Tofu wastewater treatment innovation: Effectiveness of natural zeolite as an adsorbent in the ammonium adsorption process

Waste from tofu production contains high ammonia levels in the form of ammonium, which can pollute the environment when discharged without prior treatment.Using natural zeolite as an adsorbent in treating ammonium contained in tofu waste is expected to effectively reduce the ammonium content, as natural zeolite has a high adsorption capacity.This research aims to analyze the ability of natural zeolite from Bayah, Indonesia, as an adsorbent in reducing ammonium content in tofu waste by integrating factors that influence the adsorption process such as adsorbent dose, stirring speed, adsorbent particle size, and contact time, to obtain optimal adsorption operating conditions.To achieve the research objectives, observations were conducted over a wide range: adsorbent sizes of 40-100 mesh, adsorbent mass of 1-5 grams/100 ml waste, stirring speeds of 400 and 600 rpm, and contact time of 60 minutes.The research results show that reducing the adsorbent size (40-100 mesh) and increasing the adsorbent dose (1-5 grams) has a positive impact on improving the percentage of ammonium removal achieved, but increasing the stirring speed (from 400 to 700 rpm) has the opposite effect, resulting in a decrease in the percentage of ammonium removal produced.Optimum conditions obtained at a mass of 5 grams, zeolite size of 100 mesh, and stirring speed of 400 rpm for 60 minutes, resulting in an ammonium removal percentage of 70.13%.The results of this research show that the use of natural zeolite has good prospects as an adsorbent in tofu waste treatment, although it still needs to be improved so that the percentage of ammonium removal approaches 100%.