成型表面改性生物质环境材料制备及其吸附水中多环芳烃的研究

700℃热解炭化大豆秸秆8h,经H3PO4溶液表面改性处理后,采用成型工艺技术制得成型表面改性生物质环境材料。测定了所制备的表面改性秸秆生物质环境材料的比表面积、表面形态及其对亚甲基蓝的吸附性能;以单一多环芳烃(PAHs)菲和复合PAHs萘、菲、苊为目标污染物,研究了生物质环境材料对水中有机污染物的吸附性能。结果表明,成型工艺制备的生物质活性炭的比表面积为320～359m2/g,孔隙高度发达。SEM结果显示,成型压力、热处理温度和热处理时间明显影响所制得材料的表面形态。成型工艺对亚甲基蓝吸附值影响顺序为热处理温度>成型压力>胶粘剂比例>热处理时间;成型生物质环境材料的最佳制备条件为:粘结剂比例15%、成型压力65MPa、热处理温度260℃、热处理时间90min。按此条件制得的生物质环境材料对亚甲基蓝的吸附值达135mg/g。成型工艺制备的秸秆生物质环境材料对水中菲的去除率均超过98%,与商品活性炭对菲的去除率相当;其对复合污染下3种PAHs的去除率为菲>萘>苊,对于同一PAHs,不同生物质环境材料的吸附能力存在差异。

Production of Biotechnology Fulvic Acid from Fermented Corn Straw by Microbial Community LCM9 and Its Application Effect

[Objective] The aim was to evaluate the feasibility of biotechnology fulvic acid produced by microbial community LCM9 by the use of corn straws as substrate and its application effect.[Method]Microbial community was obtained from the nature samples,and corn straws were used as fermentation substrate.The yield of biotechnology fulvic acid and its application effect was evaluated.[Result]The yield of biotechnology fulvic acid was up to 15.7% when the water content was 75.0% and fermented after 7 d using corn straws as the only source of nutrition.After 500 mg/kg of biotechnology fulvic acid was added for 5 d,the root length and bud length could be increased by 59.1% and 97.1%,respectively.[Conclusion]A higher yield of biotechnology fulvic acid could be obtained by the method in this experiment and the product could enhance the growth of wheat seedlings.

Research of Pyrolysis Oil and Catalysts of Garlic Stalks

We undertook a pyrolysis research on garlic stalks to solve its difficulty in use. We found that the inorganic salts in biomass played an important role in catalytic pyrolysis. Moreover, we studied the pyrolysis behavior under catalyst and catalyst-free conditions. The results showed that the weightlessness rate of garlic stalks was the highest at 550 ℃ under catalyst-free condition. The oil production rate increased with the increase of temperature and reached the peak at 550 ℃. Subsequently, as the temperature increased, the secondary cracking was intensified and oil production rate was decreased. The oil production rate increased significantly （almost 15%） under catalysis of KOH. However, the oil production rate was the highest at 500-600℃. What＇s more, we found that KOH played a major role in promoting decomposition of surface skin cells and subcutaneous fibrous layer of garlic stalks.

Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion

Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide （KOH） to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations of 1% （KI）, 3% （[（2）, 6% （K3） and 9% （l（4） were tested for wheat straw pretreatment at ambient temperature with a C：N ratio of 25：1.86% of total solids （TS）, 89% of volatile solids （VS） and 22% of lignocellulose, cellulose and hemi- cellulose （LCH） （22%） were decomposed effectively with the wheat straw pretreated by 6% KOH. Enhanced bio- gas production and cumulative biomethane yield of 258 ml. （g VS）-1 were obtained increased by 45% and 41% respectively, compared with untreated wheat straw. Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium （l 38%）, calcium （22%） and magnesium （16%）. These results show that TS, VS and LCH can be effectively removed from wheat straw pretreated with KOH, improving biodegradability biomethane production and fertilizer value.

