典型生活垃圾填埋场覆盖土微生物群落分析

采用第二代高通量测序技术Illumina MiSeq对典型生活垃圾填埋场覆盖土样(山东莱芜,SD;广东深圳,GD;上海老港,SH;重庆长生桥,CQ)进行16S rDNA V3~V4区高通量测序,并分析了Alpha多样性、物种组成和丰度、菌群结构及环境因子对群落结构的影响.结果表明:取自垃圾填埋场GD土样的物种种类多于其他土样,GD、SD、SH、CQ土样的Shannon指数分别为5.52±0.026、4.76±0.030、4.89±0.037、3.43±0.027;所有覆盖土样的优势菌为Alphaproteobacteria(α-变形杆菌纲)和Betaproteobacteria(β-变形杆菌纲),所占比例范围分别为12.67%~25.54%,14.35%~18.88%;SD、GD和SH三种覆盖土样的优势菌为Sphingomonas(鞘氨醇单胞菌属),分别占7.25%、10.67%、11.30%; Deltaproteobacteria(德耳塔变形杆菌纲)和Gammaproteobacteria(γ-变形菌杆纲)的相对丰度分别与TN(r=1.00,P<0.001)和TP(r=1.00,P<0.001)呈正相关关系,且结合RDA图,TN、TP和OM含量可能是SD土样区别于其他土样群落组成的主要因素.     

Effect of long-term application of corn stalks and inorganic fertilizers on fluorescence characteristics of water extractable organic matter in a meadow black soil of northeast China

ABSTRACT

Returning crop residues into fields, either alone or in combination with inorganic fertilizer, is considered as a practical way to enhance soil fertility. However, information concerning the effects of crop residues and inorganic fertilizer application on water extractable organic matter (WEOM) in soil is scarce. The aim of this study was to examine the 10-year effect of corn residue (CR) return with or without the application of nitrogen, phosphorus, and potassium (NPK) fertilizer on the quantity and quality of WEOM in a black soil of northeast China by means of ultraviolet absorbance, fluorescence excitation--emission matrix, and derived spectroscopic indices. The application of NPK fertilizers and CR, alone or together, increased the content of total soil organic carbon (SOC), water extractable organic carbon (WEOC), and ratio of WEOC/SOC, with the sequence being NPK + CR > CR > NPK > CK. Compared with control treatment, the individual application of NPK fertilizer decreased the aromaticity of WEOM. In contrast, elevated proportion of tryptophan-like fluorophore and microbially derived fulvic acid-like components with low molecular weight was detected in the WEOM. The amendment with CR alone resulted in increase in aromaticity of WEOM and proportion of plant-derived humic acid-like component with large molecular weight, accompanied by reduced proportion of tyrosine-like compounds. For the soil with CR restoration, the application of NPK fertilizer increased aromaticity of WEOM, and large molecular weight fulvic acid-like and humic acid-like compounds were found. However, the proportions of tyrosine-like and tryptophan-like compounds were diminished. The quantitative and qualitative analysis of WEOM using fluorescence spectroscopy describes responses to be observed in long-term different fertilization strategies.     

餐厨垃圾废水制备液态解磷菌剂研究

本研究探讨了餐厨垃圾废水用作发酵基质生产液态解磷巨大芽孢杆菌菌肥的可行性.结果表明,餐厨垃圾废水培养的巨大芽孢杆菌经过3~4d的调整期即进入对数生长期,第6~7d活菌数达到最大,而经过湿热预处理得到的II类废水较I类废水更适宜用作巨大芽孢杆菌的培养基质,其菌液活菌数是I类废水培养的活菌数的5倍（4.8×10¹⁵CFU/mL）.废水中的盐分对巨大芽孢杆菌的生长代谢影响显著：活菌数随着NaCl含量的增加先升高后快速降低,最利于菌种培养的NaCl浓度为10g/L.pH值和温度极显著影响巨大芽孢杆菌的生长,而摇床转速和接种量对菌株培养影响不显著,正交试验确定的较优培养条件为pH=8、T=35℃、转速80r/min、接种量2%（V/V）.餐厨垃圾废水制备的解磷菌肥可实现土壤中固化磷的有效磷化：施用0.025‰~2.5‰质量比例解磷菌剂的土壤生长的黄豆苗干重可达到按照5‰质量比例施加无机复合肥生长的黄豆苗的70.7%~84.5%,其中微生物菌肥的最佳施用量为0.25‰.     

长期施肥对水稻土酶活性及理化特性的影响

为了明确不同施肥种类对水稻土土壤肥力与酶活性的影响,以30年（1981年至今）长期定位试验地为基础,研究不同施肥处理（CK,N,P,K,NPK,2倍NPK,NPK＋猪粪）水稻田耕层（0-20cm）土壤酶活性与养分的变化趋势及其相关性。结果表明：1）施P（配施或单施）增加土壤全P、速效P含量,平衡施肥配施有机肥（NPK＋猪粪处理）土壤的有机质、全P、速效P、全N、速效N均显著增加,所有施肥处理间pH值差异均不显著;2）除了NPK处理土壤脲酶活性最高外,平衡施肥配施有机肥土壤转化酶、酸性磷酸酶、过氧化氢酶活性均较其他处理显著增加;3）酸性磷酸酶活性与土壤全P量呈负相关,过氧化氢酶、脲酶、转化酶与全N、有机质、速效N、速效P呈显著或极显著正相关;因此,水田土壤长期平衡施肥配施有机肥,能显著提高土壤肥力,增加土壤酶活性,有益于土壤生产力的持续提高。     

