A field experimental study of lignin sand stabilizing material(LSSM) extracted from spent-liquor of straw pulping paper mills

A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material(LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China's Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2 5 L/m^2 The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills.

Removal of TOC and Color in Bleaching Effluents from Straw Pulp and Paper Mill by Fe^0-H_2O_2 Process

TOC and color in the bleaching effluent from straw pulp paper process could not reach draining standard after its treatment by a biochemical process. In this study, advanced treatment by integrated micro-electrolysis （Fe^0） method and Fenton-like process was investigated under various conditions, i.e. pH, Fe/C ratio, initial I-I2O2 concentration and carrier gas. Results showed that Fe/C ratio（V/V = 1.5）, larger H2O2 dosage around 50 rag/L, lower pH（pH= 3） turned out to be particularly efficient. Temperature was a key parameter, remarkably increasing reaction rates. Carrier air not only improved reaction efficiency, but also saved H2O2 dosage. Chlorinated organic compounds could be reductive dechlorinated by Fe^0 reaction and oxidated by OH produced from Fenton process. The combination of Fe^0 and H2O2 reactions had been proved to be highly effective for the advanced treatment of such a type of wastewaters, and important advantages concerning the application in the study.

Preparation of Adsorbent with Magnesium Sulfate and Straw Pulp Black Liquor and Its Phenol Adsorption Properties

A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.

Cleaner Production of Wheat Straw Pulp HUANG

A pulping method using NH4OH with less amount of KOH as cooking liquor on wheat straw was developed. KOH could reduce consumption of NH3 and cooking time for its strong alkalinity. The effects of various pulping conditions such as composition of cooking liquor, liquid-to-solid ratio, maximum temperature, cooking time to the maximum temperature and cooking time at the maximum temperature were studied. Experimental results indicated that the rate of delignification was 85.12% and the pulp yield was 49.65% under suitable pulping conditions. It looks promising to use black liquor containing nitrogen, phosphorus, potassium and organic substance as fertilizer resources for agricultural production. A new pattern of ecological cycling may be set up between paper industry and farming.

CHARACTERISTICS OF BENTONITE AND ITS SYNERGISTIC RETENTION EFFECT WITH CPAM ON WHEAT STRAW PULP

The various properties of bentonite samples with different sources and their synergistic retention effect with CPAM on wheat straw pulps were investigated. The investigated properties of bentonite included adsorptive capacity based on methylene blue, cation-exchange capacity, swelling volume, colloidal volume, particle size and charge properties. The results show that particle size is the most important properties of bentonite for its synergistic retention effect with CPAM. Using Wyoming type sodium bentonite without drying after modification can obtain the excellent furnishes retention.

STUDY OF COORDINATED PRETREATMENT OF XYLANASE AND LACCASE ON SODA-AQ WHEAT STRAW PULP BEFORE CEH BLEACHING

Coordinated pretreatment of xylanase and laccase on Soda-AQ wheat straw pulp before CEH bleaching was studied. Results show: Pretreatment of xylanase and laccase has better effect than of sole xylanase and sole laccase; Coordination can increase pulp brightness and bleachability, improve pulp filterability of water, lighten degree of effluent pollution in bleaching workshop, and develop overall strength properties of bleached pulp.

THE OXYGEN-ALKALI BLEACHING OF THE STRAW PULP

The influences on the brightness, viscosity and Kappa of the straw pulp under the different oxygen-alkali bleaching conditions have been studied in this paper.

XYLANASE PREBLEACHING ON NaOH-AQ WHEAT STRAW PULP

Before calcium hypochlorite bleaching (H) and chlorination,alkaline extraction, calcium hypochlorite three-stage-bleaching (CEH),we used a kind of hemicellulase, xylanase, to treat wheat straw pulp from Gaoyou Papermill. Xylanase pretreatment contained tow stages, the first stage was xylanase treatment, which was followed by alkaline extraction, the second stage. The xylanase could act on partial lignin and carbohydrate, chiefly xylan. The following alkaline extraction could dissolve something that could not be removed during the first stage. The result of pretreatment was to facilitate penetration of bleaching chemicals, to reduce effective chlorine consumption and to lower pollution loading of bleaching effluent. In the case of these two bleaching processes, the enzymatic pretreatment substantially enhanced the optical properties of the pulps. To calcium hypochlorite bleaching, strength properties of pulps were improved.

ON THE BLACK LIQUOR AND RECYCLE COOKING OF AS-AQ STRAW PULP

Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.

