Study on an Advanced Treatment of Domestic Wastewater by Bio-filtration and Water-Quality Measurement System

A bio-filtration system is set up based on the analysis of a typical and simple water treatment system. The system mainly consists of a fixed device and a planting filter. We elect ryegrass as the planting-filter, because it gets best sod, mechanic filtration and bio-filtration. Effects of static bio-filtration were studied in ryegrass. The results showed that the purification effects of ryegrass were significant and the removal rates of COD in wastewater reached 71.6%, 79.7%, 79.8%, 81.7%, 83.0%, and 81.0%, respectively. Near infrared spectra was used to analyze the water-quality, mainly dealing with chemical oxygen demand (COD). A set of 20 samples of domestic wastewater with different concentrations was taken from the Animal Institution of Zhejiang Agricultural Science Organization, and the partial least square (PLS) was used to develop predictive models. To validate these models, some samples were used. The values of SEP were 22 and 32, and values of r² using the validation set of data were 0.9895, 0.9985 for COD of wastewater.