Brew temperature, at fixed brew strength and extraction, has little impact on the sensory profile of drip brew coffee

The brew temperature is widely considered a key parameter affecting the final quality of coffee, with a temperature near 93 °C often described as optimal. In particular, drip brewers that do not achieve a minimum brew temperature of 92 °C within a prescribed time period fail their certification. There is little empirical evidence in terms of rigorous sensory descriptive analysis or consumer preference testing, however, to support any particular range of brew temperatures. In this study, we drip-brewed coffee to specific brew strengths, as measured by total dissolved solids (TDS), and extraction yields, as measured by percent extraction (PE), spanning the range of the classic Coffee Brewing Control Chart. Three separate brew temperatures of 87 °C, 90 °C, or 93 °C were tested, adjusting the grind size and overall brew time as necessary to achieve the target TDS and PE. Although the TDS and PE both significantly affected the sensory profile of the coffee, surprisingly the brew temperature had no appreciable impact. We conclude that brew temperature should be considered as only one of several parameters that affect the extraction dynamics, and that ultimately the sensory profile is governed by differences in TDS and PE rather than the brew temperature, at least over the range of temperatures tested.

Pengaruh Reagen Pelindian pada Sintesis ZnO dari Debu Tungku Busur Listrik

ZnO nanoparticle was synthesized by a simple hydrometallurgical method using raw material of electric arc furnace dust (EAFD),which is a solid waste in the stainless steel industry. Electric arc furnace dust contains 68.81% Zn in the form of zincite (ZnO) and simonkolleite (H10Cl2O9Zn5). The synthesis was carried out in two main steps, i.e., leaching and alkaline precipitation. In this study, the effect of leaching reagent, leaching temperature, and leaching reagent concentration on the percent extraction of Zn in the leaching process from electric arc furnace dust and the characteristics of the resulting ZnO product were studied. The experimental results showed that leaching reagent of acetic acid gives the highest percent extraction of Zn. The results also showed that the increase of temperature and acid concentration could improve the Zn extraction percentage. At 2M acid concentration, Zn extraction percentage already achieved 100%; hence the process is independent of temperature. The ZnO product has a purity of 96%. The XRD data confirmed the nano sizes of the ZnO product. A B S T R A KZnO nanopartikel disintesis dengan metode hidrometalurgi sederhana menggunakan bahan baku berupa debu tungku busur listrik yang merupakan limbah padat industri baja tahan karat. Debu busur listrik mengandung 68,81% Zn dalam bentuk zincite (ZnO) dan simonkolleite (H10Cl2O9Zn5). Proses sintesis dilakukan dalam dua tahap utama yaitu pelindian dan pengendapan alkali. Pada penelitian ini dipelajari pengaruh reagen pelindian, suhu pelindian, dan konsentrasi reagen pelindian pada proses pelindian terhadap persen ekstraksi Zn dari debu tungku busur listrik dan karakteristik produk ZnO yang dihasilkan. Hasil percobaan menunjukkan bahwa asam asetat adalah reagen pelindian yang memberikan persen ekstraksi Zn tertinggi. Hasil percobaan juga menunjukkan bahwa semakin tinggi suhu dan konsentrasi asam yang digunakan, maka semakin meningkat persen ekstraksi Zn yang diperoleh. Tetapi pada konsentrasi asam 2M, suhu pelindian tidak terlalu berpengaruh karena dengan konsentrasi asam asetat 2M pada semua kondisi suhu pelindian, persen ekstraksi Zn yang diperoleh adalah 100%. Hasil pelindian menggunakan asam asetat pada kondisi optimum menghasilkan produk ZnO dengan kemurnian sekitar 96%. Data XRD juga menunjukkan bahwa ZnO yang terbentuk memiliki ukuran nano.

