关键词： 污水处理   节能减排   生物膜反应器   厌氧氨氧化技术   深度除磷技术  

摘要： 污水处理作为水资源循环利用和环境保护的关键环节,其过程中的能源消耗和污染物排放问题日益凸显。传统污水处理方式不仅消耗大量水资源和能源,还可能在处理过程中产生二次污染,对环境造成进一步伤害。因此,本篇文章较为详细的分析了污水处理过程中节能减排技术应用,旨在优化污水处理流程,降低能源消耗和污染物排放。

关键词： 油田污水处理   油田化学剂   杀菌剂   缓蚀剂  

摘要： 随着国家提出“碳中和、碳达峰”的战略目标,石油开采中产生的污水废水受到更多人的关注。油田污水处理中可应用油田化学剂,获得更高效的处理效果,降低污水对管道和设备的腐蚀和损害,确保对油田污水得到有效地处理,达到国家准排标准,避免造成严重的生态环境污染问题。本文将围绕油田污水处理中油田化学剂的应用进行深入研究,分析油田化学剂的作用,并针对常见的油田化学剂进行分析阐述,借助案例分析油田化学剂的实际应用效果。

关键词： 污水处理   污水再利用   生态处理   MBR处理技术  

摘要： 面对国内水资源短缺、水资源分布不均的问题,城市污水处理和污水资源再利用技术成为解决水资源短缺和环境保护的重要手段。本文结合行业情况,探讨城市污水处理的主要工艺及污水再利用方面的技术应用。介绍传统的物理化学处理方法(化学絮凝沉淀技术),其在去除悬浮物、有机物和重金属离子方面的高效性;讨论了现代生物处理技术,如膜生物反应器和电渗析复合膜分离技术,这些技术在提高出水水质和减少占地面积方面表现出显著优势,通过具体案例分析,展示了化学絮凝沉淀与生物絮凝沉淀联用技术在提高污水深度处理效果和实现再生水回用方面的应用。研究表明,通过综合运用多种污水处理技术,可以有效提高污水的处理效率和再利用水平,为城市可持续发展提供技术支持。

关键词： 水利工程   污水处理   设备设计   运行管理   优化措施  

摘要： 本文以水利工程污水处理问题为研究对象,通过对污水处理设施设计要点和运行状态进行分析,来探讨其性能的改进方法。首先,从工艺流程、设备选型、自动控制系统设计等方面详细阐述了污水处理设施的设计原则和方法。其次,对污水处理运行环节,进行了日常运行管理、设备维护保养、故障处理等方面的深入探讨。通过分析运行数据和处理结果,发现影响污水处理效率的关键因素,提出了一系列运行优化措施。最后指出,只有通过合理的设计和严谨的运行管理,污水处理过程才能实现优质、高效的运行,从而更好地保护水源,服务于水利工程的整体目标。

关键词： 改性碳纳米材料   污水处理   吸附机制  

摘要： 随着工业化进程的加快和人口规模的持续扩大,水污染问题日益严峻,尤其是有机污染物和重金属离子对水环境的危害愈加突出。作为传统的污水处理材料,活性炭、絮凝剂等存在处理效率低、重复使用率低、处理成本高等问题,因此开发高效、低成本的水处理材料成为研究重点。碳纳米材料具有优异的物理化学性质,如高比表面积、良好的化学稳定性和可调节的表面功能性,成为污水处理领域的研究热点。对碳纳米材料进行表面改性,可以显著提升其对污染物的吸附能力,其在去除有机污染物和重金属离子方面表现出色。研究表明,改性碳纳米材料为高效、绿色的污水处理提供重要的技术支持,具有广阔的应用前景。

关键词： VFA   ATP   Co-catabolism   Metabolic flux analysis   PHB  

摘要： This study quantifies metabolic features of engineered Yarrowia lipolytica strains for converting volatile fatty acids (VFAs) into poly-3-hydroxybutyrate (PHB) via C-13-metabolic flux analysis and RNA-Seq. Yarrowia lipolytica is unable to grow with C4 similar to C6 VFAs due to substrate toxicity, while propionate (C3) metabolism leads to slow growth and minimal PHB production due to enzymatic limitations in substrate assimilation pathways. Acetate is a viable but challenging VFA feedstock. Comparing to glucose, acetate catabolism results in low ATP/ADP ratios, high enzyme usage, substantial CO2 release (>50 % of input carbon), and limited NADPH. Several strategies may overcome these roadblocks: 1) glucose-VFA co-catabolism improves energy charge, alleviates metabolic imbalances, reduces flux rigidity, and lowers the enzyme expression burden;2) overexpressing acetyl-CoA synthetase and nitrogen limitation increase acetate uptake and PHB synthesis during glucose-acetate co-utilization;and 3) repression of oxidase facilitates fluxes towards PHB synthesis. The results provide insights into efficient utilization of acetate as feedstock.

