（原创）鱼类健康 第八讲 亚硝酸盐（NO2-）和硝酸盐（NO3-）
<div id="textstyle_7011" style="PADDING-RIGHT: 0px; MARGIN-TOP: 10px; FONT-SIZE: 9pt; OVERFLOW-X: hidden; WIDTH: 97%; WORD-BREAK: break-all; TEXT-INDENT: 24px; LINE-HEIGHT: normal; HEIGHT: 200px; WORD-WRAP: break-word;"><p><span>鱼类健康</span><font face="Times New Roman"><br/> </font><span>第八讲</span><font face="Times New Roman"><br/> </font><span>亚硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-</sup></font></span><span>）和硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）</span><span lang="EN-US"><font face="Times New Roman"><span> </span><span> </span>Fish Health<span> </span>August 1, 2007</font></span></p><p><span lang="EN-US"><font face="Times New Roman"> <p></p></font></span></p><p></p><p></p><p></p><p></p><p></p><p></p><p><span>前面一讲我们谈到水体中</span><span lang="EN-US"><font face="Times New Roman">NH<sub>4</sub><sup>+</sup></font></span><span>和</span><span lang="EN-US"><font face="Times New Roman">NH<sub>3 </sub></font></span><span>对鱼类健康的影响，接下来我们来看看在水中氮循环的最后两种产物（亚硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-</sup></font></span><span>）和硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>））又是如何影响鱼类健康的。在氮的水循环过程中，一个品种的硝化细菌负责把</span><span lang="EN-US"><font face="Times New Roman">NH<sub>3 </sub></font></span><span>转变为亚硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-</sup></font></span><span>），而另一品种的硝化细菌负责把亚硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-</sup></font></span><span>）转化为硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）。在这两种硝化细菌中，前者的生长速率比较高，而后者相对较慢，因此硝化系统从开始建立到最佳状态大约需要</span><span lang="EN-US"><font face="Times New Roman">30</font></span><span>天。具体硝化系统该如何建立，我们在第九讲将详细论述。</span></p><p><span>亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>在低溶度时就会对鱼产生危害，致病原理为：鱼鳃对亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>能主动吸收而后进入血液（可以看做是一种自杀行为，进化还不够完全），亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>具有一定的氧化能力，能将血红蛋白中起携带氧作用的二价铁氧化为三价铁，导致血红蛋白无法携带提供氧气，最终鱼因缺氧而死亡。由亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>溶度过高所引起的疾病被称为“棕血症”。</span><font face="Times New Roman"><br/> </font><span>“棕血症”的病理表现为鱼鳃棕红色化，浮头，鱼只食欲下降。亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>的安全溶度在水产养殖上为</span><span lang="EN-US"><font face="Times New Roman"><0.06-0.1mg/L</font></span><span>。但由于鱼的品种不同而对亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>的承受能力不同，安全溶度并非一尘不变的。在家庭观赏鱼养殖里，控制在</span><span lang="EN-US"><font face="Times New Roman"><0.02mg/L</font></span><span>比较适合。对淡水鱼“棕血症”的治疗方法主要是加盐（精盐），根据氯离子溶度</span><font face="Times New Roman"><br/> </font><span>：</span><span lang="EN-US"><font face="Times New Roman"> NO2<sup>-<span> </span></sup></font></span><span>离子为</span><span lang="EN-US"><font face="Times New Roman">9 </font></span><span>：</span><span lang="EN-US"><font face="Times New Roman">1</font></span><span>的比例添加。在这举个计算例子，在</span><span lang="EN-US"><font face="Times New Roman">100</font></span><span>升淡水中</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-<span> </span></sup></font></span><span>离子溶度为</span><span lang="EN-US"><font face="Times New Roman">0.06mg/L</font></span><span>，那么就加入</span><span lang="EN-US"><font face="Times New Roman">0.54mg/L</font></span><span>的盐，也就是</span><span lang="EN-US"><font face="Times New Roman">54mg</font></span><span>的盐。在对“棕血症”进行预防时，可保持水体中氯离子溶度为</span><span lang="EN-US"><font face="Times New Roman">60mg/L</font></span><span>，这样就能有效防止由于亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>溶度过高所带来的危害。