Advanced Materials Research Vols. 455-456

Abstract: The dynamic membrane reactor (DMBR) combined the advantages of both microbial reactor and dynamic membrane, and it’s a new municipal wastewater treatment technology. This paper summarized the technical processes, mechanisms, characteristics and application of DMBR, and the future research aspects of DMBR is also included.

Abstract: Recently, with the developing of new techniques, more new techniques has been used in the area of soil heavy metals monitoring. This paper reviewed the methods utilized in determination of total mass and morphology analysis of soil heavy metals, summarized the current research progress on soil heavy metals and pointed out the weak points of recent works. The article also forecasted the developing tendency of the methods of determination of total mass and morphology analysis of soil heavy metals.

Abstract: To reveal the relationship between nutrient input and red tide outbreaks, the effects of N/P atomic ratio on the specific growth rate of Alexandrium tamarense is analyzed under various initial phosphate concentrations in laboratory cultures. The results show that both the cell density and the specific growth rate of A.tamarense first increased when the N/P atomic ratio ≤ (N/P)_opt and then decreased when the N/P atomic ratio ≥ (N/P)_opt in low-P-grown cultures, followed by those in medium-P-grown and high-P-grown cultures. And the highest cell density in low-P-grown, medium-P-grown, and high-P-grown cultures is 1776×10⁴, 4094×10⁴ and 6891×10⁴ cells/L, respectively. The maximum specific growth rate is 4.022, 5.307 and 9.672 d^-1, respectively. It seems that the higher the initial phosphate concentrations, the greater the probability of red tide outbreaks.

Abstract: The microbiological structure characteristic and the particle diameter distribution of different sludges (aerobic excess sludge, sludge from sanitary landfill digested for one year, and granular sludge of pilot-scale expanded granular sludge bed (EGSB) reactor after 400 d of operation) were analyzed through scanning electron microscopy (SEM), transmission electron microscopy (TEM) and sieve. SEM of granules showed that the microbiological structure of the sludge from different sources had differences. But TEM proved that granules of EGSB and landfill both had similar kind of bacterial species i.e. Methanosarcina bacteri sp. There were obvious differences in the transformation trend of size distribution between different granular sludges. Three-step Model for the anaerobic granular sludge formation in sanitary landfill was put forward.

Abstract: Runoff and soil losses from earthen hillside roads are a serious problem on the Loess Plateau in China. Indoor rainfall simulation was employed to investigate hydrodynamic characteristics of runoff water, and runoff-yielding and sediment-yielding processes on earth-road surfaces with different coverage degrees of herbaceous plants. The results indicated that on the road surfaces the Froude numbers and Reynolds Numbers of runoff fell into the category of supercritical flow of laminar flow and both of them decreased like the flow velocities and unit energy of water-carrying section with the coverage degrees of herbaceous plants increased. The Manning and Darcy-weisbach friction coefficients increased with the coverage degrees of herbaceous plants increased. On the earth-road surfaces with the different coverage degrees, runoff rates initially sharply increased and then stabilized with time and both following an offset hyperbola. With the coverage degrees increased, the infiltration rates of water into the earth roads gradually increased, but the runoff rates, sediment yield rates and sediment concentration all gradually decreased. The results revealed that on the earth-road surface herbaceous plants could play a favorable role in soil and water conservation and provided a theoretical basis for understanding the relations between herbaceous plants and soil erosion.

Abstract: Four common subtropical understory sun plants from South China, i.e., Euodia lepta (Spreng.)Merr. (EL), Ilex asprella Champ. (IA), Mussaenda pubescens Ait.f. (MP), and Rhodomyrtus tomentosa (Ait.) Hassk. (RT), were sampled and determined for leaf Cu, Zn, Cd, and Pb concentrations, with an aim to investigate geographic variations in leaf heavy metal concentrations and phytoaccumulation. Significant differences were found among the 4 sampling sites for soil pH and heavy metal concentrations of Zn, Cd and Pb, with higher acidity in the 3 sampling sites from the Pearl River Delta industrial area. However, leaf pH did not vary significantly among the geographic populations of El and MP. For leaf heavy metal concentrations, significant variations were observed among the geographic populations of El for Cd; IA for Zn, Cd, and Pb; MP for Cu, Zn, Pb, and Cd; RT for Zn and Pb. The mean Biological Accumulation Coefficients (BACs) of IA for Zn, Cd, and Pb were as high as 10.38 for Zn, 18.29 for Cd, and 1.76 for Pb, respectively. Coefficient of Variation (CV) of BACs for heavy metals among different geographic populations of each species ranged from 41.99~221.83%, indicating high geographic variability in phytoaccumulation of heavy metals, and their accumulation capacity declined with the increase of soil heavy metal concentrations. This study revealed that some particular populations of IA can serve as potential hyperaccumulators for Zn and Cd, while those of MP and RT as hyperaccumulators for Pb, and the toxicity and safety of RT and IA should be further studied and assessed.

