Comparison of 17β-Estradiol Adsorption on Corn Straw- and Dewatered Sludge-Biochar in Aqueous Solutions

Removal of steroid hormones from aqueous environment is of prevailing concern because of their adverse impact on organisms. Using biochar derived from biomass as adsorbent to remove pollutants has become more popular due to its low cost, effectiveness, and sustainability. This study evaluated the feasibility of applying corn straw biochar (CSB) and dewatered sludge biochar (DSB) to reduce 17β-estradiol (E2) from aquatic solutions by adsorption. The experimental results showed that the adsorption kinetics and isotherm behavior of E2 on the two biochars were well described by the pseudo-second-order (R² > 0.93) and Langmuir models (R² > 0.97). CSB has higher E2 adsorption capacity than DSB, and the maximum adsorption capacity was 99.8 mg/g obtained from Langmuir model at 298 K, which can be attributed to the higher surface area, porosity, and hydrophobicity of this adsorbent. Higher pH levels (>10.2) decreased the adsorption capacities of biochar for E2, while the ionic strength did not significantly affect the adsorption process. The regeneration ability of CSB was slightly better than that of DSB. The possible adsorption mechanism for E2 on biochar is suggested as π–π interactions, H–bonding, and micropores filling. These results indicated that CSB has more potential and application value than DSB on reducing E2 from aqueous solutions when considering economy and removal performance.     

蚓粪生物炭的氧化处理研究

将蚯蚓粪便慢速热解制成蚓粪生物炭(VB),使用一定浓度的硝酸和硫酸分别对其氧化处理得到氧化后的蚓粪生物炭(OVB)。利用扫描电镜、红外光谱研究了OVB的孔隙、表面官能团情况,考察了氧化剂种类、浓度及处理时间对OVB吸附性能的影响。结果表明,20%硝酸氧化2 h制得的OVB-N-20%-2,其孔隙较发达、均匀,且对亚甲基蓝的去除效果最好。经红外谱图分析,VB、OVB-S-95%-2(VB经95%硫酸氧化2h)及OVB-N-20%-2官能团特征吸收峰位置相近,且在1600cm-1附近与800cm-1-600 cm-1均有吸收峰,表明蚯蚓粪便经高温热解制备的生物炭具有芳香性。     

Investigation of growth responses in saprophytic fungi to charred biomass

We present the results of a study testing the response of two saprophytic white-rot fungi species, Pleurotus pulmonarius and Coriolus versicolor, to charred biomass (charcoal) as a growth substrate. We used a combination of optical microscopy, scanning electron microscopy, elemental abundance measurements, and isotope ratio mass spectrometry (¹³C and ¹⁵N) to investigate fungal colonisation of control and incubated samples of Scots Pine (Pinus sylvestris) wood, and charcoal from the same species produced at 300 °C and 400 °C. Both species of fungi colonise the surface and interior of wood and charcoals over time periods of less than 70 days; however, distinctly different growth forms are evident between the exterior and interior of the charcoal substrate, with hyphal penetration concentrated along lines of structural weakness. Although the fungi were able to degrade and metabolise the pine wood, charcoal does not form a readily available source of fungal nutrients at least for these species under the conditions used in this study.     

生物质炭对黑土磷吸附-解吸特性的影响

利用平衡法研究添加不同质量分数的3种生物质炭(玉米秸秆、稻壳和松木)对黑土中磷吸附和解吸特性的影响.结果表明:随着生物质炭添加质量分数的增加,生物质炭对黑土中磷的吸附量先增加后减少,当添加质量分数为1.2%时,黑土对磷的吸附量最大;添加不同生物质炭对黑土中磷的吸附能力影响顺序为:松木玉米秸秆稻壳;添加松木生物质炭的黑土对磷的实际最大吸附量为0.697mg/g;添加生物质炭的黑土对磷的吸附量和解吸量均随加入磷溶液质量浓度的增加而增加,但增加幅度逐渐变小;添加生物质炭的黑土对磷的等温吸附曲线符合Langmuir吸附方程.     

