玉米根内和根际土壤溶磷细菌生物学特性研究

从玉米根内和根际土壤中分离筛选到22株溶磷细菌。根据16SrRNA基因序列分析,2株溶磷效果最好的菌株分别被鉴定为伯克霍尔德氏菌(Burkholderia sp.SY9)和泛菌(Pantoea sp.Gym7c)。同时对菌株SY9和Gym7c的溶磷能力和植物促生特性进行了进一步研究。利用磷酸钙和开阳磷矿矿粉研究了菌株释放P、Ca和Fe的效能。液体培养条件下,菌株在在磷酸钙培养基中的生长好于在开阳磷矿粉培养基中的生长,同时菌株能够合成铁载体。菌株SY9从开阳磷矿粉中释放P、Ca,和Fe的能力比菌株Gym7c强。然而菌株Gym7c从磷酸钙中释放P和Ca的能力比菌株SY9强。菌株Gym7c主要是通过合成的有机酸溶解磷酸钙并释放其中的P和Ca,而菌株SY9是通过合成的有机酸和铁载体溶解开阳磷矿粉并释放出其中的P、Ca,和Fe。溶解开阳磷矿粉的有机酸主要是葡萄糖酸而溶解磷酸钙的有机酸主要包括丁二酸、丙酸、苹果酸和酒石酸等。菌株Gym7c能够合成生长素、铁载体和1-氨基环丙烷-1-羧酸脱氨酶。菌株SY9和Gym7c对酸碱、盐和温度均表现出一定的抗性。     

好氧堆肥对难溶性磷转化的影响

在牛粪进行工厂化堆肥过程中,加入难溶性磷矿粉,探讨堆肥对难溶性磷转化能力的影响.结果表明,加入磷矿粉可使堆肥中活性有机磷、中等活性有机磷、中稳性有机磷、高稳性有机磷含量均有不同程度的提高;磷矿粉加入量为牛粪干重4%(P1DM)和8%(P2DM)的处理与未加磷矿粉的处理相比各形态磷含量分别增加120.99%、125.32%,34.86%、38.64%,27.74%、30.84%,21.38%、20.06%;P2DM和P1DM处理之间的差异分别为4.33%,3.78%,3.10%,-1.32%.电镜观察显示,堆肥后磷矿粉典型的矿物特征消失,表面呈蜂窝状.研究结果表明,通过堆肥生产富磷粪肥可为解决中国磷素资源缺乏、化学磷肥利用率低等问题提供一条生物学途径.     

生活垃圾堆肥对难溶性磷有效性的影响

生活垃圾在堆肥过程中将产生有机酸类物质,这些酸性物质对难溶性磷具有较强的溶解能力.本研究在生活垃圾堆肥过程中,加入难溶性磷矿粉,系统探讨堆肥对难溶性磷的转化及堆肥产品对磷素有效性的影响.研究表明,速效磷在堆肥中后期达到最大值,并在堆肥的后期相对稳定,堆肥结束后,扣除磷矿粉本身含有的速效磷对堆肥的影响,与不加磷矿粉堆肥相比,P₁、P₂堆肥处理方式速效磷含量增加值分别为0.87 g·kg^-1、0.76 g·kg^-1.电镜观察表明,堆肥结束后,磷矿粉表面棱角消失,呈蜂窝状.堆肥产品培肥后,富磷垃圾肥在作物生育期内,土壤速效磷含量、酸性磷酸酶活性均高于垃圾肥、腐熟鸡粪及化肥.     

Effect of low-molecular weight organic acids on phosphorus release and phytoavailabilty of phosphorus in phosphate rocks added to soils

