密闭式堆肥反应器中复合微生物菌剂对堆肥效果的影响

通过一套自制密闭式堆肥反应器系统,研究在一定的堆肥条件下,接种复合微生物菌剂对堆肥腐熟度、环境影响控制和产品质量等方面的影响。通过对堆肥温度、含水率、碳氮比(C/N)、发芽指数(GI)、氨气(NH3)排放浓度和微生物数量等指标的检测分析发现,接种复合微生物菌剂的处理组提前3.5~4.5h到达高温期,高温期持续时长多于对照3.8~4.0 d,氧气消耗快,堆肥腐熟速度快,腐熟程度高,氨气排放浓度平均低于不接种处理39%,有效地控制了臭气排放和氮素损失。认为在堆肥中接种复合微生物菌剂是解决我国目前堆肥腐熟时间过长、养分损失大、恶臭气体排放严重、环境影响严重等问题的有效途径。     

复合菌剂强化餐厨垃圾好氧生物处理性能研究

为探索复合菌剂对餐厨垃圾好氧生物处理过程和腐熟效果的影响,利用4组自制的堆肥反应器进行小规模试验。以木屑为辅料,分别投加适用于常温条件下有机质分解的菌剂碧沃丰®除污(WD)、前期筛选制备的复合耐高温菌剂(TB)和WD+TB复合微生物菌剂,以不投菌为空白组(CK),通过测定堆体总重、温度、含水率、干基有机质含量、pH值、水溶性氨氮及硝态氮、腐殖化系数(E465/E665)、电导率(EC)、种子发芽率指数(germination index GI),研究处理过程。结果表明,初始含水率为(63.5±0.5)%,初始干基有机质含量为(96.6±0.9)%,初始碳氮比为34.9±2.7,辅料20%(质量分数),接种量25 mL/kg下,(WD+TB)组堆料高温期持续时间最长、温度峰值最高,可持续7d 50 ℃以上高温,最高温度达到72 ℃;总重减量率和有机质减量率最高,分别为80.7%和64.3%,日均有机质减量率是CK组的2.13倍;水溶性氨氮和E4/E6最低,种子发芽率指数 (96.3±26.7)%最高。说明WD+TB复合微生物菌剂可以有效提升餐厨垃圾好氧生物处理效果,并显著提高堆肥效率。     

添加外源微生物对城市生活垃圾堆肥腐熟的影响

文章探究高效、低成本的圾堆肥技术,为城市生活垃圾的无害化处理和资源化利用提供科学依据。以生活垃圾为原料,采用7 d翻堆一次的方式,进行为期45 d的堆肥试验。试验设常规和添加5%发酵剂堆肥处理,研究添加外源菌剂对城市生活垃圾堆肥过程中物理和化学特性变化的影响及对堆肥腐熟度的影响。结果显示添加5%菌剂的堆肥处理在堆肥24 h后温度达到53℃,堆肥过程中最高温度达到65℃,温度保持50℃以上达24 d;使堆肥C/N迅速下降,并在35 d后,该值稳定在12.2左右;铵态氮与硝态氮比值开始迅速上升,而后逐渐下降,最终比值稳定在1.2,油菜种子的发芽指数达到85%以上。说明添加5%外源微生物菌剂能加速城市垃圾堆肥腐熟进程。     

微生物复合菌剂对污泥好氧堆肥过程的影响

研究了黄孢原毛平革菌与枯草芽孢杆菌复合菌剂在剩余污泥静态强制通风好氧堆肥中的作用.结果表明,根据堆肥过程中的温度(0~5d为中温阶段,6~12d为高温阶段,16~28d为腐熟阶段)变化,复合菌剂的变化导致堆体细菌数量明显高于空白堆体,且堆体中的嗜热真菌在高温期显著增多,促进了有机物的降解,加速了堆体的腐熟.试验组萝卜种子发芽指数(GI)相对空白组提前3d达到了50%,表明复合菌剂的加入迅速地降低了堆体的生物毒性,但由于相对浓缩效应使得堆肥产品Cd含量略有增加.     

堆肥反应器中2种微生物接种剂的堆肥效果研究

在严格控制堆肥条件的情况下,以鸡粪为堆肥基本原料,选用单一微生物巨大芽孢杆菌和复合微生物VT菌为接种剂,通过研究堆肥过程中的温度、氧气浓度、C/N、WSC(水溶性碳)、发芽指数(GI)以及脱氢酶和纤维素酶的活性动态变化来反映这2种微生物接种剂对堆肥效果的影响.结果表明,接种复合微生物菌剂VT的处理在堆肥升温和保持高温效果明显,接种微生物菌剂的2个处理的堆体内氧气浓度都较CK低,其中最低的为接种复合微生物菌剂VT的处理.接种微生物菌剂,C/N下降速度快,WSC浓度相对高,GI值上升速度明显加快,有利于加快堆肥腐熟进程,其中接种复合微生物菌剂VT的效果较单一微生物菌剂巨大芽孢杆菌好.接种微生物菌剂有利于堆肥升温期脱氢酶和纤维素酶活性增加,促进堆肥的氧化还原反应和纤维素的分解,且接种复合微生物VT的效果明显.     