</span></p><p><span>最后我们来看看硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>），硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）本身在水产养殖中是被视为相对无害的，因为其安全溶度为</span><span lang="EN-US"><font face="Times New Roman"><100mg/L</font></span><span>，相对</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>-<span> </span></sup></font></span><span>离子的安全溶度来说高了上千倍，而硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）是靠亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup></font></span><span>转化而来的，因此控制好后者就不用担心前者的危害了。在家庭养殖中，只要作到少许的换水（一天的换水量控制在</span><span lang="EN-US"><font face="Times New Roman">5%</font></span><span>以内）就能不用担心硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）的危害了。如果要对水体中硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）进行去除，可用反硝化生物过滤器，主要依靠反硝化细菌来使硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>）转变为</span><span lang="EN-US"><font face="Times New Roman">N<sub>2<span> </span></sub></font></span><span>排出水体。在这里我们就不详细讨论反硝化生物过滤器了，因为在水产养殖上和绝大多数的观赏鱼养殖中是没必要用到这套设备的。</span></p><p><span>到目前为止，我们讲过了</span><span lang="EN-US"><font face="Times New Roman">9</font></span><span>大水质标准对鱼类健康带来的影响。下图为这</span><span lang="EN-US"><font face="Times New Roman">9</font></span><span>大水质标准的安全溶度：</span></p><p><span></span><span lang="EN-US"><shapetype id="_x0000_t75" opreferrelative="t" ospt="75" coordsize="21600,21600" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"></shapetype><shapetype></shapetype><shapetype></shapetype><shapetype></shapetype><font face="Times New Roman"> <br/><img title="dvubb" alt="图片点击可在新窗口打开查看" src="http://www.hxyylt.com/skins/default/fgdown.gif" border="0"/><a href="http://www.hxyylt.com/dispbbs.asp?boardID=18&ID=641&page=1#" target="_blank" fg="Flashget://W0ZMQVNIR0VUXWh0dHA6Ly93d3cuaHh5eWx0LmNvbS9VcGxvYWRGaWxlLzIwMDctOC8yMDA3ODIwMjYxNTY0ODMxLmpwZ1tGTEFTSEdFVF0=&6684">[快车下载]</a>调整大小 p1000714.jpg：<br/><a href="http://www.hxyylt.com/UploadFile/2007-8/2007820261564831.jpg" target="_blank"><img title="dvubb" alt="图片点击可在新窗口打开查看" src="http://www.hxyylt.com/UploadFile/2007-8/2007820261564831.jpg" border="0" style="WIDTH: 500px;"/></a></font><shapetype></shapetype><shapetype></shapetype><shapetype></shapetype><shapetype></shapetype></span></p><p><span>在这张图中，左边一列为这</span><span lang="EN-US"><font face="Times New Roman">9</font></span><span>大标准的名字（从上到下：氧气，氮气，二氧化碳，</span><span lang="EN-US"><font face="Times New Roman">pH</font></span><span>，碱度，硬度，氨（</span><span lang="EN-US"><font face="Times New Roman">NH<sub>3</sub></font></span><span>）</span><span lang="EN-US"><font face="Times New Roman">, </font></span><span>亚硝酸盐</span><span lang="EN-US"><font face="Times New Roman">NO2<sup>- </sup>, </font></span><span>硝酸盐（</span><span lang="EN-US"><font face="Times New Roman">NO3<sup>-</sup></font></span><span>））。中间与列为安全溶度。右边一列为注释，注释内容在前几讲里已经讨论过了。</span></p><p><span lang="EN-US"><font face="Times New Roman"><span> </span><span> </span></font></span><span>罗松</span></p><p><span lang="EN-US"><span><font face="Times New Roman"> </font></span></span><span>完成于厦门</span><sub><span lang="EN-US"><p></p></span></sub></p><p></p></div> 要怎样才能解决这问题 <div class="msgheader">QUOTE:</div><div class="msgborder"><b>以下是引用<i>漫步雨中</i>在2007-8-2 20:56:00的发言：</b><br/>要怎样才能解决这问题</div><p>什么问题？</p>
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