Phosphorus (P) is critically needed to improve soil fertility in many parts of the world. The use of water-soluble P fertilizers, e.g., single super-phosphate and triple super-phosphate in developing countries to improve crop production has been limited primarily by their high cost. The presence of indigenous phosphate deposits in some countries provides an incentive for direct application or local chemical treatment at low cost to improve the solubility of low reactive phosphate rocks (PRs). The use of naturally occurring low-molecular weight organic acids (LMWOAs) that are produced in soil as microbial metabolites or plant exudates from dead or living cells represents a new perspective in PR research. The LMWOAs contain various functional groups that may play a significant role in PR dissolution. Little information is available, however, about the potential of LMWOAs in releasing P from PRs. This study reports P release from 12 PRs, four each of low, medium, and high reactivity, obtained from various deposits (Kodjari, Tahoua, North Carolina, Gafsa, Khouribga, Tilemsi Valley, Central Florida, Sechura, Minjingu, North Florida, Hahotoe, and Parc W) using nine LMWOAs containing mono-, di-, and tri-carboxylic groups and a mineral acid (H₂SO₄). Laboratory studies showed that the organic acids are effective in releasing P from low and medium reactive PRs, but very ineffective in releasing P from high reactive PRs. The average amounts of P released by all the organic acids from the three types of PRs were 65.5 mmol kg⁻¹ PR from the low reactive PRs, 55.1 mmol kg⁻¹ from the medium, and 11.1 mmol kg⁻¹ from the high; those released from across all the PRs were 21.9 by the mono-carboxylic acid group, 54.2 by the di-carboxylic acid group, and 57.0 mmol P kg⁻¹ by the tri-carboxylic acid group. The P released was negatively correlated with the equilibrium pH, but positively correlated with Ca released from the PRs. Laboratory incubation studies on the release of P from PRs added to soils with or without organic acids and incubated at 25 °C for 15, 30, and 45 days showed that the percentage of plant-available P released varied considerably from 0.95 in the Kodjari PR to 40.1% in the North Carolina PR and was related to PR reactivity. A greenhouse study with corn (Zea mays L.) grown for 60 days on soils treated with PRs or with PRs mixed with organic acids showed that corn response to addition of oxalic or citric acid varied with P rates and PR sources, suggesting that organic acids have potential as amendments for increasing plant-available P in PR-treated soils.     

不同类型有机酸-磷矿粉复合物对土法炼锌废渣中重金属的固定作用

为分析利用不同类型有机酸活化低品位磷矿粉形成的"有机酸-磷矿粉复合物"对铅锌冶炼废渣中重金属的固定作用,以黔西北历史遗留土法炼锌废渣为对象,研究3种类型有机酸(草酸、酒石酸及柠檬酸)活化低品位磷矿粉对土法炼锌废渣中4种主要重金属(Pd、Cd、Cu、Zn)的固定效果。结果表明:不同类型有机酸作用下土法炼锌废渣中重金属的释放存在明显差异,3种有机酸对铅锌废渣中4种重金属的活化能力表现为酒石酸柠檬酸草酸。草酸、酒石酸和柠檬酸浓度分别在0. 8、0. 8、0. 4 mol/L时对低品位磷矿粉中磷素的活化能力最强,但各有机酸-磷矿粉复合物在有机酸浓度分别为1. 2、0. 8、0. 4 mol/L时对铅锌废渣中各重金属的固定效果最好,其中,草酸-磷矿粉复合物对4种重金属的降低率为90. 67%、99. 64%、13. 63%、5. 99%,酒石酸-磷矿粉复合物对4种铅锌废渣中重金属的降低率为91. 72%、44. 2%、34. 37%、7. 51%,柠檬酸-磷矿粉复合物对4种重金属的降低率为60. 39%、8. 15%、5. 03%、-6. 12%,综合来看,浓度为1. 2 mol/L的草酸-磷矿粉复合物可更好地固定铅锌冶炼废渣中的重金属。     

硝酸根对有机磷光解释放磷酸根的影响

为了解硝酸根（NO₃^-）的光化学活性对水体中有机磷间接光解释放磷酸根过程的影响,采用室内模拟实验,研究了NO₃^-在草甘膦光解转化为磷酸根中的作用及NO₃^-浓度对该反应速度的影响,并以甲醇为羟基自由基（·OH）猝灭剂,印证了NO₃^-对富营养化湖泊水体中有机磷光解释放磷的作用.结果表明,在紫外光（UV）照射下,草甘膦可以直接光解转化为磷酸根,其磷酸根的释放量随着溶液初始pH和草甘膦浓度的增加而增大.加入NO₃^-处理,光照60min后,磷酸根的释放量由空白处理的0.05mg/L增加到了0.43mg/L.添加Fe³⁺可促进这一过程,而添加腐殖酸（HA）和碳酸氢根（HCO₃^-）则可以显著抑制磷酸根的释放.在湖泊水体中,添加草甘膦,磷酸根的释放量显著高于空白,而增加湖水中NO₃^-浓度时,磷酸根的释放量则进一步增大.在湖水/草甘膦/NO₃^-体系中添加·OH猝灭剂甲醇后,磷酸根的释放量显著降低.可见在紫外光条件下,NO₃^-的光化学作用对有机磷释放磷酸根过程具有重要影响.     

