镉超标土壤桑树修复研究进展

近年来,土壤镉污染及其防治引起世界各国的广泛关注。论文概括了土壤中镉的污染现状,总结了农田镉污染修复措施和治理方法,综述了桑树对土壤镉污染修复的研究进展。提出种桑养蚕是治理和利用我国镉污染农田的一种成功的经济生态模式。     

寒地桑树无干栽植密度对桑叶产量及蚕茧质量的影响

对黑龙江省的3个主栽桑树品种秋雨、青龙、泰来进行无干栽植密度试验的结果表明,不同桑树品种有不同的适宜栽植密度。秋雨和青龙在60000株/hm2、泰来在75000株/hm2栽植密度下产叶量达到最高。桑树合理密植对桑叶质量影响不显著,但增加到60000~75000株/hm2后,随栽植密度的增加,养蚕质量也随之下降。栽植密度对养蚕质量各因素的影响,因桑树品种不同有差异。     

创新出扦一条两剪

山西地处北方,十年九旱,无霜期短,桑树历来采用“株内春夏轮伐”的传统出扦法。随着农业产业结构的调整、山西蚕区桑树栽植形式不断变化,传统的出扦法、秋季摘叶片的方法已不适应生产的发展。为此,阳城县老科协组织科技人员攻关,对桑树管理进行出扦法和秋季收获桑叶创新试验及示范,其方法叫“两定出扦、一条两剪”,全年实行省力化条桑养蚕并取得了可喜成绩。     

蚕沙沼气循环利用模式的示范

传统的栽桑养蚕存在三个问题：一是蚕沙自然堆放,造成病原扩散;二是蚕沙未作处理直接施入农田,未能充分利用;三是养蚕消毒、加温和蚕农生活所需燃料消耗大。为了解决这些问题,提高蚕桑生产的综合效益,笔者于2007年秋季在铜梁县虎峰镇卫东村6社为12户蚕农进行“桑→蚕→蚕沙→沼气→肥料”等循环利用模式试验示范,取得成功。2009年该社29户养蚕,建有沼气池36口,取得了显著的经济效益和社会效益,解决了蚕农生产生活用能源,提供了大量的优质高效有机肥,改善了周围的生态环境,增加了蚕农的经济收入,成为铜梁县蚕沙产沼气可再生循环利用的示范先行社。     

环洪泽湖农田土壤重金属污染现状及修复对策研究

为了研究环洪泽湖地区农田土壤重金属污染状况,试验采用常规方法测定了农田土壤环境中汞、镉、铅、铬、砷等重金属含量。结果表明:环洪泽湖地区农田土壤中重金属汞和镉重度污染,其中汞含量较高的是泗洪县和洪泽县农田,泗阳县和盱眙县次之,淮阴区最低;泗阳、泗洪县农田土壤中镉含量较高,洪泽、盱眙县次之,淮阴区含量最低。     

“消毒王一号”消毒效果试验

<正> “消毒王一号”是以氯制剂为主的新型蚕室、蚕具、桑叶消毒剂,在农村大面积养蚕生产中已广泛使用。为进一步掌握该蚕药在种茧育生产中的使用效果,1998年秋季我们进行了环境消毒和养蚕试验调查,现将试验结果报告如下:     

秋蚕饲养布局与农田治虫关联性探讨

<正> 随着农田耕作方式的变化和气候条件的变暖,吴江现行的秋蚕饲养布局出现了许多弊端,制约了蚕桑生产水平的提高。笔者通过对基层农田治虫次数、时间、对象的调查,综合考虑方方面面的因素,对秋季养蚕布局的调整提出几点设想与大家共同探讨。     

提高果桑产量和品质的几种途径

<正>果桑是春季收获桑椹、秋季养蚕为主的桑树,而“大十”果桑是目前推广最多的叶果两用桑。2003年春季平望镇引进果桑,在庙头村栽植“大十”果桑2.3hm2,2004年已进入投产,并取得了一定的经济效益。     

蚕沙产沼气循环利用效益高

栽桑养蚕是铜梁县围龙镇龙井村6社农副业生产的主要产业,具有投资小、见效快、收入高等显著特点,是农民增收的有效措施。但是,传统的栽桑养蚕存在三个问题：一是蚕沙自然堆放,造成病原扩散;二是蚕沙未作处理直接施人农田,未能充分利用;三是养蚕消毒、加温和蚕农生活所需燃料消耗大。为了解决这些问题,提高蚕桑生产的综合效益,从2005年秋季,     

