Efficient degradation of lube oil by a mixed bacterial consortium

A laboratory study was performed to assess the biodegradation of lube oil in bio-reactor with 304# stainless steel as a biofilm carrier. Among 164 oil degrading bacterial cultures isolated from oil contaminated soil samples, Commaonas acidovorans Px1, Bacillus sp. Px2, Pseudomonas sp. Px3 were selected to prepare a mixed consortium for the study based on the efficiency of lube oil utilization. The percentage of oil degraded by the mixed bacterial consortium decreased slightly from 99% to 97.2% as the concentration of lube oil was increased from 2000 to 10,000 mg/L. The degradation of TDOC (total dissolved organic carbon) showed a similar tendency compared with lube oil removal, which indicated that the intermediates in degradation process hardly accumulated. Selected mixed bacterial consortium showed their edge compared to activated sludge. Scanning electron microscopy (SEM) photos showed that biofilms on stainless steel were robust and with a dimensional framework constructed by EPS (extracellular polymeric substances), which could promote the biodegradation of hydrocarbons. The increase of biofilm followed first-order kinetics with rate of 0.216 μg glucose/(cm2·day) in logarithm phase. With analysis of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC-MS) combined with removal of lube oil and TDOC, mixed bacterial consortium could degrade benzene and its derivatives, aromatic ring organic matters with a percentage over 97%.     

Physical conditions for trapping air by a microtrichia-covered insect cuticle during temporary submersion

The intertidal midge Clunio, which reproduces on exposed rocky seashores, becomes enclosed in an irregularly shaped air bubble during short submersion by incoming waves. This water-repellent property of Clunio’s cuticle is caused by a complete cover of hydrophobic microtrichia offering an effective surf tolerance. These microtrichia not only trap a thin air layer above the cuticle but also maintain a larger air bubble between the insect’s ventral side and legs. The effectiveness of the water repellence was quantitatively characterised on the basis of a known model (Crisp and Thorpe, Discuss Faraday Soc 3:210–220, 1948). The parameters of the model are the contact angle θ (>90°) at the contact line of air/water/microtrichia and the distance between individual microtrichia and their radius. When the microtrichia are 1.1 μm apart and have a radius of 0.1 μm and an estimated contact angle θ of 140°, the air layer is stable against hydrostatic pressures of up to 3 m water column. As shown by a modified version of the model, considerably larger air bubbles can be trapped by the microtrichia cover of the legs up to distances of 0.5 mm from the body. The widely spaced (about 8 μm apart) and longer setae of Clunio are not involved in the formation of air layers and air bubble.     

Influence of the wastewater composition on denitrification and biological P-removal in the S-DN-P process： （c） Dissolved and undissolved substrates

The denitrification and P-removal in the sorption-denitrification-P-removal (S-DN-P) process were carried out under various wastewater compositions. It is noted that P-removal largely depends on the wastewater composition as well to the quantity of the substrates present in wastewater fraction. Three different wastewater fractions are obtained as: raw wastewater, dissolved wastewater (obtained with filtration using 0.45 μm filter), and undissolved wastewater (i.e., infiltrate obtained by above filtration). ...     

上流式多级厌氧反应器（UMAR）处理木薯淀粉废水的研究

对自行研制的上流式多级厌氧反应器（UMAR）处理木薯淀粉废水的启动和运行特性进行了研究.结果表明,UMAR反应器启动周期短,易培养出活性高的颗粒污泥,经过40 d的运行,COD去除率可达84%,VSS/TSS由78%增加到90.4%.UMAR处理效率高,水力停留时间（HRT）为4 h,进水COD为6 250 mg/L,容积负荷为24 kg/(m³·d)时, COD去除率在75%以上.UMAR反应器对负荷提高、低pH冲击、进水水质的改变表现出良好的耐受能力.     

火电厂烟气脱硝工艺设计

NOX作为一种致命的环境污染物,是引起温室效应和光化学反应、酸雨产生的重要危害物质之一。NOX最主要排放源就是火电厂。由于传统火电厂的低氮燃烧技术已无法满足氮氧化物的排放标准。在此情况下,烟气选择性催化还原技术（Selective Catalyst Reduction,简称SCR）诞生了,这项工艺的发明有效地降低电厂氮氧化物对环境所带来的负面影响。     

复合式厌氧氨氧化反应器脱氮性能研究

采用低速机械搅拌装置,以无纺布作为固定床的填料,把搅拌床与固定床的优点有机结合起来,设计一种复合式厌氧氨氧化反应器.在反应器中,生物滞留量相对较高,微生物的性状由接种时的碎絮状很快转变成颗粒状,短期内反应器系统的脱氮性能迅速提高,启动时间大为缩短.仅用38d,反应器中总氮去除速率稳定增长至1.9kg·m·-3d-1.随...     

流化床厌氧反应器流化及反应特性研究

对流化床厌氧反应器的流化及反应特性进行研究,结果显示:床层实际初始流化流速umf为0.138～0.154cm/min,与理论计算值0.143 cm/min一致;在一定范围内,流速增大有利于反应量的提高,当流速为0.414 cm/min时,单位时间内的反应量达到最大,其值为4.66 mg/(L·min);适当提高流速有利...     

好氧及厌氧/好氧序批式工艺中磷化氢的释放

采用二次冷阱富集-气相色谱法作为磷化氢的检测方法,以高纯氮吹脱取样的方式,对好氧序批式工艺及厌氧/好氧序批式工艺中磷化氢的存在及其在工艺中的变化规律进行了研究。结果表明,两种工艺中均检测到磷化氢的存在。好氧序批式工艺中,磷化氢呈递减趋势,运行后期可间断性的检测到低水平（〈0.4 ng/L）磷化氢。厌氧/好氧序批式工艺中...     

IC＋A/O＋BIOFOR处理高浓度有机废水工程实例

江西某生物化工有限公司在生产乳酸的过程中产生大量高浓度有机废水,采用IC＋A/O＋BIOFOR联合工艺进行处理。当进水ρ（COD）平均为5 483 mg/L,ρ（NH3-N）平均为97.83 mg/L时,出水ρ（COD）平均为84 mg/L,去除率达98%;出水ρ（NH3-N）平均为12.07 mg/L,去除率为88%...     

Inhibition and recovery of nitrification in treating real coal gasification wastewater with moving bed biofilm reactor

Moving bed biofilm reactor (MBBR) was used to treat real coal gasification wastewater. Nitrification of the MBBR was inhibited almost completely during start-up period. Sudden increase of influent total NH3 concentration was the main factor inducing nitrification inhibition. Increasing DO concentration in the bulk liquid (from 2 to 3 mg/L) had little e ect on nitrification recovery. Nitrification of the MBBR recovered partially by the addition of nitrifying sludge into the reactor and almost ceased within 5 days. Nitrification ratio of the MBBR achieved 65% within 12 days by increasing dilute ratio of the influent wastewater with tap water. The ratio of nitrification decreased to 25% when influent COD concentration increased from 650 to 1000 mg/L after nitrification recovery and recovered 70% for another 4 days.