THE APPLICATION OF CATIONIC POLYACRYLAMIDE AS DRAINAGE AND RETENTION AIDS

INTRODUCTIONIn recent years, with the rapid development of paper-making technology[1], such as improvement of pa-per-machine speed, extensive use of high yield and recycling pulp, and more closed white water systems, the environment of papermaking has changed greatly and this has brought many problems, Such as water temperature increasing and water quality becoming worse, large amount of fines in pulp, and more and more aninonic trash in pulp and water. These causes drainability of pulp a…     

MODIFIED OPAL:A NOVEL STABILIZER FOR HYDROGEN PEROXIDE BLEACHING OF PULPS

The possibility of modified opal as the stabilizer of hydrogen peroxide bleaching was investigated. The results showed that the modified opal in place of sodium silicate as the stabilizer of hydrogen peroxide bleaching is feasible. At the same dosage, above 3% ISO can be increased for both wheat straw pulp and deinked pulp. The stabilizing ability of the modified opal to hydrogen peroxide bleaching of pulp is improved markedly. It is favorable for bleaching to increase temperature and time within a permissive extent. The suitable process conditions are 10% of pulp consistency, 3% of hydrogen peroxide, 1.5% of sodium hydroxide, 3% of the modified opal, 70℃ and 60 min when the modified opal is used as the stabilizer of hydrogen peroxide bleaching. At these conditions, the brightness gain can reach about 16% ISO for wheat straw pulp. In addition, it is favorable for bleaching to add a little magnesium sulfate when the modified opal is used as the stabilizer of hydrogen peroxide bleaching, the brightness of pulp can increase I%ISO if0.05% of magnesium sulfate is added. The cost analysis indicated that the modified opal is superior to sodium silicate as the stabilizer of hydrogen peroxide bleaching in economical aspect and has further the potential of market development.     

草浆木质素混凝剂处理印染废水的实验研究

印染废水由于色度深、水质变化大、生化性差等特点,是当前工业废水处理的难点和焦点之一.混凝法因成本低、操作简单、有效,成为印染废水处理的重要手段.从草浆造纸黑液中提取木质素做混凝剂,通过印染废水烧杯混凝试验,表明草浆木质素是一种有前途的混凝剂,对废水中的COD和色度具有较好的去除效果.该方法以废治废,具有较好的社会效益和经济效益.     

基于改性农业废弃物的矿山废水中重金属吸附去除技术及应用

金属硫化物矿区的尾矿在空气、水和微生物等的共同作用下,会产生大量含有毒有害重金属的酸性矿山废水,造成矿区及下游水体和土壤的严重污染.该文结合课题组研究,介绍以农业废弃物为原料开发改性玉米秸秆、花生壳、稻草等吸附材料,吸附去除酸性矿山废水中的重金属离子及其吸附机理,以及实地应用于东江源矿区污染控制示范工程中的重金属吸附去除案例,为矿区重金属污染源头控制研究提供理论基础和技术支持.     

滩涂污灌土壤吸附剂的制备研究

研究了滩涂污灌土壤吸附剂的制备方法.通过正交实验,比较了氯化锌、磷酸、氢氧化钾、盐酸几种活化剂在不同秸秆加入量、活化剂浓度、活化时间、活化温度的情况下制备的吸附剂,对水溶液中邻硝基甲苯的吸附效果影响.实验结果表明,选择盐酸活化法制备吸附剂,在秸秆加入量为15%,经2 mol/L的盐酸按液固比为1:1浸泡处理滩涂污灌土壤后,用氮气做保护气在400℃的条件下碳化1 h,制备的土壤吸附剂对水溶液中邻硝基甲苯的吸附效率可以达到90%以上.     

聚氧化乙烯助留和助滤性能的探讨

<正>聚氧化乙烯(Polyethlene oxide——简称PEO)是由环醚型的环氧乙烯在催化剂的作用下开环聚合而成的高分子物质,其通式是CH_2·CH_2O。它在水中的溶解性能随其分子量的大小而不同,一般来说,分子量越大,在水中的溶解性能越差。 聚氧化乙烯在造纸工业中的应用,国内已有一些工厂做了试验,取得了一定的成效,他们都是以分散纤维、防止纤维絮聚、提高成纸的均匀性为目的,故称之为分散剂。但普遍反映聚氧化乙烯的价格高,影响造纸厂产品的成本和利润,因此在一定程度上限制了它的使用范围。根据有关资料和我们的分析,认为聚氧化乙烯还是二种极好的助留剂和助滤剂。根据C·H·Tay等人的资料,聚氧化乙烯对纸料中细小粒子的留着作用,较聚丙烯酰胺(PAA)更大(图1)。如果我们能从实验中证实上述作用,那末对缓和聚氧化乙烯在应用中的成本和效果的矛盾,会起到一定的作用。 一、试验材料及方法     

