串联氧化塘中氮、磷去除的容积分配效应的研究

在人工模拟条件下,串联厌氧 好氧塘在总容积相同,不同的容积分配的情况下,污水中的氮、磷去除效率不同,存在最佳容积分配比：V_厌/V_总约为0.27。在最佳容积分配比处,COD、氮、磷的去除率可分别提高11.4％、26.0％、51.6％。随着负荷、污水C/N比、温度、光照时间等因素的变化,氮磷去除呈一定的变化规律。说明了串联厌氧 好氧塘氮、磷去除的容积分配效应是客观存在的,合理的容积分配对氮、磷去除尤其重要     

Effects of La3+, Ce3+ on nitrogen removal in sequencing batch reactor

Batch experiments were conducted to study the short-term biological effects of rare earth ions (La³⁺, Ce³⁺) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH₄ ⁺-N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1 mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH₄ ⁺-N removal efficiency by 15.7% and 10%–15%, respectively. When the concentrations of REEs were higher than 1 mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0 mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.     

Extruded Cornstarch-Glycerol-Polyvinyl Alcohol Blends: Mechanical Properties, Morphology, and Biodegradability

Elongation properties of extruded cornstarch were improved by blending with glycerol. Further blending of starch-glycerol with polyvinyl alcohol (PVOH) resulted in significant improvements in both tensile strength (TS) and elongation at break. Samples of starch-glycerol without PVOH equilibrated at 50% relative humidity had a TS of 1.8 MPa and elongation of 113%, whereas those containing PVOH had a TS and elongation of 4 MPa and 150%, respectively. Dynamic mechanical analysis (DMA) of starch-glycerol-PVOH blends showed that decreases in glass transition temperatures (T _g values) were proportional to glycerol content. Scanning electron microscopy (SEM) of fractured surfaces revealed numerous cracks in starch-glycerol (80:20) samples. Cracks were absent in starch-glycerol (70:30) samples. In both blends, many starch granules were exposed at the surface. No exposed starch granules were visible in blends with added PVOH. Starch-glycerol samples incubated in compost lost up to 70% of their dry weight within 22 days. Addition of PVOH lowered both the rate and extent of biodegradation.     

指数施肥对杉木苗期基质中微生物功能多样性的影响

为向轻型基质容器苗合理施肥,实现苗木养分精准调控提供理论依据,以杉木优良无性系"洋061"轻型基质容器苗为研究对象,设置7个施氮处理[对照(CK,0 mg/株)、常规集中施肥处理(CF1,40 mg/株)、常规分次施肥处理(CF,240 mg/株)、指数施肥(EF1,40 mg/株;EF2,80 mg/株;EF3,12...     

组合菌株固态发酵鱼粉废液和豆粕工艺研究

鱼粉废液中富含蛋白、多肽等多种成分,豆粕是一种优质的植物蛋白源。为了实现蛋白资源的回收和高效利用,对鱼粉废液和豆粕混合物进行微生物固态发酵的工艺研究。实验以可溶性多肽和胰蛋白酶抑制因子(TI)含量作为检测指标,确定了最优发酵条件,即纳豆芽孢杆菌和植物乳酸杆菌复合配比2∶1,接种量6%,豆粕与鱼粉废液浓缩液比(w/v)1∶0.8,起始温度35℃,发酵时间48 h。该条件下发酵产物中的可溶性多肽含量增至22.64%,TI降至1.38 mg/g,益生菌数量达11.6×109CFU/g。通过对比发酵原料和终产物,表明鱼粉废液和豆粕经微生物复合发酵后,品质得到明显改善。     

华南地区春季冷锋云系中污染物的输送

研究了华南春季冷锋云系中污染物的三维输送和酸沉降特点.该地区低空经常存在一个稳定的逆温层结构,且混合层顶也较低,有利于污染物在层内聚集.冷锋南下时,锋前上升气流把原稳定层中的污染物抬升并送入云内,形成“逆温层内累积——被锋面抬升——高空平流输送——湿沉降到地面”的循环.一个地方排放的污染物可以造成其周围几百公里范围内云和降水的酸化.轨迹烟团模式计算的结果也表明,即使在冷锋的北来气流作用下,本地源的影响仍是主要的.     

Research on buildings impacting on aerosol diffusing in urban area using remote sensing

Employing remote sensing method to interpret the building volumetric ratio and aerosol status in Guangzhou, China. The relation between them and identified characteristics of their spatial distribution was analyzed. Results showed that building density and aerosol status are strongly correlated. It is indicated that the resistance of building to aerosol diffusing is one of factors influencing air pollution in urban area. On the basis of calculated results, building voluminous ratio of 5.6 is taken as the threshold impacting on aerosol diffusing, so the buildina voluminous ratio of Guanazhou should be limited to less than 5.6 in order to alleviate air pollution.     

废水营养比对固定化藻菌去除污染物的影响及动力学研究

海藻酸钙作载体的固定化藻菌小球,经壳聚糖覆膜后,用于模拟废水的处理。通过研究废水初始氨氮浓度及碳氮比对固定化藻菌小球处理效果的影响,发现初始氨氮浓度为50 mg/L时,氨氮的去除率达最高值74.4%;碳氮比为35∶1时,COD去除率达最高值77.7%。系统最佳氮磷比与碳氮比分别为5∶1和35∶1。固定化藻菌降解有机物的动力学过程为一级不可逆生化反应过程,其降解速率常数约为0.099 h-1。     

多目标决策方法在防台风中的应用

提出了一种基于不确定信息和蒙特卡罗模拟的多目标决策方法,在投入一定的情况下,选取最合适的台风防灾减灾措施.该方法允许决策者对不同属性指标给出相应的效用函数和属性权重区间值,通过随机选取权重值和效用函数区间内的值相乘得出结果,并使用蒙特卡罗模拟技术对结果进行了敏感性分析.最后,以浙江省台风灾害防灾减灾措施的比较为例,详细讨论了该方法的应用.