Effect of nitrogen fertilizer on biomass production and nodulation behavior of Pongamia pinnata Pierre seedlings under nursery conditions

At the seedling stage, a small amount of N is required to boost growth of leguminous plants. A pot experiment was conducted to observe the effect of N fertilizer on various growth parameters and nodulation behavior of Pongamia pinnata under nursery conditions. After the estab- lishment of seedlings, four nitrogen treatments, 0, 40, 80 and 100 kg-ha^-1 N were applied in two equal splits. Monthly observations were taken for the morphological parameters viz. plant height, collar diameter, leaf number, root length, root shoot ratio, nodule number and weight per plant. Maximum plant height was recorded after application of N at 40 kg.ha^-1. Seasonally, the difference in collar diameter in rainy season was signifi- cantly higher than in winter or summer. However, more leaves were produced per plant at N-40 and N-100 treatments in winter and rainy seasons. Higher root length was recorded in rainy season than in winter or summer. Root biomass was higher than for stems or leaves. Seasonal effects of N-80 and N-40 treatments on leaf dry weight were significantly higher than for N-100 or N-0. Stem dry weight was higher at N-40 than at other treatments in winter and summer seasons. Root：shoot ratio was higher throughout winter to early summer. Nodule biomass was 2-3 times higher in rainy season compared to winter or summer. Maximum nodule number and biomass per plant were highest at N-40, followed by N-0, N-80 and N-100 treatments. New nodule formation started from June to the end of September. Maximum biomass per plant was recorded at N-40, followed by N-80, N-100 and N-0. Nitrogen treatment effect and seasonal behaviour interaction were not significant. Significantly higher numbers of nodules per plant were recorded in rainy season followed by summer and winter for all treatments. Higher nitrogen doses suppressed growth while lower doses promoted growth in Pongamia pinnata. Therefore, the lower nitrogen dose i.e., N-40 Kg.ha^-1 applied in two equal splits was suitable at the initial nursery stage for the increase in nodula- tion and biomass production.

Investigation of the role of Ca(OH)2 in the catalytic Alkaline Thermal Treatment of cellulose to produce H2 with integrated carbon capture

The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a carbon-neutral process that has the potential to be carbon-negative.This study has shown that the conversion of cellulose tosuppressedcan be achieved through the reforming of gaseous intermediates in a fixed bed of 10%Ni/ZrO2.Reforming occurs at low temperatures≤773 K,which could allow for improved sustainability.

The effect of particle size and amount of inoculum on fungal treatment of wheat straw and wood chips

Background： The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains（0.5, 1.5 or 3.0 % per g of wet weight of substrate） added to the substrates. Also, wheat straw and wood chips were chopped to either 0.5 or 2 cm.Effectiveness of the fungal treatment after 0, 2, 4, 6, or 8 wk of incubation was determined by changes in chemical composition, in vitro gas production（IVGP） as a measure for rumen degradability, and ergosterol content as a measure of fungal biomass.Results： Incomplete colonization was observed for C. subvermispora treated wheat straw and L. edodes treated wood chips. The different particle sizes and amounts of inoculum tested, had no significant effects on the chemical composition and the IVGP of C. subvermispora treated wood chips. Particle size did influence L.edodes treatment of wheat straw. The L. edodes treatment of 2 cm wheat straw resulted in a more selective delignification and a higher IVGP than the smaller particles. Addition of 1.5 % or 3 % L. edodes inoculum to wheat straw resulted in more selective delignification and a higher IVGP than addition of 0.5 % inoculum.Conclusion： Particle size and amount of inoculum did not have an effect on C. subvermispora treatment of wood chips. At least 1.5 % L. edodes colonized millet grains should be added to 2 cm wheat straw to result in an increased IVGP and acid detergent lignin（ADL） degradation.

