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首页> 外文期刊>Aquacultural Engineering: An International Journal >Feed and treat: What to expect from commercial diets
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Feed and treat: What to expect from commercial diets

机译：饮食：从商业饮食中得到什么

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Basic data describing the physical characteristics of fish fecal waste are important in the design of effective solid waste management in aquaculture, especially in land-based facilities such as recirculating aquacultural systems (RAS). This study describes the physical properties of feces from rainbow trout fed eight different commercially available and widely used diets in Germany. Additional data from an earlier but unpublished study pertaining to feces derived from two rather extreme all-vegetarian diets are also presented for consideration of the settling properties. The diets were tested on duplicate groups of 50 rainbow trout in a flow-through aquaculture system. The effects of the diets on the physical properties of fecal particles such as particle size distribution (PSD), modeled settling velocity and rheological character were examined and the effects of each diet on fish health, growth and feed utilization were determined. Specific growth rate (SGR) and feed conversion ratio (FCR) for the different diets ranged from 0.98%d(-1) +/- 0.012% d(-1) to 1.39% d(-1) +/- 0.012% d(-1) and 0.97 +/- 0.017 to 1.61 +/- 0.017 (mean +/- S.E.), respectively. The density of presoaked feces was significantly lower than that of intestinal feces and ranged from 1.01013 +/- 0.00692 g cm(-3) to 1.04547 +/- 0.00692 g cm(-3) (mean +/- S.E.). Stability data were in the range from 390.12 +/- 29.4 Pa to 1214.79 +/- 29.0 Pa for elastic modulus and from 62.12 +/- 6.1 Pas to 232.68 +/- 6.0 Pa s for dynamic viscosity. Based on the stability and PSD data theoretical efficiencies for removal of fecal waste using a drum filter showed remarkable variation, ranging from 82.5 to 95.9% (60 mu m gauze). Based on the same data, theoretical removal by a sedimentation basin with routinely using overflow rates of 0.057 cm s(-1) to 0.394 cm s(-1) ranged from 62.8 to 93.8%. Both fecal density and PSD have an exponential impact on settling performance. Increasing fecal density improves the removal efficiency of a sedimentation basin by about 20%, however sedimentation was seen to be a less robust and efficient removal technique than drum filtration. Sedimentation systems also experience additional problems with respect to leaching. Turbulence that was mimicked in this study reflects to an optimal fish farm, which means disintegrating effects are mainly caused by fish motion. If disintegrating units e.g. pumps are used, which are known to promote further particle breakdown the effects would be amplified. The results demonstrate the central importance of density of suspended solids in defining removal efficiencies and suggest that manipulation of fecal density might offer a new and effective means of managing and optimizing waste output from aquaculture operations. This study describes the basic properties of fecal wastes generated by commercial diets and can be used as a basis for further research
机译：描述鱼粪废物物理特征的基本数据对于设计有效的水产养殖固体废物管理非常重要，特别是在陆地设施（例如循环水产养殖系统（RAS））中。这项研究描述了德国饲喂八种不同的可商业获得和广泛使用的饮食喂养的虹鳟鱼粪便的物理特性。还提供了来自较早但尚未发表的研究的其他数据，这些数据与源自两种相当极端的全素食饮食的粪便有关，以考虑沉降特性。在流通式水产养殖系统中，对每组50只虹鳟鱼的饲料进行了测试。检查了日粮对粪便颗粒物物理性质的影响，例如粒径分布（PSD），模型化的沉降速度和流变特性，并确定了每种日粮对鱼类健康，生长和饲料利用率的影响。不同日粮的比生长率（SGR）和饲料转化率（FCR）为0.98％d（-1）+/- 0.012％d（-1）至1.39％d（-1）+/- 0.012％d （-1）和0.97 +/- 0.017至1.61 +/- 0.017（平均+/- SE）。预浸泡的粪便的密度显着低于肠道粪便的密度，范围从1.01013 +/- 0.00692 g cm（-3）到1.04547 +/- 0.00692 g cm（-3）（平均+/- S.E.）。稳定性数据的弹性模量为390.12 +/- 29.4 Pa至1214.79 +/- 29.0 Pa，动态粘度为62.12 +/- 6.1 Pas至232.68 +/- 6.0 Pa s。根据稳定性和PSD数据，使用鼓式过滤器去除粪便的理论效率显示出显着变化，范围为82.5％至95.9％（60微米纱布）。基于相同的数据，通常使用0.057 cm s（-1）至0.394 cm s（-1）的溢流速率进行的沉淀池理论去除范围为62.8至93.8％。粪便密度和PSD都对沉降性能产生指数影响。粪便密度的增加将沉淀池的去除效率提高了约20％，但是，与鼓式过滤相比，沉淀法被认为是一种不那么可靠和有效的去除技术。沉淀系统在浸出方面还遇到其他问题。本研究中模拟的湍流反映了一个最佳的养鱼场，这意味着崩解作用主要是由鱼的运动引起的。如果要崩解，例如使用已知能进一步促进颗粒分解的泵，其效果将得到放大。结果证明了悬浮固体的密度在确定去除效率方面的核心重要性，并表明粪便密度的控制可能为管理和优化水产养殖作业的废物提供一种新的有效手段。这项研究描述了商业饮食产生的粪便废物的基本特性，可以作为进一步研究的基础

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