Physicochemical and structural characterization of biochar derived from the pyrolysis of biosolids,cattle manure and spent coffee grounds

In the framework of circular economy, the need of new feedstock materials for the production of alternative new products is of high priority. Biowastes such as manure, sewage sludge (biosolids, BS) and food-waste are used as raw materials for the production of biochar. The present study aims at characterizing biochars produced from three distinct biowastes (i) manure from cattle waste (manure-derived biochar; MDB), (ii) biosolids (BS) from a conventional Urban Wastewater Treatment Plant (UWTP) (biosolids-derived biochar; BDB), and (iii) spent coffee grounds (SCG)-derived biochar (SCGDB). Samples were slowly pyrolyzed in a small-scale kiln with a capacity of 20–24 kg. The samples were heated under nitrogen atmosphere at approximately 6–7 °C min⁻¹ up to the desired temperature (550 °C) and held for 1.5h. The physicochemical characterization of biochars showed the production of alkaline materials with similarities and variations in their characteristics, which depend to the type of feedstock used. The surface area of the raw materials was considerably low (<0.1 m²/g) and increased after pyrolysis to 14.03 m²/g, 3.98 m²/g and 1.53 m²/g for MDB, BDB and SCGDB, respectively. The high %C content, the low H/C ratio and the FTIR adsorption peaks revealed high aromaticity, polymerization and carbonization of the biochars and the presence of several functional groups. These, are some of the biochar properties which could lead to different sorption mechanisms of organic and inorganic contaminants. Also, they presented good stability in soil, which enables to be used as soil amendment and C sequestration mechanism. Finally, the produced biochars showed promising properties for environmental applications.     

A typology of Southern African biofuel feedstock production projects

Biofuel expansion is happening rapidly within Southern Africa, and already tens of thousands of hectares have been planted, with millions more being contemplated. As is expected with such a new and dynamic industry, this development has taken place in a relatively ad hoc fashion with the various role-players adapting as they respond to lessons learnt from experience, a changing policy environment and other external factors such as the global recession of 2008/2009. This emerging industry is extremely diverse and it is clear that biofuel projects differ enormously in their intent, feedstock choice and management practices. Some projects aim at satisfying local fuel self sufficiency whilst others focus on national and export markets driven by mandatory blending targets. In addition the area planted by a single farmer or company can range from under 1 ha intercropped with food crops to monocropped plantations of tens of thousands of hectares. In attempting to understand the potential sustainability of the industry there is a clear need for a typology which groups projects with common sustainability issues and concerns. Comparing like with like can greatly reduce the complexity of the biofuel debate; help identify areas of most concern and assists in identifying strategies for enhancing sustainability.     

Effects of infestations of the storage mite Tyrophagus putrescentiae (Acaridae) on the presence of fungal species and mycotoxin production in stored products

The storage mite Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) is one of the most important pests of stored foods (cheese, corn, oats, wheat, soy etc.), and is found in heavy infestations. Mites can infest food that are stored under unsatisfactory sanitary conditions, which may also provide conditions for fungi growth, which indicates mite-fungus association. However, little is known about the influence of T. putrescentiae on mycotoxins production under different stored products over time. The main objective of the present study was to identify the fungal species present in oats, corn, and wheat flour associated with T. putrescentiae infestations, and evaluate mycotoxin production before and after six months storage with these infestations. Wheat, corn and oat grain samples were compared, and each crop was stored in six containers infested by T. putrescentiae. Three remaining containers were stored under the same temperature and humidity conditions without introducing the mites, which worked as control. We obtained 55 fungi isolates, and the majority were identified with 99% or 100% of identity and ≥97% of coverage with type strains of each fungal species. Mycotoxin concentrations analyzed from corn flour stored for six months decreased with and without T. putrescentiae (p < 0.05). Regarding mycotoxin concentration with T. putrescentiae, aflatoxin increased in oats (p < 0.05) while zearalenone decreased in wheat (p < 0.05). Our findings proved that T. putrescentiae could significantly induce mycotoxin production in stored products evaluated for six months.     