Abstract: With extremely complicated geological conditions, there is abundant coalbed methane in the China's Ordos Basin Area. As a result of coexistence of different pressure systems in the same one naked well section, there are so many problems taking place occasionally during the drilling process, such as the formation lost circulation and collapse, which require the drilling fluid with a perfect rheology behavior and inhibitive to improve the well-bore containment. The coalbed methane well completions are diverse, usually including vertical well, horizontal well, multi-branch well, and other different well types. So the drilling fluid must have cuttings carried effectively and protect formation damaged to ensure that the process of drilling is security and smooth. Lots of drilling methods are used in the coalbed methane drilling, besides normal nearly balanced drilling, the under balance drilling fluids such as the air, fog, foam, etc particularly improved. All this drilling fluids require itself working compatibility with other fluids in the hole. Therefore, the special state-funded science and technology project has developed a novel bionic Fuzzy-Ball drilling fluid to meet the coalbed methane. Without additional equipments, this novel drilling fluids can be made, with non-solid phase and low density, 0.8~1.0 g/cm³. The inert solids can also be used to adjust the property to more than 1.0g/cm³, matching the near/under-balanced drilling. The formation well-bore containment can effectively improve to meet to the more than 1000 meters coalbed methane drilling in the open or low pressure formation, To portable cuttings effectively under low rate, the ratio of yield point and plastic viscosity can be adjusted to 1.0Pa/mPa•s or more. Combined with the air drilling, this novel Fuzzy-Ball material could not be converted to fluid to solve the formation water production, cavings, completion and other operations. 10 wells application of using the Fuzzy-Ball drilling fluid to complete the coal bed methane wells overcoming water production, collapse, lost circulation and air drilling etc, taking five branches well FL-H2-L, "U" horizontal well DFS-02-H2, water production and collapse well J35, air drilling CLY22 for examples, are introduced to indicate the bionic Fuzzy-Ball fluid application on the coalbed methane drilling spot.

Abstract: Humic acid and protein are two major organic matter types encountered in natural and polluted environment, respectively. This study employed Triple Pulse Experiments (TPEs) to investigate and compare the influence of Suwannee River Humic Acid (SRHA) (model humic acid) and Bovine Serum Albumin (BSA) (model protein) on colloid deposition in a column packed with saturated iron oxide-coated quartz sand. Study results suggest that adsorbed SRHA may inhibit colloid deposition by occupying colloid sites on the porous medium. Conversely, BSA may promote colloid deposition by a ‘filter ripening’ mechanism. This study provides insight to understand the complex behavior of colloids in organic matter-presented aquifers and sand filters.

Abstract: Based on the development of elastic flexible filler, a new device for ship sewage treatment which utilizes the new elastic flexible filler was designed. The Main factors influencing the disposal efficiency of the device were researched and analyzed, using an Simulative ship sewage as raw wastewater. The experimental results reflected that the biofilm grew faster under the condition that the surface area of the elastic flexible filler was larger. The relationships among the microorganism growth period, characteristics of elastic flexible filler, biofilm thickness and characteristics of ship sewage were presented. Other factors which influenced the disposal effect were also discussed. The results showed that the device had excellent performance because of effective elastic flexible filler and integrative design.

Abstract: With the rapid development and versatile applications of nanotechnology, a large quantity of nanoparticles (NPs) has been released into the environment. It has been one of the most popular studies that concerning the toxic effect of NPs to the algae in aquatic ecosystem. The membrane integrity of algal cells was assessed using different methods when algae were treated by CuO NPs in the absence and presence of Suwannee river fulvic acid (SRFA), one of DOM. We found SRFA could increase the toxicity of CuO NPs to cell membrane due to the more stable NPs suspension in the presence of SRFA. Results additionally indicate that maybe oxidative damage caused by CuO NPs was the primary reason that led to membrane structure and function failed.