大豆秸秆生物炭对废水中Ni(II)的吸附性能

为了能以更有效更经济的方法去除废水中的Ni(Ⅱ),选用成本低廉的大豆秸秆制备生物炭作为吸附剂,研究了炭化温度、溶液pH、吸附剂投加量、溶液温度、Cd(Ⅱ)质量浓度对吸附效果的影响,得到了最佳的吸附条件,开拓了去除重金属镍的新方法,同时研究了生物炭对Ni(Ⅱ)的吸附动力学和吸附等温线。实验表明,大豆秸秆生物炭对Ni(Ⅱ)有较好的吸附性能,Ni(Ⅱ)质量浓度为20mg/L,炭化温度为500℃,pH为7,投加量为0.2g,室温为25℃,Cd(Ⅱ)质量浓度为0为最佳吸附条件。吸附反应符合准二级动力学方程。吸附等温线符合Langmuir模型,25℃时饱和吸附量为14.38mg/L。扫描电镜分析显示,炭化使得秸秆孔道结构增多,表面粗糙程度加剧,比表面积增大,从而提高了吸附性能。     

不同施肥模式对杨树人工林土壤微生物功能多样性的影响

土壤微生物多样性是维持人工林土壤生产力的重要组成部分。为了解不同施肥处理对杨树人工林土壤微生物多样性的影响,以苏北沿海地区8年生杨树人工林为对象开展施肥试验,共设置6种施肥处理:CK(对照)、T1(NPK复合肥)、T2(有机肥)、T3(生物炭)、T4(NPK复合肥+生物炭)、T5(有机肥+生物炭),采用Biolog-Eco法测定了土壤微生物的功能多样性。研究结果表明:①各种施肥处理都不同程度地促进了土壤微生物的生长。T4、T5处理增加了土壤pH、TC(全碳)、TC/TN(全碳氮比),它们的土壤微生物量也显著最高。T3处理可能改变了土壤微生物群落结构。②T2、T3、T4、T5处理都增加了土壤微生物整体活性和碳源利用能力,其中T5处理碳源利用能力显著高于其他处理,而T1处理减弱了微生物碳源利用。③土壤微生物对碳源的利用能力存在季节差异,在不同季节从强到弱依次表现为夏季、春季、秋季、冬季; 生物炭配施有机肥改变了微生物对碳源利用能力的季节动态,表现为春季最高。     

Influence of surface characteristics on carbon disulfide catalytic hydrolysis over modified lake sediment biochar and research on deactivated mechanism

A series of lake sediment biochar (LSB) catalysts modified by metal oxides and basic functional groups were utilized for removal of carbon disulfide (CS₂) in yellow phosphorus tail gas. The influences of preparation and modification conditions for surface characteristics of Fe-KOH/LSB on removal of CS₂ were investigated. Surface area and pore structure analyses indicated that preparation processes were aimed to increase the micropore structure of LSB. Diffuse reflection using transform of Fourier infrared radiation results showed that Fe had high hydrolysis activity for CS₂ and low oxidation activity for H₂S. Thermogravimetric/differential thermal analysis results indicated that low calcination temperature was not conducive to the generation of Fe₂O₃ and high calcination temperature led to the oxidation of LSB. CO₂ temperature programmed desorption results stated that high alkalinity site strength could improve the catalytic hydrolysis performance. High KOH content could enhance alkalinity site strength but led to the block of pore. These modification factors mainly controlled the catalytic hydrolysis ability of Fe-KOH/LSB. X-ray photoelectron spectroscopy results claimed that the deactivation of Fe-KOH/LSB was attributed to the generation of S and sulfate, and the consumption of active component. In the deactivation process, S and sulfate generated and covered the activity sites, and Fe₂O₃ was converted into FeSO₄ or Fe₂(SO₄)₃, which led to the deactivation.     