Hydraulic and carbonizing actions of sulfuric acid to straw pulp and paper black liquor

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Pulping of Wheat Straw with Caustic Potash-Ammonia Aqueous Solutions and Its Kinetics

A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio, maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cook- ing to 100℃, the supplementary delignification phase from 100℃ to 155℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH - ]. The activation energy of the delignification reaction was 29.75kJ·mol-1 and the rate equation of delignification was also obtained.

BIOPULPING OF WHEAT STRAW WITH PHANEROCHAETE CHRYSOSPORIUM

Wheat straw was cut into a certain size range and treated with a strain of the white rot fungus Phanerochatete Chrysosporium for 5 days before subjected to a chemi-mechanical treatment. Chemical analyses revealed the effects of the white rot fungus on the wheat straw components. SEM was applied to observe the changes in fiber micromorphological structures. CODcr of the effluent from the sulfonation treatment of wheat straw was also discussed. Handsheets made from the treated and untreated wheat straw exhibited different optical and physical properties after chemi-mechanical pulping.

Sulfite-Formaldehyde Pulping and Oxygen Delignification of Wheat Straw

In this study,wheat straw pulp was prepared by sulfiteformaldehyde(SF) pulping combined with oxygen delignification to develop a sustainable methodology for chemical pulping of straw materials.The bleachability of oxygen-delignified SF pulp was also evaluated by hypochlorite bleaching.The results indicated that the Na_2SO_3 charge played an important role in lignin removal during SF pulping as well as oxygen delignification.The efficiency of oxygen delignification of wheat straw SF pulp was markedly high.After the oxygenation stage,the Kappa number decreased by over 50%(the original Kappa number of SF pulp was lower than 30) when the Na OH charge was in the range of 3%~5%.The optimal conditions for preparing bleached pulp via combined SF pulping and oxygen delignification involved the use of 12% of Na_2SO_3 and 3% of Na OH,respectively.Pulp with relatively high brightness,a low Kappa number,as well as an acceptable viscosity could be obtained when oxygen-delignified SF pulp was bleached with hypochlorite under a low active chlorine dosage.

麦草浆中木质素含量对防油剂作用效果的影响

在含氟防油剂经济用量范围内,针对麦草高得率浆抄造纸张防油效果不理想的问题,本研究对麦草高得率浆进行氧脱木质素处理,得到一系列不同卡伯值的麦草浆,探讨了麦草浆中木质素含量对防油剂作用效果的影响。结果表明,麦草浆中木质素含量对含氟防油剂的作用效果有明显影响,在防油剂质量分数1%(相对于绝干浆)的条件下,当麦草浆卡伯值降至<50.0时,麦草浆抄造纸张具有初步防油效果;当麦草浆卡伯值为30.0~50.0时,随着卡伯值降低,麦草浆抄造纸张的防油等级逐渐上升;当麦草浆卡伯值降至<30.0时,麦草浆抄造纸张防油等级达到最高等级(7级)。利用Owens-Wendt-Rabel-Kaelble (OWRK)法分析纸张的表面自由能,随着麦草浆中木质素的脱除,纸张的表面自由能不断降低,而极性比率不断升高,表明木质素的脱除有利于提高纸张防油效果。麦草浆中木质素含量也会影响防油剂用量,在一定防油等级要求下,麦草浆的卡伯值越低,所需防油剂用量越少。

基于制浆废液和麦草废渣的生物质颗粒燃料预测模型的建立及分析

以麦草制浆备料工段中产生的麦草废渣和制浆过程产生的制浆废液为原料,通过混合压缩成型工艺制备麦草废渣颗粒燃料,以期提高制浆造纸工业废弃物的利用价值。为探究制浆废液对生物质颗粒燃料成型的影响机制,参照麦草废渣组分,将粉末状商业纯纤维素和半纤维素在质量比10.17∶7.62下与制浆废液混合,制备生物质颗粒燃料模型,并通过曲线拟合建立生物质颗粒燃料预测模型,探究制浆废液中固形物含量对颗粒燃料成型性能及其物理性能的影响机制。结果表明:制浆废液可以提高燃料颗粒间的黏结力,有利于颗粒燃料成型,改善了麦草废渣颗粒燃料的物理性能。当制浆废液固形物含量为10.28%时,麦草废渣颗粒燃料显示出较好的物理性能,其抗渗水性为84.90%,压缩应力为1.45 MPa。生物质颗粒燃料预测模型对麦草废渣颗粒燃料物理性能的预测结果误差小于5%,显示出较高的预测精度。研究结果可为生物质颗粒燃料的制备技术提供理论参考,同时为制浆造纸工业废弃物的综合利用提供新思路。

