微藻油脂制备生物柴油的研究

利用正己烷从异养生长的小球藻(脂类化合物含量高达细胞干重的55%,是自养藻细胞(14%)的4倍)细胞中提取获得了大量油脂。这些异养微藻油脂在30℃、醇油物质的量比为56∶1以及浓硫酸催化条件下经酯交换反应4h可形成高质量的生物柴油。微藻生物柴油的密度为0.864kg.L-1、粘度5.2×10-4(40℃)、热值高达41MJ.kg-1。这些特征与传统柴油相当,且微藻生物柴油具有更低的冷滤点(-11℃)及良好的发动机低温启动性能,因此其应用价值更高。     

市政污水处理工艺与回用技术分析

随着污水治理的不断深入,政府所处的经营环境已经逐渐从工业废水转变到城市污水上,在这一背景下,政府必须转变经营思想。充分尊重社会发展规律,重视污水污染和水循环再利用问题,并对现阶段的城市污水处理办法进行全面调整,才能够尽快适应现阶段污水处理的全新要求。为此,基于水资源短缺和水环境恶化的情况,对城市污水处理问题的综合管理战略进行了分析,希望能够对污水处理单位发展起到一定的帮助。     

以新型高效沼气为纽带的畜牧场污水治理技术

依据新型高效沼气池特点与先进性，通过具体分析山区与沿海畜禽场推广该工艺沼气运行效果与成本效益，推广该工艺沼气工程能解决畜牧业发展带来严重环境污染问题。     

农村生活污水治理建设规划分析——以浙江省东阳市为例

本文通过对浙江省东阳市农村生活污水治理现状及重点、难点问题开展分析,从治理模式、治理措施和设施运维等方面探讨农村生活污水治理建设方式和规划实施中应重点关注的问题。农村生活污水治理工作主要采用纳管、相对集中治理和管控治理等三种模式;采用纳厂、提升改造、撤并和保留四类措施。规划实施过程中应重点关注规划实施顺序、资金筹措、工艺技术、治污降碳,协同增效、运维管理及监管机制等问题。     

市政集中供暖企业在供热管理方面问题分析——以富平城南热力有限公司为例

以富平城南热力有限公司为研究对象,对该公司供热管理的各个方面进行有序细致的分析。经过分析可以发现,富平城南热力公司在供热管理方面存在一定的问题,需要及时解决,并根据存在的问题找出了原因。最后,结合企业目前状况并联系实际情况提出了解决这些问题的合理对策及建议。     

市政污泥干燥特性的实验研究和模拟分析

采用薄层干燥的方式对嘉兴市某污水处理厂的脱水市政污泥在不同厚度和温度下的干燥特性进行实验研究,并通过引入薄层干燥模型,对薄层市政污泥干燥过程进行模拟分析。结果表明：厚度越小或干燥温度越高,污泥干燥速率越快。当温度从70 ℃上升到130 ℃时,最大干燥速率从0.025 87 g·（g·min）−1上升到0.081 58 ...     

污水源热泵供热的工程应用及分析

齐鲁石化水厂原来利用热电厂蒸汽换热后制备低温热水对车间和办公楼进行供热,运行费用高.根据该厂有丰富的工业污水的特点,现设计采用污水源热泵机组为车间及办公楼提供热.分析表明,一个采暖季即可节省运行费用约68万元,而且使用效果良好.     

污水处理厂节能降耗措施及效益分析——以湖南省某再生水厂为例

本文以湖南省某再生水厂为例,介绍了污水处理厂节能降耗措施和效益,重点研究了改良式序批间歇反应器(MSBR)工艺技改对污水处理厂提质降耗、中水回用等方面的应用效果。结果表明,通过采用MSBR工艺技改,水质明显提升,实现了节能、节药、节水的效果。此外,通过推广中水回用和光伏等可再生能源利用,进一步降低了污水处理能耗。本案例对于污水处理厂节能降耗、减污降碳具有一定借鉴意义。     

市政污水处理面临的常见问题及对策分析

随着现代化进程的加快,城市建设的规模越来越大,生态环境的破坏愈发严重,阻碍了城市的健康、可持续发展。为了响应国家关于生态建设的号召,各大城市纷纷作出响应的行动,开展各种生态环境保护的活动,污水处理就是其中之一。本文分析了市政在进行污水处理过程中面临的问题,并探讨了解决对策,希望对提高城市污水处理的质量有所帮助。     

