Penelitian ini bertujuan untuk mengetahui massa biosorben optimum, waktu kontak optimum dan konsentrasi pewarna optimum dalam biosorpsi lumpur aktif terhadap pewarna remazol teknis serta mengetahui pengaruh proses biosorpsi terhadap kadar COD (Chemical Oxygen Demand) pewarna  remazol teknis. Proses biosorpsi dilakukan dengan sistem batch pada berbagai variasi massa biosorben, waktu kontak dan konsentrasi pewarna remazol teknis. Larutan pewarna remazol teknis sebelum dan sesudah biosorpsi dianalisis secara kuantitatif dengan spektrofotometer UV-Vis. Penentuan kadar COD dilakukan pada larutan remazol teknis sebelum dan sesudah adsorpsi. Efisiensi biosorpsi dinyatakan dalam bentuk konsentrasi teradsorpsi dibagi konsentrasi mula-mula larutan dan dikalikan 100%. Hasil penelitian menunjukkan bahwa: massa lumpur aktif yang memberikan efisiensi terbesar pada biosorpsi remazol blue yaitu 5 gram dengan efisiensi biosorpsi 6,83% sedangkan untuk remazol red adalah 150 gram dengan efisiensi biosorpsi 67,19%. Waktu optimum dalam biosorpsi remazol blue menggunakan lumpur aktif adalah 15 menit dengan efisiensi biosorpsi 7,98%, sedangkan untuk remazol red adalah 75 menit dengan efisiensi biosorpsi 9,30%. Konsentrasi optimum dalam biosorpsi remazol blue menggunakan lumpur aktif adalah 200 ppm dengan efisiensi biosorpsi 6,19% dan untuk remazol red 600 ppm dengan efisiensi biosorpsi 9,10%. Kadar COD  pewarna remazol blue mengalami penurunan sebesar 22,22% setelah proses biosorpsi dengan lumpur aktif.

Chromium is one of the parameters of the heavy metal pollutant in the environment. An adsorption of chromium can be used to reduce the content of chromium cation. The study aimed to reduce the concentration of Cr cations in the water waste by using adsorbents kaolinite and Na-kaolinite with the pH variation of the solution. The adsorbents used were kaolinite and Na-saturated kaolinite. There were four steps to conduct this study, including the preparation of kaolinite, making waste simulation, testing the adsorbent, and the data analysis of cation adsorbed. Before the adsorbents were used, it was characterized using the FTIR and XRD methods. The results of the characterization by FTIR showed that the kaolinite and Na-kaolinite adsorbents didn't give significant difference; both adsorbents had the uptake of the clusters that were almost the same. While the XRD characterization on the adsorbent kaolinite appeared with spectra of 2θ = 21.23 and 41.93 which indicated the presence of quartz with contrast on Na-kaolinite that was not visible. On the other hand, Na-kaolinite appeared with spectra of 2θ = 12.6, which indicated the presence of halloysite. The percentage of the cation Cr 3+ that adsorbed was increased concurrently along with the increasing of pH. It indicated that the pH gave significant effect toward the adsorption process. The adsorbent of Na-kaolinite was stronger in adsorbing Cr 3+ as compared with kaolinite at low pH, because the addition of Na + on the kaolinite could result in the distance between the layers became larger and the reduced cluster of quartz in the sample.

This study aims to determine the ability of adsorption of chitosan on Cr (III) and Fe (III) ions simultaneously in various concentration variations. As research subject is chitosan isolated from crab shells and made through three stages namely deproteination stage, demineralisasi and deasetilasi. As the object of research is the adsorption power of chitosan against Cr (III) and Fe (III) metal ions, both for each ion and simultaneously. The adsorption process using a batch system is carried out for 24 hours at room temperature under optimum pH system conditions with a 1: 100 (w / v) adsorbent ratio at concentrations of 100 ppm to 1000 ppm. Chitosan adsorption is the ratio between the amount of metal ions adsorbed per gram of chitosan, adsorbat concentration is determined using Atomic Absorption Spectrophotometer The results showed that the adsorption capacity of chitosan on Fe (III) was stronger than Cr (III) in both single adsorption and simultaneous adsorption, and the process was classified as coadsorption.