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《环境工程学报》2016,(5)
秸秆是重要的沼气工程原料,秸秆预处理对其后续厌氧消化效率影响巨大。采用田间裹包青贮方法,设计3因素正交实验,考察了秸秆含水率、压缩比和添加剂对玉米秸秆发酵时间和厌氧消化产沼气的影响。结果表明:秸秆经过裹包青贮,发酵总时间(total fermentation time,TFT)减少1~2 d,累积产气量达到总产气量的90%所用时间(TFT90%)减少了40%~50%,消化效率明显提高;秸秆含水率对产气效果有明显影响,随着含水率增加,单位总固体(total solid,TS)累计产气量(cumulative biogas yields per TS,CBYT)和沼气日产率(biogas yields rate average day,BYR)由高到低排序为:35%~40%,40%~45%,30%~35%;秸秆压缩比对产气效果有明显影响,随着压缩比的增加,其对CBY和BYR的效应由高到低排序为:185、143与138 kg/m3;添加剂类型对产气效果亦有明显影响,在不同添加剂处理下,其对CBYT和BYR的效应由高到低排序为:尿素处理甲酸处理无添加剂处理;正交实验极差分析表明,对CBYT和BYR的影响排序为:含水率﹥压缩比﹥添加剂,其田间裹包青贮进行厌氧发酵的优化组合为:青贮秸秆含水率为35%~40%,压缩比为185 kg/m3,添加剂为营养型,青贮20 d,CBYT和BYR达到最大,分别为646.57 m L/g和173.25 m L/(d·g)。 相似文献
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《环境工程学报》2017,(4)
为了开发出农业生物质废弃物合理利用的新途径,使粉末状活性炭产品利于实际运用中的运输,本文以生物质废弃物—稻草为原料,使用聚乙烯醇缩丁醛(PVB)为粘结剂制备出粉末状稻草活性炭(AC)并将其成型。探究了粘结剂浓度、AC/PVB的质量比和成型压力等对材料的强度以及吸附H_2S性能的影响,并利用SEM、FT-IR和XRD分析了活性炭的结构。研究发现:当成型压力为15 MPa、粘结剂浓度为4%、粘结剂与炭的质量比为1∶1时,成型活性炭对H_2S的吸附性能最好,吸附时间可达70 min,强度可以达到15 N·cm~(-2);结构分析显示制备出的成型稻草活性炭,具有规则排列的孔洞,PVB的加入对炭的表面官能团未产生明显的影响,但加入量过大则会使活性炭的孔堵塞,影响H_2S的吸附。 相似文献
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污泥渗水砖的制备研究 总被引:2,自引:0,他引:2
结合压制成型和传统的烧结砖工艺,实验以城市生活污泥、黄河淤泥、煤矸石及砂为原料,制备渗水铺地砖。通过正交试验得到最优工艺参数为w(黄河淤泥)∶ww(煤矸石)∶w(污泥)∶w(砂)=33%∶22%∶15%∶30%、成型压力为20 MPa、烧结温度为1 100℃、保温时间为1.5 h,骨料砂的粒径为1~2 mm。制备的成品抗压强度为21.8 MPa,渗水系数为1.03×10-2 cm/s。并对成型压力及烧结温度对渗水砖抗压强度及渗水系数的影响进行了讨论。 相似文献
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不同质量比的膨松剂对家庭生物有机垃圾堆肥的影响 总被引:2,自引:0,他引:2
为解决家庭生物有机垃圾堆肥反应中含水率高、含有机质多等问题,选择秸秆作为膨松剂对家庭生物有机垃圾进行堆肥处理,重点研究添加不同质量比的膨松剂对堆肥反应中堆体温度、含水率、有机质、pH、电导率及堆料质量减少率等评估堆肥质量参数变化的影响.结果表明,添加质量分数为5%、10%及20%的膨松剂的堆肥反应在第2天堆体温度超过55℃,并持续3 d以上,而添加质量分数为30%的膨松剂堆肥由于其含水率较低(约55%)在整个堆肥反应中堆体温度都低于55℃;堆肥1周内,有机质及含水率下降显著;添加20%膨松剂堆肥的堆料质量减少率最为明显,达39.6%;堆肥反应中,pH在5.5~8.5,在腐熟期pH趋于稳定,呈弱碱性;电导率随堆肥进行呈上升趋势,4种不同质量比膨松剂堆肥产品的电导率均位于1.88~1.96 mS/cm,可以安全使用. 相似文献
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不同接种量的微生物秸秆腐熟剂对蔬菜副产物堆肥效果的影响 总被引:3,自引:0,他引:3
为了明确不同接种量的微生物秸秆腐熟剂对蔬菜副产物堆肥效果的影响,以玉米秸秆为调理剂,在调节初始物料含水率为63%和C/N为28的条件下,设置了B1(堆肥混合物+1%秸秆腐熟剂)、B2(堆肥混合物+3%秸秆腐熟剂)、B3(堆肥混合物+5%秸秆腐熟剂)和CK(堆肥混合物+3%灭菌惰性载体)4个处理,测定不同堆肥处理对温度、含水率、碳氮比(C/N)、半纤维素、纤维素、木质素、总养分含量、发芽指数等指标的影响.结果表明,蔬菜副产物堆肥接种微生物秸秆腐熟剂均能够使堆肥周期缩短,有效降低堆肥含水率,提高有机质的降解幅度,并且使堆肥中半纤维素、纤维素、木质素降解率分别提高1.03%、1.16%和1.47%;氮磷钾养分含量也比不接种处理平均提高0.48%.4个处理的总体堆肥效果表现为:B2>B1 >B3>CK. 相似文献
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与液态微生物菌剂相比,固态菌剂的保藏时间长,菌种不易退化失活,且便于存储及运输,对降低菌剂运输及使用成本具有重要意义。在优化固态微生物菌剂制备关键影响因素的基础上,通过3因素3水平正交实验获得了最佳制备方法,即以腐熟物料作为载体,投加4%的海藻糖,含水率为15%。将所得固态微生物菌剂保存一定时间后,以食品厂污水处理剩余污泥和玉米秸秆的混合物为堆肥原料进行好氧堆肥,发现不同保存时间的固态微生物菌剂的堆肥效果相近,均可使堆体在18 h左右进入55℃以上的高温期,高温持续时间长,所得堆肥产品的理化性质也相差不大,且均符合我国生物有机肥标准(NY 884-2012)中的相关要求,所得固态菌剂的制备方法具有重要的实际价值。 相似文献
