植物基与固废基生物炭的结构性质差异

选取3种植物类原材料（玉米秸秆、小麦秸秆和青草）和3种固体废物类原材料（猪粪、蛋壳和污泥），在350℃下转化为生物炭，对2类生物炭的性质进行分析测定比较。结果表明，2类生物炭的pH与等电荷点（PZNC）相近，均在8．0-10．0范围内。植物生物炭中碳含量为56．8％-60．0％，高于固体废弃物生物炭（13．4％～39．1％）；产率和灰分分别为22．3％-45．0％和21．8％-22．3％，低于固体废弃物生物炭（44％～55．7％和45．1％～90．4％）；后者的阳离子交换能力（CEC）为49～334cmol／kg，显著高于前者（46．3—50．1cmol／kg），而其阴离子交换能力（AEC）为12．0～16．0cmol／kg，低于植物生物炭（33．5—63．2cmol／kg）。XRD分析表明植物生物炭含有大量KCl，而固体废物生物炭中主要矿物为CaOOz。2类生物炭的结构与性质差异显著，使它们在固碳、土壤改良、环境污染治理等方面有不同应用效果。

改性植物生物炭去除水中四环素类抗生素的研究进展

四环素类抗生素滥用和缺乏有效去除技术导致广泛残留并诱导产生耐药细菌,已成为世界环境问题之一。植物生物炭具有来源广、成本低、易制备、资源有效利用和环境友好等优点,在环境修复领域,特别是抗生素污染物去除方面备受关注。本文综述了改性植物生物炭对四环素类抗生素的去除效果,讨论环境因素对改性生物炭性能的影响并深入探讨去除机制,分析目前植物生物炭改性过程中存在的局限性,并展望未来改性方向。

植物源生物炭材料的制备及其在农药残留领域中的应用进展

随着农药的广泛使用,其已普遍存在于环境中,对人们的身体健康产生巨大影响。因此,环境中农药残留的去除和分析检测对保护人体安全健康至关重要。同时,农药在环境中残留浓度低,需要一种对目标物有较强选择性和富集作用,并对环境影响小的前处理吸附剂。植物源生物炭是由植物源生物质作为碳源衍生得到的材料,其比表面积大、孔容量高、表面官能团可调节,且环境相容性好,其原料植物源生物质的价格低廉、来源广泛并可再生,是一种廉价高效的吸附剂。该文主要综述了近10年来植物源生物炭用于环境中农药残留去除和分析检测前处理的应用进展。其中在农药残留去除方面的应用主要包括降低农药在土壤中的移动性,修复手性农药造成的污染,负载降解农药的细菌及作为化肥的缓释载体。在农药残留分析检测前处理方面,植物源生物炭可用作分散固相萃取、固相微萃取和磁性固相萃取的吸附剂来选择性吸附水果和蔬菜中的有机磷类和三唑类农药,以及水环境中的有机氯类农药。另外,还介绍了植物源生物炭的吸附机理,详细阐述了基于计算模拟如密度泛函理论、分子动力学模拟和巨正则蒙特卡洛模拟的吸附机理研究并讨论了其优势。最后,总结了植物源生物炭在农药去除和农药残留分析检测前处理方面应用的优势,指出了其在农药残留领域应用待解决的问题。

Stabilization of heavy metals in biochar pyrolyzed from phytoremediated giant reed(Arundo donax) biomass

The pyrolysis of phytoremediated giant reed(Arundo donax)biomass could cause secondary pollution of heavy metals.The stabilization of heavy metals in the pyrolysis process with external materials such as Al2O3,CaCO3,FeCl3and NaOH,wasstudied.The results showed that37%As and97%Cd in biochar were stabilized when giant reed powder was pyrolyzed at250°Cwith5%Al2O3for2h.Furthermore,59%Pb in biochar was stabilized at400°C with5%CaCO3for1h.Under biochar produced inoptimized pyrolysis conditions,Cd mainly existed in a residual fraction,while Pb and As mainly existed in oxidizable fraction inBCR analysis.In XRD analysis,As was only found in Ca2As2O7;Cd in biochar mainly existed in Cd(AlCl4)2,CdPbO3or CdSO3;and Pb mainly existed as Pb3O2SO4.