The effects of ultraviolet radiation on growth,biomass, lipid accumulation and biodiesel properties of microalgae

The effect of UV light on growth, biomass, lipid accumulation and biodiesel properties of microalgae was studied. A Microalgae strain Chlorella sorokiniana UUIND6 was cultivated for 14 days as under LED light (Control) and microalgae were exposed to UV light (280–320 nm) in the middle of the photoperiod for 3 days. The growth rate of microalgae was analyzed by spectrophotometer and cell counting, while oil accumulation was analyzed by improved Nile red method. Results showed that microalgae under UV light treated algal cells showed less growth. FAMEs profile of UV treated algal cells mainly contains hexadecanoic acid (C16), stearic acid (C18) fatty acids. PUFA found in very less amount in UV treated cells as compared to control.     

Comparison of dairy wastewater and synthetic medium for biofuels production by microalgae cultivation

This study is concerned with comparing raw dairy wastewater (DWW) with blue-green medium (BG11 medium) for biofuel production. Three microalgae strains (Chlorella sp., Scenedesmus sp., and Chlorella zofingiensis) were cultured in tubular bubble column photobioreactors with two media separately. After 8 days of cultivation, DWW was demonstrated to be more suitable medium for microalgae biomass and lipid production than BG11 medium. The biomass and lipid produced within wastewater provided suitable feedstocks for anaerobic digestion and biodiesel conversion. Nutrients in wastewater were efficiently removed (>90% total nitrogen removal, approximately 100% ammonia removal, and >85% total phosphorus removal) during this process.     

Culture of four microalgal strains for bioenergy production and nutrient removal in the meliorative municipal wastewater

Microalgae have been considered as the most promising sources of alternative bioenergy. For the purpose of saving costs, the present work focused on the potential use of microalgae in the meliorative municipal wastewater, which contains 90% municipal wastewater and 10% dairy wash wastewater. Four microalgal species, Palmellococcus miniatus, Neochloris oleoabundans, Scenedesmus quadricanda #507, and Chlorella zofingiensis, were cultured in pure municipal wastewater and meliorative municipal wastewater, respectively, for 5 days. Their biomass accumulation and removal rates of nitrogen and phosphate were measured. Results showed that the growth rates of Neochloris oleoabundans, Palmellococcus miniatus, and Chlorella zofingiensis in meliorative municipal wastewater (>0.8 g·L^–1·d^–1) were significantly higher than that in municipal wastewater (2.6 g·L^–1·d^–1), while there was no significant difference between the growth rates of Scenedesmus quadricanda #507 in meliorative municipal wastewater and in municipal wastewater. Neochloris oleoabundans exhibited the highest growth rate (0.86 g·L^–1·d^–1) and relatively high nutrient removal capacity. Scenedesmus quadricanda #507 had the highest P removal rate of over 94%. The four species have a similar N removal rate at about 90%. The results showed that the highest average removal rate of N and P were about 23.1 mg·L^–1·d^–1 and 7.1 mg·L^–1·d^–1. Furthermore, the content of lipid or carbohydrates increased and a different profile of fatty acids were found compared to those in municipal wastewater. Cellular components changes of microalgae in meliorative municipal wastewater were favorable as raw materials for bioethanol and biodiesel production. Cultivation with meliorative municipal wastewater is a win-win culture mode that facilitates the biomass production, lipid and carbohydrate accumulation, and wastewater purification.     

Biomass and lipid production of marine microalgae using municipal wastewater and high concentration of CO2

In order to reduce the cost of the production of microalgae for biodiesel, the feasibility of using the mixture of seawater and municipal wastewater as culture medium and CO₂ from flue gas for the cultivation of marine microalgae was investigated in this study. Effects of different ratios of municipal wastewater and 15% CO₂ aeration on the growth of Nannochloropsis sp. were examined, and lipid accumulation of microalgae was also studied under nitrogen starvation and high light. It was found that optimal growth of microalgae occurred in 50% municipal wastewater, and the growth was further significantly enhanced by aeration with 15% CO₂. When Nannochloropsis sp. cells were transferred from the first growth phase to the second lipid accumulation phase under the combination of nitrogen deprivation and high light, both biomass and lipid production of Nannochloropsis sp. were significantly increased. After 12 days of the second-phase cultivation, the biomass concentration and total lipid content increased from 0.71 to 2.23 g L⁻¹ and 33.8–59.9%, respectively. This study suggests that it is possible to utilize municipal wastewater to replace nutrients in seawater medium and use flue gas to provide CO₂ in the cultivation of oil-bearing marine microalgae for biodiesel.     