高温解磷菌对堆肥所添加难溶性磷素转化的试验研究

为提高堆肥产品中可利用磷素含量,采用不接种解磷菌剂、不添加磷矿粉处理(CK),不接种解磷菌剂、添加磷矿粉处理(CP),接种解无机磷菌剂、添加磷矿粉处理(CMP)3种处理进行了堆肥试验,并对堆肥不同时期样品中磷组分的动态变化进行分析.结果表明,与CK比较,在堆肥不同时期, CMP、CP处理有机态磷、水溶性磷、速效磷均呈不同程度的增加.堆肥结束后, CP、CMP处理有机态磷、水溶性磷、速效磷与CK比较的增加值分别为2049.8、4188.6mg/kg,264.2、648.7 mg/kg,954.0、3576.4mg/kg,其中CMP处理分别是CP处理的2.04、2.46、3.75倍.试验结果证明,采用高温解无机细菌接种,可明显促进堆肥中添加难溶性磷矿粉的转化效率,提高堆肥产品中植物可利用磷素含量.     

耐高温解磷菌的筛选及解磷能力研究

以高温堆肥为原料,通过无机磷培养基筛选、耐高温驯化得到5株耐高温解磷菌,命名为P1～P5.各菌株最佳生长温度为40～50 ℃,其中P1可在35～53 ℃生长,P2～P5在35～50 ℃生长.通过50 ℃高温摇床发酵培养,分别测定了耐高温解磷菌P1～P5的发酵液中ρ(水溶性磷),ρ(微生物量磷),总解磷量和pH.结果表明,在50 ℃下摇床振荡培养耐高温解磷菌P1～P5,7 d后发酵液中ρ(水溶性磷)为30.9～47.6 mg/L,ρ(微生物量磷)为116.4～164.4 mg/L,总解磷量为152.1～201.6 mg/L,发酵液pH明显为酸性,但其与菌株解磷能力没有显著的相关性.在解磷方面,ρ(微生物量磷)明显高于ρ(水溶性磷),因此ρ(微生物量磷)是分析解磷菌解磷能力不可忽视的重要部分.5株解磷菌均具有良好耐高温能力及解无机磷的生理生化功能.      

海水和海洋沉积物中总磷的测定

系统介绍了海水和海洋沉积物中总磷的测定方法，选用Ｋ２Ｓ２Ｏ８为氧化剂将有关形式的Ｐ转化成ＰＯ＾３－４，连同样品中原有的ＰＯ＾３－４－起用以抗坏到为还原剂的磷钼蓝法测定。方法的精密度６％，回收率为９１％－１０７％。     

不同磷肥对水稻根表铁膜及砷镉吸收的影响——以石灰岩黄壤性水稻土为例

为寻求砷(As) 镉(Cd)复合污染稻田安全利用的有效措施,以贵州石灰岩区As、Cd复合污染黄壤性水稻土为材料,采用盆栽试验,研究了6种磷肥对土壤As、Cd有效性、水稻根表铁膜及As、Cd吸收的影响.结果表明:与对照相比,羟基磷灰石(HAP)、生物酶活性磷肥(BCP)、钙镁磷肥(CMP)处理使土壤pH值显著提高,磷酸二氢钙(MCP)、磷酸二氢钾(MKP)、过磷酸钙(SSP)处理使土壤pH值显著降低.所有磷肥处理均降低了土壤有效Fe含量,其中HAP、MCP、CMP的降低效果显著.HAP显著降低了土壤有效Cd和有效As含量;MCP和BCP显著提高土壤有效Cd含量,但对土壤有效As无显著影响;SSP显著降低了土壤有效Cd含量,但显著提高土壤有效As含量.不同磷肥使水稻根表铁膜数量提升0.6%~27.1%,铁膜数量与铁膜中Cd、As含量分别呈极显著(R²=0.555**)和显著(R²=0.525*)正相关关系.MCP、MKP、BCP显著降低了糙米Cd、As含量,HAP、SSP、CMP显著降低了糙米Cd含量,但对糙米As含量无显著影响.磷肥均使Cd叶→颖壳的转运系数下降,MKP、MCP能抑制As从根到茎的转运,BCP能抑制As从叶到颖壳的转运.磷肥降低水稻糙米Cd、As含量与铁膜数量增加、水稻体内Cd、As转运变化有关.     

