[Improvement of the Dewaterability of Excess Activated Sludge with Mixed Yeasts by Degrading Extracellular Polymeric Substances].

The dewaterability of excess sludge directly affects the efficiency and cost of sludge disposal, and improving sludge dewaterability is a crucial way to reduce sludge volume. This study proposes a method to improve the dewaterability of residual sludge by using mixed yeast strains to degrade extracellular polymeric substances (EPS) in activated sludge. Firstly, the mixed cells of three yeast strains were injected into the sterilized EPS solution to investigate the degradation efficiency of EPS components.

Optimum Matching Model Using Long-Term Computing on Safer Rural Domestic Water Supply Based on Rainwater Harvesting.

A safe rural domestic water supply project has been initiated based on different consumption uses. Long-term computation method and the water balance principle are used to analyze the yearly water demand. Water supply and demand balance is achieved through regulated planning of the rainwater collection surface area and water storage capacity.

Dynamic seesaw model for rapid signaling responses in eukaryotic chemotaxis.

Directed movement of eukaryotic cells toward spatiotemporally varied chemotactic stimuli enables rapid intracellular signaling responses. While macroscopic cellular manifestation is shaped by balancing external stimuli strength with finite internal delays, the organizing principles of the underlying molecular mechanisms remain to be clarified. Here, we developed a novel modeling framework based on a simple seesaw mechanism to elucidate how cells repeatedly reverse polarity.

[Effect of SRT on Stability of Yeast-SBR in Treating Oil-containing Wastewater].

Sludge retention time(SRT) is a crucial parameter to influence the stability of biological wastewater treatment systems. Especially, the effects of SRT on yeast-wastewater treatment remain unclear. In this study, mixtures of yeast strains were applied to treat oil-containing wastewater in sequencing batch reactors(SBR) and the effects of sludge retention time(SRT as 5, 10, 20, 40 d) on the removal efficiency of pollutants, contents and composition of extracellular polymeric substances(EPS), yeast cells settleability and yeast communities were investigated.

[Fertility and Environmental Impacts of Urban Scattered Human Feces Used as Organic Granular Fertilizer for Leaf Vegetables].

The disposal of urban scattered human feces has become a difficult problem for the management of modern city. In present study, the scattered human feces underwent the collection, scum removal, flocculation and dehydration, finally became the granular fertilizer; the effects of the ratio of fertilizer to soil on the growth of the pakchoi and the quality of soil and leaching water were evaluated, and the feasibility of granular fertilizer manuring the pakchoi was discussed by pot experiments. The results showed that the granular fertilizer significantly enhanced the production of the pakchoi which were not polluted by the intestinal microorganisms under the experiment conditions; meanwhile, at the proper ratio of fertilizer to soil, the concentration of these microorganisms in the leaching water was lower than that in the control check.

[Efficiency and yeast community structure of oil-containing treatment system inoculated by different yeast strains complex wastewater].

Ten yeast stains were grouped and applied in pilot-scale sequencing batch reactors to treat oil-containing wastewater. The efficiency and stability of different reactors were discussed and yeast community structure was investigated by PCR-DGGE method. The results show: the group consisting of O2, G1 and W1 is markedly superior to others in efficiency and stability respects; the group absence of these 3 stains fails to form a system with high efficiency and good stability; O4 and G2 strains lead to turbid supernatant fluid and are eliminated from system step by step; the distribution of yeast cells in settlement sludge varies with different stains.

[Treatment of oil-manufacturing wastewater by yeast-SBR system].

Eight yeast strains were applied to a sequencing batch reactor (SBR) to treat high-strength oil-containing wastewater. The removal performance, yeast cultivation method and key factors affecting the stability of system were discussed. The results show yeast sludge with MLSS of 19 g/L and SVI of 35 mL/g can be obtained in 6 d in an open system without any molds and bacteria inhibitor addition; In 30 d continuous wastewater treatment, COD and oil removal rate achieve 86.

[Effects of nitrogen on performance and yeast morphology of yeast-SBR system].

Effects of nitrogen on yeast cell morphology, settleability and performance of wastewater treatment were investigated in treating oil-containing wastewater by yeast-SBR system. The results show that: nitrogen supply affects directly yeast biomass, settleability, pH and treatment efficiency of system; the absence of nitrogen induces the transformation of certain yeast cells from single cell to hypha morphology. Based on an overall consideration of efficiency and stability of yeast-SBR system, the optimum BOD/N ratio of influent is 20/1.

[Inactivation of T4 phage in water environment using proteinase].

The inactivation effectiveness of proteinase to viruses was investigated by using T4 phage as a model virus. The results showed that the inactivation effectiveness of proteinase to T4 phage was obvious. In the optimum conditions and 67.