Charge transport and luminescent properties of PMMA-dehydrate nanotubed titanic acid nanocomposites

In this paper, we doped p-type conductivity dehydrated nanotubed titanic acid (DNTA) into insulator polymer poly(methyl methacrylate) (PMMA). The electric properties of this nanocomposite were investigated. The photoluminescence efficiency of fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) in PMMA matrix was enhanced by doping with DNTA. Moreover, screen effect by DNTA with high permittivity caused the emission from DCJTB to be blue-shifted.     

接种发酵对酸菜品质的影响

以青菜为原料,选用鼠李糖乳杆菌、嗜酸乳杆菌和发酵乳杆菌3种乳酸菌进行人工接种试验,设计了7个配方,发酵时间为8d,研究发酵菌种对酸菜总酸含量和亚硝酸盐含量的影响,确定最适合酸菜发酵的菌种,并研究接种发酵对酸菜的氨基酸含量和挥发性风味物质成分的影响。结果表明,当鼠李糖乳杆菌、嗜酸乳杆菌和发酵乳杆菌的比例为1:1:1时,酸菜总酸含量升高最快,亚硝酸盐含量最低且无明显的亚硝峰出现,为最适合酸菜发酵的菌种。接种发酵酸菜的氨基酸种类和含量均高于自然发酵的酸菜,挥发性风味物质成分的种类和相对含量均低于自然发酵的酸菜。     

Reuse of water purification sludge as raw material in cement production

The feasibility of partial replacement of siliceous raw material for cement production with water purification sludge (WPS) was investigated by X-ray diffraction, free-lime analysis, compressive strength testing and toxicity characteristics leaching procedure (TCLP). It is found that WPS has no negative effects on the consumption of free lime and the formation of clinker minerals. The samples with WPS from 4 to 10 wt.% have higher 3 days and 7 days strengths than the control. After 28 days, however, only WPS replacements <7% increased the strength of samples. It is noteworthy that heavy metals in WPS were almost completely incorporated into the clinkers, and up to 28 days the heavy metals were not detected in the leachates. From the above results of clinker minerals, compressive strength and leaching tests, it can be concluded that WPS has the potential to be utilized as an alternative raw material in cement production.     

贵州蓝莓蜜TaqMan探针实时荧光PCR检测方法的建立与应用

该研究利用TaqMan特异性探针实时荧光PCR检测手段,建立了高效、精准鉴别贵州特色（中蜂）蓝莓蜜的方法。对贵州白竹林、麻卡和乌卡坪三个地域的蓝莓种植区蓝莓蜜进行采集（包括意蜂蓝莓蜜）,同时购买市售蜂蜜及加拿大蓝莓蜜,该方法通过采集贵州麻江县白竹林地区蓝莓种植园及蜂场周围蓝莓同花期26种植物样本,基于植物基因组中trnL基因序列的多序列比对,设计蓝莓trnL基因特异性引物,并进行TaqMan探针验证。结果表明,本研究设计的TaqMan探针特异性强,建立的TaqMan探针实时荧光PCR检测方法能检测到蓝莓花粉DNA最低浓度为0.3 ng/μL;利用建立的方法对11种市售蜂蜜和贵州蓝莓蜜样本进行检测,发现贵州蓝莓蜜的Ct值为24～26,蓝莓花粉数在800～1 700颗,其余蜂蜜Ct值在30以上,表明该方法能够有效实现贵州蓝莓蜜和其他蜂蜜的区分,具有良好的应用前景。     

An experimental approach to produce hydrogen and methane from food waste using catalyst

Anaerobic co-digestion of food waste, cow dung, and sludge solution is experimented in the presence of calcium peroxide (CaO₂) as the catalyst to produce hydrogen and methane as a source of renewable energy. The substrate to inoculum ratios (v/v) of 1:1(S1), 1:2(S2), 1:3(S3), 1:4(S4) and 1:5(S5) are investigated in separate fermentative and methanogenic reactors. The result from the fermentative reactors indicate maximum hydrogen concentration of 26.34% with cumulative yield of 114.1 mL/g total solid (TS) in S3 compared to the other samples. Methanogenic reaction shows the highest methane concentration of 54.13% in S3. The highest daily (average) and cumulative biogas yield of 5.36 mL/g TS and 201.9 mL/g TS respectively are identified in S3. A maximum carbon dioxide concentration of 63.11% is found in S1. Overall, the substrate to inoculum ratio of 1:3 is spotted to be optimal for effective hydrogen and methane production during the anaerobic co-digestion process.