Synthesis of porous iron hydroxy phosphate from phosphate residue and its application as a Fenton-like catalyst for dye degradation

Phosphate residue is a kind of hazardous solid waste and if not properly disposed of, could cause serious environmental contaminations. The abundant iron salt available in phosphate residue can be used to prepare photo-Fenton catalytic reagent for wastewater treatment. In this study, the phosphate residue was effectively purified by a hydrothermal recrystallization method, reaching an iron phosphate purity of 94.2%. The particles of iron phosphate were further processed with ball milling with th...     

三种有机酸对磷酸钙法回收模拟养猪场污水中磷的影响

采用磷酸钙(Calcium Phosphate,CP)结晶法回收模拟养猪场污水中的磷,考察了不同pH值条件下,3种有机酸(柠檬酸、丁二酸和乙酸)对模拟污水中磷去除率的影响,并利用扫描电镜和X射线衍射仪对结晶产物进行了表征.结果表明,CP结晶反应的最佳pH值约为9.5.在相同pH值条件下,柠檬酸对CP结晶反应中磷的去除效率和速率均有显著影响,高浓度柠檬酸能够完全抑制CP结晶反应,导致磷的去除率小于5%.相比之下,丁二酸和乙酸对磷的去除效率和速率影响不明显.3种有机酸对CP结晶产物的形状没有明显影响,所得产物均呈不定形的块状,但产物体积大小会随有机酸浓度升高而明显减小.不同浓度丁二酸和乙酸存在条件下均能得到羟基磷酸钙(Hydroxylapatite,HAP)晶体,但柠檬酸的存在会影响所得产物晶形.     

Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium<Emphasis Type="Italic"> Azospirillum</Emphasis> spp.

In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.     

淹水土壤土-水界面磷素迁移转化研究

通过室内PVC土槽实验,模拟了淹水条件下土壤上覆淹水和孔隙水中磷的释放及其影响因素Eh值、pH值、Fe2 、Fe3 和溶解有机质(DOC),以及土壤中无机磷组分的转化,并通过偏最小二乘主成分分析法分析影响磷迁移转化的因素,得到主要影响因子.实验结果表明,54d淹水期间,上覆淹水可溶性磷浓度大于孔隙水的磷浓度,前者累积释磷量是后者的16倍;土壤磷的释放主要以Fe-P、O-P和Al-P为主, Ca-P基本不变,其中以Fe-P的贡献最大,淹水期间比初始值减少了30.4%～72%;主成分分析表明, Eh值、Fe2 Fe3 和DOC是影响上覆淹水磷释放的主要因子, DOC络合Fe2 和Fe3 成水溶性三元复合体,释磷机制以络合增溶为主;DOC是影响土壤孔隙水磷释放主要因子,释磷机制以竞争吸附为主,高浓度铁离子的存在阻止了孔隙水中磷释放.     

Influence of moderate pre-oxidation treatment on the physical, chemical and phosphate adsorption properties of iron-containing activated carbon

A novel adsorbent based on iron oxide dispersed over activated carbon(AC) were prepared, and used for phosphate removal from aqueous solutions. The influence of pre-oxidation treatment on the physical, chemical and phosphate adsorption properties of iron-containing AC were determined. Two series of ACs, non-oxidized and oxidized carbon modified by iron(denoted as AC-Fe and AC/OFe), resulted in a maximum impregnated iron of 4.03% and 7.56%, respectively. AC/O-Fe showed 34.0%–46.6% higher phosphate removal efficiency than the AC-Fe did. This was first attributed to the moderate pre-oxidation of raw AC by nitric acid, achieved by dosing Fe(II) after a pre-oxidation, to obtain higher iron loading, which is favorable for phosphate adsorption. Additionally, the in-situ formed active site on the surface of carbon, which was derived from the oxidation of Fe(II) by nitric acid dominated the remarkably high efficiency with respect to the removal of phosphate. The activation energy for adsorption was calculated to be 10.53 and 18.88 kJ/mol for AC-Fe and AC/OFe, respectively. The results showed that the surface mass transfer and intra-particle diffusion were simultaneously occurring during the process and contribute to the adsorption mechanism.     

酸雨对旱地红壤磷素释放的影响研究

为了探明酸雨对红壤磷素释放的诱导效应 ,采用室内模拟酸雨淋溶土柱的方法 ,研究了酸雨作用下旱地红壤磷素释放的特征与规律 .结果表明 ,从长期的淋溶效果来看 ,酸雨可促进红壤磷的释放 ,且酸雨pH值越低 ,磷累积释放量越大 ;磷释放的动态变化在不同土壤之间存在一定的差异 .红壤磷素的释放强度主要取决于土壤有效磷含量 ,而与阳离子交换量关系不大 .磷释放量与钙释放量相关性很弱 ,与铝释放量呈较强的正相关性 ,与铁释放量呈显著的正相关性 .酸雨对红壤磷释放的促进作用主要是由于酸雨对铁铝化合物尤其是铁化合物的溶蚀作用所至 .     