高温菌剂的添加时间对污泥堆肥指标影响研究

为研究高温菌剂对堆肥指标的影响,实验采用对照方法,分别设计了不加菌剂(1号)、在堆肥开始时加入常温菌(2号)和高温菌剂(3号)、在堆肥物料升温至45℃左右加入高温菌剂(4号)四种处理方式,探讨发酵过程中堆肥温度、水分、pH值、NH4+-N、总氮和有机质含量变化。结果显示:4号堆体升温是最快的,且4号堆体在各项堆肥指标上均明显优于其他三组。说明后加高温菌剂能够加快堆肥的升温速度,更好地促进有机物的降解,提高堆肥的最高温度,延长堆肥高温期,且能在一定程度上控制高温阶段pH,减少氮素流失,提高污泥堆肥效果。     

覆盖处理对猪粪秸秆堆肥中氮素转化和堆肥质量的影响

为了探讨覆盖措施对堆肥化中氮素转化与堆肥质量的影响,在自制的强制通风静态堆肥箱中,模拟研究了覆盖腐熟堆肥后,下层猪粪秸秆堆肥及覆盖层中氮素形态和其他腐熟度指标的变化.结果表明:覆盖处理降低了下层堆肥中的含水率、种子发芽指数(GI值)、升温期和高温期的pH值,增大了降温期后的堆肥电导率EC值,而对堆温影响不大.覆盖处理未改变堆制初期下层堆肥中氨气的释放总量,只延缓了氨气的释放时间,但明显增加了降温期后堆肥中硝态氮和有机氮的含量.在堆制期间,覆盖处理的下层堆肥中硝态氮、有机氮、总氮和总磷含量的增幅分别比对照高66.7％、33.8％、32.7％和138.6％;而有机碳降解率、铵态氮和腐殖质含量的降幅则分别比对照低1.1％、8.0％和3.7％.覆盖层中pH值、铵态氮和硝态氮含量的变化说明腐熟堆肥能够吸收下层堆肥释放的氨气并进行硝化作用;覆盖层的腐熟堆肥总体上进行了矿化作用,从而影响了下层堆肥的氮素转化过程及质量.     

复合微生物菌剂对污泥堆肥的作用效果研究

为了研究复合微生物菌剂对污泥堆肥的作用效果,以消化污泥、锯末和回流堆肥为原料,接种不同剂量（0、0．2％、0．5％）的复合微生物菌剂进行室外露天堆肥,分析了温度、含水率、pH值、全碳（TC）、全氮（TN）、种子发芽指数（germination index,GI）的动态变化,结果表明：各堆体温度保持在50℃以上的时间均超过7d,满足堆肥卫生标准;接种复合微生物菌剂的堆体升温速率和温度最高值均大于未接种堆体,接种复合微生物菌剂有利于增加堆体水分散失量,加快堆体有机质降解速度,降低堆体氮的损失量,提高GI值;其中微生物菌剂接种量为0．5％的堆体,接种处理对水分散失、氮损失的控制和GI值的增加效果较明显。     

EM发酵菌在畜禽粪便自然堆肥中的应用研究

畜禽粪便污染是农村主要环境污染,目前农村普遍采用自然堆肥方式处理.本实验模拟自然堆肥方式,加入EM菌微生物菌剂,在高温期进行翻堆通风,通过厌氧和好氧堆肥共同作用,粪便达到腐熟.堆肥过程中跟踪测量堆体温度、并对TOC、TN、TP、TK等技术参数检测,实验结果表明,加入EM菌剂后,发酵周期缩短为自然堆肥腐熟周期的1/3,有效提高高温期最高温度15℃,营养成分没有明显降低.     

农业废弃物静态高温堆肥过程中纤维素酶活性的变化

在静态通气条件下,以养殖场鸡粪、猪粪、牛粪为材料,小麦秸秆作为调节物质.研究了堆肥过程中纤维素酶活性变化特性及其与堆肥温度的关系,旨在为农业废弃物资源化利用提供科学依据.结果表明:添加微生物菌剂后堆体升温迅速.堆肥1-2d后进入高温期,且高温腐解持续16-20d;对照处理在堆肥4-5d后进入高温期,持续时间仅为7-8d;整个堆肥过程中加菌剂处理的堆体温度高于对照.加菌剂处理在堆肥10-12d时纤维索酶活性达最高,依次为牛粪(0.642 mg·g-1·d-1)>鸡粪(0.457 mg·g-1·d-1)>猪粪(0.380 mg·g-1·d-1);对照处理推迟2d达纤维素酶活性高峰,且酶活性高峰值低于同等物料的加菌剂处理,依次为牛粪(0.491 mg·g-1·d-1)>猪粪(0.335 mg·g-1·d-1)>鸡粪(0.258 mg·g-1·d-1),整个堆肥过程中加菌剂处理平均纤维紊酶活性较对照提高了33.17%(牛粪)、20.17%(鸡粪)和12.4%(猪粪).堆肥初期堆肥温度过高不利于微生物的活动,纤维素酶活性在堆肥开始的3-4d低于初始水平.而后迅速上升.当堆肥温度等于或者低于60℃后,纤维素酶活性与有机物料温度变化间有显著正效应,对照处理两者间为线性关系,加菌剂处理两者间呈显著指数递增关系.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.