硅酸盐细菌解钾兼拮抗活性菌株的筛选

从紫色土壤中分离筛选出具有解钾拮抗双重活性的硅酸盐细菌CS1和CS29菌株。接菌处理,其水溶性钾分别增加75％和65％,转化率达0．82％和0．72％。两株菌对革兰氏阳性的蜡样芽孢杆菌,金黄色葡萄球菌,藤黄八叠球菌等和革兰氏阴性的大肠杆菌均有较强的抑菌活性。筛选菌株中91．2％具有解钾活性,但拮抗活性菌株只占总数的11．6％,表明二性状之间无相关关系。表4参7     

渤海排污口邻近海域异养细菌的组成与分布

对渤海4个重点监测排污口（北塘、大蒲河、弥河和虞河）邻近海域异养细菌的组成和分布进行了调查研究。结果表明,分离到的各排污口邻近海域的细菌隶属于变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、放线菌门（Acti-nobacteria）和拟杆菌门（Bacteroidetes）4个细菌类群,其中变形菌门的细菌最丰富。各排污口的优势菌有所不同,北塘、弥河2个采样点的优势菌分别为Bacillus sp．、Pseudoalteromonas sp．,大蒲河采样点的优势菌为Vibrio sp．和Oceanospirillum sp．,虞河采样点的优势菌为 Shewanella sp．和 Bacillus sp．。多维尺度分析表明,北塘和虞河采样点的细菌种群特征较相近,细菌种群分布特征可能与排污口的海洋环境有一定的相关性。     

水样发光细菌急性毒性测试的方式与表征

选取不同类型的环境和污染源水样开展了发光细菌毒性测试,针对不同环境管理目标,探讨了急性毒性定量表征方式。发光细菌急性毒性测试在环境应急监测、水源早期生物预警中,采用绘制毒性预警基线图的方式比较可行。在污染源监督监测中,对于发光抑制率低于60%、无法求出EC50的样品,采用等效毒性参照物的质量浓度表征废水的毒性;对于发光抑制率高于60%,采用稀释因子表示样品的毒性更直观可靠。     

Lead Solubilization and Accumulation by Two Strains of Pseudomonas Obtained from a Contaminated Alfisol's Effluent in Southwestern Nigeria

Two strains of Pseudomonas species (B₂ and D₅)selected from an array of lead solubilizing and accumulatingbacteria obtained from the effluent contaminated soil samples of abattery manufacturing factory were studied. Increase in pH between 4.0 and 6.0 favoured the growth of isolates: Peaklog₁₀ cfu mL^–1 values of 7.1, 7.5 and 8.5 wereobtained at pH 4, 5 and 6, respectively.Cell bound lead concentrations for B₂ (0.34 mg mL^–1)and D₅ (0.30 mg mL^–1) obtained by direct contact withPbs were greater than lead concentrations of 0.89 and 0.25 mg mL^–1 for B₂ and D₅, respectively,obtained in dialyzed cultures. These cell bound lead concentration in undialyzed cultures were alsogreater than lead concentrations of 0.03 and 0.07 mg mL^–1 for B₂ and D₅ in culture supernatants. Glucose addition did nor improve lead accumulation in the isolates.Exploitation of such isolates for the biotreatment of lead ladeneffluent was conducted.     

Effect of some herbicides on activities of microorganisms and enzymes in soil

Abstract

Laboratory tests were conducted with eight herbicides, atrazine, butylate, ethalfluralin, imazethapyr, linuron, metolachlor, metribuzin and trifluralin, applied to a loamy sand at rate of 10 μg/g to determine if these materials caused any serious effects on microbial and enzymatic activities related to soil fertility. Some herbicides showed an effect on bacteria and fungi for the first week of incubation, but, subsequently, the populations returned to levels similar to those obtained in the controls. After several herbicide treatments there appeared to cause a slight depression of nitrification. Sulfur oxidation was better than that obtained with untreated soil in all treatments. Oxygen consumption was increased significantly after 96 hr incubation with atrazine. The soil dehydrogenase and amylase activities were inhibited by ethalfluralin treatment respectively for 1 wk and 1 day, and p‐nitrophenol liberation was inhibited for 2 hrs by all herbicide treatments. Results indicated that the herbicidal treatments at the level tested were not drastic enough to be considered deleterious to soil microbial and enzymatic activities which are important to soil fertility.     