软水中富里酸对铜管/磷酸盐体系溶解性铜释放影响

通过静态模拟试验研究了在软水体系中富里酸对铜管/磷酸盐缓蚀行为的影响,结果表明,富里酸含量、软水pH值、停留时间影响磷酸盐对铜管的缓蚀作用;高浓度的富里酸(16mg/L,以TOC计)明显增加溶解性铜释放,且从新铜管释放溶解性铜浓度高于老化6个月和12个月的铜管;在富里酸存在下,pH值较低时显著增加溶解性铜的释放,随着pH值的增大,富里酸对溶解性铜的释放影响降低;在96h的停留过程中,溶解性铜的释放浓度不断发生变化,表明富里酸与铜离子形成的络合物影响磷酸与铜的相互作用,从而影响磷酸盐对铜管的缓蚀效果.     

高效除磷渗滤床填料筛选及连续流动态运行特性

磷是造成水体富营养化的重要因素之一,深度去除污染水体中的磷,具有重要的环保意义.为此,本研究比较了多种填料包括海绵铁及其改性填料、钢渣、活性氧化铝、活性炭的吸附除磷特性及动力学,探究了除磷机理,构建了高效除磷渗滤床,考察了动态连续流运行条件下的除磷特性.结果表明酸改性海绵铁具有最高的饱和磷吸附容量,为19.45 mg·g^-1,碱改性海绵铁、活性氧化铝、钢渣、未改性海绵铁及活性炭的饱和磷吸附容量分别为10.91、8.70、7.73、3.39和1.34 mg·g^-1.在此基础上,利用高效除磷填料酸改性海绵铁和钢渣构建了除磷渗滤床,开展了连续240 d的连续流实验,在磷容积负荷为6 g·d^-1·m^-3条件下,渗滤床累积磷吸附量达到10215 mg,单位容积吸附量达到1.62 kg·m^-3.总之,利用酸改性海绵铁和钢渣构建的除磷渗滤床具有较高的除磷效率和性能,可以作为除磷单元与现有的水污染治理及净化工艺耦合,提高或拓展系统除磷功能.     

滇池沉积物中磷的释放行为研究

滇池分为草海和外海两个水体,且草海污染较外海严重,但是外海的藻类爆发的频率和强度都高于草海。通过实验室模拟,研究了滇池草海与外海沉积物中磷的释放行为及其藻类爆发程度不同的原因。结果表明,两个沉积物中磷的释放动力学都表现了非单一的扩散过程,拟二级动力学模型可以较好描述释放过程。草海比外海总磷高7倍,但是在水中的释放只高2倍。对两个沉积物而言,由于与表面附着的磷有竞争作用,溶解胡敏酸的加入都显著增大了磷的释放。与草海相比,外海的水交换速率慢、水深浅、沉积物有机质含量低、内源磷释放强以及对外源磷缓冲能力弱,这些特征都是有利于藻类爆发的条件。研究表明抑制滇池藻类爆发要同时考虑对外源磷和内源磷的控制。     

酸碱性调节对初沉污泥氮磷和有机质释放的影响

在调节pH值分别为3.0和10.0的条件下,与pH值保持原状相对比,研究了15～20℃下初沉污泥水解酸化过程中氨氮、磷酸盐和溶解性COD(SCOD)、碳水化合物、蛋白质和挥发性脂肪酸(VFAs)等有机质组分的释放。结果表明,强酸条件,特别是强碱会抑制氨氮的释放,试验周期结束时,碱性条件氨氮的释放量为1.28 mg/g TS,远小于对比试验(6.97 mg/g TS);磷酸盐的释放量表现为酸性>碱性>对比试验,反应至第4天时各条件下的释放量即趋于稳定,分别为2.47 mg/g TS、1.23 mg/g TS和1.18 mg/g TS;碱性条件下,各有机质组分的释放量大于其他条件,其中总VFAs波动较大,在第8天左右的产生量接近最大值,为201.59 mg COD/g VS,且以乙酸为主,其余组分在较短的时间里接近或达到最大值后保持相对稳定。