Potential energy production from organic waste and its environmental and economic impacts at a tertiary institution in Palestine

Municipal solid waste (MSW) is one of the most well-known biomass resources that can be utilized to produce renewable energy. Numerous countries are plagued by the proliferation of waste, particularly organic waste that can be utilized for energy recovery. Palestine suffers from inefficient solid waste management, and only recently have a few projects focused on bioenergy production been implemented. Throughout the years, the city of Tulkarm experiences power outages which cause a challenge to the Palestine Technical University-Kadoorie campus in Tulkarm. Thus, the possibility of energy recovery from the organic portion in Palestine Technical University-Kadoorie was evaluated. The analysis of an economic impact included discussions of a number of economic aspects, including Levelized cost of energy, internal rate of return, present worth, annual worth, and payback period. On the other hand, a carbon dioxide savings analysis and gas emission were evaluated. The outcomes of the energy optimization demonstrated that the suggested system could supply the institution with an average of roughly 7 MWh of electrical energy. According to the economic study, this project offers 0.25 million dollars in present value, 0.144 million dollars in annual value, a 13 percent internal rate of return, a payback period of 6 years, and a levelized cost of energy of 0.11 dollars for each kWh generated. Additionally, the environmental assessment revealed that this system might reduce CO₂ emissions by around 8,343,778 tons. For effective waste management, energy recovery, and emission reduction, it is advised to implement anaerobic digestion technology.     

Toward sustainable use of natural resources: Nexus between resource rents,affluence, energy intensity and carbon emissions in developing and transition economies

Sustainable use of natural resources would entail ensuring that derived economic benefits today do not undermine the welfare of generations to come. On this basis, this study examines the nexus between natural resource rents and carbon dioxide (CO₂) emissions disaggregated into production and consumption-based (i.e., trade-adjusted) CO₂ emissions for a selected panel of 45 developing and transition economies over the period 1995–2017. The empirical model also incorporates the impacts of population, affluence, and energy intensity. The results show that affluence increases production-based CO₂ emissions by 1.407%, with the EKC's predicted inverted U-shaped curve only explaining consumption-based CO₂ emissions. Economic reliance on natural resource rents and energy intensification contribute 0.022% and 0.766%, respectively, to CO₂ emissions embedded in territorial production inventories and 0.035% and 0.583%, respectively, to CO₂ emissions embedded in consumption inventories. The bootstrap non-causality test shows that historical data on each variable has significant predictive power for future CO₂ emissions from both sources. The historical information about natural resource rents has significant predictive power over the future levels of affluence and energy intensity. Clearly, the results show that the environmental impact of natural resource rents is stronger when CO₂ emissions are adjusted for trade and varies among the countries, with Bangladesh, Guinea, India, Malaysia, Mexico, Nigeria, Pakistan, Saudi Arabia, Vietnam, and Zimbabwe among the most affected countries. Overall, this study provides motivation for policies to keep the use of natural resources within sustainable limits.     

A multidecadal oscillation in precipitation and temperature series is pronounced in low flow series from Puget Sound streams

In Pacific Northwest streams, summer low flows limit water available to competing instream (salmon) and out-of-stream (human) uses, creating broad interest in how and why low flows are trending. Analyses that assumed linear (monotonic) change over the last ~60 years revealed declining low flow trends in minimally disturbed streams. Here, polynomials were used to model flow trends between 1929 and 2015. A multidecadal oscillation was observed in flows, which increased initially from the 1930s until the 1950s, declined until the 1990s, and then increased again. A similar oscillation was detected in precipitation series, and opposing oscillations in surface temperature, Pacific Decadal Oscillation, and Interdecadal Pacific Oscillation series. Multidecadal oscillations with similar periods to those described here are well known in climate indices. Fitted model terms were consistent with flow trends being influenced by at least two drivers, one oscillating and the other monotonic. Anthropogenic warming is a candidate driver for the monotonic decline, and variation in (internal) climatic circulation for the oscillating trend, but others were not ruled out. The recent upturn in streamflows suggests that anthropogenic warming has not been the dominant factor driving streamflow trends, at least until 2015. Climate projections based on simulations that omit drivers of multidecadal variation are likely to underestimate the range, and rate of change, of future climatic variation.     