Assessment of Biomass Productivities of Chlorella vulgaris and Scenedesmus obliquus in Defined Media and Municipal Wastewater at Varying Concentration of Nitrogen

Microalgae are emerging as one of the most promising long-term sustainable sources of renewable energy. Studies were conducted on two freshwater Chlorophytes, Chlorella vulgaris and Scenedesmus obliquus to evaluate heterotrophic growth rate and biomass productivity in filter-sterilized defined medium (BG 11) and municipal wastewater, both with varying concentrations of nitrogen (N). For each isolate, cultures were separately incubated in triplicate at room temperature with constant agitation on a shaker at 150 rpm for 9 days. In 0.25 mg N/L BG11 medium, the growth rate and biomass productivity of C. vulgaris were 0.28 day-1 and 3.5 g·L-1, respectively. In wastewater, the same amount of N addition resulted in a higher growth rate 0.44 day-1 and associated biomass productivity of 4.96 g·L-1. Increasing N levels to 0.5 mg N/L in BG11 caused an increase in growth rate (0.37 day-1) and biomass productivity (4.28 g·L-1), while the increase in N in wastewater caused growth to decline to 0.32 day-1 with decreased biomass productivity of 2.19 g·L-1. A further increase in N to 1.0 mg N/L in BG11 caused an increase in the growth rate (0.43 day-1) and a decrease in biomass productivity (3.64 g·L-1), while in wastewater, growth rate and productivity of C. vulgaris were 0.32 day-1 and 2.31 g·L-1, respectively. Overall, C. vulgaris grew faster and produced greater biomass than S. obliquus under comparable conditions. Based on high growth rate and biomass productivity of C. vulgaris, it could be a potential candidate for further consideration for simultaneous wastewater treatment and biofuel production.

Biosorptive Removal of Lead Ions from Aqeuous Stream by Using Leaves, Stems and Roots of Momordica charantia Biomass

Water pollution is one of the most important issues of the 21st century. It takes place when the pollutants are being entered into a water reservoir without any treatment. Heavy metals are one of the major harmful pollutants that exist in the water;therefore, it is necessary to remove these toxic metals to keep our environment safe. Biosorption is an ecofriendly and economical technique for the elimination of these toxic metals from polluted water. In this research work roots, stems, and leaves of Momordica charantia (Bitter gourd) were used as biosorbent for the elimination of Pb (II) ions from aqueous solution. Many different parameters such as metal ion solution pH, biomass dosage, initial metal ions concentration and contact time were optimized in the batch experiments. The calculated results revealed that biosorption of Pb (II) was maximum at solution pH 5, biosorbent dosage of 0.1 g and 100 ppm of initial metal ions concentration within 240 minutes of contact time. M. charantia’s leaves showed the highest level of lead biosorption capacity (47.62%), followed by stems (42.36%) and roots (38.47%). The Freundlich isotherm and pseudo-second order kinetics model fitted well for the analytical data. The results indicated that Momordica charantia is an effective biosorbent for Pb (II) ions elimination from wastewater.

砷污染治理背景下阳宗海浮游植物生物量的时空分布模式及驱动因子

在社会经济发展和流域开发持续的背景下,砷污染已成为我国部分水体面临的重要环境问题,目前对砷污染防控的生态效应与修复效果评价仍缺乏系统识别。湖泊生态系统中浮游植物是重要的生产者,砷等重金属污染可以直接影响浮游植物生长、物种演替和初级生产力水平,浮游植物已成为指示砷污染水平及其生态效应的敏感指标。本研究以长期受到砷污染胁迫并经历污染治理的阳宗海为研究对象,设置南、中、北3个调查位点,于2015年4月-2019年12月对浮游植物和水质因子开展季节调查和空间分析,通过识别浮游植物生物量的时空分布模式与驱动因子,评价了砷污染与治理下浮游植物生物量的变化机制和生态修复效果。调查结果显示,采样期间阳宗海浮游植物以蓝藻门为主,浮游植物的生物量范围为0.7~30.4 mg/L,平均生物量在2016年最低((3.0±1.8)mg/L)、在2017年最高((10.5±8.9)mg/L)。ANOVA分析结果显示,浮游植物生物量存在显著的季节差异而空间差异不明显。相关分析结果显示,阳宗海浮游植物生物量与砷浓度和透明度呈显著负相关,而与水体温度和p H呈显著正相关。多元线性回归分析进一步显示,砷和水温是驱动阳宗海浮游植物生物量变化的显著环境因子。由此可见,在重金属污染湖泊经过修复后,水体砷遗留物的毒性效应仍然对浮游植物生长产生了明显的抑制作用,表明了水体重金属污染物可能具有长期的沉积物释放作用与持久的生态毒理效应。

