RESUMO
In order to study the smart management of dairy farms, this study combined Internet of Things (IoT) technology and dairy farm daily management to form an intelligent dairy farm sensor network and set up a smart dairy farm system (SDFS), which could provide timely guidance for dairy production. To illustrate the concept and benefits of the SDFS, two application scenarios were sampled: (1) Nutritional grouping (NG): grouping cows according to the nutritional requirements by considering parities, days in lactation, dry matter intake (DMI), metabolic protein (MP), net energy of lactation (NEL), etc. By supplying feed corresponding to nutritional needs, milk production, methane and carbon dioxide emissions were compared with those of the original farm grouping (OG), which was grouped according to lactation stage. (2) Mastitis risk prediction: using the dairy herd improvement (DHI) data of the previous 4 lactation months of the dairy cows, logistic regression analysis was applied to predict dairy cows at risk of mastitis in successive months in order to make suitable measurements in advance. The results showed that compared with OG, NG significantly increased milk production and reduced methane and carbon dioxide emissions of dairy cows (p < 0.05). The predictive value of the mastitis risk assessment model was 0.773, with an accuracy of 89.91%, a specificity of 70.2%, and a sensitivity of 76.3%. By applying the intelligent dairy farm sensor network and establishing an SDFS, through intelligent analysis, full use of dairy farm data would be made to achieve higher milk production of dairy cows, lower greenhouse gas emissions, and predict in advance the occurrence of mastitis of dairy cows.
RESUMO
Naphthalene sulfonic acid is widely used in the industry. In this study, H acid (1-amino-8-naphthol-3,6-disulfonic acid) was selected as the characteristic pollutant, and the alkali-activated, thermally-activated, and alkali-heat-complex activated persulfate (PS) degradation of H acid was analyzed. The effects of other factors on complex activation were discussed. The experimental results showed that with the addition of calcium oxide from 0 to 1250 mg ·L-1, the H acid removal rate increased from 42.5% to 82.8% after 100 min of reaction. The removal rate of H acid in thermal activation is positively correlated with temperature. The removal rate of H acid at 65â is 77.5%, and the apparent activation energy is 37.85 kJ ·mol-1. Although composite activation speeds up the reaction rate, rapid degradation of PS at high temperatures caused the degradation of H acid to be worse than single thermal activation. The change in PS concentration did not significantly improve the removal rate of H acid, and the inorganic anion CO32- was not conducive to the removal of H acid. Compound activation is not ideal for the mineralization of H acid, and the removal rate of TOC is only 16%. GC-MS identified the degradation product of H acid as terephthalic acid, indicating that phthalic anhydride may be formed after the naphthalene ring is opened.
