Nghiên cứu các yếu tố ảnh hưởng đến việc hòa tách bùn thải có chứa đồng của quá trình sản xuất bản mạch điện tử

Copper recovery from waste mud of printed circuit boards (PCBs) via a three steps (leaching, filtration and electrowinning) process was studied. The copper mud was leached by the sulphuric acid leachant to form a concentrated copper ion solution for electrolysis. X-Ray diffraction, EDX, UV-Vis spectrophotometer, and ICP-MS analyses were done to characterize the structure and the ingredient of the solid samples and also determine the concentration of the liquid samples. The influences of the leaching solution content, concentration, time, temperature, ratio of solid and liquid phase, stirring speed and size of waste mud on the efficiency of waste mud leaching by sulfuric acid media were studied. The copper leaching was optimized done in the 1 M sulphuric acid solutions at room temperature for one hour. The solid/liquid phase ratio is 14 %, the copper mud grain size is 0.1 mm and the stirring speed is 600 rpm. The obtained results from this study are planning in the actual deployment of the Hanoi Urban Environment One Member Limited Company in Viet Nam. Keywords. Copper muds, leaching, PCBs fabrication

Implementation of feed intervention strategies for improved livestock nutrition and productivity in Mai Son district, Son La province, Vietnam

Livestock production in Vietnam is critical in reducing poverty and increasing income particularly for ethnic minorities in the Northwest Highlands. Improved livestock management and productivity can be achieved through better feed management and increased cultivation of improved forages, to meet animal nutrition demand. This study aimed at assessing feed intervention strategies to address context-specific feed-related challenges, mainly winter-feed shortage, for improved animal nutrition and livestock productivity in Mai Son district, Son La province, Vietnam. These interventions included promoting the uptake of improved forage varieties (grasses and legumes) and capacity building on animal nutrition techniques including feed processing and preservation, feed mix and feeding regimes for cattle and pigs. Willing farmers selected various forage varieties, were provided with seeds and planting materials to grow on their farms and guided on forage planting, management, and utilization. Local partners and stakeholders supported various activities and ensured successful implementation amidst the restrictions arising from the Covid 19 pandemic. Farmers reported increased awareness on feed technologies, increased yield, and availability of high-quality feed for their livestock, as well as challenges encountered in applying different feed-related techniques. Initial results from this study show the potential of feed and forage technologies in improving livestock productivity and lays a foundation for scaling these interventions to other regions of Vietnam