The deflectors influence on flow complexity,bed morphology,sediment transport and water quality of urban lotic waters - A laboratory study

In this laboratory study different combinations of bed (sand, pebble gravel [gravel], and a mix of sand and gravel) and flow (typical and overtopping) were experimented with to investigate the impact of porous deflectors in flow diversity, water quality, and fish performance in prismatic open channels. Deflectors changed the gradually varied flow to a rapidly varied flow, as a sudden change in the water depth was observed at the deflectors, and this change was large for smooth beds. With the presence of gravel, the scouring near the downstream deflector was almost twice that of the sand bed, and with the scouring at its own upstream deflector, irrespective of whether the flow was typical or overtopping. This behavior was a result of sand mobilization due to shear stress and sand mobilization aided gravel transport. The mixed bed showed less gravel movement compared to the gravel-only bed. The percentage of sediment washed out was minor for all bed scenarios, indicating that sediment transport was local. Relative to the sand bed without deflectors (representing a typical urban canal), deflectors resulted in reduced and improved water quality (in terms of sediment load) for sand, and mixed bed, respectively. The fishes found refuge and were comfortable in the pool areas created by deflectors unlike in channels without deflectors where they showed exhaustion.     

Physico-chemical characterization of Residual Household Waste for energy recovery in insular territories: Case study of Reunion Island

Waste-to-energy is a promising approach to face the current challenge of waste overproduction in Reunion Island, a French territory. In this particular context of an isolated and tropical territory, it is essential to study the properties of potential feedstocks to choose the most appropriate conversion process. This article reports on the composition of Residual Household Waste from Reunion Island and its physico-chemical parameters. Twelve representative samples of Residual Household Waste were subjected to thermal and elemental analysis. The results showed that their composition had a significant influence on the physico-chemical properties, including calorific value. Residual Household Waste from the selective sorting (rich in wood, plastic, and sanitary textiles) as well as dry mixed RHW are the most interesting for energy recovery. Due to their high volatile matter and high carbon content, and their low moisture content, these types of waste have a high calorific value exceeding 18 MJ/kg. Furthermore, the RHW sample comply with the environmental and health criteria applied by French regulations concerning halogen and heavy metal. Thus, it seems that Residual Household Waste can be an alternative to conventional fuels used in incineration or pyro-gasification processes. However, the study also points the need for a pre-treatment process for these wastes. Indeed, it is necessary to sort them correctly in order to avoid the risks of pollution and important maintenance. And more importantly, drying beforehand is unavoidable to improve combustibility and obtain optimal energy conversion.     

武汉市一次污染过程的局地流场和边界层结构的数值模拟

利用2013年11月武汉市逐日空气质量资料、地面气象观测资料、NCEP/NCAR再分析资料和L波段雷达探空资料，通过WRF模式模拟空气污染生消过程中的局地气象条件变化，探讨特殊地形条件下边界层结构变化和局地环流在污染物生消过程中的作用和影响。结果表明：（1）武汉地区当背景环流场强的时候，由地形引起的局地流场对污染物扩散的影响就弱，反之当背景环流场弱的时候, 地形对流场影响明显:夜间为山风，白天为谷风。夜间山风与偏西北气流及偏东气流在武汉及周边地区辐合，形成气流汇聚带，在武汉地区形成一个反复污染带,即由地形引起的局地流场对污染物扩散的贡献就大；（2）武汉地区发生空气污染时，地面湿度较高，边界层呈上干下湿状态，其特征为暖而干且有偏东小风，这导致污染物不断堆积和重污染过程的形成。     