Treatment of Cyanide-Free Wastewater from Brass Electrodeposition with EDTA by Electrodialysis: Evaluation of Underlimiting and Overlimiting Operations

Growing environmental concerns have led to the development of cleaner processes, such as the substitution of cyanide in electroplating industries and changes in the treatment of wastewaters. Hence, we evaluated the treatment of cyanide-free wastewater from the brass electroplating industry with EDTA as a complexing agent by electrodialysis, aimed at recovering water and concentrated solutions for reuse. The electrodialysis tests were performed in underlimiting and overlimiting conditions. The results suggested that intense water dissociation occurred at the cathodic side of the commercial anion-exchange membrane (HDX) during the overlimiting test. Consequently, the pH reduction at this membrane may have led to the reaction of protons with complexes of EDTA-metals and insoluble species. This allowed the migration of free Cu2+ and Zn2+ to the cation-exchange membrane as a result of the intense electric field and electroconvection. These overlimiting phenomena accounted for the improvement of the percent extraction and percent concentration, since in the electrodialysis stack employed herein, the concentrate compartments of cationic and anionic species were connected to the same reservoir. Chronopotentiometric studies showed that electroconvective vortices minimized fouling/scaling at both membranes. The electrodialysis in the overlimiting condition seemed to be more advantageous due to water dissociation and electroconvection.

Penentuan Kondisi Optimum (Konsentrasi HCl dan Konsentrasi Ion Merkuri) pada Ekstraksi Ion Hg2+ Menggunakan Teknik Emulsi Membran Cair

Study on the extraction of mercury ion had been done using emulsion liquid membrane technique. The aim of this study was to determine the optimum condition on mercury ion extraction in solutions those include variations in concentration of HCl solution (0.5 to 2.5) M and variation in concentration of mercury (15-35) ppm.This study was conducted using laboratory experimental method with benzoyl acetone as cation carrier, kerosene as membrane phase, HCl solution as an internal phase, Span-80 and Span-20 as surfactants, and mercury solution as the sample. Determination concentration of mercury ion in external phase was analysed using UV-Vis spectrophotometer. The result showed that the concentration of HCl solution resulted in the optimum percentage of extraction with the percent extraction of 95.31% was at 2 M. In addition, the concentration of mercury solution resulted in percent optimum extraction of 96.58% was at a concentration of 30 ppm.

Penentuan Perbandingan Volume Fasa Membran dan Volume Fasa Internal serta Lama Waktu Ekstraksi pada Proses Ekstraksi Ion Merkuri Menggunakan Teknik Emulsi Membran Cair

This study aimed to determine the optimum condition on the extraction process of mercury ions with the variables of study on the ratio of membrane phase volume and internal phase volume (Mp:Ip) and the extraction time which will provide the greatest percent extraction. Sample used in this study was an artificial sample containing Hg(II) ions with a concentration of 10 mg/L. Hg(II) ions will be distributed into internal phase through membrane phase formed from a mixture of surfactants, kerosene and chelating compounds. Concentration of mercury ions remained in the samples was analyzed using a UV-VIS spectrophotometer at a wavelength of 490 nm with ditizon as a complex. The optimum condition was achieved at a volume ratio of membrane phase (Mp) with internal phase (Ip) of 2:2, and the extraction time was for 10 minutes, where percent extractions were 66.11% and 82.23%, respectively.

Ekstraksi Ion Merkuri MenggunakanTeknik Emulsi Membran Cair dengan Variasi Konsentrasi Benzoil Aseton dalam Fasa Membran dan Variasi pH Fasa Eksternal

Mercury ion extraction using the liquid membrane emulsion technique with the variation of benzoil aseton concentration in membrane phase and variation of pH of external phase has been done. The sample containing Hg2+ ions with a concentration of 20 mg/L. Variation of benzoil aseton were concentration of 0.01 M, 0.015 M, 0.02 M and 0.025 M, whereas variation of external phase pH used were 1,5; 2; 2,5; 3 and 3,5. The measurement of extraction was conducted by using UV-Vis spectrophotometer. The results showed that the largest percent extraction on the extraction of mercury ions in solution by using liquid membrane emulsion was at a concentration of benzoil aseton 0.02 M with the percentage of extraction 79.33% and the pH external phase 2 with the percentage of extraction 85.30%.

