降解菌ZQ5与紫茉莉对芘污染土壤的联合修复

在温室盆栽条件下,通过单独种植紫茉莉、单独接种多环芳烃(PAHs)模式化合物芘的专性降解菌ZQ5和两者的联合修复的3种处理,对芘污染土壤的修复效果进行了研究。结果表明,经90 d修复后,植物-微生物联合修复可将人工污染土壤中的芘降解81.1%,将石油污染土壤中的芘降解50.3%,其修复效率明显高于其他2种处理,是紫茉莉修复的1.98倍,是降解菌ZQ5修复的1.39倍。ZQ5的不同接菌量对于修复60 d后的降解率影响不大。外源生物修复条件下,10～20 cm土壤的修复效率要高于5 cm土壤;自然降解条件下,5 cm土层降解率略高于其他土层。     

CS-Fe和CS-Fe/Ni的制备及其用于去除钴离子

以氯化铁为铁源,硼氢化钠为还原剂,壳聚糖为稳定剂,采用液相还原法制备壳聚糖稳定纳米铁（CS-Fe）;并以氯化铁为铁源,硫酸镍为镍源,硼氢化钠为还原剂,壳聚糖为稳定剂,采用液相还原共沉淀法制备壳聚糖稳定纳米铁镍（CS-Fe/Ni）。通过SEM、EDS、XRD、FT-IR等表征手段,对所制备的CS-Fe和CS-Fe/Ni的形貌及微观结构进行表征,并以Co²⁺为目标去除物评价CS-Fe和CS-Fe/Ni的反应活性。初步研究表明,制成的CS-Fe含有单质纳米铁,颗粒多数以30~90 nm球形颗粒为主;而CS-Fe/Ni材料中含有纳米铁镍,颗粒多数以30~60 nm球形颗粒为主;在相同的实验条件下,反应60 min,CS-Fe/Ni对Co²⁺的去除率高达100%,但是CS-Fe仅为88%,即CS-Fe/Ni对Co²⁺的去除率比CS-Fe高。     

制革废水中好氧反硝化菌的筛选及其特性

从制革废水中分离得到1株好氧反硝化菌ZY1,并对ZY1的反硝化能力进行了研究。通过16S rDNA序列分析,确定ZY1为地衣芽孢杆菌(Bacillus licheniformis)。在初始NO2--N质量浓度为80 mg/L、DO为5.7 mg/L、废水温度为30℃、废水pH为8.0、废水中Cr3+质量浓度为110 mg/L、反应时间为24 h的条件下,ZY1菌对NO2--N的降解率大于98%。     

Annual input fluxes of heavy metals in agricultural soil of Hainan Island,China

The accumulation of heavy metals in farmland has become an important issue related to food security and environmental risk. The annual inputs of heavy metals (As, Cd, Hg, Pb, Cr, Cu, and Zn) to agricultural soil for a full year in Hainan Island have been studied. Three fluxes through the cultivated horizon were considered: (1) atmospheric depositions, (2) fertilization, and (3) irrigation water. The corresponding samples were collected and analyzed on a large regional scale. The total input fluxes show obvious spatial variability among different regions. The inventory of heavy metal inputs to agricultural land demonstrates that agricultural soil is potentially at risk of heavy metal accumulation from irrigation water. The potential at risk of heavy metal accumulation from atmospheric deposition and fertilizer is relatively low compared to irrigation. The results indicate that Hg is the element of prior concern for agricultural soil, followed by Cd and As, and other heavy metal elements represent little threat to the environment in the study area. This work provides baseline information to develop policies to control and reduce toxic elements accumulated in agricultural soil.     

