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一、测定原理在酸性条件下。漂白粉溶水后所产生的次氯酸可以将m氧化释放出碘,其释放出碘的量与有氧化作用的次氯酸根的量成正比;利用淀粉和碘呈蓝色反应作指示剂,再用硫代硫酸钠滴定至蓝色消失,由消耗的标准硫代硫酸钠用量即可计算出有效氯的含量,其化学反应式如下：ZHCI 相似文献
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为探讨黄鳝(Monopterus albus)血液适宜抗凝剂种类和最佳使用浓度,实验比较了6种常用抗凝剂对黄鳝外周血的抗凝效果及DNA质量的影响。结果显示:ACD、EDTA、肝素、草酸钾、草酸盐和柠檬酸钠的最佳抗凝终浓度分别为0.10×、0.50‰、0.016‰、0.63‰、0.025×和8.00‰,以上浓度能有效抑制凝血,且血细胞死亡率最低。最佳抗凝浓度下的短暂处理对血细胞DNA的质量无明显影响,但随着处理时间的延长,抽提获得的DNA含量均出现了不同程度的下降,含有ACD和EDTA的血液中DNA的含量下降最多,其次是草酸盐、草酸钾和柠檬酸钠,而加入了肝素的血液中DNA的稳定性最高,其含量无显著下降。 相似文献
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使用不同种类的石灰,主要是增加养殖水体的缓冲能力,并提高pH。本文着重讨论水质管理中不同种类石灰的作用。一、石灰的种类1.农用石灰或石灰石即碳酸钙,是由石灰石简单粉碎而得。养殖中所使用的石灰,其碳酸盐含量不应低于75%,粉碎较细的石灰非常适宜养虾池使用,多用于增加养殖水体的缓冲能力。因其对pH没有大的影响,可相对大量使用,正常使用量为100kg/公顷～300kg/公顷。2.熟石灰即氢氧化钙,由在大约800℃～900℃温度下烧炼石灰石而制得,燃烧后需往热的石灰石上加水。熟石灰用于增加养殖水体或土壤的pH,使用量一般为50kg/公顷～100kg/公顷。由于熟石灰对pH有一定的影响,而养虾池多在下午pH达到最高,因此建议不要在下午施用。 相似文献
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无机碳和磷添加对两种沉水植物磷富集和灰分磷组成的影响 总被引：1，自引：0，他引：1
研究不同沉水植物对水体磷的富集和生物沉积能力,为湖泊生态修复中沉水植物优势种的选择提供理论依据。研究的沉水植物为菹草(Potamogeton crispus)和粉绿狐尾藻[Myriophyllum aquaticum(Vell)Verdc],每个锥形瓶4～5株,鲜重约1 g;锥形瓶中装有含无机碳和磷的培养液200 mL。外加无机碳为NaHCO_3,添加浓度1.5 mmol/L;无机磷为K_2HPO_4,添加浓度0.1 mg/L。添加药品后溶液的pH值通过1 M的HCl和1 M的NaOH调整到8.2～8.3。试验时间为1周,培养结束后检测植物全磷、植株灰分磷及灰分磷的组成。结果表明:菹草培养12 h后,溶液pH显著上升,pH漂移值显著高于粉绿狐尾藻;无机碳含量低于粉绿狐尾藻培养液,无机碳浓度显著性影响了△pH和溶液最后的无机碳含量,但磷浓度对△pH和无机碳含量无显著影响。无机碳添加和磷水平均显著影响了菹草的灰分总磷,但无机碳的贡献百分比(55.34%)高于磷(26.73%);无机碳添加显著影响了粉绿狐尾藻灰分总磷,而磷水平显著影响植物干重全磷。无机碳和磷浓度均显著影响了2种沉水植物灰分磷中H_2O-P百分比,但无机碳的影响占比更高(菹草46.16%,粉绿狐尾藻75.78%)。在试验处理条件下,2种植物的钙磷均占比最高,能通过降低水体磷含量抑制浮游植物的生长。 相似文献
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采用苦味酸-CTMAB分光光度法、EDTA滴定法、双硫腙法分别对杀灭菊酯、Ca2 和Cu2 养殖三角帆蚌水体中的含量进行了定量监测,研究了不同浓度对吸收作用的影响.结果表明三角帆蚌对杀灭菊酯、Ca2 和Cu2 均有一定的沉积作用,在持续处理30 d后,能使水体中这些化合物的含量明显下降.其中,杀灭菊酯在三角帆蚌存活条件下,浓度越大,沉积速度就越快;Ca2 在三角帆蚌体内的沉积量也与水样中的钙浓度有关;Cu2 沉积在三角帆蚌存活条件下,浓度越大,沉积速度就越慢,并且这种沉积量影响着三角帆蚌的存活率. 相似文献
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该文研究了蜂窝煤渣在不同吸附时间、水体pH值、蜂窝煤渣用量和磷初始浓度等条件下,对水体中磷的吸附规律。结果表明,随着反应时间的延长,溶液中磷的去除率提高,60min左右可以达到吸附平衡;pH值对溶液中磷的去除率有一定影响,但不是很明显;蜂窝煤渣用量越多,磷的去除率就越高,但用量达到1g/100mL以后,去除率的增加就不显著;蜂窝煤渣对磷的去除率一般可以达到90%以上,因此,蜂窝煤渣作为废水除磷吸附剂具有很好的开发前景。 相似文献
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通过体外试验，探讨了培养条件的改变对蟹源拟态弧菌(HX-4)产毒量的影响。结果表明，培养基种类、氯化钠浓度、初始pH、溶解氧、培养温度和时间的不同均可影响细菌产毒量，HX-4菌株的最佳产毒条件为细菌接种于起始pH为8．0，含0．5％NaCl-BHI培养基，28℃振荡培养36h或静置培养48h。同时，通过动物实验测定了外毒素的致病性，结果显示，外毒素粗提液对小鼠及河蟹均有致病性。粗提液的溶血活性越高，对动物的致死率也越高。具有蛋白酶活性而无溶血素活性的粗提液，对动物只有致病性，而无致死性。 相似文献
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为研究河鲀鱼精蛋白的制备工艺,以菊黄东方鲀(Takifugu Flavidus)精巢为原料,以鱼精蛋白提取率为指标,通过单因素试验研究NaCl溶液的pH、硫酸浓度、硫酸用量、提取温度、提取时间以及乙醇用量等单因素对鱼精蛋白提取率的影响,在此基础上,采用响应面法优化鱼精蛋白的提取工艺条件。结果显示,采用响应面法优化获得河鲀鱼精蛋白的最佳提取工艺条件为:NaCl溶液pH 8.5,硫酸浓度0.6 mol/L,硫酸用量4.0倍沉淀体积,提取温度45℃,提取时间2.4 h,乙醇用量4.0倍沉淀体积,此时鱼精蛋白提取率达到19.07%。研究表明,响应面法对河鲀鱼精蛋白提取条件的优化方案合理可行,可为河鲀精巢的开发利用提供参考依据。 相似文献
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鳕鱼骨钙片的制备及其生物利用 总被引：2，自引：0，他引：2
为有效利用鳕鱼加工中产生的鱼骨下脚料,研究采用碱醇法制备了鳕鱼骨钙粉,探讨了鳕鱼骨钙片制备方法,同时以Wistar大鼠为模型研究鳕鱼骨钙片的生物学功效。结果表明,采用NaOH和乙醇浸泡制取鳕鱼骨钙粉的最佳工艺参数为1mol/L NaOH溶液,浸泡时间30h,乙醇浓度60%,浸泡时间15h,制取的鳕鱼骨粉钙含量为27.8%,磷含量12.2%,蛋白质含量3.67%,脂肪含量0.44%。骨粉色泽洁白,无任何异味;粘合剂选用浓度为4%的聚乙烯吡咯烷酮乙醇溶液,填充剂与奶粉的配比为1∶2;崩解时间实验显示鳕鱼骨钙片崩解时间小于12min,无须添加崩解剂。动物实验表明,鳕鱼骨钙片2g/(kg.d)和鳕鱼骨钙片5g/(kg.d)可显著提高大鼠血钙、血磷和骨钙含量,具有促进骨生长、提高骨密度和防止骨质疏松的功效。 相似文献
