Rubber is a historical crop in Sri Lanka and now Sri Lanka is one of the leading rubber producers in the world. Even though rubber production is a well-established industry in the country, treatment of wastewater from rubber production plants is still an ongoing issue. Most of the industrial scale rubber production plants are equipped with wastewater treatment facilities. But small-scale rubber producers who cover 77% of country’s rubber production have no available treatment facilities for wastewater from their rubber production. Also not enough research has been conducted for identifying effectiveness of currently applied treatment facilities to treat rubber wastewater in Sri Lanka. This study focuses on identifying the characteristics of Sri Lankan rubber wastewater and effectiveness of available wastewater treatment facilities in rubber production plants in Sri Lanka. Assessing efficiencies of applied wastewater treatments was performed by analyzing the characteristics of influents and effluents of treatment facilities. The characteristics of rubber wastewater and current situation of applied treatments were identified in the study including high inefficiencies in removing nitrogen in wastewater to required limit.
This study aimed to assess the effectiveness of activated carbon (AC) in removing methomyl from water.Batch and fixed-bed column experiments were conducted to investigate the potential of AC for methomyl adsorption and to identify the optimal conditions for its application in water treatment.The batch experiments determined that activated carbon could adsorb methomyl at a rate of 32.70 mg/g after 300 m of contact.The highest adsorption capacity of 35.35 mg/g was observed at pH 2. Further agitation speed experiments revealed that turbulence is critical in controlling the solid-liquid mass transfer mechanism.The result from the pseudo-first-order adsorption kinetic equation was consistent with the experimental data, and the Langmuir adsorption isotherm better described the methomyl adsorption of activated carbon.The fixed-bed column experiments showed that the adsorption efficiency was depleted after continuous use after 19 hours (1,140 m), corresponding to the adsorption equilibrium point.
