Determining the Growth and Wastewater Treatment Ability of Para Grass (Brachiaria mutica) Vegetation in the Stabilization Ponds

Abstract

Aquatic plants can be used to treat wastewater in an environmentally acceptable way. Para grass (Brachiaria mutica) is grown in a water stabilisation pond in this study. Para grass is leafy and leaf blades are hairy, up to 0.3 m long and 0.16 – 0.2 m wide. The growth cycle of para grass was studied for 35 days, and it was discovered that the grass grew quite quickly for the first 20 days, but then began to blossom and grow more slowly from day 20 to 21. In both rainy and dry seasons, para grass grew equally well in the first 12 days. In the next 12 days, however, para grass growth is better in the rainy season than in the dry season. In the 24 – day cycle, 1m2 of dry grass contain the highest yield of nutrients, i.e. 174.6g carbohydrate, 18.97g nitrogen and 2.85g phosphorus. The wastewater was treated well in the stabilisation pond, which is covered by para grass. When the flow rate is reduced to 0.25 m3/h, this system is capable of handling pollutants such as COD, total N, total P better than 0.35 m3/h. The percentage removal efficiency of COD, TN, TP at 0.25 m3/h is 64.3%, 51.8%, 49.1%, respectively. After treatment, the wastewater was treated with column A (COD, TN, TP, pH) QCVN 40: 2011/BTNMT with a retention time of 5.3 days and reusable. This research direction is suitable for the current sustainable development because proposes a method with low cost, friendly to the environment, easy to operate and the use of plant species which are available in Vietnam. The first section in your paper.