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The ethylenediaminetetraacetic acid (EDTA) method was compared with two other P‐fractionation methods, Sedex and Hieltjes & Lijklema (H. & L.), in order to choose a suitable method that extracts better the inorganic (inorg‐P) and organic (org‐P) phosphate from marine aquaculture sediments. The EDTA method gave reliable results and did not change the P‐composition of the sediments during the analysis. The Sedex method can be improved if the quantity of pre‐extracted org‐P is separately determined after digestion, and the org‐P can thereby corrected. The Sedex method underestimates the org‐P present in the sediments (?59%), whereas the calcium‐bound phosphate (CaCO3≈P) is overestimated (+17%) in comparison with the EDTA method. The NaOH and HCl used in H. & L. method are not specific to extract inorg‐P from the sediments. To provide optimal extractions of inorg‐P in muddy sediments containing 1% org‐C and 15% CaCO3, the EDTA method was optimized according to extraction times, dithionite concentration and solute/solid ratio. Five extractions of 2‐h duration each with Ca‐EDTA are required to extract more than 95% of the iron‐bound phosphate (Fe(OOH)≈P) while the extraction of CaCO3≈P with Na‐EDTA takes more than 96 h. The concentration of dithionite up to 1% did not influence the amount of P and Fe extracted (P=0.098 and 0.174 respectively), whereas a solute/solid ratio of 40:1 was best suitable for the optimal extraction of Fe(OOH)≈P. These conditions can be applied to analyse P composition of other marine pond sediments having similar texture and chemical composition. 相似文献
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《Journal Of Applied Aquaculture》2013,25(3):77-88
Abstract There were strong correlations between soil pH and pHof water (R2 = 0.810) and total alkalinity (R2 = 0.724) in laboratory soil-water systems prepared with acidic rainwater and pond soil samples from Thailand. Moreover, water pH and total alkalinity were highly correlated (R2 = 0.987). Although soil carbonate concentration was not correlated with total alkalinity, there was a correlation between the product of soil carbonate and soil organic carbon and total alkalinity (R2 = 0.482). Other soil properties, exchange acidity, cation exchange capacity, base saturation, and total sulfur, were either not correlated or weakly correlated with total alkalinity. Total alkalinity did not exceed 20 mg/L except in systems with soils containing free carbonate. A method that estimates the amount of liming material needed to completely base-saturate bottom soils and provides an excess of carbonate, should be used in Thailand and other places. Calcitic agricultural limestone gave higher total alkalinity concentration in soil-water systems than dolomitic agricultural limestone. There usually would be no justification for selecting higher-priced dolomitic limestone for use in ponds. 相似文献
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Stanislaus Sonnenholzner Claude E. Boyd 《Journal of the World Aquaculture Society》2000,31(3):358-375