USE OF GEOSTATISTICS TO EVALUATE WATER QUALITY CHANGES DUE TO COAL MINING1

ABSTRACT: Large variability of water quality data often makes it difficult to judge whether or not the conditions in an aquifier or a stream are deteriorating or not the conditions in an aquifer or a stream are deteriorating or improving. A technique for separation of variograms into positive and negative difference components is proposed. This technique was applied to water quality data from a requality improved with time on the stripmined and undisturbed areas, declined in a seep and an adjoining stream and remained about the same in the deep mined zone.     

MODELING FECAL COLIFORM CONTAMINATION IN THE RIO GRANDE1

This study examines sources of fecal coliform in Segment 2302 of the Rio Grande, located south of the International Falcon Reservoir in southern Texas. The watershed is unique because the contributing drainage areas lie in Texas and Mexico. Additionally, the watershed is mostly rural, with populated communities known as “colonias.” The colonias lack sewered systems and discharge sanitary water directly to the ground surface, thus posing an increased health hazard from coliform bacteria. Monitoring data confirm that Segment 2302 is not safe for contact recreation due to elevated fecal coliform levels. The goal of the study was to simulate the observed exceedences in Segment 2302 and evaluate potential strategies for their elimination. Fecal coliform contributions from ranching and colonia discharges were modeled using the Hydrologic Simulation Program‐Fortran (HSPF). Model results indicated that the regulatory 30‐day geometric mean fecal coliform concentration of 200 colony forming units (cfu) per 100 milliliters is exceeded approximately three times per year for a total of 30 days. Ongoing initiatives to improve wastewater facilities will reduce this to approximately once per year for 14 days. Best management practices will be necessary to reduce cattle access to streams and eliminate all exceedences. The developed model was limited by the relatively sparse flow and fecal coliform data.     

石灰-聚铁法处理硫酸厂废水的研究

对各种处理硫酸厂废水的方法者了探讨,选择了以百石灰和聚合硫酸铁为药剂去除废水中砷,硫等污染物的方法。该法工艺简单,混凝剂投加量少,运行费用低,处理后的废水可达到排放标准。     

测定单个粒子的薄膜法及其应用

本文介绍改进后的薄膜法,主要是形态分析法和复合薄膜法。它们都是基于粒子和薄膜反应生成物的形态特征通过电镜来确定粒子成分的。前者可以检测单个酸性粒子,检出下限为７ ×１０－ １９ｇ;后者能同时检出一个粒子中所含的ＮＯ－３ 和ＳＯ２ －４ ,检出下限分别为３ ×１０－ １５ｇ 和７ ×１０－ １８ｇ。利用该方法对广州大气粒子进行了观察,结果表明改进后的薄膜法完全适用于对单个粒子的观察和测定。     

Experimental study on the effect of fly ash content in cemented paste backfill on its anti-sulfate erosion

ABSTRACT

In order to study the effect of fly ash content in cemented paste backfill (CPB) on its anti-sulfate erosion, the apparent phenomenon, strength development, and hydration products change the law of CPB with different fly ash content under long-term soaking of 5% sodium sulfate solution were studied by the macrotest and microanalysis, in addition, the mechanism of CPB anti-sulfate attack was analyzed by combining with a scanning electron microscope (SEM). The results indicated that the effect of sulfate environment on the strength of fly ash cemented paste backfill (FCPB) was mainly determined by the hydration products in the FCPB at different soaking times. In the early soaking stage, the formation of ettringite (AFt) in FCPB could improve its compactness, which was conducive to improving the strength of FCPB. In the late soaking stage, there were ettringite-type erosion damage and gypsum erosion-type damage internal of the FCPB with low content fly ash, resulting in microfracture, cracking of the FCPB, and reducing the strength. CPB with an appropriate content of fly ash could improve the internal structure of the FCPB to achieve the purpose of anti-sulfate erosion.