Flow rate analysis of wastewater inside reactor tanks on tofu wastewater treatment plant

The research aimed to analyse the flow rate of the wastewater inside reactor tanks which were placed a number of bamboo cutting. The resistance of wastewater flow inside reactor tanks might not be occurred and produce biogas fuel optimally. Wastewater from eleven tofu factories was treated by multi-stages anaerobic process to reduce its organic pollutant and produce biogas. Biogas plant has six reactor tanks of which its capacity for waste water and gas dome was 18 m3 and 4.5 m3, respectively. Wastewater was pumped from collecting ponds to reactors by either serial or parallel way. Maximum pump capacity, head, and electrical motor power was 5m3/h, 50m, and 0.75HP, consecutively. Maximum pressure of biogas inside the reactor tanks was 55 mbar higher than atmosphere pressure. A number of 1,400 pieces of cutting bamboo at 50-60 mm diameter and 100 mm length were used as bacteria growth media inside each reactor tank, covering around 14,287 m2 bamboo area, and cross section area of inner reactor was 4,9 m2. In each reactor, a 6 inches PVC pipe was installed vertically as channel. When channels inside reactor were opened, flow rate of wastewater was 6x10-1 L.sec-1. Contrary, when channels were closed on the upper part, wastewater flow inside the first reactor affected and increased gas dome. Initially, wastewater flowed into each reactor by a gravity mode with head difference between the second and third reactor was 15x10-2m. However, head loss at the second reactor was equal to the third reactor by 8,422 x 10-4m. As result, wastewater flow at the second and third reactors were stagnant. To overcome the problem pump in each reactor should be installed in serial mode. In order to reach the output from the first reactor and the others would be equal, and biogas space was not filled by wastewater, therefore biogas production will be optimum.Published versio

Preliminary Insights on the Spatial Ecology, Population Demography, and Sexual Dimorphism of the Critically Endangered Sulawesi Forest Turtle (Leucocephalon yuwonoi)

Sulawesi Forest Turtles (Leucocephalon yuwonoi) are critically endangered and endemic to the island of Sulawesi. We conducted radiotelemetry and capture-mark-recapture to study their spatial ecology, habitat selection, activity patterns, and demography in February-April and June-July, 2019. The average area occupied by 14 turtles using the minimum convex polygon (MCP) method was 0.49 ± 0.42 ha (standard deviation [SD]), whereas using the fixed 50% kernel density method averaged 0.076 ± 0.061 ha (SD). Males (mean = 0.53 ± 0.40 ha, N = 7) occupied a larger area (MCP method) than females (mean = 0.44 ± 0.46 ha, N = 7) but the difference was not statistically significant. Turtles took refuge in habitat containing significantly more canopy cover, broadleaf plant cover, and more and deeper ground cover than that in random plots. Males were predominantly active at night and females were exclusively so. We caught 25 adult females, 16 adult males, and 38 unsexed juveniles in two stream sections. Estimated population size (95% confidence intervals) in the lower stream was 17 turtles (15-28) in the wet season and 10 turtles (8-21) in the dry season. The population estimate in the upper stream was 25 (24-33) and 13 (9-28) turtles in the wet and dry seasons, respectively. Our study provides important baseline ecological data that can be used to inform future conservation and recovery programs for the species.</p