浅谈蚕沙产沼气循环利用效益

<正>栽桑养蚕是铜梁县虎峰镇卫东村6社家副业生产的主要产业,具有投资小、见效快、收入高等显著特点,是农民增收的有效措施。但是,传统的栽桑养蚕存在三个问题:一是蚕沙自然堆放,造成病原扩散;二是蚕沙未作处理直接施入农田,未能充分利用;三是养蚕消毒、加温和蚕农生活所需燃料消耗大。为了解决这些问题,提高蚕桑生产的综合效益,笔者于2007年秋季在该社周大超等12户蚕     

Ecotoxicologic relations on a large pig-fattening farm located in a lignite mining area and near and solid-fuel electical power plant]

Major contaminants identified in 1983-1984 on a pig fattening farm with an output of 60,000 pigs per annum, located in a lignite mining area and near a solid fuel power plant, were mercury, cadmium, lead, chromium and aflatoxin B1 (Tab. I, II, III, IV). Feed samples were collected from througs to assess the contamination load at feed uptake. Permissible concentrations of mercury, chromium, cadmium, aflatoxin B1, lead and atrazin in the feed were exceeded in 56, 50, 31, 19, 6 and 6% samples, respectively (Tab. I). Stable dust deposits, in which the contaminants concentrate, (Tab. I) proved to be a suitable material for assessing the type and level of environmental contamination. Permissible concentrations of mercury, cadmium and lead in porcine muscles were exceeded in 65, 51 and 24% samples, respectively (Tab. III). Corresponding values of mercury, cadmium, lead and aflatoxin B1 in the liver were 27, 27, 16 and 3%, respectively (Tab. III) and those of mercury, lead and chromium in kidneys 24, 22 and 5%, respectively (Tab. III). Rather surprisingly, elevated pancreatic concentrations of aflatoxin B1 were found (Tab. IV). Pigs fattened in the contaminated environment (i.e. fed contaminated feed mixtures, inspiring contaminated dust and absorbing percutaneously contaminants form dust deposits on the body surface) showed: 1) Impairment of the genetic apparatus (percentage of aberrant peripheral leucocytes elevated to 6.2%); 2) a certain degree of immunosuppression (concentrations of IgG, IgM and IgA reduced by 16.9, 45.1 and 45.0%, respectively); 3) higher feed consumption per 1 kg weight gain (4 kg) and lower average daily weight gain (0.57 kg); 4) increased incidence of health disorders (dermatitis in 25%, pancreatopathy in 13%, liver dystrophy in 8% and femoral fracture in 6% of the pigs). Unfortunately, the authors were not allowed to analyse ash and solid emissions from the power plant. Therefore the share of the emissions in the overall environmental contamination on the fattening farm could not be quantified. The personnel, working in the contaminated environment for a prolonged period, is endangered most of all by stable dust, being exposed to its mechanical, chemical, allergic and infectious effects (Tab. I). In addition to the chemical contaminants, 21 mould genera and species, six mite species and numerous saprophytic and some pathogenic bacteria were demonstrated in stable dust samples in our earlier experiments. Consumption of meat and organs from pigs fattened in a contaminated environment is associated with the risk of an increased uptake of various contaminants.(ABSTRACT TRUNCATED AT 400 WORDS)     

Lead concentrations in blood and milk from periparturient dairy heifers seven months after an episode of acute lead toxicosis

In September 1988, 100 of 300 yearling dairy heifers developed blindness, tachypnea, foaming at the mouth, chewing, and facial fasciculations. Twenty-five animals died. Lead toxicosis was diagnosed based on the clinical signs and the presence of excessive concentrations of lead in whole blood, liver, kidney, and rumen contents of affected animals. The source of the lead was sudan grass silage that had been contaminated by soil that contained up to 77,000 mg/kg of lead. Lead concentrations were determined approximately 7 months after the acute episode of lead toxicosis. Whole blood and milk samples were obtained from heifers and a group of control cows 2 weeks prior to (blood only), at the time of, and 2 and 4 weeks after freshening. No lead was found in any of the milk samples (detection limit = 0.055 mg/liter). Animals that had been severely affected by lead toxicosis experienced a transient increase in whole blood lead concentrations at freshening that was not high enough to be considered toxic. No similar increases in blood lead were observed for control cows or heifers that had experienced milder toxicosis. These findings suggest that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.     