微藻处理含抗生素类废水研究进展

随着抗生素的广泛应用,含抗生素类废水的处理问题已然迫在眉睫。微藻技术已被证实具有降解抗生素污染物的潜力,现已被行业学者广泛研究。微藻作为混合营养型生物,可以通过吸收CO_(2)和营养物质来合成糖类、蛋白质和脂质等化合物,现已被证实具有降解污染物的潜力。综述了利用微藻处理含抗生素废水的传统方法和新型方法、多种方法协同处理的效果及其优劣势。探讨了处理后微藻的生物质合成情况、抗生素的降解机制并比较了这些机制的贡献。最后总结了目前利用微藻处理含抗生素类废水的不足并且阐明了后续需重点关注的研究方向,以期为日后微藻处理抗生素进一步规模化发展和资源化利用打下基础。

山竹皮吸附剂对铜离子的吸附行为及其燃烧特性研究

以山竹果皮渣为原料,经过异丙醇脱色、碱性试剂活化制备出吸附材料,用于吸附溶液中的铜离子。实验结果表明,pH值升高有利于山竹皮吸附剂吸附铜离子,最大吸附容量达1.5 molCu^(2+)/kg,且30 min内可达到吸附平衡。负载铜离子数量对吸附剂燃烧热分解的特征温度有显著影响,铜离子浓度低于2 mmol/L时,负载的铜离子数量增加,其开始热分解以及剧烈燃烧分解的温度点显著降低;铜离子浓度高于2 mmol/L后,其热分解温度特征值不再发生明显变化。铜离子在燃烧过程中扮演催化剂的作用,能有效促进燃烧反应。

不同基质处理对蒜头果幼苗生长的影响

为提高蒜头果(Malaniaoleifera)幼苗品质和造林成活率,以泥炭土、轻基质、黄心土、松针、蛭石和珍珠岩为原料,设计9个不同基质处理,测定蒜头果幼苗生长和生物量指标,并分析其与基质理化性质的相关性,结合主成分分析对不同基质处理进行综合评价。结果表明,在不同基质处理下,蒜头果幼苗生长指标均存在差异。T5处理的苗高和地径总生长量均最高,分别为69.39 cm和8.31 mm。T1处理的地上部分鲜质量总重、全株鲜质量、地上部分干质量总重和全株干质量均最高,分别为36.13、69.97、15.57和25.94 g。T8处理的地下部分鲜质量和地下部分干质量均最高,分别为37.03和11.13 g。苗高与土壤密度呈显著负相关,与速效磷含量呈显著正相关,与速效氮和速效钾含量均呈极显著正相关。地径与土壤密度呈极显著负相关,与田间持水量和总孔隙度均呈显著正相关,与速效氮和速效钾含量均呈极显著正相关。幼苗地上部分鲜质量、全株鲜质量和地上部分干质量均与总孔隙度呈显著正相关。全株鲜质量与速效氮含量呈显著正相关。T1处理的叶生物量和全株生物量均最高,综合得分最高;T5处理的苗高和地径均表现最好,叶生物量低于T1处理;T8处理的根系生长最好,最有利于幼苗地下部分生长;这3个基质配方均适用于蒜头果幼苗培育。

蒸汽爆破对木质纤维素高值化利用的研究进展

木质纤维素生物质是一种量大面广且廉价易得的可再生资源,已逐步实现由生物质向生物燃料、饲料原料和其他附加值产品的开发及应用,这样的高值转化与综合利用成为“走绿色发展道路、构建绿色生产体系”的重要部分。然而,木质纤维素的天然抗降解屏障及其独特的理化性质,纤维素-半纤维素-木质素三大组分的刚性网络一直是高效转化的瓶颈所在,合理有效的预处理技术则是资源化进程的关键步骤。本文落脚于木质纤维素生物质的基本组成和结构特性分析,在总结物理法、化学法、生物法等传统预处理方法优劣势的基础上,着重阐述了蒸汽爆破的发展历程、加工类型、适用范围、工作原理、反应阶段、技术特点、影响因素、主要参数和可能的副产物效应等,以及在生物质的纤维改性、结构变化、溶解特性、低聚糖制备、活性成分提取与反刍饲料化利用层面的研究进展。此外,还指出蒸汽爆破辅以真菌、细菌为主的微生物发酵,以及糖酶外源添加的后处理流程的发展趋势。最后,归纳了蒸汽爆破在未来商业化、工业化和规模化生产推广中可能面临的困难和挑战,分析提出相应的突破点和解决策略。并就蒸汽爆破技术对常见副产物类型饲料原料的降解效果,及其在单胃动物日粮中的合理应用进行展望,以期为该技术对生物质资源的开发、增值、饲料化应用的诸多潜能提供新思路和技术指导。