ENZYMATIC BLEACHING OF WHEAT STRAW SODA-AQ PULP BY LMS TREATMENT

Laccase has been proven that it has a good selectivity and efficiency in pulp bleaching. In this paper, the effects of LMS (Laccase Mediator System) treatment on delignification and bleaching of wheat straw pulp at various conditions, such as laccase dosage,temperature, oxygen pressure and pH, were investigated. The TCF sequence including LMS can bleach the wheat straw pulp to 81% ISO brightness with good strength. The synergetic biobleaching of LMS and xylanase of wheat straw pulp was also investigated. It was found that the final brightness and strength of synergetic biobleaching pulps increased to a certain extent and the bleaching selectivity was improved. The combination of the enzymes is feasible for the delignification and bleaching.     

面向21世纪的农作物秸秆材料工业

围绕贯彻天然林保护政策和中国木材资源短缺的实际,提出了用农作物秸秆替代木材原料发展材料工业的构想,从农作物秸秆贮量、特性和加工方法等方面探讨了开发农作物秸秆材料工业的可能性,介绍了几种农作物秸秆材料产品,如秸秆板材料、秸秆建筑材料、秸秆包装材料、秸秆模压材料等,讨论了２１世纪中国农作物秸秆材料工业的发展前景。     

无机电解质对淀粉在纸浆上吸附的影响

考察了无机电解质 Na Cl、Na2 SO4 和 Al2 ( SO4 ) 3 对淀粉在混合木浆和麦草浆上吸附的影响 .实验结果表明 :在使用的盐浓度范围内 ,无机盐的存在可促进原淀粉在两种浆上的吸附 ,但大幅减小阳离子淀粉的吸附率 .三种无机电解质对淀粉吸附的影响也各不相同 .这些结果能被氢键作用机理、邻位水层模型和DLVO理论解释     

隔膜电解法处理草浆黑液

进行了隔膜电解法处理草浆黑液的可行性实验研究．隔膜电解法实验采用铸铁作牺牲阳极,石墨作阴极,多孔性的滤过式隔膜将阳极区与阴极区分开;阳极及其附近有铁的氧化与水解反应,碱木素的取代反应;阴极有析氢反应;水分子和钠离子在势场力作用下透过隔膜从阳极区进入阴极区,碱木素分子被隔离在阳极区;阳极区不断加入黑液,取走木素沉淀,阴极区不断取走回收碱液,从而实现碱液与木素的分离．在电流为1A、电压为8V及室温条件下电解12h,阳极区黑液的色度、悬浮物及COD的去除率分别为66.4%,75.3%和94%,碱回收率达到94%以上．实验结果表明,作为一种处理黑液的碱回收技术,隔膜电解法处理草浆黑液比较容易直接嫁接到制浆工艺中,有可能成为解决草浆碱回收技术的新途径．     

改性硅灰石在新闻纸造纸业中的双重环境效应

介绍了一种新型矿物填料——改性硅灰石在新闻纸中的应用。样品采自云南省腾冲县，加工成1250目的超细纤维，其长径比为15左右，经化学改性处理，添加到脱墨纸浆中制作新闻纸。实验室手抄片和工业试验结果表明，改性硅灰石能极大地改善再生新闻纸的白度、不透明度和适印性。加入有10％～15％改性硅灰石的新闻纸(定量44～47g／m^2)具有高白度(58％～60％)、高强度(裂断长3800～4000m)和高不透明度(95％～97％)，属高质量新闻纸。另一方面，由于改性硅灰石具有对油墨粒子、细小纤维和有机物有良好的吸附性，添加改性硅灰石的新闻纸在造纸过程中排出的废水易于处理，废水经简单沉淀后所含BOD和COD，以及重金属元素含量极低，达到综合排放国家一级标准。改性硅灰石在造纸业方面显现出保护森林和水体的双重环境效应，是造纸业中一种性能优秀的新型功能填料。     

改良木聚糖酶辅助漂白芦苇浆的工艺研究

采用分子改良后的木聚糖酶对芦苇浆进行生物预处理,考察了改良木聚糖酶辅助漂白的效果。结果表明,酶预处理可以降低CEH三段漂白中氯化C段的氯气用量60%。改良木聚糖酶预处理辅助漂白芦苇纸浆最佳条件为:pH为7.0,温度60℃,浆浓(质量分数)5%,酶用量12μmol/(min.g),预处理时间60 min。在此条件下C段氯用量降至对照的40%时,酶处理漂后样品白度可达到84.0%(ISO),高出对照样的白度3.7%(ISO)。改良木聚糖酶预处理还能够改善纸浆漂后样的物理性能。     

改性微粒硅溶胶的研制及应用机理研究

The preparation and their application in papermaking of aluminium modified silica sol (AMS) and boron modified silica sol (BMS) were first investigated in China. At the same time the structures and configurations of AMS and BMS were first time authenticated. The modified silica sol microparticle system was detailedly and systemically studied with colloid charge titration. On the research of flocculation mechanism the laser sizer was also first time used to determine the floc size. Results showed that sodium silicate was treated and acidification was carried out by means of strongly acid cation exchange resins and obtained almost sodium free acid sols. The acid sol obtained after acidification was then made alkaline.     