Cadmium-induced DNA damage and mutations in Arabidopsis plantlet shoots identified by DNA fingerprinting

Random amplified polymorphic DNA (RAPD) test is a feasible method to evaluate the toxicity of environmental pollutants on vegetal organisms. Herein, Arabidopsis thaliana (Arabidopsis) plantlets following Cadmium (Cd) treatment for 26 d were screened for DNA genetic alterations by DNA fingerprinting. Four primers amplified 20-23 mutated RAPD fragments in 0.125-3.0 mg L⁻¹ Cd-treated Arabidopsis plantlets, respectively. Cloning and sequencing analysis of eight randomly selected mutated fragments revealed 99-100% homology with the genes of VARICOSE-Related, SLEEPY1 F-box, 40S ribosomal protein S3, phosphoglucomutase, and noncoding regions in Arabidopsis genome correspondingly. The results show the ability of RAPD analysis to detect significant genetic alterations in Cd-exposed seedlings. Although the exact functional importance of the other mutated bands is unknown, the presence of mutated loci in Cd-treated seedlings, prior to the onset of significant physiological effects, suggests that these altered loci are the early events in Cd-treated Arabidopsis seedlings and would greatly improve environmental risk assessment.     

生物表面活性剂在城市污泥静态强制通风好氧堆肥中的作用

采用静态强制通风好氧堆肥模式对城市剩余污泥进行堆肥降解,并研究了生物表面活性剂鼠李糖脂对堆肥过程的作用。结果表明,堆肥过程中,添加了质量分数为0.015%鼠李糖脂溶液堆制处理和空白对照堆制处理的堆温变化都明显呈现出中温期0～5 d、高温期6～12 d和降温期13～28 d 3个阶段。实验组比空白组的堆体升温快、高温期持续时间长、堆体的含水率高。鼠李糖脂的添加,使实验组的微生物数量高于空白组。添加鼠李糖脂的堆体和空白堆体的种子发芽指数(GI)在堆肥结束时分别为53.70%和50.80%,说明鼠李糖脂促进了堆肥的腐熟,但由于相对浓缩效应,堆肥产品的重金属含量略高于空白堆体。生物表面活性剂的介入促进了堆肥中木质纤维素的初步降解。研究表明,添加鼠李糖脂能够改善堆肥处理的微环境,促进有机质降解和堆肥的腐熟。     

Pt and Pd in sediments from the Pearl River Estuary,South China: background levels,distribution, and source

Purpose  

This study assessed the concentrations of platinum (Pt) and palladium (Pd) in surface sediments and sedimentary cores collected from the Pearl River Estuary with a view of evaluating the distribution, background levels, possible sources, and contamination level of anthropogenic Pt and Pd.     

基于RS/GIS技术的“十一五”期间塔里木河流域生态环境质量综合评价分析

"十一五"是新疆经济飞速发展的五年,同时也是重大生态保护工程十五实施期。本文采用国家环境保护部制定的《生态环境状况评价技术规范》(HJ/T192-2006)分别对新疆"十五"末与"十一五"末生态环境质量进行综合评价分析。结果显示:塔里木河流域生态环境质量总体处于较差水平,各县(市)生态环境质量以较差和差为主,二者面积总和在全区总面积60%以上;与"十五"末相比,全区生态环境质量保持稳定,无明显变化。呈现总体趋于稳定,局部区域有所改善的特征。     

土壤石油污染环境容量的评估与模拟研究

文章基于对某滨海油区环境和生态进行调研分析的结果,选择一般参数法、综合估值法和数值模拟法三种方法对土壤石油污染的环境容量进行评估和模拟研究。研究分析了污染物在土壤中的时空分布,预测分析污染物迁移趋势和范围,综合探讨了研究区土壤石油污染的环境容量,可为制订有关环境标准和加强土壤石油烃排放管理提供技术依据和参考。     

氢自养生物还原去除地下水中对硝基氯苯（p-NCB）的实验研究

采用批式实验讨论了氢自养还原菌在厌氧条件下,利用氢气作为电子供体还原地下水中对硝基氯苯的可行性及其影响因素。结果表明,氢自养菌能利用氢气生物还原对硝基氯苯,并产生中间产物对氯苯胺,继而进一步还原脱氯产生苯胺,该过程可提高对硝基氯苯的可生化性。对硝基氯苯在初始阶段还原速率较快,最高去除速率达到610μg/（L.d）,随后逐渐降低达到稳定。影响因素实验表明,在一定浓度范围内提高对硝基氯苯浓度对其去除率影响较小,但硝基进一步还原和脱氯效果降低;氢自养菌还原硝基氯苯的最适宜pH值在7.0~8.0之间;水中的硝酸盐和对硝基氯苯对电子供体存在竞争,硝酸盐反硝化对对硝基氯苯还原具有抑制作用。