Chemical and physical analyses were conducted on bottom soil samples from 74 brackish-water ponds representing 40 shrimp farms in Ecuador. Most ponds had soils with pH > 6 and total carbon concentrations < 2.5%. Carbon was mostly in organic form, for the average concentration of carbonate carbon was 0.06%. The C: N ratio was 8 to 10 in soils with < 2.5% carbon. In ponds built in former mangrove areas, soil carbon was > 2.5% and C: N ratios were 25 to 30. Ponds soils in former mangrove areas also tended to be high in total sulfur and low in pH. Lack of correlation between carbon and sulfur in mangrove soils suggested that most of the sulfur was inorganic and presumably in sulfides. Soils containing above 0.4% free carbonate (as equivalent CaCO3 ) had pH values > 7. Although carbonate concentration was a major factor controlling soil pH, calcium hardness of pond waters was strongly influenced by salinity (and calcium) in the water supply. Total phosphorus concentrations averaged 898 mg/kg, and dilute acid extractable phosphorus usually accounted for 25–35% of the total. Concentrations of major cations and minor elements varied greatly in soils and exhibited ranges of up to three orders of magnitude. Contrary to opinions of shrimp producers, many pond soils in Ecuador are not acidic and few soils have a high organic matter content. Proper use of soil and water testing could greatly improve the efficiency of liming and other soil management practices. 相似文献
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固定化光合细菌在中华绒螯蟹人工育苗中的应用 总被引：19，自引：0，他引：19
用包埋法制备固定化光合细菌,并通过制备方法及使用方法的改进,使净化水质效果得到改善。四种不同包埋载体的试验结果表明,含３％沸石的海藻酸钙凝胶珠强度最大,净化水质活性最高。水体中ＮＹ３－Ｎ,ＮＯ２－Ｎ的含量及ＣＯＤ值的下降度随包埋比的增大而增大。对固定化光合细菌的用量及活化处理方法进行了探讨。 相似文献
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A series of experiments was conducted to research sensitive indicators for phosphorus status of fish using post‐juvenile rainbow trout. Fish were fed up to 24 days with semipurified diets that varied in phosphorus content. Concentrations of glucose‐6‐phosphate, ATP, creatine phosphate, glucose, total lipids and total cholesterol in blood or skeletal muscle were relatively unchanged by the 24 days of dietary phosphorus restriction. Inorganic phosphorus and ATP levels in the blood, however, correlated significantly and positively. Inorganic phosphorus levels in plasma and urine were significantly lower in fish fed phosphorus‐deficient diets than phosphorus‐supplemented diets. Urinary phosphorus excretion peaked 6–10 h after feeding fish with diets containing potassium phosphate. Fish receiving either commercial feeds or experimental diets containing phosphorus as fish bone excreted trace amounts of phosphorus in the urine. Faecal content of phosphorus significantly increased when the diet containing potassium phosphate was supplemented with calcium carbonate. Urinary phosphorus concentration was found to be a rapid and sensitive indicator for dietary intake of phosphorus and probably phosphorus status of the fish, and had an advantage over conventional response variables in estimating dietary phosphorus requirement especially with large commercial‐size fish. 相似文献