Characterization Techniques as Supporting Tools for the Interpretation of Biochar Adsorption Efficiency in Water Treatment: A Critical Review

Over the past decade, biochar (BC) has received significant attention in many environmental applications, including water purification, since it is available as a low-cost by-product of the energetic valorisation of biomass. Biochar has many intrinsic characteristics, including its porous structure, which is similar to that of activated carbon (AC), which is the most widely used sorbent in water treatment. The physicochemical and performance characteristics of BCs are usually non-homogenously investigated, with several studies only evaluating limited parameters, depending on the individual perspective of the author. Within this review, we have taken an innovative approach to critically survey the methodologies that are generally used to characterize BCs and ACs to propose a comprehensive and ready-to-use database of protocols. Discussion about the parameters of chars that are usually correlated with adsorption performance in water purification is proposed, and we will also consider the physicochemical properties of pollutants (i.e., K_ow). Uniquely, an adsorption efficiency index BC/AC is presented and discussed, which is accompanied by an economic perspective. According to our survey, non-homogeneous characterization approaches limit the understanding of the correlations between the pollutants to be removed and the physicochemical features of BCs. Moreover, the investigations of BC as an adsorption medium necessitate dedicated parallel studies to compare BC characteristics and performances with those of ACs.     

载锆玉米秸秆生物炭的结构表征及磷吸附效果

以玉米秸秆为原料,利用氧氯化锆浸渍-限氧热解法制备一种新型的载锆生物炭阴离子吸附剂.采用场发射扫描电镜(FE-SEM)、傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)和比表面积测定(BET-N₂)等手段,对空白生物炭(BC)及载锆生物炭(Zr-BC)的形貌、组成及结构进行表征.结果表明:热解后的生物炭表面形貌粗糙,均发育有裂纹和蜂窝状大孔结构;与BC相比,Zr-BC比表面积和平均孔径都有降低,且表面元素含C量大幅降低,含O量显著增加,Zr质量分数达到15.7%;Zr-BC表面主要官能团有羟基(-OH)、羧基(-COOH)、锆羟基氧化物等,构成吸附性能的结构基础;当pH值为2时,Zr-BC对磷酸盐吸附效果最显著,符合Freundlich等温吸附线模型.通过多种阴离子混合吸附测试发现,Zr-BC对水中磷酸盐有较高吸附量,且选择性较高.     

生物炭添加对土壤冻融过程中温室气体排放的影响

【目的】研究模拟生物炭添加对土壤冻融过程中二氧化碳(CO₂)、甲烷(CH₄)和氧化亚氮(N₂O)排放的影响,为冻融期土壤温室气体的减排提供参考。【方法】以伊犁河谷典型农田为研究对象,野外采集原状土柱,并在室内模拟不同幅度的冻融过程(+5 ℃、-5 ℃～ +5 ℃和-10 ℃ ～ +10 ℃),探求冻融过程中土壤CO₂、CH₄和N₂O排放对生物炭添加(0、20和40 t/hm²)的响应特征。【结果】与不添加生物炭的处理相比,添加生物炭会使冻融过程中的土壤CO₂排放量提高1.1～1.4倍,但该影响远小于冻融作用对土壤CO₂排放的促进作用(为CK的1.5～3.2倍); 虽然冻融作用未显著(P > 0.05)影响土壤CH₄的累积排放量,但生物炭的添加显著(P < 0.05)促进了45.5%～81.8%的CH₄吸收量; 冻融作用使土壤N₂O的累积排放量提高了1.3～3.0倍,生物炭降低了冻融过程中10.2%～30.9%的土壤N₂O排放量,但在多数情况下这种减小并不显著(P > 0.05)。【结论】模拟生物炭添加会增加土壤冻融过程中CO₂的排放,也会促进CH₄的吸收和N₂O的减排。