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.     

Catalytic degradation of toxic organic dye using an aluminum-doped Cu0.4Zn0.6-xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6) spinel ferrite in a photo-Fenton system

Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum-doped copper zinc ferrite, Cu_0.4Zn_0.6-xAl_xFe₂O₄ (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co-precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal-oxygen bond vibration at 539 and 427 cm⁻¹ attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X-ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al³⁺ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo-Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo-second order kinetics and the Langmuir isotherm.     

废旧硬质聚氨酯泡沫塑料的木质素改性及再生

采用含有二乙二醇(DEG)和乙醇胺(ETA)的双组分解交联剂降解废旧硬质聚氨酯泡沫塑料(PU硬泡),并利用降解得到的低聚物多元醇与木质素复合制备出性能增强的再生PU硬泡。通过对制备的再生PU硬泡的红外光谱、密度、吸水率、抗压强度、热稳定性、导热系数、热重曲线等进行分析测试,考察m(DEG)∶m(ETA)对再生PU硬泡性能的影响。实验结果表明:m(DEG)∶m(ETA)=1∶3时废旧PU硬泡的降解效果最好;木质素加入量为2.0%(w)时再生PU硬泡的密度低、抗压强度高、保温性能良好,达到国家标准《建筑绝热用硬质聚氨酯泡沫塑料》(GB/T 21558—2008)的品质要求。     

Ozone facilitated degradation of caffeine using Ce-TiO2 catalyst

The ozone initiated oxidation of 1,3,7-trimethylxanthine (caffeine), commonly found in wastewaters as model compound is reported using cerium (Ce)/titanium dioxide (TiO₂) as catalyst. The effect of pH and loading of ceria on titania were investigated. Effect of reaction conditions on degradation of caffeine based on their pseudo first-order rate constants were compared. The combination of catalyst Ce-TiO₂ and ozone aeration significantly enhanced the degradation of caffeine compared to uncatalysed ozonation. The oxidation of caffeine ensued via the free radical mechanism, through enhanced ozone decomposition into OH radicals. Ce/TiO₂(0.5?wt%) showed good activity in degradation of caffeine at pH 6, in both natural stream and river water samples showing about 60% total organic carbon removal in 2?h ozonation period. Using liquid chromatography-mass spectroscopy, degradation products were analysed. A reaction intermediate and one final product were positively identified. Nano-catalysts with different loadings of Ce on TiO₂ synthesized by sol-gel route were characterized by scanning electron microscope, transmission electron microscopy, BET and powder X-ray diffraction spectrum techniques. The results showed that the material retained a highly ordered mesoporous structure and possessed large surface area.     

Higher-efficiency for combined photovoltaic-thermoelectric solar power generation

Solar energy application in a large spectrum has the potential for high-efficiency energy conversion. Though, solar cells can only absorb photon energy of the solar spectrum near their band-gap energy, and the remaining energy will be converted into thermal energy. The use of the thermoelectric generator becomes a necessity for convert this thermal energy dissipated so as to increase efficiency conversion.

This paper analyses the feasibility of photovoltaic-thermoelectric hybrid system and reviews their performance in order to optimize harvested energy. Regarding the thermoelectric effect, a new method of the ambient energy harvesting is presented. This method combines thermoelectric generators and the effects of heat sensitive materials associated to photovoltaic cells in phase change for generating both energy day and night. Experimental measures have been conducted primarily in laboratory conditions for a greater understanding of hybridization phenomena under real conditions and to test the actual performance of devices made. Results show that the hybrid system can generate more power than the simple PV and TEG in environmental conditions. This hybrid technology will highlight the use of renewable energies in the service of the energy production.     

膨润土吸附水中有机污染物的应用进展

论述了膨润土的吸附机理,介绍了膨润土的物理及化学改性方法及其对有机染料废水,焦化废水,烟草废水,煤泥水,含酚类、石油烃类、抗生素废水及微污染水等的处理效果。针对膨润土作为环保吸附剂存在的问题指出了今后的研究方向:1)将研究成果应用于实际废水;2)研究环境友好且效果好的改性工艺及材料;3)研究新的吸附剂制备形式;4)加大膨润土在废气处理上的研究力度;5)研制吸附效果更佳且能处理复杂成分污水的新型复合吸附剂。     

Subcritical water oxidation of propham by H2O2 using response surface methodology (RSM)

This study was conducted to investigate the degradation of propham, which is a compound that pollutes water and seriously threatens human health, by subcritical water oxidation and using H₂O₂ as an oxidising agent. The maximum total organic carbon removal rate of propham was obtained as 73.65% at 40 min of treatment time and 60 mM of H₂O₂ concentration and 373 K of temperature. In addition, response surface method based on the Box-Behnken design was applied to design the degradation experiments of propham for determination of the combined effects of process variables, namely temperature, concentration of oxidising agent and treatment time. The proposed quadratic model of propham degradation, which was examined with the analysis of variance, was used for navigating the design space. The R² and adjusted R² values of the model were determined as 0.9921 and 0.9819 respectively. It was shown that propham was effectively degraded, thus could be removed from the water by using an environmentally friendly method.     

一种新型铋基光催化剂的合成及其可见光催化性能

采用水热法合成铋基光催化剂Bi4VO8Br,通过X-射线粉末衍射、扫描电镜等手段对其进行表征.选择甲基橙为目标降解物来评价不同条件下合成的Bi4VO8Br在可见光下的光催化活性,发现pH 3、反应时间15 h、反应温度160℃为材料水热合成的最佳条件.考察了Bi4VO8Br在可见光及紫外光下对几种农药和增塑剂的光催化降解性能,显示了Bi4VO8Br对不易光解的含苯环有机物的可见光高活性.五氯酚的光催化过程影响因素优化结果表明,可见光和紫外光分别照射120 min和20 min,其降解率分别达到97％和99％,Bi4VO8Br表面上活性基团的捕获即空穴的氧化作用是主要反应原理.     

城市大气中挥发性有机化合物监测技术进展

挥发性有机物(VOCs)是臭氧及二次有机颗粒物(SOA)的主要前体物。近年来,我国逐步将VOCs纳入大气污染物控制体系。准确可靠的监测技术是大气VOCs研究及控制的重要前提保障。按照采样方法、分析方法 2个方面介绍并讨论了城市大气中VOCs的现有监测方法,较为详细地介绍了几类广泛采用的离线及在线监测技术,简要讨论了目前VOCs监测中存在的一些问题,展望了今后的发展趋势。     

废水中甲基橙的电化学降解

以FTO导电玻璃作为阳极、石墨电极作为阴极电解模拟甲基橙废水,优化了工艺条件,并对甲基橙的降解机理进行了初步探究。实验结果表明,在NaCl投加量5 g/L、电压8 V、废水pH 6、初始甲基橙质量浓度6.0 mg/L的优化条件下电解30 min,废水的脱色率达91.3%,COD降低了62%。机理研究结果表明,电解产生的羟基自由基与甲基橙发生氧化还原反应,破坏了甲基橙的显色基团,使其内部某些化学键发生断裂,从而达到脱色的目的。