生物化学机械法制浆过程麦草废渣基棒状颗粒燃料的性能分析

为提高农业废弃物麦草全组分资源化利用效率,本研究将生物化学机械法制浆过程产生的麦草废渣和制浆废液进行混合,利用液压成形技术制备了麦草废渣基棒状颗粒燃料(简称颗粒燃料),探讨了麦渣粒径和废液添加量对颗粒燃料形貌、稳定性、物理性能和燃烧性能的影响。结果表明,颗粒燃料制备的较优工艺条件为:麦渣粒径范围[0.22,0.90)mm,制浆废液添加量36.31%。该条件下制备的颗粒燃料具有较好的稳定性、物理性能和燃烧性能,其松弛密度为1.50 g/cm^(3),抗跌碎性为99.94%,抗渗水性时间为105 min,横向抗压强度为75.1 MPa,径向抗压强度为1.53 MPa,热值为11 715 J/g,燃烧时间可达99 s。

半纤维素对玉米秸秆皮Lyocell纤维性能的影响

探讨了半纤维素对Lyocell纤维制备时溶浆过程以及纺丝过程的影响,研究了半纤维素对Lyocell纤维的力学、抗原纤化和染色等性能的影响。试验可知:使用市售质量分数50%的NMMO溶剂在90℃温度下即可完全溶解玉米秸秆皮浆粕;半纤维素含量较高的玉米秸秆皮浆粕的流动性更好,制成的Lyocell纤维的染色性能和抗原纤化性能更好,断裂伸长率较大,结晶度较小。

THE LIGNIN CONTENT IN BLACK LIQUID OF STRAW AS-AQ BY ULTRAVIOLET SPECTROPHOTOMETER

The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.

Harnessing of Chemically Modified Rice Straw Plant Waste as Unique Adsorbent for Reducing Organic and Inorganic Pollutants

Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacrylate (DMAEM) on it using potassium permanganate/nitric acid redox system. This was done to obtain six levels of poly (DMAEM)—rice straw graft copolymers (PDMAEMRS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMRS 1 to PDMAEMRS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form rice straw co-polymer—metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and rice straw dose were studied in detail. It was found from the obtained results that;the residual metal ions removal from their aqueous solutions increased with 1) increasing the extent of grafting of PDMAEMRS i.e. from PDMAEMRS 1 to PDMAEMRS 6;2) increasing the pH of the metal ions solution complex from 1 to 8;3) increasing the rice straw dosage from 0.50 to 2.0 g, then leveled off thereafter;4) increasing the time of the reaction up to 20 minute then leveled off after that. On the other hand, Pb (II), Cd (II) and Hg (II) ions were also removed from their solutions with different extent. Furthermore, the prepared co-polymer could be recovered by washing the metal ions from the complex with weak acid 1 N HNO3 (pH 2) and the metal-binding activity of the rice straw was slightly reduced by this process. Finally, the ability of PDMAEMRS to remove three types of acid dyes from their solutions was also reported.

闽牧6号杂交狼尾草产量特征及其资源化利用研究

【目的】分析闽牧6号杂交狼尾草的种植潜力和社会经济效益。【方法】分别在2015-2017、2018-2020年栽培闽牧6号杂交狼尾草和对照热研4号王草,比较他们在不同试验区的产量和营养成分含量,并分析闽牧6号杂交狼尾草饲喂肉猪的效果。【结果】在福建省5个试验点多年测产中,只有福清海口和福州平潭的闽牧6号杂交狼尾草年均鲜草产量(145600和92850 kg/hm^(2))均显著高于对照(129600和85750 kg/hm^(2));而在全国5省3年区试比较中,闽牧6号杂交狼尾草在福建建阳、广西南宁、广东广州、海南儋州和云南元谋5个试验区的年均干草产量均高于对照,但差异不显著,其干草产量、营养品质、性状稳定性等综合评价较好;利用闽牧6号杂交狼尾草饲喂肉猪,0.5 kg/(头·d)草浆饲喂肉猪效果最佳,可以提高肉猪的氨基酸总量,降低料肉比,每头可以增加经济效益30~70元。【结论】闽牧6号杂交狼尾草的生产性能及稳定性较好,适宜区域广泛,草浆饲喂肉猪经济效益明显。