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Plínio S. Furtado Carlos A. P. Gaona Luis H. Poersch Wilson Wasielesky Jr. 《Aquaculture International》2014,22(3):1009-1023
The reduction in alkalinity and pH occurs due to the consumption of inorganic carbon by bacteria present in the biofloc. The objective of the study was to evaluate the effects of different doses of calcium hydroxide on the water quality and growth performance of the Litopenaeus vannamei in a biofloc system. The experiment consisted of four treatments with three repetitions for each treatment: Control treatment (TC), in which the pH maintained above 7.2 due to the application of 0.05 g L?1 of calcium hydroxide, and treatments T10, T20 and T40, in which daily doses of calcium hydroxide equivalent to 10, 20 and 40 % of the total amount of feed offered to the shrimp, respectively, were added to the environment. Twelve experimental units (150 L) were stocked with 85 juveniles of L. vannamei (0.18 ± 0.06 g), corresponding to a density of 425 shrimp m?3, and cultivated for 56 days. The values of alkalinity and pH for treatments TC and T10 were similar and significantly lower (p < 0.05) than those for treatments T20 and T40, which differed (p < 0.05) between each other. In terms of growth performance, TC, T10 and T20 performed significantly better (p < 0.05) than T40. There were no significant differences (p > 0.05) in the survival rates. The results obtained indicate that doses of 0.05 g L?1 of calcium hydroxide or daily applications between 10 and 20 % of the total amount of feed offered to the shrimp can be used for the correction of alkalinity and pH. 相似文献
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天然滁州鲫氨基酸成分分析与营养价值评价 总被引：2，自引：0，他引：2
应用生化分析方法对滁州鲫鱼中氨基酸成分进行了定量分析,并对氨基酸含量进行营养分析评价。结果显示：滁州鲫鱼中氨基酸总量为86.35%（占干重）,其中8种必需氨基酸和2种半必需氨基酸总量为36.76%,4种呈味氨基酸含量为29.29%,必须氨基酸总量和呈味氨基酸含量均高于草鱼、鲢、鳙鱼等鱼类。表明滁州鲫较之其他鱼类是一种营养价值高,肉质鲜美的鱼类。 相似文献
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Maria Prost Maria Studnicka Jadwiga Niezgoda 《Aquaculture (Amsterdam, Netherlands)》1974,3(3):287-294
Experiments were carried out on the influence of quicklime, ammonia water, ‘Neguvon’ — Bayer and desiccation on the vitality of leeches. It was found that the efficacy of quicklime depends on its CaO content, on the dose of this compound, and, above all, on the pH of calcium hydroxide formed by mixing quicklime with water. The borderline value in this case is pH = 8.6. Quicklime containing 49% CaO did not affect the mature forms of leeches or their larvae in cocoons. The efficacy of other kinds of quicklime (53% CaO, 93% CaO and 99% CaO) also depended on the pH produced. Quicklime containing 99% CaO proved the most effective in destroying mature leeches and their cocoons; at the concentration of 250 ppm, it produces a pH higher than 8.6 (Table I).In acceptable doses, ammonia water affects neither mature leeches nor their larvae in cocoons.‘Neguvon’ — Bayer, though effective against mature leeches, does not affect the vitality of the larvae in cocoons in doses acceptable for practical use.Under laboratory conditions, drying up kills leech larvae in 24 h. This is therefore a radical means of combatting these parasites. 相似文献
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