Forecasting China’s primary energy demand based on an improved AI model

An improved energy demand forecasting model is built based on the autoregressive distributed lag (ARDL) bounds testing approach and an adaptive genetic algorithm (AGA) to obtain credible energy demand forecasting results. The ARDL bounds analysis is first employed to select the appropriate input variables of the energy demand model. After the existence of a cointegration relationship in the model is confirmed, the AGA is then employed to optimize the coefficients of both linear and quadratic forms with gross domestic product, economic structure, urbanization, and technological progress as the input variables. On the basis of historical annual data from 1985 to 2015, the simulation results indicate that the proposed model has greater accuracy and reliability than conventional optimization methods. The predicted results of the proposed model also demonstrate that China will demand approximately 4.9, 5.6, and 6.1 billion standard tons of coal equivalent in 2020, 2025, and 2030, respectively.     

船舶螺旋桨射流对湘江河床底泥扰动影响分析

船舶航行时螺旋桨产生的射流会对河道水流产生扰动,这种扰动是否能引起河床底泥的再悬浮需要更深入的论证分析。通过对比分析螺旋桨射流发展规律的研究成果,以湘江典型河段为研究对象,结合实船测量结果和此段河流地质资料,探讨了螺旋桨射流对湘江长株潭段河床底泥扰动的影响,并对此段河床底泥起动和悬浮条件进行了理论分析。结果表明:在周围环境流速较低的条件下,螺旋桨射流初始速度、河床水深及泥沙粒径是决定泥沙是否运动的主要因素。湘江长株潭河段已基本库区化,大部分河道平均水深远大于航道的标准水深2.8 m,河床泥沙平均粒径大于0.87 mm,其中细颗粒泥沙很少,由于螺旋桨射流断面平均流速小于泥沙起动流速,悬浮指标计算值远大于4,因此可以判断船舶正常航行在该段河流时底泥难以起动和再悬浮。     

固定化斜生栅藻净化畜禽废水中氨氮和磷的影响因素

为探讨Cu2+、p H和流速对固定化斜生栅藻去除畜禽废水中NH+4-N、TP效果的影响,在实验室条件下模拟实际污水处理过程,并采用正交实验方案对结果进行分析。结果表明低质量浓度Cu2+(0~0.05 mg/L)改善藻的净化效果,高质量浓度Cu2+(0.50~5.00 mg/L)抑制藻的净化效果;在p H较高的条件下(p H=9),固定化斜生栅藻的净化效果明显提高;流速对结果没有明显影响。通过正交实验,得出固定化斜生栅藻去除畜禽废水中NH+4-N、TP的优化条件如下:Cu2+质量浓度为0.05 mg/L,p H为9,流速为0.3 m/s。此时NH+4-N去除率为96.11%,TP去除率为97.53%。     

密相塔半干法烟气脱硫塔内加湿降温及其对脱硫效率的影响

为了实现密相塔半干法脱硫工艺的精确加湿进一步提高系统脱硫效率,利用推导出的传热传质计算方法,得到烟气温度降低和加水量的关系.结合3组密相塔半干法工程实际数据,发现理论计算值和实测值误差区间仅为2.9％ ～5.4％.通过选取河北某钢厂210 m2烧结烟气密相塔半干法脱硫项目实际在线检测数据,发现循环脱硫灰含湿量为3％的系统脱硫效率整体高于含湿量为5％和4％的样品,最大值达93.56％.通过粒度分析、扫描电镜、X射线衍射及差热-热重对2种不同含湿量的循环脱硫灰进行表征,结果表明,含湿量为3％的循环脱硫灰较含湿量为5％的样品粒径小、比表面积大,无团聚现象,物相分析还证实相对于含湿量为5％样品,其Ca(OH)2和结晶水含量少,几乎都是CaSO4和CaS03干态物质,因此脱硫反应进行彻底,脱硫效率较高.