以溶解氧浓度作为SBR法模糊控制参数

采用ＳＢＲ法处理石油化工废水,根据反应器内有机物降解与溶解氧浓度（ＤＯ０的相关性,提出了以ＤＯ作为ＳＢＲ法的模糊控制参数。通过大量试验,总结出反应实始阶段（８￣１０ｍｉｎ）溶解氧浓度不仅能够间接地反映进水有机物浓度（ＣＯＤ０,而且对整个反应过程都有重要影响。溶解氧的高低主要受曝气量大小控制,因此可根据初邕阶段溶解氧的浓度及变化情况预测进水有机物浓度,进而实现对曝气量的模糊控制。同时,还发现当有机物     

Optimization of polyhydroxybutyrate (PHB) production by excess activated sludge and microbial community analysis

In this study, a high value-added and biodegradable thermoplastic, polyhydroxybutyrate (PHB), was produced by excess activated sludge. The effects of the nutritional condition, aeration mode, sodium acetate concentration and initial pH value on PHB accumulation in the activated sludge were investigated. The maximum PHB content and PHB yield of 67.0% (dry cell weight) and 0.740gCODgCOD(-1) (COD: chemical oxygen demand), respectively, were attained by the sludge in the presence of 6.0gL(-1) sodium acetate, with an initial pH value of 7.0 and intermittent aeration. The analysis of the polymerase chain reaction (PCR)-denaturing gradient-gel-electrophoresis (DGGE) sequencing indicated that the microbial community of the sludge was significantly different during the process of PHB accumulation. Three PHB-accumulating microorganisms, which were affiliated with the Thauera, Dechloromonas and Competibacter lineages, were found in the excess activated sludge under different operating conditions for PHB accumulation.     

Applications of photosynthetic bacteria for medical fields

The medical applications of photosynthetic bacteria are summarized. Photosynthetic bacteria can produce various types of physiological active substance such as vitamin B(12), ubiquinone (coenzyme Q10), 5-aminolevulinic acid (ALA), porphyrins and RNA. In particular, photosynthetic bacterial ALA was commercially applied to cancer diagnosis and treatment. Recently, ALA has been applied to the treatment of acne vulgaris and the suppression of the inflammatory response to coronary and iliac injuries. In addition, the recent applications of RNA from a marine photosynthetic bacterium as a medical supplement for immune improvement and suppression of infection are described. Furthermore, the feasible application of a biopolymer consisting of RNA from a photosynthetic bacterium as a drug delivery system (DDS) to cancer treatment is described.     

搅拌与溶氧对黄原胶发酵的影响

黄原胶是由黄单胞菌分泌的一种胞外酸性杂多糖，几十年来国内外许多学者对黄原胶的生物合成机理、黄胶产生菌的生理生化特性及其发酵工艺等方面进行了较系统的研究。西方综述了利用机械式生物反应器发酵生产黄原胶时，搅拌转速与溶氧对黄原胶发酵过程中的各种参数的控制以及黄原胶质量的影响。     

有机阴离子和溶解氧对稳定纳米铁去除水中铬(Ⅵ)的影响

以硼氢化钾为还原剂,壳聚糖为稳定剂制备纳米零价铁,研究有机阴离子(柠檬酸根、草酸根和乙二胺四乙酸根)和溶解氧对壳聚糖稳定纳米铁去除Cr(Ⅵ)的影响,并探讨其影响机理.结果表明,5.357 mmol·L-1的铁与0.769mmol·L-1的Cr(Ⅵ)反应80 min后,在有机阴离子浓度为4mmol·L-1时,柠檬酸根和草...     

神经网络PID在APMP废水处理中的应用

针对APMP废水处理过程存在严重非线性、大时滞等控制难点,提出了基于神经网络PID的APMP废水处理控制方案.     

DCS设计中DI／DO的有关问题探讨

对ＤＣＳ设计中ＤＩ／ＤＯ卡件的选用、ＤＩ／ＤＯ的隔离型式、接点型式及有关接线和供电等问题进行了较详细的描述，且发表了建设性见解。     

Experimental simulation of biodegradation in rivers: Oxygen, organic matter and biomass concentration changes

Dissolved oxygen (DO) and biochemical oxygen demand (BOD) concentration changes after an organic matter discharge into a river have been studied in the absence of oxygen transfer. According to these laboratory experiments, biodegradation of various organic compounds (glucose, glutamic acid, starch, ovalbumin and ethanol) in Seine river samples incubated at 15 30°C follow a biphasic behaviour. During a lag-phase of 10–20 h, DO decreases linearly (0.12 ppm h⁻¹ at 20°C), whereas BOD is constant. During a subsequent aerobic exponential phase, DO and BOD uptake are proportional and increase exponentially with time (0.13 h⁻¹ at 20°C). Using cell ATP as biomass indicator, the latter phase was shown to correspond to a cell division step. A kinetic model was developed for stimulating DO and BOD concentration changes after a waste water discharge at temperatures ranging between 15 and 30°C.     

MBR处理垃圾渗滤液的短程硝化研究

研究了膜生物反应器处理垃圾渗滤液的现象及机理,研究表明,反应器内存在较好的短程硝化效果。考察了DO、Ph、C/N等对有机物和氨的去除效果以及对同步硝化反硝化的影响。试验结果表明,在pH值为7.0～8.5,温度为25℃,DO为0.75 mg/L的条件下,短程效果最好,亚硝态氮的积累稳定在90%左右,氨氮去除率可达95%以上,但总氮去除率仅有50%,其原因是碳源不足。