Effects of Microbial Agents on Kitchen Waste and Rice Straw Composting

In order to clarify the influence of microbial agents on kitchen waste and rice straw composting, an aerobic composting experiment was conducted by setting three kinds of combined bacterial agents to study the temperature change in the composting, and pH value, nutrient contents, C/N and heavy metal content after composting through. The three kinds of combined bacterial agents were as follows:B1 with effective strains: Bacillus subtilis, yeast and Trichoderma sp.;B2 with effective strains: Bacillus amyloliquefaciens, yeast and lactic acid bacteria;B3 with effective strains: Bacillus subtilis, yeast and lactic acid bacteria. Results showed that the addition of microbial agents had signifcant effects on temperature change,nitrogen and phosphorus content and C/N of the compost. T1, T2, and T3 treatments lasted for 8, 5 and 4 d in the thermophilic phase above 60℃, respectively. The total nitrogen content of each treatment was 14.90, 15.50 and 13.80 g/kg respectively after composting. The total phosphorus content of each treatment was 4.87, 4.17 and 3.70g/kg respectively at the end of composting. The C/N of each treatment was 20.94,22.63, and 22.65 respectively at the end of composting. The application effect of B1bacteria agent on the composting of kitchen waste and rice straw was better.

Production of bio-ethanol by consecutive hydrogenolysis of corn-stalk cellulose

Current bio-ethanol production entails the enzymatic depolymerization of cellulose,but this process shows low efficiency and poor economy.In this work,we developed a consecutive aqueous hydrogenolysis process for the conversion of corn-stalk cellulose to produce a relatively high concentration of bio-ethanol(6.1 wt%)without humin formation.A high yield of cellulose(ca.50 wt%)is extracted from corn stalk using a green solvent(80 wt%1,4-butanediol)without destroying the structure of the lignin.The first hydrothermal hydrogenolysis step uses a Ni–WO_(x)/SiO_(2)catalyst to convert the high cumulative concentration of cellulose(30 wt%)into a polyol mixture with a 56.5 C%yield of ethylene glycol(EG).The original polyol mixture is then subjected to subsequent selective aqueous-phase hydrogenolysis of the C–O bond to produce bioethanol(75%conversion,84 C%selectivity)over the modified hydrothermally stable Cu catalysts.The added Ni component favors the good dispersion of Cu nanoparticles,and the incorporated Au3+helps to stabilize the active Cu^(0)-Cu^(+)species.This multi-functional catalytic process provides an economically competitive route for the production of cellulosic ethanol from raw lignocellulose.

Sweet Corn Production and Nutritive Value of Stover with Manure Enriched with Rock Phosphate Fertilizer and Biodecomposer

Zea mays var. saccharata （sweet corn） is an important crops grown for food and feed in the tropics. In Indonesia, most of the land used for crops production is characterized by acid pH and low levels of nitrogen and phosphorus. Phosphorus fertilizers have been widely used to improve soil fertility in Indonesia. Given the high cost of superphosphate （SP）, the focus is now on rock phosphate （RP） fertilizer, which is relatively cheaper than SP and shows high solubility in acid condition. The combination of RP and manure during the decomposing process and the addition of decomposing microbes may be a promising technique to overcome the problem. A field experiment was conducted on a vertisol soil （low pH and low available nitrogen and phosphorus）. The objective of the research is to evaluate the effect of combinations of manure enriched with RP （granular and non-granular） with three different decomposing microbes （EM4, starTmik and stardec） on sweet corn and dry matter production, phosphorus （P） and calcium （Ca） content in above-ground biomass. A completely randomized design with seven treatments and four replicates was used in this experiment. The size of the plots was 3 m x 2.5 m. The treatments were TO （manure）, T1 （manure ＋ EM4）, T2 （manure ＋ starTmik）, T3 （manure ＋ stardec）, T4 （manure granular ~ EM4）, T5 （manure granular ＋ starTmik）, T6 （manure granular ＋ stardec）. The manure was enriched with RP 66 kg P/ha （150 kg P2Os/ha） and inoculated with the biodecomposer according to the assigned treatment. The manure was applied in a rate of 30 t/ha. All plot received 125 kg KC1/ha （150 kg K20/ha） and 200 kg urea/ha as basal fertilization. Sweet corn was harvested 70 d after planting. Sweet corn plants were cut close to the ground and analyzed for dry matter yield （DM） and P and Ca content in the biomass. Result showed that sweet corn and DM yield and P content were not significantly influenced by the treatments. Ca content in the above-ground biomass, in turn, differed among the treatments. Manure enriched with RP fertilizer was not significantly diferent on Ca content of stover. Thus, it seems that no gain occurs in sweet corn production and nutritive value of stover from the addition of microbes to manure enriched with RP in a acid vertisol soil. In conclusion, manure enriched with RP with or without biodecomposer, in granular or non-granular form, resulted in similar on sweet corn and DM production, P and Ca content of stover.