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对微波修复氯丹污染土壤进行研究,重点考察了含水率、微波辐射时间、碱浓度、活性炭添加量和土壤量对其中氯丹降解的影响。结果表明:(1)总体上,氯丹降解率随着含水率的增加而先增加后减少,随着微波辐射时间的延长而增加。当含水率为20%、微波辐射15min后,α-氯丹和γ-氯丹的降解率分别增加到65%和56%。(2)总体上,氯丹降解率随着微波辐射时间的延长而不断增加,7min后氯丹的降解过程基本趋于平衡。10mol/L氢氧化钠溶液存在条件下氯丹降解效果最好,15min时α-氯丹和γ-氯丹的降解率分别为94%和82%。(3)氢氧化钠溶液最佳摩尔浓度为10mol/L。(4)添加1.0g活性炭条件下,氯丹降解率随着微波辐射时间延长而迅速增加,15min时α-氯丹和γ-氯丹的降解率分别为98%和94%。(5)当土壤和活性炭的质量比固定为15∶1时,随着土壤量的增加,氯丹降解率明显增加。 相似文献
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调理剂和通风方式对污泥生物干化效果的影响 总被引:6,自引:2,他引:4
采用了自主设计的污泥生物干化实验室模拟系统,研究了调理剂、物料配比和通风方式等实验条件对脱水污泥生物干化的影响效果。研究结果表明,与锯末相比,秸秆有利于反应物料温度的上升,含水率下降程度更大;利用秸秆调节污泥初始含水率在60%和65%的实验条件下时,物料的平均含水率分别下降了7%和6%,当初始含水率65%时,生物堆体的温度和含水率没有明显的变化;与连续通风相比较,间歇通风的实验条件有利于生物堆体的温度的升高和干化效果;在该实验中,最佳的生物干化条件是以秸秆为调理剂,初始含水率调至65%以下,以间歇方式进行通风。 相似文献
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城市河流水质常规评价技术研究 总被引:11,自引:0,他引:11
运用综合水质标识指数法,对我国河流水质评价面临的关键技术问题,包括水质评价方法、水质评价项目,水质级别评价,水环境功能区达标评价、水质定性评价、河流及水系整体水质比较、水质随时间和空间变化等作了明确界定,并介绍了在上海河流水质评价中的应用。 相似文献
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改善深圳河水质的补水方案及生态影响初步分析 总被引:3,自引:0,他引:3
深圳河旱季天然径流量小而污染负荷高,为了改善河流水质,在削减入河污染物的同时有必要采取补水措施。利用水质模型,计算了不同污水处理率下,分别以污水资源化再生水、珠江口海水和大鹏湾海水为补水水源时,深圳河达到基本不黑臭所需的补水量。讨论了补水方案对河流水质、盐度、水动力条件的改变及其对生态系统的影响。研究表明,引海水对河流生态系统的冲击不容忽视。而污水资源化是较优的补水方案。 相似文献
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Dichloromethane (DCM) is a toxic volatile compound which is found in the ground waters and wastewaters of the pharmaceutical, chemical, textile, metal-working and petroleum industries. DCM inhibits the growth of aquatic organisms, induces cancer in animals and is potentially carcinogenic for humans. This article aims to review existing water treatments for DCM removal, focusing on recent technological advances. Air stripping, adsorption and pervaporation were found to be effective in separating DCM from water with a process efficiency of about 99%, 90% and 80% respectively. Electrocatalysis over Cu-impregnated carbon fiber electrode, photo irradiation over TiO2 and photo-Fenton process led to the complete decomposition of DCM. Aerobic and anaerobic water treatment achieved 99% and 95% removal of DCM respectively. The maximum efficiencies observed for acoustic cavitation, radiolysis and catalytic degradation of CH2Cl2 were 90%, 92% and 99% respectively. Ozonation and persulfate oxidation showed lower DCM degradation efficiencies, not exceeding 20%. Further combination of different water treatment methods will further increase DCM degradation efficiency. 相似文献