Pengaruh Ion Logam Cu(II) Terhadap Persen Ekstraksi Ion Pb(II) Menggunakan Teknik Emulsi Membran Cair

This study aimed to determine effect of Cu(II) ion toward percent extraction of Pb(II) ion using emulsion liquid membrane technique. Variation concentrations of Cu(II) added were 0, 50, 100, 150, 200 and 250 ppm with the initial concentration of Pb(II) was 245 ppm. This extraction used benzoyl acetone as a chelating agent. The extraction results were measured by Spectrodirect. The results showed that percent extraction of Pb(II) ion prior addition of Cu(II) ion was 99.09%, but after addition of Cu(II) to a concentration up to 250 ppm, the percent extraction of Pb(II) ions turned to decrease by 97.92%.

Pengaruh Ion Logam Cd(II) Terhadap Ekstraksi Ion Timbal(II) Menggunakan Teknik Emulsi Membran Cair

This study aims to study on the effect the addition of Cd (II) metal ions towards extraction of lead (II) ions using liquid emulsion membrane technique. Various concentrations of Cd (II) ions used in this study were 0, 50, 100, 150, 200, and 250 ppm. Benzoyl acetone was used as a chelating agent for extraction. Spectrophotometer spectrodirect was used to measure extraction products. The results showed that percent extraction of lead (II) ion prior additional Cd(II) ion was 99.06%, and it was decreased up to 97.95% after additional Cd(II) ion up to 250 ppm.

Application of reverse osmosis to petrochemical industry wastewater treatment aimed at water reuse

Purpose The purpose of this paper is to apply reverse osmosis (RO) to the treatment of industrial wastewater from a large petrochemical complex in Southern Brazil, in order to verify the conditions of liquid effluent reuse and improve them, especially to reduce the consumption of natural water by some production structures such as boilers and cooling towers. Design/methodology/approach The petrochemical wastewater was submitted to pretreatment using a sand filter and activated carbon filters. Tests were conducted using RO equipment with a production capacity of 0.25 m3h−1 composed of a spiral membrane module with a membrane area of 7.2 m². Pressures of 8, 12 and 15 bar were applied with reject flow maintained constant at 10 Lm−1. Findings The experiment results indicated optimum RO performance since more than 90 percent extraction was obtained for most of the compounds present in the petrochemical wastewater. Originality/value By checking the aspects involved, as well as providing some relevant considerations about, this study promotes the application of RO to get a satisfactory water reuse in similar industries, thereby decreasing both the volume of water extracted from wellsprings and the amount of wastewater released into water bodies.

PENGARUH PERBANDINGAN KONSENTRASI TBP : D2EHPA DAN KONSENTRASI PENGEMBAN DALAM FASAORGANIK PADA EKSTRAKSI PERAK DARI LIMBAH FOTO ROENTGEN

Photo roentgen used for examination of internal organs can produce wastes that are harmful to health and the environment because they containing silver metal ion(Ag+) inform of silver thiosulfate complex ([Ag(S2O3)2]-3). Therefore it was necessary for the separation of Ag metal so that the metal does not pollute the environment and can be used economically. One way to separate the metal Ag is by solvent extraction techniques. This study aimed to determine the effect of concentration ratio of TBP:D2EHPA and carrier compound concentration in the organic phase of the percent extraction of silver metal then applied to the sample photo roentgen waste. Extraction of the metals Ag done by varying the ratio of the combined carrier concentration of TBP and D2EHPA in kerosene by concentration ratio was 0: 1; 0.25: 0.75; 0.5: 0.5; 0.75: 0.25 and 1: 0 M as well as by varying the carrier concentration in the organic phase ranging from 0 M; 0.5 M; 1 M and 1.5 M. Measuring the concentration of metal ions Ag+in water phase before and after extraction was determined by atomic absorptionspectrophotometer (AAS) at a wavelength of 328,22 nm then calculated percent extraction. Based on the research that obtained the highest percent extraction on single used carrier compounds and compound concentration carrier D2EHPA in optimum water was 0.5 M with 58.22% percent extraction. Applications optimum conditions to the extraction of silver metal obtained from photo roentgenwaste percent extraction was 10.27%.