Allelopathic Potentials of Some Crop Residues on the Germination and Seedling Growth of Chromolaena Odoratum L.

The allelopathic effects of aqueous extracts of rice husk （Orza sativa L.） and sorghum stem （Sorghum bicolor L.） on the germination and seedling growth of Chromolaena odoratum L. were investigated. The extracts of the two crop residues exhibited inhibitory effects on the germination and seedling growth of Chromolaena odoratum L. The degree of retardation demonstrated in both extracts was concentration dependent. However the results obtained revealed that the retardation was more pronounced in the rice husk extract-treated seeds. However statistical analysis （P 〈 0.05% level） revealed that the degrees of inhibition of radicle and plumule obtained from various extracts treated seeds of both extracts were not significantly different when compared to those obtained from the control experiments as well as those obtained from the varying extract concentrations.

Microbial Biomass Carbon Trends in Black and Red Soils Under Single Straw Application: Effect of Straw Placement, Mineral N Addition and Tillage

Quantifying trends in soil microbial biomass carbon (SMBC) undercontrasting management conditions is important in understanding thedynamics of soil organic matter (SOM) in soils and in ensuring theirsustainable use. Against such a background, a 60-day greenhousesimulation experiment was carried out to study the effects of strawplacement, mineral N source, and tillage on SMBC dynamics in twocontrasting soils, red sol (Ferrasol) and black soil (Acrisol). Thetreatments included straw addition + buried (T1); straw addition +mineral N (T2); and straw addition + tillage (T3).

Effect of Integrated Nutrient Management on Growth and Productivity of Hybrid Rice

Sustaining rice （Oryza sativa L.） productivity at high level is a great challenge, particularly in areas where rice productivity declines in spite of following recommended nutrient management practices. Nutrient management by integrating organic manures, inorganic fertilizers and biofertilizers may play an important role in improving and sustaining rice productivity. In this study, the authors tried to evaluate the suitable proportion of organic manures and inorganic fertilizers along with biofertilizer to maximize growth and productivity of hybrid rice on sandy-loam lateritic soils of West Bengal, India. The crop having 50% recommended dose of fertilizer （RDF） ＋ 50% recommended dose of nitrogen （RDN） through mustard oil cake （MOC） and 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer significantly increased plant height, number of tillers/m2, leaf area index （LAI）, dry matter accumulation （DMA） and crop growth rate （CGR） at initial and vital period of grain growth over those of 25% RDF ＋ 75% RDN through MOC and 100% RDN through MOC. The former two treatments also increased number of panicles/m2 and number of grains/panicle over those of only organic manuring （100% RDN） or only chemical fertilization （100% RDF） or 25% RDF ＋ 75% RDN through MOC. Crop with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC produced 20.2%-33.8% higher grain yield and 11.0%-33.3% greater straw yield, and paid higher gross and net returns over other treatments. This study suggests growing hybrid rice with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC for better growth, higher productivity and greater profit.

Comparative Study on the Pyrolysis Behaviors of Corn Stalk and Pine Sawdust Using TG-MS

The pyrolysis behaviors of corn stalk(CS) and pine sawdust(PS) were investigated with thermogravimetry-mass spectroscopy(TG-MS).The peak temperature of PS was higher and the main decomposition region shifted to higher temperature compared with CS,which implied that the hemicellulose and cellulose of PS were more thermally stable than those of CS.However,the hemicellulose and cellulose of PS were more easily decomposed into gaseous products than those of CS during pyrolysis.The pyrolysis process of biomass can be described by a two-step independent first-order kinetic model.This fundamental study provides a basic insight into the biomass pyrolysis,which is beneficial for understanding the pyrolysis mechanism of biomass and developing an advanced thermal process for effective utilization of biomass.

