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71.
海洋活性胶原肽酶解液的脱色脱腥工艺 总被引:1,自引:0,他引:1
以富含胶原的海产品下脚料为原料,用海洋碱性蛋白酶894水解,得到具有清除羟自由基活性的酶解液.采用一次正交回归实验设计及结果分析,建立回归方程,研究了活性炭、β-环糊精、酵母三者用量及温度、pH和作用时间6因子及其可能存在交互作用的变化关系对该酶解液综合脱色脱腥效果的影响.结果表明,在给定取值范围内,pH对综合脱色脱腥效果影响高度显著,酵母添加量、pH与酵母添加量的交互作用影响显著,其它因子及其可能的交互作用影响不显著,得最佳工艺为:温度37℃、pH 4.0、活性炭0.8%、β-环糊精和酵母分别为0.1%,作用30 min.此时,综合脱色脱腥效果值为90.90,蛋白回收率为98.02%,羟自由基清除率的IC50浓度从原来的1.42 mg·mL-1增加到1.62 mg·mL-1. 相似文献
72.
我国废旧木材回收利用需要解决的问题 总被引:8,自引:0,他引:8
合理、有效地利用废旧木材是节约木材的有效途径之一,对于创建节约型社会、发展循环经济具有重要意义。废旧木材回收利用是一项利国利民的伟大事业,需要社会各界的支持。 相似文献
73.
根据无土栽培营养液废液的几个处理阶段归纳了紫外线、臭氧、加热、沙滤和综合灭菌等多种营养液废液灭菌方法;活性炭和纳米TiO2催化2种植物自毒物质去除方法以去除植物自身所排出的有机酸等毒性物质;几种温度、养分等在线监测和调配装置;以及植物营养梯级吸收利用、鱼菜共生水产养殖的后续利用方法,最后对营养液废液利用的研究进行展望,旨在为今后有效利用无土栽培营养液废液研究提供参考,减少营养液废液对环境的污染。 相似文献
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Rapid nitrate leaching losses due to current agricultural N management practices under the humid tropical environmental conditions
of the Pacific island of Guam may contaminate fresh and salt water resources. Potential environmental contamination of the
Northern Guam aquifer, which is overlain by shallow limestone-derived soils, is a major public concern because the aquifer
is the sole underground source of fresh water for the island. The objectives of this study were to examine the use of waste
office paper as a possible management alternative for reducing nitrate leaching due to N fertilizer applications in northern
Guam while also providing sufficient N for crop growth. In a laboratory study, increasing rates of waste paper application
reduced NO3
–-N leaching up to approximately 200 days after incorporation of N fertilizer and paper treatments. Subsequent mineralization
of immobilized N from paper applications was also observed, although cumulative NO3
–-N leaching at the highest rate of paper addition was lower than the control after 394 days of incubation. The effect of waste
paper on N availability and NO3
–-N leaching after application of N fertilizer at rates up to 500 kg N ha–1 was also evaluated in two field experiments planted with sweet corn (Zea mays var. rugosa Bonaf.) during consecutive dry and wet periods. Leaching losses of NO3
–-N were higher during the wet cropping season, leading to lower crop yields and crop N uptake. Combining paper with N fertilizer
reduced NO3
–-N leaching losses but also decreased crop ear yields up to N fertilizer application rates of 250 kg N ha–1 during the dry cropping season and up to rates of 100 kg N ha–1 during the wet period. Although combining waste paper with N fertilizer reduced NO3
–-N leaching losses, no improvements in fertilizer N recovery were observed during the field experiments. This lack of crop
response may be due to the importance of early season N availability for the short-season horticultural crops grown on Guam.
We suggest that the application of waste paper may be a useful management practice to reduce NO3
–-N leaching losses when high soil NO3
–-N levels remain after cropping due either to crop failure or to over-application of N fertilizer.
Received: 11 May 1999 相似文献
76.
Effects of long-term waste water irrigation on soil organic matter, soil microbial biomass and its activities in central Mexico 总被引:4,自引:0,他引:4
The effect of long-term waste water irrigation (up to 80 years) on soil organic matter, soil microbial biomass and its activities
was studied in two agricultural soils (Vertisols and Leptosols) irrigated for 25, 65 and 80 years respectively at Irrigation
District 03 in the Valley of Mezquital near Mexico City. In the Vertisols, where larger amounts of water have been applied
than in the Leptosols, total organic C (TOC) contents increased 2.5-fold after 80 years of irrigation. In the Leptosols, however,
the degradability of the organic matter tended to increase with irrigation time. It appears that soil organic matter accumulation
was not due to pollutants nor did microbial biomass:TOC ratios and qCO2 values indicate a pollutant effect. Increases in soil microbial biomass C and activities were presumably due to the larger
application of organic matter. However, changes in soil microbial communities occurred, as denitrification capacities increased
greatly and adenylate energy charge (AEC) ratios were reduced after long-term irrigation. These changes were supposed to be
due to the addition of surfactants, especially alkylbenzene sulfonates (effect on denitrification capacity) and the addition
of sodium and salts (effect on AEC) through waste water irrigation. Heavy metals contained in the sewage do not appear to
be affecting soil processes yet, due to their low availability. Detrimental effects on soil microbial communities can be expected,
however, from further increases in pollutant concentrations due to prolonged application of untreated waste water or an increase
in mobility due to higher mineralization rates.
Received: 28 April 1999 相似文献
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