LED光源在海水养殖水体中传播特征解析

Analysis of Propagation Characteristics of LED Light Source in Aquaculture Water

光是影响水生动物生长和发育的重要环境因子,其在养殖水体中的传播特征仍未明确。本研究选取红光(波峰为645 nm)、绿光(510 nm)、蓝光(445 nm)、UVA(355 nm)以及全光谱(蓝光激发硅酸盐荧光粉辐射的白光波长范围可达400~800 nm)5种LED光源,调整辐射照度为60 W/m2,研究其在不同养殖水质环境中的传播规律,为满足室内工厂化水产养殖对象的光生物学需求,实现养殖光环境标准化调控提供参考。结果显示,5种不同光谱特征的LED光源在深井海水中的透光率随水深增加呈降低趋势,不同光源间变化趋势存在差异。当透光水深为10 cm时,绿光透光率最大,为(46.01±4.03)%,UVA最小,为(26.01±2.53)%;当透光水深为150 cm时,各光色透光率均小于1.5%;5种不同光色的光源在水体中的透光率衰减曲线均符合乘幂函数。水体对LED光的吸收在不同的光谱区域是不同的,具有明显的选择性,水对光谱中红外部分的吸收最为强烈,对可见光谱波段中的红色、黄色和绿色光谱区段的吸收也十分显著;LED光源在养殖水体中衰减严重,水深是影响LED光源在水体中传播的主要因素(P<0.01),其次是总悬浮物(TSS)和化学需氧量(COD),但不同光源在养殖水体中受TSS和COD含量的影响程度不同。光在水体中的衰减由水对光的吸收以及散射作用引起,且光在不同波段的衰减率主要由水生介质的吸收光谱决定。

Light is an important environmental factor affecting the growth and development of aquatic animals,and its propagation characteristics in aquaculture waters are still unclear.In this experiment,five light emitting diode(LED)light sources were selected:red(peak at 645 nm),green(510 nm),blue(445 nm),UVA(355 nm),and full spectrum(the wavelength of white light emitted by blue light excited silicate phosphor can reachλ400~800 nm).The radiation irradiance was adjusted to 60 W/m^2,and the propagation law of irradiance was studied under different breeding water quality environments to provide references in order to meet the photobiological requirements of indoor factory aquaculture and the standardization control of aquaculture environment.The experimental results showed that the transmittance of five different LED light sources decreases with the increase in water depth.The variation trends of different light sources were different.When the water depth was 10 cm,the green light showed the largest transmittance(46.01%±4.03%),whereas UVA showed the lowest value(26.01%±2.53%).When the water depth was 150 cm,the light transmittance of all five light sources was less than 1.5%.The attenuation curves of light transmittance in water of five different light colors all agree with power function.The absorption of LED lights by water was discrepant in different spectral regions and has obvious selectivity.Most of the infrared and ultraviolet parts of the spectrum were absorbed by water.The absorption of the red,yellow,and green spectra in the visible spectrum band is also significant.LED light is severely attenuated in aquaculture water,and water depth is the main factor affecting LED light propagation(P<0.01),followed by total suspended solids(TSS)and chemical oxygen demand(COD).However,the extent to which different light sources are affected by TSS and COD content in aquaculture water varies.The attenuation of light in water is caused by the absorption and scattering of light by water,and the attenuation rate of light in different wave bands is mainly determined by the absorption spectrum of aquatic media.