Enhancement of Cd Solubility and Bioavailability Induced by Straw Incorporation in Cd-Polluted Rice Soil

Of the factors affecting migration and bioavailability of toxic metals in heavy metal contaminated soil, DOC （dissolved organic carbon） provides binding sites for metal cations and reduces the fixation and adsorption of heavy metals by soil solid phase. Elevation of DOC level due to the direct incorporation of crop residues may lead to enhanced accumulation of toxic metals in crop body grown in polluted farmland. In this study, an incubation experiment and a pot experiment were conducted respectively to investigate the effects of wheat straw incorporation on DOC level, cadmium availability, and Cd accumulation in rice plant, and to establish the relation between Cd solubility and DOC level. A Cd-contaminated rice soil was used and incorporated with different rates （0%, 0.5% and 1%） of wheat straw in both experiments. Results showed that the change pattern of Cd in soil solution was very similar to that of DOC level. Wheat straw addition significantly elevated Cd and DOC level in soil solution while NH4NO3-extrated Cd was not affected. There existed a close linear correlation between soluble Cd and DOC level. Enhanced Cd accumulation in rice plant, grown in a Cd contaminated soil, induced by wheat straw incorporation was observed in this study.

Effect of barley straw biochar application on greenhouse gas emissions from upland soil for Chinese cabbage cultivation in short-term laboratory experiments

Chinese cabbage was cultivated in upland soil with the addition of biochar in order to investigate the potential for reduction of greenhouse gas emissions. Barley straw biochar(BSB) was introduced in a Wagner pot(1/5000a) in amounts of 0(BSB0, control), 100(BSB100), 300(BSB300), and 500(BSB500) kg 10a^(-1). After the addition of BSB into the upland soil, carbon dioxide(CO_2) emission increased while methane(CH_4) and nitrous oxide(N_2O) emissions decreased. The highest CO2 flux was measured for the BSB500 sample,(84.6 g m^(-2)) followed by BSB300, BSB100, and BSB0 in decreasing order. Relative to those of control, the total CH_4 flux and N_2O flux for the BSB500 treatment were lower by 31.6% and 26.1%, respectively. The global warming potential(GWP) of the treatment without biochar was 281.4 g CO_2 m-2 and those for treatments with biochar were in the range from 194.1 to 224.9 g CO_2 m^(-2). Therefore, introducing BSB into upland soil to cultivate Chinese cabbages can reduce the global warming potential.

Cultivation Practice of Pleurotus Fossulatus on Rice Straw

Pleurotusfossulatus, a member of oyster mushrooms, was successfully cultivated on rice straw. At least two flushes of fruit body developed at 22 ℃. The first flush of fruit body initiation took place on the 21 st day and second one appeared on 38th day. The biological efficiencies （BE） were found to be 30.8% and 14.6% for first and second flush, respectively. The differentiation pattern of pileus and gills of this mushroom was found to be different from that of other reported species of oyster mushroom. The mushroom （P. fossulatus） took about 20 days for spore formation from primordia initiation and this time span was noted to be highest among all the published reports about any other Pleurotus spp. The BE were 25.9% and 12.5% in first and second flush, respectively when the mushroom was harvested on 18th day （after its initiation of primordia）, i.e., before gill formation. However, the BE was found to be 14-16% lesser in comparison to that harvested after sporulation.

Bioproduction of Ethanol in Separate Hydrolysis and Fermentation and Simultaneous Saccharification and Fermentation from Cassava Stalks

Cellulose biomass is being investigated as a potential substrate for bioethanol production. Cassava stalks were successfully converted to ethanol by fermentation using Saccharomyces cerevisiae TISTR5048, S. cerevisiae KM1195, S. cerevisiae KM7253 and co-culture of S. cerevisiae TISTR5048 and Candida tropicalis TISTR5045. The objective of this study was to assess the ethanol production from cassava stalks by dilute-acid pretreatment and enzymatic hydrolysis that were convertible into ethanol by mono-culture and co-culture of yeast strain. Cassava stalks 1.5% （w/v） in 0.1 M sulfuric acid was pretreated for 30 min at 135 ℃ under the pressure of 15 lb/inch2. The pretreated cassava stalk suspensions were neutralized to pH 5.5 for saccharification process. The enzyme solution （a-amylase, amyloglucosidase, cellulase, xylanase and pectinase solubilized in buffer pH 5.0） was used for hydrolysis ofpretreated cassava stalk at 50 ℃ for 24 h. The hydrolyaste was supplemented with additional nutrients. The culture was incubated at 30 ℃. The pretreatment of the stalk with dilute-acid resulted sugar yield of 0.57 g/g dry matter from enzymatic hydrolysis, which was higher than dilute-alkaline-pretreated and distilled water-pretreated stalk. The sugar hydrolysate was bioconverted to ethanol with separate hydrolysis and fermentation （SHF） and simultaneous saccharification and fermentation （SSF）. The highest ethanol yields of 98.43% and 95.29% were obtained in SHF and SSF, respectively by S. cerevisiae KM1195. The fermentation time of SSF process was 24-32 h shorter than that of the SHF （= 56 h）, but not significantly leading to difference in ethanol production （5.42 g/L-6.22 g/L for SSF; 5.9 g/L-6.23 g/L for SHF）.

