升温过程干法半干法脱硫灰中硫酸盐的稳定性研究

[目的]研究不同气氛、湿度和温度对脱硫灰中硫酸盐稳定性的影响。[方法]通过改变气氛、脱硫灰湿度、焙烧温度的条件，研究干法和半干法脱硫灰中硫酸盐的稳定性。[结果]在空气条件下，当焙烧温度为450—700℃时，脱硫灰中的CaSO3能迅速氧化成性质稳定的CaSO4；当焙烧温度为750～1050℃时，脱硫灰中的CaSO3能同时发生氧化和分解，部分CaSO3分解为CaO和SO2。在氮气条件下，CaSO3在650℃开始分解。随着脱硫灰湿度的增加，SO2的逸出量越大，CaSO3的分解率越大，同时由CaSO4的分解产生SO2。在800～1050℃，SO2的逸出量随着温度的升高而增加。[结论]450～1050℃，SO2的最大排放浓度为101．4mg／m^3，远远低于国家标准（800mg／m^3），在脱硫灰渣的再利用中对环境不会造成危害     

不同态锌在动物体内代谢的比较

锌是动物体内必需微量元素之一,具有重要的生物学功能,实验用葡萄糖酸锌、硫酸锌、氯化锌和醋酸锌给小白鼠饮水,锌浓度为100PPm。结果表明:肝脏、肾脏、眼球和血液中锌含量均以葡萄糖酸锌组最高,达峰值最快,依次为硫酸锌、氯化锌和醋酸锌,100PP锌对小白鼠有轻度的毒性作用。     

玉米幼苗根系对硫酸盐(Na235SO4)亲和性配合力的研究

本文以来源不同的9个玉米自交系及其按双列杂交组成的36个杂交种为材料，研究了玉米幼苗根系对硫酸盐(Na₂³⁵SO₄)亲和性(Km)的配合力。结果表明：m以非加性基因效应较重要，Km与产量间有密切关系。鉴定出可供五米育种中利用的2个自交系“合二”、“292”及具有更广泛适应性和高产特性的3个杂交组合：5005、5022、5030。     

Effects of phosphogypsum or calcium sulfate on aluminon reactive aluminum in solutions at varying pH

Abstract

Growing evidence of positive crop responses to gypsum or phosphogypsum (PG) application in acid soils strongly support the use of these amendments as an ameliorant of subsoil acidity. Although gypsum improves Ca availability in subsoils, its role in alleviation of Al toxicity needs careful attention. In the current study, either PG, CaSO₄.2H₂O or CaCl₂.2H₂O was added (to supply 12 mM Ca) to solutions containing 40 μM Al at pH 4.1 + 0.1. Solution pH was gradually raised to 4.5, 4.8 and then to 5.3 at various time intervals during 25 d aging of the solutions at 25 + 1^OC.

Concentration of Al measured by aluminon method without preacidification and preheating, referred to as “reactive Al”; in this paper, was 16 μM in 2 g L^‐1PG solution without added Al. This accounted 38% of total soluble Al in PG solution. Addition of 2 g L^‐1PG to solution containing 40 μM Al, resulted in only 42% of total Al in solution present in forms reactive with aluminon. According to MINTEQ speciation model, Al in solution was present as an entirely complexed form with F^‐. An increase in solution pH up to 5.3 had no effect on measured concentration of reactive Al or predicted distribution of Al species.

Addition of CaSO₄.2H₂O to 40 μMAl solutions had no effect on the concentration of reactive Al within pH 4.1 ‐4.8, however, up to 62% of total Al was in a form complexed with SO₄ ^2‐, as predicted by MINTEQ model. The concentration of reactive Al decreased by 60% at pH 5.3. Addition of CaCl₂.2H₂O also had no effect on the concentration of reactive Al within pH 4.1 ‐ 4.8. Nearly 73 ‐ 94% of total Al was present in Al³⁺form. An increase in pH to 5.3, decreased the concentration of reactive Al by 27%. The results suggest that ion‐pairing of Al with F^‐would appear to be a possible mechanism for alleviation of Al toxicity by PG at pH range 4.1 ‐ 5.3. With regard to CaSO₄.2H₂O, at pH 4.1 ‐ 4.8 ion‐pairing with SO.₄ ^2‐appears to be possible mechanism for the alleviation of Al toxicity. In addition, at pH 5.3 a considerable decrease in reactive Al was evident which would further alleviate Al toxicity.     