镉胁迫对两种狼尾草不同生育时期生长性能、光合作用特征及镉吸收转运差异的影响

采用盆栽法研究在不同浓度(0、5、25、50、75、100mg·kg~(-1))镉胁迫下美洲狼尾草(ML,Pennisetum americanum)和杂交狼尾草(ZL,P.americanum×P.purpureum)不同生育期的生长指标、光合作用特征,并比较两者耐镉性和对镉吸收转运差异。结果表明,1)相同生育期下,随Cd浓度的增加两种狼尾草株高先升高后降低,叶宽没有显著性变化,鲜重和干重逐渐降低;2)同一生育期,ML的叶绿素a和叶绿素b含量均高于ZL;低Cd浓度(5mg·kg~(-1)),对植株的光合指标影响不大,但Cd浓度增加后,各处理与对照相比显著下降(P0.05),高浓度Cd处理对ZL光合作用影响要大于ML;3)ML生长性能受Cd胁迫影响比ZL要小,但ZL富集系数高于ML,ML耐镉性更好,而ZL修复镉污染土壤的能力更强;4)根系是主要富集部位并且镉从根系往地上部位转移系数较低,3个生育期中幼苗期植株中Cd含量最高。     

吸附剂和营养元素对肉牛体内铅、镉排泄的影响

为了探讨吸附剂蒙脱石及营养元素铜、锌、铁、硒对肉牛体内铅、镉是否具有促排作用,试验选择40头杂交牛随机分为富硒组、微量元素组、蒙脱石组、对照组,每组10头,试验期为150 d,在试验期内每隔1个月收集1次肉牛尿液、粪便测定铅、镉含量;饲养试验结束后屠宰,采集各组织样品测定铅、镉含量。结果表明:肉牛尿液铅、镉排泄量没有明显增加;在8月份,各组粪镉含量均高于对照组(P<0.05或P<0.01);在9—11月份,与对照组相比,各组粪镉含量均无显著差异(P>0.05);在8,11月份,各组粪铅含量均无显著差异(P>0.05);在9,10月份,富硒组和微量元素组粪铅含量均低于对照组,蒙脱石组粪铅含量与对照组相比无显著差异(P>0.05)。说明在饲料中适量补充吸附剂蒙脱石,短期内对肉牛体内铅、镉有明显的促排作用;而补充营养元素铜、锌、铁、硒后,短期内在肉牛体内对镉有促排作用,对铅无促排作用,长期给予不能有效降低肉牛体内铅、镉的蓄积。提示应合理使用饲料添加剂。     

市售乳扇和乳饼中8 种有害元素污染状况分析

对市售乳扇和乳饼样品中8 种有害元素污染情况进行调查分析。对某市部分区县具有代表性的农贸市场及超市的乳扇和乳饼进行采样,并将样品通过石墨湿法消解,采用电感耦合等离子体质谱法检测,内标法定量,同时测定分析样品中砷（As）、铅（Pb）、汞（Hg）、镉（Cd）、铬（Cr）、硼（B）、铝（Al）、钡（Ba）8 种有害元素。结果表明：市售乳扇和乳饼样品未受金属元素Hg和Cd的污染,受元素B、As、Ba及Pb污染程度相对较轻,但乳扇样品被元素Al和Cr污染较严重,乳饼中Ba元素污染程度相对较高;乳扇和乳饼样品中普遍含有Cr、Ba和Pb元素,乳扇中元素污染程度大于乳饼,相关部门应加强对乳扇和乳饼作坊的监管,规范生产工艺,严格把关污染环节,加强生产环节污染监管力度,确保此类乳制品的质量安全。     

Trace mineral profile in blood and hair from cattle environmentally exposed to lead and cadmium around different industrial units

The present investigation was carried out to assess the trace mineral profile in blood and hair from cows environmentally exposed to lead and cadmium and to examine if these toxic heavy metals in blood and hair could affect blood copper, cobalt, zinc and iron concentrations and their accumulation in hair. Respective blood and tail hair samples were collected from adult cows above 3 years, reared in different industrial localities. Samples were also collected from urban areas with small industrial units (n = 55) and areas supposed to be free from pollution. The concomitant exposure of animals to both the heavy metal pollutants was not recorded in either of the industrial or urban locality. Blood lead was significantly (P < 0.01) correlated with blood copper (r = -0.339), cobalt (r = -0.224) and iron (r = -0.497). The increasing blood lead concentrations, irrespective of area of collection of samples, was associated with declining blood copper and iron, and cows with blood lead level above 0.60 mug/ml had significantly (P < 0.05) lower blood copper and iron. The higher blood lead but not cadmium significantly influenced the accumulation of lead (r = 0.323, P < 0.01) and cadmium (r = 0.204, P < 0.01) in hair possibly leading to significantly (P < 0.05) higher accumulation of both lead and cadmium in hair from cattle around lead-zinc smelters and closed lead-cum-operational zinc smelter, where blood cadmium level was comparable with that from unpolluted area. Concentration of zinc (r = 0.237, P < 0.01) and iron (r = 0.183, P < 0.01) but not copper and cobalt in tail hair was significantly influenced by their respective blood concentration. Both the hair lead and cadmium had a significant (P < 0.01) positive correlation with hair copper (r = 0.234, 0.294), zinc (r = 0.489, 0.775), and iron (r = 0.385, 0.643) concentrations. Thus, it is concluded from the present study that the higher blood lead concentrations in cattle irrespective of locality/industrial operations areas affected trace elements profile in blood and hair.     