Rice Straw-Derived Biochar Properties and Functions as Cu(Ⅱ) and Cyromazine Sorbents as Influenced by Pyrolysis Temperature

In this study, biochars from rice straw （Oryza sativa L.） were prepared at 200-600 ℃ by oxygen-limited pyrolysis to investigate the changes in properties of rice straw biochars produced at different temperatures, and to examine the adsorption capacities of the biochars for a heavy metal, copper（II） （Cu（II））, and an organic insecticide of cyromazine, as well as to further reveal the adsorption mechanisms. The results obtained with batch experiments showed that the amount of Cu（II） adsorbed varied with the pyrolysis temperatures of rice straw biochar. The biochar produced at 400 ~C had the largest adsorption capacity for Cu（II） （0.37 mol kg-1） among the biochars, with the non-electrostatic adsorption as the main adsorption mechanism. The highest adsorption capacity for cyromazine （156.42 g kg-1） was found in the rice straw biochar produced at 600 ℃, and cyromazine adsorption was exclusively predominated by surface adsorption. An obvious competitive adsorption was found between 5 mmol L-1 Cu（II） and 2 g L-1 cyromazine when they were in the binary solute system. Biochar may be used to remediate heavy metal- and organic insecticide-contaminated water, while the pyrolysis temperature of feedstocks for producing biochar should be considered for the restoration of multi-contamination.

Effects of Epigeic Earthworms on Decomposition of Wheat Straw and Nutrient Cycling in Agricultural Soils in a Reclaimed Salinity Area:A Microcosm Study

Earthworms, one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones, exert important influ- ences on soil functions. A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain. Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments： control with no earthworms, regular density （RD） with two earthworms, and increased density （ID） with six earthworms. The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms. Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period. In contrast, concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms. Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller, but more metabolically active microbial biomass. Concentrations of inorganic nitrogen and NO^-N increased significantly with the increase in earthworm density at the end of the incubation （P ~ 0.05）, resulting in a large pool of inorganic nitrogen available for plant uptake. Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.

Soil Carbon Sequestration Potential as Affected by Management Practices in Northern China:A Simulation Study

Soil has been identified as a possible carbon （C） sink for sequestering atmospheric carbon dioxide （CO2）. However, soil organic carbon （SOC） dynamics in agro-ecosystems is affected by complex interactions of various factors including climate, soil and agricultural management practices, which hinders our understanding of the underlying mechanisms. The objectives of this study were to use the Agricultural Production Systems simulator （APSIM） model to simulate the long-term SOC dynamics under different management practices at four long-term experimental sites, Zhengzhou and Xuzhou with double cropping systems and Gongzhuling and Urtimqi with single cropping systems, located in northern China. Firstly, the model was calibrated using information from the sites and literature, and its performance to predict crop growth and SOC dynamics was examined. The calibrated model was then used to assess the impacts of different management practices, including fertilizer application, irrigation, and residue retention, on C dynamics in the top 30 cm of the soil by scenario modelling. Results indicate a significant SOC sequestration potential through improved management practices of nitrogen （N） fertilizer application, stubble retention, and irrigation. Optimal N fertilization （Nopt） and 100% stubble retention （R100） increased SOC by about 11.2%, 208.29%, and 283.67% under irrigation at Gongzhuling, Zhengzhou, and Xuzhou, respectively. Soil organic carbon decreased rapidly at lJriimqi under irrigation, which was due to the enhanced decomposition by increased soil moisture. Under rainfed condition, SOC remained at a higher level. The combination of Nopt and R100 increased SOC by about 0.46% under rainfed condition at /Jr/imqi. Generally, agricultural soils with double cropping systems （Zhengzhou and Xuzhou） showed a greater potential to sequester C than those with single cropping systems （Gongzhuling and Urumqi）.