关键词： 生活污水   工业废水   处理工艺  

摘要： 本文围绕城市生活污水与工业废水处理工艺展开了深度剖析。从二者鲜明且复杂的特性为出发点,对多种处理工艺进行了细致入微的探讨。在阐述每种工艺原理的基础上,进一步深挖其在实际应用中的真实状况,既涵盖已获取的显著成果,也不回避现存的诸多问题。与此同时,针对处理工艺所面临的诸如成本高企、效率瓶颈等难题,以及智能化、绿色化等未来发展趋向,展开了全面研究。文中重点突出优化处理工艺对于环境保护的非凡意义,其与生态平衡和可持续发展息息相关。此外,特别针对城市生活污水和工业废水协同处理这一前沿方向,深入剖析了其潜藏的优势与面临的重重挑战。

关键词： 污水处理   固体废物处理   异味处理  

摘要： 在工业化进程的持续推进下,污水及固废处理行业的发展水平大幅提升,在其不断发展的过程中,所产生的臭气因具有破坏力强、覆盖面广、治理困难等特点,对相关企业的发展造成了影响,同时对生态环境也造成巨大威胁。文章聚焦污水及固废处理行业中臭气治理技术的应用,探究提高企业臭气治理效能的方法,包括燃烧法、活性炭吸附法、水洗涤法以及生物吸附法,以期为相关人员提供参考。

关键词： 污水处理   硝基苯类化合物   监测技术  

摘要： 硝基苯类化合物于污水处理进程中难以被有效清除,给生态环境带来了极大的威胁。本文以硝基苯的化学特性及其在污水处理里的行为特点为起点,深度探究了当下监测技术的适用范畴与存在的局限,涵盖高效液相色谱、气相色谱 - 质谱联用、电化学传感、综合监测等手段。同时,联系复杂的水质背景以及实际运用的需要,指明了技术应用的优化路径,例如增强检测的灵敏度、改良智能化监测系统以及达成经济与性能的平衡。通过剖析监测数据和治理成效的关联,探讨硝基苯污染治理的科学之道,以此提升硝基苯的监测水准,更优地开展污水治理工作。

关键词： 税务筹划   小微企业   税务风险   税务管理   提升竞争力   税收优惠政策   水污染问题   污水处理  

摘要： 城市化和工业化加速发展,我国城市用水需求不断增加,但水资源短缺和水污染问题日益严峻。污水处理行业作为环保事业的重要组成部分,近年来得到了快速发展。然而,污水处理小微企业在税务筹划方面面临诸多挑战,如何合理利用税收优惠政策优化税务管理,成为企业提升竞争力和实现可持续发展的关键。文章将从污水处理小微企业的税务筹划现状出发,分析其存在的税务风险,并提出具体的税务筹划策略。

关键词： hemp   extract   aging process   biodegradable polymers   aliphatic polyesters   degradation processes  

摘要： Biodegradable biopolymers like polyhydroxybutyrate (PHB) hold promise for sustainable packaging, but their inherent degradability reduces material stability. Synthetic stabilizers, though effective, raise environmental and potential toxicity concerns. This study explores a multifunctional natural anti-aging agent: a hemp extract rich in cannabidiol (CBD) and cannabichromene (CBC). PHB composites with varying hemp extract concentrations were prepared and subjected to thermooxidative and weathering aging. Characterization employed FTIR-ATR, carbonyl index, and spectrophotometry. Static mechanical properties, DSC, and surface free energy (SFE) were also assessed. Notably, the hemp extract exhibited stability under ambient conditions but showed migration with time and aging. The results suggest a plasticizing effect on PHB and highlight the contrasting roles of the extract: inhibiting thermooxidative aging while potentially accelerating aging under atmospheric conditions. This opens avenues for tailoring material durability, further evaluated by life cycle analysis (LCA). This work represents one of the first investigations into hemp extract as an anti-aging agent for eco-friendly polymers, expanding the knowledge base of natural multifunctional additives.