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Current status of agricultural and rural non-point source Pollution assessment in China 总被引:26,自引:0,他引:26
Edwin D. Ongley Zhang Xiaolan 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1159-1168
Estimates of non-point source (NPS) contribution to total water pollution in China range up to 81% for nitrogen and to 93% for phosphorus. We believe these values are too high, reflecting (a) misuse of estimation techniques that were developed in America under very different conditions and (b) lack of specificity on what is included as NPS. We compare primary methods used for NPS estimation in China with their use in America. Two observations are especially notable: empirical research is limited and does not provide an adequate basis for calibrating models nor for deriving export coefficients; the Chinese agricultural situation is so different than that of the United States that empirical data produced in America, as a basis for applying estimation techniques to rural NPS in China, often do not apply. We propose a set of national research and policy initiatives for future NPS research in China. 相似文献
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Since China has the largest population in the world, the available water resources per capita in China are very limited. With
the rapid economic development that is currently occurring, the shortage of water resources at the national level has become
extremely critical. How to solve the problems due to water scarcity and water pollution has received increasing attention
from the Chinese government and various communities. In order to provide a sustainable development environment for 1.6 billion
people in the future, the whole country has started to reform urban water resources management systems in terms of related
policies, regulations, methodologies, and technologies focusing on improving the efficiency and effectiveness in water use.
Urban water quota management has now become a core strategy in developing a water resources governance model for water demand
management aiming at establishing a water-saving society. This paper introduces the main stages and the processes of implementing
water quota management in China, analyzes the basic principles, and expounds the elements, information foundation, core module
and operational model of the urban water quota management system. It has been demonstrated that urban water quota management
has made some remarkable contribution not only in transforming the pattern of water mode and strengthening water management
enforcement but also in integrating various management methods in saving water and preventing pollution. 相似文献