Investigation of the Effect of Compaction on the Anaerobic Digestion Process

This paper aims to evaluate the effects of compaction on the anaerobic biodegradability of straw. In the study, compaction tests were carried out at different applied pressures, i.e., 0 (CK), 277 (T1), 555 (T2), and 1109 Pa (T3), respectively. The changes in physicochemical indicators (i.e., pH, VFA, COD, and DHA) of the liquid digestate were monitored. Factor analysis was adopted to analyze biogas production's main factors in the bath Anaerobic digestion (AD) process. Changes in the surface structures and composition of solid digestate were analyzed. The results showed that the maximum gain in biogas production was 298.35mL·g− 1TS for the T2 reactor, significantly higher than that of CK and T3 reactors. The effect of compaction on the physicochemical index of liquid digestate was not significant during the batch-type AD process. The factor analysis results suggested that the major factors affecting biogas production were influenced by the compaction and varied based on the different stages of digestion. Scanning electron microscopy (SEM) showed that the straw surface was damaged as the compaction increases; however, the degree of damage was not significant. This research concluded that compaction on gas production via changing the environment during the bath AD process and proper compaction could positively affect biogas' yield, while excessive compaction will inhibit gas production.

Assessment of a Physicochemical Indexing Method for Evaluation of Tropical River Water Quality

This paper attempts to evaluate the Malaysian water quality indexing method that has been criticized for its ineffectiveness. The indexing method is referred to as the Water Quality Index of the Department of Environment, Malaysia (DOE-WQI). This index was assessed against two other indices (River Ganga Index and Minimal Water Quality Index (WQImin)) and a modified DOE-WQI was also proposed. DOE-WQI and WQImin are physicochemical indices, whereas the River Ganga Index and modified DOE-WQI are indices with the inclusion of a microbiological parameter. The assessment was conducted based on the water quality of tropical rivers in Malaysia, with specific reference to Sarawak River and its tributaries. Water quality in terms of pH, dissolved oxygen, conductivity, turbidity, total suspended solids, biochemical oxygen demand, chemical oxygen demand, ammoniacal nitrogen, and fecal coliform count (FCC) was measured from 18 stations in December 2015, January 2016, and March 2016. Generally, the river was characterized with high FCC with the four indices significantly correlated. The results demonstrated the shortcomings of the existing DOE-WQI; the physicochemical index assigned water quality to a better class than its actual conditions without taking into consideration the FCC.

Lipolysis and oxidation of lipids during egg storage at different temperatures

The aim of this study was to investigate lipolysis and lipid oxidation of stored eggs at different temperatures (4 and 22°C) by evaluating the changes in physicochemical index, lipid profiles, enzymatic activity, and oxidative index. The results showed that the changes in physicochemical index were more significant at 22°C than at 4°C. Weight loss, moisture content, and pH of egg yolk increased significantly (P < 0.05), whereas the yolk index decreased during storage. However, there was no significant difference in lipid profiles between 4 and 22°C storage temperature. The lipid composition analysis demonstrated that lipid hydrolysis took place during egg storage and resulted in a marked decrease of PL and increase of FFA. It was also found that the content of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI) decreased significantly during storage. The correlation analysis showed that the lipid degradation is significantly positively related to lipase activity (P < 0.05), and the marked changes of lipid fractions are results of both hydrolysis and oxidation. It can be concluded that the egg physicochemical index and lipase activity were greatly influenced by temperature during storage, but the yolk lipid stability was not significantly influenced by storage temperature.

Research of the Processing Technology and Quality Standard of Indocalamus latifolius Leaves

This paper regards the Indocalamus latifolius leaves as the research object, aiming to explore the influence of the new processing technologies and the traditional ones on the Indocalamus latifolius leaves through technologies of harvesting, fractionating, drying and vacuum sealing, marinating, and freezing, etc. Then it prepares the product grade, physicochemical index, health indicators and product qualification criteria to provide a theoretical reference for their further development.

Relationship between Physico-Chemical Properties and Related Enzymic Activities by Inoculating Microorganism Agent in the Composting Process

In the research, the duck farm cushion and organic waste of duck hatching plant and slaughter and processing plant were used as compost materials, single factor 4 levels 3 replications design was carried out. Effects of adding different doses (0%, 0.35%, 0.40%0.40%, 0.45%) of microorganism agent (consisted ofthermophilic BacillusandSerratia) on compost physicochemical indexes including temperature, moisture content, C/N, germination index, total N, total P, total K, available N, available P, available K, and the enzymic activities including urease, cellulase, dehydrogenase, catalase and protease. There were four treatments in this experiment, three was with adding different doses (0.35%, 0.40%, 0.40%, 0.45%) of microorganism agents, one was without adding microorganism agent (control). The results showed that, adding microorganism agent treatment had faster temperature rising, higher temperature and longer high temperature duration than control. At the end of composting, C/N of those with adding microorganism agent were significantly lower than control (P<0.05), germination index, total N, total P, total K, available N, available P, available K were significantly higher than control (P<0.05). Urease, dehydrogenase, Catalase and protease activities were significantly higher than control (P<0.05), however, those with adding microorganism agent were not significantly higher than control (P>0.05).Enzyme activity of experimental treatments and the physicochemical index shows a good correlation. In conclusion, adding 0.35% microorganism agent was optimum for composting in this research.