关键词： micro/nanofibrous scaffolds   centrifugal spinning technology   tissue engineering   PLA   PHB   PCL   PBS   bioartificial adipose tissue   hierarchical inner porosity of fibers   mesenchymal stem cells  

摘要： We compared the applicability of 3D fibrous scaffolds, produced by our patented centrifugal spinning technology, in soft tissue engineering. The scaffolds were prepared from four different biocompatible and biodegradable thermoplastics, namely, polylactide (PLA), polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), and poly(1,4-butylene succinate) (PBS) and their blends. The combined results of SEM and BET analyses revealed an internal hierarchically organized porosity of the polymeric micro/nanofibers. Both nanoporosity and capillary effect are crucial for the water retention capacity of scaffolds designed for tissue engineering. The increased surface area provided by nanoporosity enhances water retention, while the capillary effect facilitates the movement of water and nutrients within the scaffolds. When the scaffolds were seeded with adipose-derived stem cells (ASCs), the ingrowth of these cells was the deepest in the PLA/PCL 13.5/4 (w/w) composite scaffolds. This result is consistent with the relatively large pore size in the fibrous networks, the high internal porosity, and the large specific surface area found in these scaffolds, which may therefore be best suited as a component of adipose tissue substitutes that could reduce postoperative tissue atrophy. Adipose tissue constructs produced in this way could be used in the future instead of conventional fat grafts, for example, in breast reconstruction following cancer ablation.

关键词： Azotobacter   molecular weight   phasins   PHB  

摘要： BackgroundPoly(3-hydroxybutyrate) (P3HB) is a polymer that presents properties similar to those of conventional plastics. The objective of the present study was to evaluate the influence of oxygen transfer rate (OTR) on the production and molecular weight of P3HB synthesized by the OP-PhbP2- and OP-PhbP3+ mutant strains of Azotobacter vinelandii, which have inactivated the gene that expresses the PhbP2 phasin and overexpresses the PhbP3 phasin genes, *** high OTRmax (6.0 +/- 0.04 mmol O2 L-1 h-1) mutant OP-PhbP3+ exhibited a higher growth rate (0.12 +/- 0.01 h-1) and P3HB production (6.77 +/- 0.19 g L-1) than that achieved in the cultures using the OP-PhbP2- mutant and OP wild-type strains (5.0 +/- 0.1 g L-1 for both strains). Under that condition, the OP-PhbP3+ strain also exhibited a lower specific oxygen consumption rate. In contrast, under a low OTRmax (2.8 +/- 0.06 mmol O2 L-1 h-1), the OP-PhbP2- strain had a better performance, reaching 4.5 +/- 0.35 g L-1 of P3HB, during the stationary phase (36-72 h). Both mutant strains produced a polymer with a high molecular weight (close to 8000 kDa), regardless of the OTR of the cultures, which remained constant throughout the fermentation. In contrast, the molecular weight produced by the OP strain was in the range 5500 to 6700 kDa under the two conditions ***, our results revealed the biotechnological potential of using modified strains, which overexpress PhbP3 phasin or have inactivated the gene that expresses the PhbP2 phasin, for the production of P3HB, affording a higher molecular weight than that produced by the OP strain. (c) 2024 Society of Chemical Industry (SCI).

关键词： alternative substrates   bioplastics   PHB   polyhydroxyalkanoates   vegetable oils  

摘要： The use of polyhydroxybutyrate (PHB) can help diminish fossil chemical dependency because it can partially replace petrochemical plastics due to its biodegradability and similar mechanical properties. However, its production costs are high compared with fossil-based plastics. Alternative carbon sources can be used in the fermentation media because they are renewable and low-cost. Vegetable oils are especially attractive due to their high carbon content, contributing to high production rates per gram of substrate. This work aimed to produce PHB from Cupriavidus necator LPB1421 using either corn or soybean oil as the sole carbon source. Urea was the best nitrogen source, enabling a DCW production of 4.35 g/L (corn oil) and 10.4 g/L (soybean oil). After media optimization, the DCW of corn oil reached 22.13 g/L, with 57.46% PHB accumulation (12.71 g PHB/L), whereas soybean oil led to a DCW of 19.83 g/L, with 54.91% PHB accumulation (10.89 g PHB/L). This media composition was employed in a kinetics assay, revealing similar fermentation parameters among both oils and a yield of 0.2118 g PHB/g for corn oil and 0.1815 g PHB/g for soybean oil. These results open the possibility of integrating PHB production with biofuel manufacturing in a bioethanol/biodiesel biorefinery concept.

关键词： bioremediation   reductive dechlorination   adsorption   polyhydroxyalkanoates   biochar   dehalococcoides  

摘要： Actions for improving water quality are critical and include the remediation of polluted groundwater. The effectiveness of the remediation strategy to remove contamination by chlorinated solvents may be increased by combining physicochemical treatments (i.e., adsorption) and biological degradation (i.e., biological reductive dechlorination (BRD)). Recent studies have shown the potentialities of bio-based materials for bioremediation purposes, including polyhydroxybutyrate (PHB), a biodegradable microbial polyester tested as a fermentable source of slow-release electron donors. Further, a low-cost biochar derived from the pyrolysis of pinewood waste (PWB), used as sorbent material, has recently been proposed to accelerate reductive microbial dehalogenation. Here, we propose a coupled adsorption and biodegradation (CAB) process for trichloroethylene (TCE) removal in a mini pilot-scale reactor composed of two reactive zones, the first one filled with PHB and the second one with PWB. This work aimed to evaluate the performance of the CAB process with particular regard to the effectiveness of the PWB in sustaining the biofilm, mostly enriched by Dehalococcoides mccartyi. The main results showed the CAB system treated around 1300 L of contaminated water, removing 102 mg TCE per day. Combining PHB and PWB had a positive effect on the growth of the dechlorinating community with a high abundance of Dhc cells.