氮肥、磷肥、粉煤灰和CaCO3对As(Ⅲ)胁迫下小麦幼苗生物效应及成熟期籽粒As含量的影响

采用盆栽的方法,研究了在As污染土壤中施加氮肥、磷肥、粉煤灰和CaCO₃对小麦籽粒萌发、幼苗生理及成熟期籽粒w(As)的影响,并探讨了4种改良剂对在As污染土壤上种植小麦的有效改良方法. 结果表明:适量的氮肥、磷肥、粉煤灰和CaCO₃对As污染土壤的小麦萌发和幼苗生长具有明显的促进作用,能有效缓解As对小麦的毒害,并降低成熟期籽粒的w(As). 表现为出苗率、幼苗株高、植株鲜重增大,w(叶绿素a)升高,丙二醛(MDA)含量和w(游离脯氨酸)下降,成熟期籽粒的w(As)降低.      

Fluoride distribution in the environment along the gradient of a phosphate-fertilizer production emission (southern Brazil)

Airborne fluoride was determined in the rainwater, surface soil and groundwater along a gradient of emission of a phosphate fertilizer factory in Rio Grande, southern Brazil. Concentrations of fluoride in rainwater and groundwater achieved 3 mg l⁻¹ and 5 mg l⁻¹, respectively, and were dependent on pH. The fluoride deposited from emissions accumulated in a superficial horizon of soil in quantities comparable to those in the manufactured end-products—up to 23,000 mg kg⁻¹. Fluoride distribution in the environment is controlled by physical–chemical parameters of emission, rain intensity and soil properties. The highest fluoride concentrations were registered at a close distance of up to 2 km from the factory. The distribution of fluoride in groundwater resembled the same distribution in rainwater due to the high permeability of the local soils. Fluoride penetration to the groundwater also depended on the type of vegetation cover. The groundwater in woodland areas was less affected by contamination of fluoride than in the grassland areas, most probably because of the influence of eucalyptus throughfall, which increases the pH of wet precipitates.     

高盐浓度对工业废水生化处理的影响研究

研究了生物制药废水的不同含盐量对生化处理系统效果的影响,以及对该系统中的生物学变化规律的影响。在含盐量低于2.5×104mg/L时,废水生化处理系统COD去除率可稳定在92%左右,污泥活性良好;随着进水盐浓度的增加,含盐量达到2.5×104mg/L时,污泥活性开始受到抑制,COD去除率急剧下降至80%左右;当废水含盐量达到3.5×104mg/L时,污泥活性明显受到抑制,污泥絮体开始部分解体,COD去除率下降到60%左右;当废水含盐量达到6.0×104mg/L时,污泥活性系统趋于崩溃,原生动物近乎绝迹,污泥絮体细碎分散,可见少量球形游离细菌,COD去除率仅有45%左右。     

生活垃圾转化高效生物有机肥料的肥效研究

利用城市生活垃圾制备高效生物有机肥料,分别应用于小麦、黄瓜、玉米等作物,并观察施肥后对农作物及土壤理化性质的影响,结果表 明生活垃圾转化成高效有机肥料对作物生长有明显的促进作用,可增强作物抗病能力,增加农作物产量,还可以提高土壤肥力,改善土壤结构。      

Chlorophenol tolerant and degradative bacteria isolated from a river receiving pulp mill discharges

A screening was carried out in a river receiving pulp mill discharges (BioBio river, central Chile) to study the bacterial population able to tolerate and degrade chlorophenols. In four selected stations and at different seasons, water samples were taken from the river. Total bacterial population and the number of chlorophenol tolerant bacteria were counted. Bacterial tolerance to 25, 50, 100, 200 and 400 μg/ml of 2,4‐dichlorophenol (DCP), 2,4,6‐trichlorophenol (TCP) and pentachlorophenol (PCP) was determined. Strains able to tolerate at least 400 μg/ml chlorophenols were found. Eighteen bacterial strains able to use chlorophenols as the sole carbon source were isolated: five of them were Pseudomonas fluorescens, two Alcaligenes sp., one Citrobacter freundii, one Aeromonas sp. and nine unidentified Gram negative bacilli. A good correlation (r ² = 0.758) between the logarithm of DCP tolerant bacteria and the content of adsorbable organic halogen (AOX) at low dilution in the river water was established. Four groups of tolerant bacteria were found: growing on PCP and DCP, growing on PCP and TCP, growing only on PCP and growing only on TCP.     

Toxicity of cadmium nanoparticles to Bacillus subtilis

The study deals with the toxicological impact of cadmium nanoparticles (Cd NPs) on Bacillus subtilis as a model Gram-positive bacterium. Cadmium oxide (CdO) NPs (～22 nm) and cadmium sulfide (CdS) NPs (～3 nm) were used in this study. Both the NPs were found to inhibit the cell viability of B. subtilis when added to the culture at mid-log phase, the viable cell number declined with increasing concentration of Cd NPs. At mid-log phase, 15 mg L^?1 CdO NPs inhibited growth by ～50%, whereas at 30 mg L^?1 growth completely ceased. Under the same conditions, CdS NPs inhibited growth by ～50% at a concentration of 8 mg L^?1, and at 20 mg L^?1 growth was completely retarded. The cells changed their morphological features to a filamentous form with increasing Cd NPs exposure time, leading to associated with clumping. NPs treated cells when stained with 4′, 6-diamino-2-phenylindole, showed filamentous multinucleated bead structure, suggesting irregularities in cell division. Increasing intracellular oxidative stress due to Cd NPs exposure might be one of the reasons for the cell morphological changes and toxicity in B. subtilis.