枣树枝改性生物炭对水溶液中锌离子的吸附性能研究

通过水热碳化枣树枝生成水热炭,以氯化锌为活化剂对水热炭进行活化,得到枣树枝改性生物炭,所得生物炭表面具有丰富的孔结构及高度芳香化结构。以枣树枝改性生物炭为吸附剂吸附溶液中Zn^(2+),在吸附时间80 min、溶液pH=9、改性生物炭投加量700 mg/L、反应温度55℃、Zn^(2+)初始浓度30 mg/L条件下,Zn^(2+)去除率达到99%以上;吸附过程与Freundlich吸附模型拟合度高,表明改性生物炭对Zn^(2+)的吸附过程为多层分子吸附;改性生物炭经5次循环吸附与解吸后,对Zn^(2+)去除率仍在97%以上。

咖啡渣在纺织领域的研究现状

生物质能是环境友好型能源,具有低成本、易获得、无污染等优点。咖啡渣作为生物质能中的食品废弃物类,因其含有咖啡因、油脂、蛋白质等有效成分以及单宁酸、咖啡酸等多酚类物质,可广泛应用于农业、食品、环境、医药、纺织等领域,制得的产品具有成本低廉、绿色环保等优点并展现出优良特性。概述近年来咖啡渣用于纺织领域中染色、印染废水处理以及新型纤维开发3个方面的研究情况。从基本应用性能(染色、吸附性能等)、附加性能(抗氧化、抗紫外线、抗菌性能等)以及处理中能源耗用情况、处理后二次废弃物处理情况等方面,分析当前咖啡渣材料用于纺织领域的发展现状及存在的问题,并对其发展前景进行展望。

基于碱热处理联合工艺的真实生物质制高纯氢气及其三组分影响研究

生物质碱热处理(ATT)制氢技术具有工艺简单、条件温和的特点,是一种高效的热化学制氢技术。本文采用ATT、催化蒸汽重整与碱吸收的联合工艺实现真实生物质向高纯H_(2)的直接转化,重点探究真实生物质类型以及三组分(纤维素、半纤维素和木质素)相互作用对ATT过程和联合工艺制氢效果的影响。结果表明:真实生物质ATT制H_(2)产量与三组分的含量有关,通过ATT联合工艺制备了高产量和高纯度的H_(2)(>99.9%),该工艺对于不同的真实生物质具有普适性。真实生物质中的木质素软化熔融会阻碍纤维素和半纤维素转化为焦炭,纤维素和半纤维素生成的活性炭会促进木质素衍生炭的碱化反应,从而影响ATT过程中H_(2)和CH_(4)的生成速率峰值和峰值温度,而三组分之间的相互作用对真实生物质ATT及其联合工艺中H_(2)和CH_(4)的产量影响较小。

生物滤池反冲洗过程中生物量和生物活性的分析

用生物膜过滤柱对污水进行深度处理的中试研究表明 ,滤柱挂膜期间低强度的反冲洗 ,使局部积累的生物在滤柱全层得到重新分布 ,生物活性得到增强 ,挂膜时间缩短 30 %.生物量和生物活性同滤层高度有良好的正向相关性 ,从而推导出 q(x) =∫x0m(x)n(x)dxx 为单位体积滤料的生物平均需氧量 ,利用该式可得出生物膜过滤柱最佳反冲洗气强度 .突破传统普通快滤池用膨胀率来确定反冲洗气强度的做法 ,采用生物量和生物活性来确定反冲洗气强度对于生物膜过滤柱来说更符合其本身的生物特性 ,从而更具有实用价值 .

生物质水热转化工艺优化与液体产物特性研究

为了研究生物质在水热降解过程中产物的分布及其液体产物特性,首先通过正交试验对生物质水热转化的工艺进行优化,根据不同的目标产物探索最优工艺条件,并对生物质样品的种类、反应温度、停留时间、原料质量和粒径等反应因素的变化规律进行研究,所得重质油产率最佳工艺条件是：采用松木屑为原料,温度250℃,停留时间15 min,原料质量10 g,水质量110 g,生物质粒径80-150目,此时松木屑的干基重质油产率（质量分数）为28.00%。最后结合正交试验结果,选取棉秆为原料,研究单因素反应条件（温度、时间、粒径以及催化剂）下产物产率分布和液体产物特性。结果表明,在无催化剂加入的试验中,温度300℃,停留时间10 min,粒径80~150目下棉秆重质油产率（质量分数）最大为24.14%;当K2CO3作为催化剂,停留时间为20 min时,重质油产率由未添加催化剂时的18.00%提高至29.86%,催化剂的加入在提高油产率的同时,对油的组份也产生了影响,酸类和酮类物质减少,油的p H值提高。

