the surface of soil stabilized with Portland cement should be moistened with a spray of some water or cover with materials (such as plastic sheet)，but the surface of soil stabilized with Perma-Zyme need not spray water and cover with materials in the actual project construction.
Abstract: The dairy industry has become an important industry for increasing employment and peasants' income and optimizing agricultural structure, but the dairy public safety events frequently broke out. This paper firstly introduced the situation of dairy development and comprehensively analyzed the dairy public safety supervision system in China from supervision agencies and system, particularly from the dairy industry policies, laws and regulations, industry technical standards and quality-control system. The results showed that China’s dairy public safety is facing several outstanding problems such as unclear functions of public safety supervision departments, imperfect policies and laws, lack of testing methods and inspection standards, backward technical standards and so on. Finally, some policy-recommendations were put forward.
Abstract: Corrosion of aluminium anode in the seawater will reduce the life of the aluminum-air cell. It has been recognized that addition of inhibitor into the seawater electrolyte is an effective method that may prevent the corrosion of aluminium anode.The corrosion inhibition behavior of aluminium anode after addition of CeCl3 with different concentrations in simulated seawater has been investigated in this paper. EIS results showed that there was a significant increase of corrosion resistance when the concentration of CeCl3 reached 500mg·L-1 in simulated seawater, compared to the case without inhibitor. Potentiodynamic polarization curves showed that CeCl3 was a cathodic inhibitor in simulated seawater. SEM and XPS confirmed that the cerium oxide/hydroxide were formed at micro-cathodic areas of aluminum surface,which decreased the corrosion rate of aluminium anode.
Abstract: The contents of lead and cadmium in the leaves of Chinese Rose along 4th ring roads in Beijing were determined respectively, and index of air environment pollution of plants was introduced to study the relationship between the content of lead and cadmium in leaves and air pollution. The results revealed that the air quality based from lead content in leaves at many locations belong to strongly polluted status, while the air quality based on cadmium content of Chinese Rose leaves at many location belonged to extremely polluted status. It is practical to evaluate air pollution conditions using content of heavy metal (such as lead and cadmium) in leaves of plant.
Abstract: Seven natural organic acids were added to moderate artiﬁcial Cr-contaminated soil to investigate the effects of natural organic acids on growth of maize and phytoextraction of chromium by maize. The results showed that most organic acids promoted the height growth of maize except for humic acid in Cr-contaminated soil. The total dry weight increased only with oxalic acid treatment. The natural organic acids can change the dry matter distribution of the shoot and the root. The total uptake of chromium by the shoots of maize showed the highest with citric acid treatment (p<0.01), followed by succinic acid, tartaric acid and malic acid treatment, indicate that citric acid has the potential to be used for phytoremediation of Cr-contaminated soil.
Abstract: To enhance our understanding on plant invasions in China, we conducted a comparative study of the checklists of the alien invasive plants in China published during 1998-2008. Our results showed that species diversity of the invasive plants in China was relatively small, in consideration of the huge flora and diverse habitats in China. The results also indicated that there was a big turnover of species composition among the seven checklists. The fast-growth of species diversity of alien invasive plants during 1998-2008 and the exponentially increasing trend confirmed the early warnings. There was an increasing trend observed on those from Asia and Africa from 1998-2008. We suggested that extensive and intensive communication was pressingly needed among ecologists, taxonomists and authors of the checklists. The establishment of the checklist of alien invasive plants with high reliability and timely maintenance, which can accommodate the rapid turnover of the invaders, was one of the chief tasks in the research of plant invasions in China.
Abstract: An Internal Circulation Impinging Stream Biofilm Reactor (ICISBR) was developed and used for treatment synthetic organic wastewater with corncob as biofilm carriers. Effects of COD loading rates and aeration rates on COD removal and DO contents were investigated. COD removal efficiency increased together with effluent COD with increasing COD loading rates. As the aeration rate was increased, the DO content also increased together with COD removal efficiency up to an optimum aeration rate of 0.3m3h-1. Beyond this optimum aeration rate a significant decrease in DO content and COD removal efficiency were experienced. This study could provide theoretic basis for the ICISBR treating organic wastewater.
Abstract: Compared biological sand filtration system with conventional water treatment, taking micro-polluted water river as source water. The results show that biological filtration system is excelled to conventional water treatment, the removal rate of CODMn, NH4+-N, chromaticity and turbidity is 34~56％, 78.7~92%, 53~68%, 90% by biological sand filtration system; however, the removal rate of CODMn, NH4+-N, chromaticity and turbidity is only 11~30%, 4.7~25%, 38~54%, 60~80% by the conventional water treatment and the remval effection is instability; therefore, biological filtration system is pertinency and feasibilty in the micro-polluted source water.
Abstract: According to the water quality characteristics, micro-polluted source water treatment by ozone combined processes. The results show that the average removal efficiencies of algae, CODMn, NH4+-N, turbidity, chromaticity by bio-pretreatment filter are 72.0%, 14.5%, 80.5%, 58.6% ,26.0%, respectively; while the whole average removal efficiencies by pre-ozonation tank following bio-pretreatment filter had increased at the different dosages of ozone, such as algae 12.0%, CODMn 19.5% ,NH4+-N 7.5%, turbidity 10.9%, chromaticity 34.5%, respectively; and the optimal dosages of ozone are between 0.7 and 1.5mg/L. Furthermore, compared with the conventional water treatment process, all kinds of combined water treatment processes are better than the conventional one, of which the combined process Ⅲ with granular activated carbon (GAC) adsorption tank is obviously the best, all the average removal efficiencies of algae, CODMn, NH4+-N, turbidity, chromaticity can reach 82%, while whose operation expenditure is higher than any others, so it should be considered comprehensively in the practice.