Simulation analysis of municipal solid waste pyrolysis and gasification based on Aspen plus

To predict and analyze the municipal solid waste (MSW) pyrolysis and gasification process in an up-draft fixed bed more veritably and appropriately, numerical modeling based on Gibbs energy minimization was executed using the Aspen plus software. The RYield module was combined with the RGibbs module to describe the pyrolysis section, while the RGibbs module was used for the gasification section individually. The proposed model was used to forecast and analyze the target performance parameters including syngas composition, lower heating value (LHV) and carbon conversion rate under different conditions of the gasification temperatures, and ratios and types of gasifying agents. The results indicate that there is a good agreement between the experimental data and the simulated data obtained using this model. The predicted optimum gasification temperature is approximately 750°C, and the best ratio of water vapor as gasifying agent is around 0.4. The mixture of flue gas and water vapor has an economical and recycled prospect among four commonly used gasifying agents.     

微重力条件对小球藻固碳能力与油脂积累的影响

为了提高微藻的固碳效率和产脂速率,在模拟的微重力条件下,利用CO2培养蛋白核小球藻。实验结果表明:微重力条件和CO2对蛋白核小球藻的生长具有协同促进作用;与普通条件下通入空气培养蛋白核小球藻相比,在微重力条件下通入浓度为10%的CO2培养蛋白核小球藻120 h后,蛋白核小球藻的生物量浓度提高了178%;在普通条件下,蛋白核小球藻的固碳效率为2.64±0.41 mg/(L·h),在微重力条件下,蛋白核小球藻的固碳效率为17.28±0.42 mg/(L·h);在普通条件下通入CO2后,蛋白核小球藻细胞中的不饱和脂肪酸含量升高,而在微重力条件下通入CO2后,蛋白核小球藻细胞中的不饱和脂肪酸含量会下降。     

城市固体废弃物热重分析及热解动力学研究

对城市垃圾典型组分（塑料、橡胶、果皮、织物、纸板等）进行热重分析及热解动力学研究。热重分析结果表明，塑料组分开始分解的温度较高，但分解速率最快；橡胶组分开始分解反应的温度相对较低，且分解速率相对较慢。果皮、织物和纸板类以纤维和木质类物质为主要成分，其热解特性较为相似。热解动力学研究表明，橡胶的热解活化能最高，最难分解，且热解符合二维扩散机理；塑料的热解相对较容易，符合一维扩散机理。而果皮、织物和纸板类的活化能较低，它们的热解符合体积缩小机理。     

Effect of outdoor conditions on the growth and lipid accumulation of six green algae

Microalgae are considered as an alternative feedstock for producing biodiesel. In this study, six oil-producing algae were cultivated with natural sunlight outdoors. The highest lipid content, biomass productivity, and lipid productivity were 29.99%, 208.42 mg/l/d, and 69.84 ml/d, respectively. In addition, the photosynthetic efficiency of PS II (Fv/Fm) was kept high during the cultivation and the preferred fatty acids (C16–C18) for producing biodiesel were more than 95% of total fatty acids for all of the strains.     

Productivity analysis of fractured wells in reservoir of hydrogen and carbon based on dual-porosity medium model

Hydrogen is usually locked in energy-rich organic compounds and there is almost no pure hydrogen in nature. Organic compounds produced in reservoirs of hydrogen and carbon are an important source of hydrogen production. Understanding the productivity characteristics reservoirs of hydrogen and carbon is the important step to ensure adequate hydrogen energy. This study analyzes the production of hydraulically fractured organic reservoir of hydrogen and carbon. First, based on the diffusion mechanism in reservoir matrix, a multi-scale dual-porosity medium model of reservoir of hydrogen and carbon is established. Then, the mathematical model is solved and verified through a historical matching of field gas production data. Finally, parameter analysis was performed to determine the key parameters to improve the recovery efficiency in organic reservoir of hydrogen and carbon. Results show that improving fracture permeability can improve gas recovery efficiency of hydrocarbon reservoirs. The matrix desorption can develop natural gas production for a long period. Long sizes of hydraulic fractures have large contact surfaces for gas diffusion and increase gas generation and cumulative gas production. The proposed model can predict and analyze the production performance of reservoirs of hydrogen and carbon.