A rapid determination method for chemical oxygen demand in aquaculture wastewater using the ultraviolet absorbance spectrum and chemometrics

Abstract

The ultraviolet (UV) absorbance spectrum was studied for the fast determination of chemical oxygen demand (COD) in aquaculture wastewater.

An online surface water COD measurement method based on multi-source spectral feature-level fusion

“…Aer the sample was cooled to room temperature, a portable spectrophotometer (DR 2800, Hach, USA) was used to perform the measurement of COD value. 6…”

“…It can select more precise features with minimal redundancy. 6 It starts with one initial feature, then a new one is selected at each iteration (on the principle of minimal redundancy), and end when a specied number of N features is reached. 21 In this part, we applied SPA on the two types of spectra, respectively, to achieve precise features.…”

“…5 So the main logic for these methods is to obtain the corresponding relationship through a large amount of water sample COD values (measured by wet chemistry) and the corresponding spectral change or sensor response. 3,6,7 With regards to the technology based on spectrophotometry, many scientists use the UV-Vis absorbance at 254 nm wavelength as an input, due to the strong linear correlation with organic content and the absorbance at 254 nm under ideal conditions. 8 However, the UV-Vis absorbance at 254 nm can easily be inuenced by scattering, which can cause a signicant deviation and raise the degree of uncertainty in the obtained result.…”

Prediction of Chemical Production Based on Neural Network

“…In 2006, the research group of Hinton [11] medical assisted treatment [27][28][29], forecasting [30][31][32], aquatic products, [33][34][35] intelligent driving [36][37][38], and so on. Although MLP architectures have many advantages, they are relatively inefficient in highdimensional spaces, which can lead to over fitting in model training.…”

Graphene oxide coated quartz sand as a high performance adsorption material in the application of water treatment

“…6 Many methods or technologies such as chemical precipitation, membrane processes, ion exchange, electrolysis, adsorption processes have been developed to remove the contaminations from wastewater. [7][8][9][10][11] However, each method has been found to be limited by cost, complexity, efficiency as well as by secondary waste. 2 Among these technologies, adsorptive removal of organic matter and heavy metals is widely applied because this method is easy to handle, relatively low cost, and effective at low concentration.…”