试论全生物质农业

 农业发展历史表明,几千年来的农业是以生物质的作物果实和畜禽肉蛋奶为生产对象的,而占生物量60%的作物秸秆和畜禽粪便只是“农业废弃物”。现代生物质转化技术则可以将这些“农业废弃物”以及所有可利用的生物质转化为种类繁多的生物质能源和生物基产品并再获大幅增值。这是对农业新资源的开发和资源的循环利用,是在污染物的无害化和资源化利用中保护环境,并生产种类繁多的绿色产品。因此,农业在从事种植和养殖的同时,应将“非粮生物质”纳入农业生产系统,由“半生物质农业”或“部分生物质农业”发展到“全生物质农业”或“全生物质利用农业”。     

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

INTRODUCTIONXylanase pretreatment can produce many small holes on pulp surfaces and cross section by removing part xylose that may be sucked back or exists in style of LCC. Thus penetrability of following chemicals. Olsen [1] observed coordinated pretreatment of xylanase and lignin enzyme (compound of lignin peroxide enzyme and manganese peroxide enzyme) had better delignification than sole xylanase and sole laccase lignin enzyme. So we can forecast that coordinated pretreatment of xylan…     

酸化水解-UBF-混凝沉淀处理工艺在造纸黑液中的应用

利用厌氧酸化水解一上流式污泥床过滤复合反应器-混疑沉淀处理工艺对苇浆、草浆等黑液进行厌氧分解过滤、加药混凝处理,从黑液中回收木质素,去除造纸黑液中的有机物,出水水质可以达到(GWPB-1999)《造纸工业水污染物排放标准》,从而为苇浆、草浆造纸黑液的综合处理开拓了重要途径。     

EFFECTS OF PROCESSING OPERATIONS ON ZETA POTENTIAL AND CATIONIC DEMAND OF PULPS

Thc zeta potential and cationic demands of various kraft pulps - unbleached, bleached and beaten to different freeness levels were determined in the laboratory. The zeta potential of pulp where the final stage was a lignin degrading and dissolving treatment such as alkaline extraction or hypochlorite was lower than the unbleached pulp. The cationic demand of unbleached pulp was higher compared to that of bleached pulp. Beaten pulps showed larger cationic demands than the unbeaten pulps, which can be attributed to the larger specific surface area of pulp components. Fibres become increasingly electronegative when beaten and therefore cationic demand of pulps increases with beating. When the zeta potential method is used with furnishes of different freeness,the linear relationship is observed. However, the slope is decreasing with the decrease in freeness of the pulp.     

微波辐射应用于麦草浆漂白工艺的研究

将微波辐射代替传统水浴加热应用于H2O2麦草浆漂白工艺中。研究了微波辐射时间、辐射功率、H2O2用量和NaOH用量等因素对纸浆漂白效果的影响。通过与传统水浴加热漂白对比发现,达到相应白度时微波辐射漂白时间大大缩短;微波辐射漂白纸浆粘度没有过多下降;微波辐射漂白废水中的残余过氧化物只有水浴漂白的10%。正交实验结果表明H2O2用量的影响最大,其次是微波辐射时间和NaOH用量,影响最小的是微波输出功率。最佳实验条件为微波辐射功率240?W、辐射时间25?min、H2O2用量5％和NaOH用量4％时纸浆白度约为59％ISO,纸浆粘度大于620?mL·g-1,纸浆硬度约为390。     

降解稻草对蓝藻生长的抑制作用

研究证明在有氧条件下经过一个月以上降解的稻草对铜绿微囊藻等4种实验室培养的蓝藻具有明显的生长抑制作用。然而,灭菌的降解稻草(121℃, 15min)并没有抑藻效果。这说明伴生微生物的降解作用对于稻草的抑藻因子的产生和释放是必要的。没有经过降解处理的干稻草没有抑藻效果。表明利用稻草控制自然水体水华发生是一个具有潜在实用价值的新途径。     

硅藻土吸附剂处理含磷废水的研究进展

硅藻土作为一种用途广泛的非金属材料,在废水处理中的应用受到重视。主要介绍了硅藻土的理化性质、吸附功能以及国内外的利用现状,阐述了硅藻土相关产品的用途和硅藻土处理草浆造纸废水的效果参数,对近年来改性硅藻土和硅藻土基复合吸附剂的制备方法及其在废水中除磷的研究现状,包括对添加某些特定金属阳离子对硅藻土进行改性的问题进行了综述,并展望了其未来的发展趋势。