促红细胞生成素在铅镉联合胁迫致雏鸡贫血中的作用

为研究促红细胞生成素(EPO)在铅镉联合胁迫致雏鸡贫血中的作用,选用60只7日龄公雏鸡,平均分为对照组、铅组、镉组和铅镉组,每日经口灌服染毒,分别于第1、3、7天染毒后,检测雏鸡血液学指标和网织红细胞数量,并进行骨髓象的观察及红细胞膜ATP酶活性、红细胞渗透脆性和血清EPO含量的检测。结果表明铅镉单独染毒使雏鸡发生贫血,网织红细胞数量先增加后降低,骨髓象增生先活跃后受抑制,红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性降低,红细胞渗透脆性增加,血清EPO含量先增加后降低,铅镉联合染毒也表现出上述变化,且较单独染毒组变化明显(P<0.05或P<0.01)。本研究证实铅、镉单独及联合染毒均可引起雏鸡发生贫血,贫血类型主要为再生障碍性和溶血性贫血,且铅与镉存在显著的协同效应;EPO参与了铅镉联合胁迫致雏鸡的贫血作用。     

母鼠妊娠期铅镉联合暴露对仔鼠脑损伤病理学变化的影响

为探讨母鼠妊娠期铅镉联合暴露对新生鼠生长发育及脑组织病理学变化的影响,20只怀孕SD母鼠被随机分为4组,即A组为对照组(饮用蒸馏水)、B组为铅组(300mg/L)、C组为镉组(10mg/L)、D组为铅+镉组(300mg/L+10mg/L)。采用饮水染毒,期间记录母鼠体质量及临床症状,染毒结束后记录新生鼠体质量及脑质量,并采集新生鼠大脑皮质观察其病理组织学变化,染毒时间为21d。结果表明,与对照组比较,各染毒组母鼠体质量均低于对照组,但差异不显著(P>0.05);而新生鼠体质量均显著低于对照组(P<0.05),脑质量也明显下降,除C组无显著性差异外,其余各组差异显著(P<0.05);病理组织学变化显示,光学显微镜观察大脑皮质未见明显异常,透射电镜下可见各染毒组神经细胞核染色质浓缩,线粒体肿胀、嵴部分或完全消失。铅镉联合毒性明显强于铅镉单独作用,铅镉联合表现协同毒性效应,镉在铅镉联合毒性损伤中发挥主要作用。     

铅、锌污染下蜀葵的生长生理响应和富集转运特性研究

为选用蜀葵(Alcea rosea(Linn.)Cavan.)修复铅、锌污染土壤提供理论依据,本研究通过盆栽模拟试验,探究不同浓度铅、锌污染下蜀葵的重金属富集转运特性和耐性解毒机制.结果表明:低浓度的铅、锌污染促进蜀葵增高、叶片增大,随着污染浓度增加,蜀葵的生长受到抑制,部分叶片黄化;高浓度污染下,蜀葵渗透调节物质增多...     

镉对体外培养鸡脾淋巴细胞膜抗氧化功能的影响

以终浓度为10μmol/L CdCl2对体外培养淋巴细胞进行染毒,分别培养12、24、36、48和72h时收集细胞,提取体外培养脾淋巴细胞膜,采用试剂盒比色的方法,分别检测了细胞膜GSH-Px、SOD的活性、膜MDA和SA含量及培养液LDH的活性,来观察镉性细胞损害时细胞膜的抗氧化功能和通透性。结果显示,随着镉作用时间的延长,淋巴细胞膜GSH-Px、SOD的活性降低,MDA生成量增加,试验组与对照组差异显著（P〈0.05）或极显著（P〈0.01）;培养液中LDH活性升高,膜SA含量降低。表明镉可使淋巴细胞膜的抗氧化功能降低,膜完整性被破坏。