Switchgrass Biochar Effects on Plant Biomass and Microbial Dynamics in Two Soils from Different Regions

Biochar amendments to soils may alter soil function and fertility in various ways, including through induced changes in the microbial community. We assessed microbial activity and community composition of two distinct clayey soil types, an Aridisol from Colorado （CO） in the U.S. Central Great Plains, and an Alfisol from Virginia （VA） in the southeastern USA following the application of switchgrass （Panicum virgatum） biochar. The switchgrass biochar was applied at four levels, 0%,0, 2.5%, 5%, and 10%, approximately equivalent to biochar additions of 0, 25, 50, and 100 t ha^-1, respectively, to the soils grown with wheat （Triticum aestivum） in an eight-week growth chamber experiment. We measured wheat shoot biomass and nitrogen （N） content and soil nutrient availability and N mineralization rates, and characterized the microbial fatty acid methyl ester （FAME） profiles of the soils. Net N mineralization rates decreased in both soils in proportion to an increase in biochar levels, but the effect was more marked in the VA soil, where net N mineralization decreased from -2.1 to -38.4 mg kg^-1. The 10% biochar addition increased soil pH, electrical conductivity, Mehlich- and bicarbonate-extractable phosphorus （P）, and extractable potassium （K） in both soil types. The wheat shoot biomass decreased from 17.7 to 9.1 g with incremental additions of biochar in the CO soil, but no difference was noted in plants grown in the VA soil. The FAME recovery assay indicated that the switchgrass biochar addition could introduce artifacts in analysis, so the results needed to be interpreted with caution. Non-corrected total FAME concentrations indicated a decline by 457o and 34% with 10% biochar addition in the CO and VA soils, respectively, though these differences became nonsignificant when the extraction efficiency correction factor was applied. A significant decline in the fungi：bacteria ratio was still evident upon correction in the CO soil with biochar. Switchgrass biochar had the potential to cause short-term negative impacts on plant biomass and alter soil microbial community structure unless measures were taken to add supplemental N and labile carbon （C）.

Effects of Enriched Biochars Containing Magnetic Iron Nanoparticles on Mycorrhizal Colonisation,Plant Growth,Nutrient Uptake and Soil Quality Improvement

At present, there is little commercial sale of biochar, since farmers find they can not gain a return on their investment in this amendment in the first few years after its application, because of the high cost associated with large application rates. To overcome this constraint, development of artificially aged enriched biochar-mineral complexes(BMCs), having a higher mineral content, surface functionality, exchangeable cations, high concentration of magnetic iron(Fe) nanoparticles, and higher water-extractable organic compounds has been undertaken by a combined team of researchers and a commercial company. Two biochars produced under different pyrolysis conditions were activated with a phosphoric acid treatment. A mixture of clay, chicken litter, and minerals were added to the biochar, and then this composite was torrefied at either 180 or 220?C. In this study a pot experiment was carried out in glasshouse conditions to determine the effects of four different BMCs, with different formulations applied at rates of 100 and 200 kg ha-1, on the mycorrhizal colonisation, wheat growth and nutrient uptake, and soil quality improvement. It was found that the phosphorus(P) and nitrogen uptake in wheat shoots were significantly greater for a low application rate of BMCs(100 kg ha-1). The present formulation of BMC was effective in enhancing growth of wheat at low application rate(100 kg ha-1). The increase in growth appeared due to an increase in P uptake in the plants that could be partly attributed to an increase in mycorrhizal colonisation and partly due to the properties of the BMC.

Effects of Biochars and Other Organic Soil Amendments on Plant Nutrient Availability in an Ustoxic Quartzipsamment

A sandy soil, Nampong soil （classified as Ustoxic Quartzipsamment）, was incubated under controlled condition i） to compare the mineralization of major plant nutrients derived from different types of biochars and other organic soil amendments; ii） to examine their effects on soil properties and plant nutrient availability; and iii） to evaluate the plant nutrient losses in leachate from the rooting zone of soil incorporated with the different amendments. The experiment was arranged in a completely randomized design with 3 replications. Five treatments of soil amendments used were cassava stem base biochar （CSB）, rice husk biochar （RHB）, chicken manure （CM）, compost （CP）, and no amendment application （control）. The RHB treatment released the highest amounts of mineralized NO^-N, available P and K （2.30-17.26, 5.50-42.90 and 43.00-187.63 mg kg-1, respectively） while the CM treatment releasing the highest NH4＋-N in the range of 1.86-53.67 mg kg-1. The CSB and RHB treatments showed better continuity of mineralization of nutrients than the treatments of CM and CP, particularly in the case of the CSB treatment. In the soil column incubation experiment, the amounts of NH4＋-N and NO3-N in all treatments barely changed on Day 1 to Day 30 of incubation and then the amounts increased markedly on Day 60. On Day 601 the RHB treatment contained a very high amount of NO3--N （〉 250 mg kg-1）. This suggests that N would become more available 30 d after the incorporation. The CM treatment gave the highest amounts of organic matter and available P in the ranges of 4.64-8.94 g kg-1 and 14.41-36.33 mg kg-1, respectively, during the 60-d column incubation. The CSB treatment tended to have higher available K throughout the measuring period. The NO3--N was leached from the soil column quite quickly on Day 1 of incubation while the loss of NH^-N decreased slightly from Day 1 until the end of the measurement. The amounts of P and K losses varied with the type of soil amendments, and the pattern of the loss was irregular.