Nutrient Recovery from Rubber Industry Wastewater as Struvite by Mg-Biochar

Nutrients are present in high concentrations in wastewater from the rubber industry. Without dealing with this concentrated level of nutrients in the wastewater before discharging them into a water body, it could cause the major issue of eutrophication. One way to lower and recover the nutrient levels in the water is by using struvite technology by adjusting some wastewater conditions such as pH, where then the struvite can be formed in an equal-molar ratio of Mg:P:N of 1:1:1. However, the conventional method will not be able to remove the maximum concentration of nutrients. Therefore, Mg-impregnated biochar is an alternative method to increase the efficiency. The results showed that the conventional method for struvite formation had the lowest phosphorus recovery efficiency (78.63%). Meanwhile, un-impregnated biochar and Mg-impregnated biochar had higher efficiencies which were 84.58% and 99.89%, respectively. Mg-impregnated biochar recovered the highest percentage of the nutrients in wastewater. This method not only promotes biomass waste recycling but also emphasizes the economic importance of struvite production and improves the nutrient content in both struvite and biochar, which can be used as soil conditioners.