ETP Bio Media MBBR Carrier for South American Industrial Effluent Treatment Plants Our BM-ETP-BIO ETP (Effluent Treatment Plant) bio media is a chemically-resistant suspended biofilm carrier purpose-engineered for industrial effluent treatment applications in South America . Unlike standard municipal-grade carriers, BM-ETP-BIO features a proprietary virgin HDPE formulation with chemical resistance additives that withstand aggressive industrial effluents from food and beverage