镉硫交互作用对茭白膳食纤维含量的影响

[目的]探求镉硫交互作用对茭白产品器官膳食纤维含量的影响。[方法]以茭白（Zizania latifolia Turcz．）的单季茭品种蒋墅茭和双季茭品种葑红早为试材,比较在有机肥、无机肥处理下,镉硫交互处理对2个品种茭白产品器官中膳食纤维及粗纤维含量的影响。[结果]随硫处理浓度的增加,2个茭白品种产品器官中膳食纤维、不溶性膳食纤维、粗纤维的含量呈持续下降的变化趋势,而可溶性膳食纤维的含量则持续上升,各浓度硫处理间差异显著。肥料处理闷以无机肥处理时茭白产品器官中的总膳食纤维、不溶性膳食纤维、粗纤维含量高于有机肥处理,而可溶性膳食纤维则低于有机肥处理。[结论]硫肥的施用能促进茭白可溶性膳食纤维含量的增加。     

硫酸盐作为共存电子受体对微生物Fe(Ⅲ)还原过程的影响

Fe(Ⅲ)和SO42-都是水稻土中主要的电子受体,对厌氧过程中的电子传递起着重要作用。本研究采用土壤浸提液厌氧培养和纯培养的试验方法,探讨了SO42-作为电子竞争受体对不同水稻土微生物群落和铁还原细菌的Fe(Ⅲ)还原过程的影响。土壤浸提液培养试验结果表明,添加SO42-后Fe(Ⅲ)还原受到显著的抑制,Fe(Ⅲ)反应速率随着浓度的增加而降低。随着培养时间延长,Fe(Ⅲ)还原反应依然可以进行,Fe(Ⅱ)最终累积量达到与CK2相同的水平。在利用铁还原菌的纯培养试验中,添加SO42-对供试的四株铁还原菌的Fe(Ⅲ)还原过程并未产生抑制效应,表明铁还原菌本身并不受SO42-的影响。     

An alternative model for fetal loss disorders associated with mare reproductive loss syndrome

Fertile chicken eggs were used as an alternative model for large animals to evaluate suspect toxic dietary ingredients for fetal loss disorders associated with mare reproductive loss syndrome (MRLS) and fetal losses in other livestock. Nitrate, ammonia, and sulfate may react with proteinaceous compounds to enable the formation of abiotic pathogenic nanoparticles which were constant findings in pathognomonic placental lesions associated with non-infectious fetal losses of previously unknown etiology in mares, chickens and other livestock. The pathogenic nanoparticles may be produced naturally by toxic elements associated with air pollution that affect pasture forages or crops, unintentionally by reactions of these elements in protein-mineral mixes in dietary rations, or endogenously within tissues of fetuses and adult animals. The nanoparticles may form niduses in small vessels and predispose animals to a host of secondary opportunistic diseases affecting the reproductive, respiratory and gastrointestinal tracts of animals. The newly recognized abiotic pathogenic micro and nanoparticles are associated with MRLS. The discovery of the pathogenic nanoparticles led to the identification of nitrate, ammonium, and sulfur, in the form of sulfate, that seemingly enable the formation of the pathogenic nanoparticles in embryonic and fetal tissues.     

Increased sulfate availability in saline water promotes hydrogen sulfide production in fish organic waste