摘要： J-1040

关键词： PHA   PHB   Sorghum   Brown midrib   Lignin   Alkaline pretreatment liquor  

摘要： The aim of this work was to evaluate the use of stover from brown midrib (bmr) grain sorghum to produce polyhydroxyalkanoates (PHAs). These mutants produce lignin with novel compositions and/ or reduced lignin content that was hypothesized to result in higher PHA production than when using a wild-type sorghum stover. Five sorghum stover samples [wild-type (control) and four bmr mutants [bmr2, bmr6, and bmr12, and a double bmr mutant: bmr6 and bmr12 (stacked)] were evaluated as substrates for poly(3-hydroxybutyrate) (P(3HB)) production. When the main sugars in non-detoxified alkali-pretreated sorghum stover hydrolysates (SSHs) were metabolized by Paraburkholderia sacchari for P(3HB) production, the SSHs from bmr plants were demonstrated to be promising feedstocks with a maximum P(3HB) concentration of 7.2 g/L from the bmr6 SSH, while a maximum P(3HB) concentration of 4.2 g/L P(3HB) was produced using wild-type SSH. Moreover, the highest maximum Y-[P(3HB)/sugars] were achieved using stacked SSH and bmr12 SSH (0.44 g/g and 0.42 g/g, respectively). Furthermore, Cuprivadus necator was utilized to evaluate P(3HB) synthesis from the alkaline pretreated liquor (APL) remaining after sorghum stover pretreatment and an oxidative enzyme-mediator-surfactant system (OEMS) was used to improve P(3HB) production from the APLs. A 28-fold increase in PHB production from the bmr2-APL with OEMS compared to the fermentation of the same APL with no OEMS was observed. This is the first published report to use grain sorghum stover to produce polyhydroxyalkanoates (PHAs). Also, a novel combination of PHA production from both sugars and lignin is reported.

关键词： Polyhydroxybutyrate   Biodegradation   PHB depolymerase   Crystal structure   alpha/( hydrolase   Polymer-adsorption site  

摘要： Poly((R)-3-hydroxybutyrate) (PHB) is a microbial biopolymer widely used in commercial biodegradable plastics. PHB degradation in cell is catalyzed by PHB depolymerase (PhaZ), which hydrolyzes the polyester into mono- and/or oligomeric (R)-3-hydroxylbutyrates (3HB). A novel intracellular PhaZ from Bacillus thuringiensis (BtPhaZ) was identified for potential applications in polymer biodegradation and 3HB production. Herein, we present the crystal structure of BtPhaZ at 1.42-& Aring;resolution, making the first crystal structure for an intracellular PhaZ. BtPhaZ comprises a canonical alpha/( hydrolase catalytic domain and a unique alpha-helical cap domain. Despite lacking sequence similarity, BtPhaZ shares high structural homology with many alpha/( hydrolase members, exhibiting a similar active-site architecture. Alongside the most conserved superfamily signature, several new conserved signatures have been identified, contributing not only to the formations of the Ser-His-Asp catalytic triad and the oxyanion hole but also to the active-site conformation. The putative P-1 subsite appears to have limited space for accommodating only one 3HB-monomer, which may provide an explanation why the major hydrolytic product for BtPhaZ is monomeric form. Furthermore, a cluster of solvent-exposed hydrophobic residues in the helical cap domain forms an adsorption site for polymer-binding. Detailed structural comparisons reveal that various PhaZs employ distinct residues for the biopolymer-binding and hydrolysis.

关键词： bioplastic   bacteria biopolymers   bioeconomy   polyhydroxyalkanoates   PHA   biodegradable  

摘要： Polyhydroxybutyrate (PHB) is a biodegradable natural polymer produced by different prokaryotes as a valuable carbon and energy storage compound. Its biosynthesis pathway requires the sole expression of the phaCAB operon, although auxiliary genes play a role in controlling polymer accumulation, degradation, granule formation and stabilization. Due to its biodegradability, PHB is currently regarded as a promising alternative to synthetic plastics for industrial/biotechnological applications. Azohydromonas lata strain H1 has been reported to accumulate PHB by using simple, inexpensive carbon sources. Here, we present the first de novo genome assembly of the A. lata strain H1. The genome assembly is over 7.7 Mb in size, including a circular megaplasmid of approximately 456 Kbp. In addition to the phaCAB operon, single genes ascribable to PhaC and PhaA functions and auxiliary genes were also detected. A comparative genomic analysis of the available genomes of the genus Azohydromonas revealed the presence of phaCAB and auxiliary genes in all Azohydromonas species investigated, suggesting that the PHB production is a common feature of the genus. Based on sequence identity, we also suggest A. australica as the closest species to which the phaCAB operon of the strain H1, reported in 1998, is similar.