Optimization and Kinetic Study of Ende-Natural Zeolite as Candidates of Ammonia Adsorbent on Broiler Chicken Litter

. Zeolite Natural Ende (ZNE) is a local material from Ende, East Nusa Tenggara which can be used as an adsorbent candidate to reduce environmental pollution due to poultry farm wastes. The purpose of this study is to obtain optimal conditions and adsorption kinetics of ZNE as an adsorbent in terms of absorbing NH 3 , water content, and neutralizing pH on broiler litter. This study consisted of 3 stages such as sample preparation, optimization of acid concentration, particle size, contact time, adsorbate concentration, as well as determination of ZNE-methylene blue adsorption kinetics. The results of analysis revealed that the best conditions are using 1 M H 2 SO 4, particle size 80 mesh, contact time for 30 minutes with an adsorption capacity of 1.999 mg/g and methylene blue 80 ppm as an optimal condition. Furthermore, ZNE-methylene blue adsorption kinetics model is the second order type 1 kinetics by R 2 = 1, and also adsorption rate constant is 0.0019 g.mg -1 .min adsorben optimum kinetika adsorpsi adsorben menyerap NH 3 , kadar pH ayam Broiler. terdiri dari 3 tahapan yaitu preparasi sampel, optimasi parameter uji (konsentrasi asam, ukuran partikel, waktu kontak dan konsentrasi optimum adsorbat), dan penentuan kinetika adsorpsi ZAE-metilen blue. Hasil analisis menunjukkan bahwa kondisi optimum meliputi H 2 SO 4 1 M, ukuran partikel 80 mesh, waktu kontak 30 menit dengan kapasitas adsorpsi sebesar 1,999 mg/g dan konsentrasi optimum metilen blue sebesar 80 ppm. Model kinetika adsorpsi metilen blue menggunakan adsorben ZAE adalah kinetika orde dua tipe 1 dengan nilai R 1 dan konstanta laju adsorpsi sebesar 0,0019 g.mg .menit . Zeolit memiliki kemampuan adsorbsi yang baik sehingga diaplikasikan sebagai material campuran alas kandang ayam broiler untuk mengurangi kadar amonia dalam urin dan feses.


INTRODUCTION
The problem faced by the farmers in the management of broiler chicken maintenance is the smell of ammonia from the litter which pollutes the environment. Ammonia is one of the gases which is resulting from the decomposition of nitrogenous waste in excreta, such as uric acid, unabsorbed protein, amino acids and other non-protein nitrogen (NPN) compounds due to the activity of microorganisms in feces. In addition, ammonia gases produced can reduce the performance of poultry, and as a medium for the spread of disease (Riza et al., 2015). The presence of chicken manure with high strongly humidity supports the proliferation of bacteria. Ammonia levels can increase if the cage ventilation is poor, the air temperature is extreme, and the cage contents are too dense. High levels of ammonia will greatly disrupt the environment as well as reduce livestock productivity. As a result, production costs will increase because the resistance of the chickens to diseases will decrease such as respiratory diseases, chicken colds and epilepsy. In addition, the health and comfort of workers will be disturbed due to bad environmental conditions (Riza et al, 2015 can also improve feed palatability and weight gain of livestock and reduce broiler mortality (Ibrahim and Allaily, 2012). As the research reported by Ngapa et al. (2016) regarding the structure of the natural zeolite Ende, by modifying the pore structure of the zeolite using 3 M HCl and resulting in an increased cation exchange capacity (CEC) of up to 75%.
Furthermore, Ende-natural zeolite is also more resistant to heat so the calcination process up to 600 O C does not damage the structure of natural zeolite, in contrast to synthetic zeolite which is not resistant to heat (Ngapa et al., 2016). Therefore, this work was focusing on optimal conditions and kinetic study of natural zeolite before applied to broiler chicken litter as ammonia adsorbent. Furthermore, this study could be essential information in terms of developing adsorbent in Indonesia.

Materials
The natural zeolite materials used in the study was taken from Nangapenda, Ende

Determination of optimum concentration of H2SO4
Optimization of the concentration of H2SO4 using a concentration variation of 1; 3; and 5 M to determine the concentration of H2SO4 which gives the highest absorption. A total of 1 g of zeolite with a particle size of 80 meshes was added with 15 mL of 80 ppm methylene blue solution. The solution was agitated using a shaker and centrifuged at 1500 rpm for 30 minutes. The separated filtrate was measured for absorbance at 664 nm as the maximum wavelength (Ngapa & Ika, 2020). The highest absorption results will be used as the optimum concentration to activate 4 types of zeolite particle sizes (20, 40, 60, and 80 mesh).

Optimum particle size determination
A total of 1 gram of each natural zeolite particle size 20, 40, 60, and 80 mesh were added with 25 mL of optimum concentration H2SO4, shaken at room temperature for 15 minutes. The filtered filtrate was measured absorbance at 664 nm. The highest absorbance is the optimum particle size.

Optimum contact timing
A total of 1 gram of natural zeolite with

Activation of Natural Ende Zeolite (ZNE)
The ZNE activation process was carried out by adding H2SO4 with concentrations of 1,   Figure 2). Theoretically, the surface area of the zeolite will be larger if the particle size of the adsorbent is smaller so that more methylene blue is adsorbed on the surface of the zeolite.
The purpose of the ZNE particle size limit at 80 mesh is that the particles are able to interact with the size of the rice husk so that the zeolite does not pass on the floor. The choice of rice husk as one of the mixed ingredients with zeolite because the husk has the ability to absorb water and provide air cavities in the litter (Anwar et al., 2014). In addition, if the particle size of zeolite is too small (> 80 mesh), it may be consumed by the chickens.

Optimum Concentration of Adsorbate
The interaction between ZNE and methylene blue at various concentrations showed the ability to absorb adsorbate.
According to figure 3 that there is an increase in absorption from a concentration of 20 ppm to 100 ppm. This is occurred due to the number of available zeolite active sites exceeds the concentration of methylene blue that the adsorption process runs effectively (Caparkaya & Cavas, 2008). However, when the concentration of adsorbate above 100 ppm, adsorption efficiency decreased significantly because all zeolite active sites were filled so the addition of methylene blue concentration could not be absorbed properly (Ngapa & Ika, 2020). This is due to the zeolite active sites were saturated with methylene blue and even the bonds were released. The result showed that there was a decreased intensity of ZAEmethylene blue complex colour which is simultaneously by dropped dramatically of absorbance from 120 ppm to 160 ppm ( Figure   4). in this study are first-order kinetics type 1, firstorder kinetics type 2, first-order kinetics type 3, second-order kinetics type 1, second-order kinetics type 2, second-order kinetics type 3, Elovich kinetics, Bangham kinetics and Weber-Morris intra particle diffusion (Wang & Guo, 2020). The type of kinetics and the results of adsorption capacity are shown in Figure 5 and Table 1.