The risk of hydrogen sulfide (H₂S) production can be a challenge in marine land-based recirculating aquaculture systems (RAS). Hydrogen sulfide is a toxic gas that can cause massive fish mortality even at low concentrations, and in addition, serious odour problems in the surroundings. It is a bacterial by-product originating from the degradation of organic matter in sulfur-rich waters such as marine waters. In order to hinder H₂S production in marine land-based RAS, more information on the H₂S production conditions and the associated microbiology is needed. In this study, the production of H₂S from rainbow trout (Oncorhynchus mykiss) organic waste was examined using a novel H₂S measurement method under a range of salinities (0, 5, 10, 15, 25 and 35 g/L) in anaerobic mixed reactors, and the microbial communities as well as abundance of sulfate reducing bacteria (SRB) were characterized. The maximum H₂S concentration increased from 23.1 ± 8.2 mg H₂S/L at 0 g/L salinity to 153.9 ± 34.1 mg H₂S/L at 35 g/L salinity. Similarly, the H₂S production rate increased from 5.6 ± 0.2 at 0 g/L salinity to 26.4 ± 12.7 mg of H₂S produced per day at 35 g/L salinity. The highest H₂S production was recorded after increased availability of volatile fatty acids, which were produced by fermentative bacteria from phyla Firmicutes and Bacteroidetes that dominated the microbial communities after day 5. The traditional sulfate reducing bacteria (SRB) were found only at 0 and 5 g/L salinity, while at higher salinities, H₂S production was carried out by novel unquantifiable SRB. The results demonstrate that H₂S can be a pronounced problem in marine RAS, although it can be controlled through preventing anaerobic conditions within the system.     

Humic-rich peat extracts inhibit sulfate reduction, methanogenesis, and anaerobic respiration but not acetogenesis in peat soils of a temperate bog

To understand why anaerobic ombrotrophic peats can be very low in methane after drainage related afforestation, we analyzed the competition of sulfate reducing, humus reducing, and methanogenic microorganisms by incubating ombrotrophic peats of the Mer Bleue bog, Ontario. Sulfate, sulfide, and sulfate containing peat dissolved organic matter (DOM) from an afforested site were added in reduced and oxidized redox state. Sulfate and acetate concentrations were analyzed, bacterial sulfate reduction (BSR) and CO₂ and CH₄ production quantified, and results analyzed by ANOVA. DOM was characterized by Fourier transformed infrared and fluorescence spectroscopy and analyzed for trace elements. CH₄ production (116 nmol cm⁻³ d⁻¹) and BSR rate (102 nmol cm⁻³ d⁻¹) were similar in ‘controls’. BSR in treatments ‘sulfate’ (73 nmol cm⁻³ d⁻¹) and ‘sulfide’ (118 nmol cm⁻³ d⁻¹) did not significantly differ from ‘controls’ but addition of DOM significantly diminished BSR down to 0.4 nmol cm⁻³ d⁻¹ (Kruskal Wallis test, p < 0.05). CH₄ production decreased with sulfate (16%, not significant) and sulfide addition (40%, p < 0.05) and CO₂ production increased (treatment ‘sulfate’, p < 0.05). Addition of all DOM extracts (67 mg L⁻¹) almost completely suppressed methanogenesis and CO₂ production (p < 0.05), but acetate accumulated compared to the control (p < 0.05). The DOM applied contained carboxylic, aromatic and phenolic moieties and metal contents typical for peat humic substances. We conclude that a toxic effect of the intensely humified DOM occurred on both methanogenic and sulfate reducing bacteria (SRB) but not on fermenting microorganisms. As yet it is not clear what might cause such a toxic effect of DOM on SRB and archaea.     

烤烟烟叶卷曲症状的诊断及其机理研究Ⅱ. 组织分析和水培试验

对基地不同程度缺钙症状的烤烟植株的组织分析结果表明,烟株叶片反转卷曲的畸形症状的程度与叶片内钙含量呈反相关,而与烟叶内硫酸根离子和磷的含量呈正相关。基地新垦红壤中只是因为使用商品有机肥1号才有大量的硫酸根和磷酸根可供烟株吸收。水培试验结果证明,高浓度的磷酸根离子能够诱导烟株缺钙的症状,营养液中钙浓度越低,磷酸根浓度越高,诱发的烟叶缺钙的症状出现时间越早,程度越严重。从而证明基地出现的因施用商品有机肥1号而诱导烤烟缺钙症状的机理确是由于该有机肥所含的大量磷酸根、硫酸根等阴离子与根际土壤中的钙形成溶解度更低的硫酸钙盐或磷酸盐的沉淀,因此阻碍了Ca2 的吸收,以及烟株大量吸收磷酸根和硫酸根导致体内钙的转运和再利用困难所致的。