This paper presents the characteristic MIMO 2x4 antenna for 5G communication system. The proposed antenna works at 28 GHz and simulated by using CST simulation software. The antenna uses RT Duroid 5880 substrate with dielectric constant of 2.2. The MIMO antenna consists of eight elements with rectangular patches and inset feeding. Thedimension of patch (Wp x Lp) is 6 mm x 8 mm. There are three (3) antenna configurations derived in this paper such as; single element, 1x4 elements and 2x4 elements. The MIMO 1x4 elements antenna configuration is designed based on the single element antenna with the distance between center to center elements antennas of 5 mm. The MIMO 2x4 antenna is formed from the MIMO 1x4 element configuration with the opposite direction. The 2x4 element antenna, a distance between opposite antenna elements is 10 mm. From the simulation results, it is shown that by increasing the number elements of antenna affect to the directivity and the return loss. Antenna with 2x4 elements has 14 dBi of directivity with the return loss of -19 dB. While antenna with 1x4 elements, the directivity obtained is 14.3 dBi with return loss of -18 dB.

Liquid waste produced by palm oil mills needs to be monitored regularly to avoid pollution and negative impacts of waste before being discharged into rivers. Monitoring of pollution levels of palm oil effluent is carried out in wastewater disposal ponds. In this study, a website-based prototype of a palm oil effluent monitoring system was designed and built. This prototype monitors the level of pollution of liquid waste in the liquid waste disposal pond. Monitoring the level of pollution of this liquid waste takes a sample of waste at one of the palm oil mills located in Kuantan Singingi, Riau. This research uses a pH sensor and a water turbidity sensor. Provision of calcium oxide is carried out if the level of acidity of the liquid waste and the level of turbidity of the liquid waste is in poor condition. The measurement results are then displayed directly on the website that was built. From the results of field tests, it was found that the liquid waste is very acidic, so it is necessary to add calcium oxide to reduce the acid content.