脂磷生物量作为活性生物量指标的研究

脂磷法是目前应用较为广泛的一种测定生物量的方法,为证明该方法的测定结果能够代表活性生物量,采用不同的消毒剂量(0.10～2.20 mg/L)和接触时间(0～120 min),对生物膜和土壤样品的生物量同时用HPC法和脂磷法进行了测定。结果表明,两种方法所得生物量的变化趋势大体一致,尤其是在高消毒剂量下,当基于培养的HPC法不能测定出可培养生物量时,脂磷法的测定结果也为零,表明脂磷法的测定结果也可以代表样品中活性生物量的水平;而在低消毒剂量下脂磷法的测定结果远远高于HPC法的,进一步说明了脂磷法在测定不可培养型活性生物量方面具有优势。

锯末在重金属废水处理中的应用

锯末是一种来源丰富且价格低廉的农林废弃物,作为低成本吸附剂在环境污染治理中日益受到重视。它能有效去除废水中的重金属。作者综述了近年来锯末在不同类型重金属废水处理中的研究与应用进展,分析了生物质处理废水的吸附机理、影响因素、吸附动力学,指出了生物质吸附法处理废水的发展方向。

耕作措施对土壤水热特性和微生物生物量碳的影响

通过山西寿阳设置的8a田间定位试验,比较了全量秸秆还田、免耕覆盖和常规耕作3种耕作措施下土壤含水量、温度及土壤微生物生物量碳变化。结果表明:免耕覆盖与全量还田处理显著提高土壤含水量,与常规耕作相比表层土壤体积含水量在玉米苗期、拔节期、灌浆期和成熟期分别高出18%、22%、29%、21%和3%、10%、12%、13%,具有保水保墒的作用。在苗期不同耕作措施对土壤温度的影响达到显著水平,5 cm处免耕覆盖、全量还田与常规耕作处理土壤温度依次为:18.12、18.76和19.44℃,免耕覆盖和全量还田处理平均温度比常规耕作分别低1.32℃和0.69℃。土壤微生物量碳在整个生育期动态变化是首先迅速上升在玉米生育高峰期(拔节期)达到最高峰,然后开始下降,成熟期趋于平缓。免耕覆盖与全量还田处理下玉米各生育期土壤表层微生物量碳显著高于常规耕作,在苗期、拔节期、灌浆期和成熟期分别比常规耕作高出70%、40%、85%和30%和10%、20%、15%和15%。土壤微生物量碳与土壤温度和土壤含水量相关和极相关。

酸预处理对生物质热裂解规律影响的实验研究

在自制的热裂解机理实验台上进行了不同酸处理对稻壳以及白松的热裂解影响实验研究。经过盐酸浸泡后,稻壳中的金属离子含量明显降低;经盐酸洗涤后的稻壳热裂解焦油产量升高,由原始物料时的41.74%增加到7%盐酸洗涤后的52.88%,而气体和焦炭产量相应降低,并且随着盐酸浓度的增加,对应的趋势更加明显。酸洗涤后稻壳热裂解气体产物主要由CO和CO2组成,其产量相比原样都有所降低;不同种类的酸对生物质热裂解规律的影响存在差异,盐酸因其去离子效果最好而对生物质热裂解产物分布影响最强;对白松原样以及酸洗后白松的微观结构进行了电镜分析,结果发现,硫酸对白松的微观结构产生了明显的影响。

生物质垃圾转化为生态肥料的水热技术试验研究

在2L的高压反应釜中,利用水热技术,对甘蔗渣、树叶和菜皮3种生物质垃圾的转化产物和机理进行了研究。结果表明,在反应温度为140℃～260℃、反应时间为1～4h、催化剂为Na2CO3的条件下,生物质转化得到的产物中含有大量的腐植酸物质。此外,研究了温度、时间和催化剂等条件对产物中腐植酸物质的含量的影响,并对产物中的含氧基团进行了测定。通过比较发现,在温度为160℃、时间为1.5h的条件下,固态产物中的腐植酸含量能达到45%左右。这类腐植酸物质可以作为生态肥料,具有良好的肥效和经济价值。