Effects of Various Precipitants on Iron Removal from a Zinc Concentrate Pressure Leaching Solution

Autoclave leaching of zinc concentrate (Sphalerite) is an environmentally friendly process compared to roasting, which discharges pollutants into the atmosphere. Due to the amount of iron in the final product, a study is proposed to evaluate different reagents for eliminating iron from the autoclave outcome, minimizing Zn losses. The colloid formation, zinc losses, iron removal, phase separation stage characteristics (sedimentation and filtering), and reagent costs were used to evaluate six-iron precipitating reagents: CaO, Na2CO3, CaCO3, NaOH, MgO, and Ca(OH)2. CaO shows 99.5% iron removal and 87% zinc recovery. Although CaO was one of the reagents with significant zinc recovery, it presented operational difficulties in the filtration stage due to the high viscosity of the mixtures. Finally, Ca(OH)2 is the reagent recommended due to its ease of use, zinc yield recovery, electrowinning efficiency, and iron precipitate filtration rate. Zinc recovery was above 80%, while the iron concentration in the solution was below 50 ppm.

The research of the composition of mineral component of compact bone tissue after flow delipidation using the optic method

The results of the research of bone mineral component (BMC) composition using the Raman spectroscopy method are presented in the work. The subjects of the research were the groups of BMC samples made of compact bone tissue of cows using “Lyoplast”® technology where vacuum delipidation of initial material was replaced by the flow one by washing it out in hydrogen peroxide and ether. The solution filtration after bone tissue demineralization was used as additional treatment. The results of the experiment show that the flow delipidation can be used for preparing this biomaterial (BMC), which is cost-effective compared to standard vacuum cleaning and additional filtration stage can be rejected.

Performa Tryptone Bile X-Glucuronide (TBX) yang disuplementasikan dengan Cefotaxime sebagai Medium Selektif Untuk Skrining ESBL-E.coli dari Sampel Lingkungan

Identification of ESBL-E.coli from environment without selective medium will be challenging to do considering that E.coli mixes with various other microorganisms in the environment. This study aimed to determine the performance of TBX Agar supplemented with Cefotaxime as a selective medium for ESBL-E. coli screening from 138 water samples of environmental sampling obtained from rivers, open sewers in the market, poultry slaughterhouses and hospital waste water inlets and outlets around Jakarta. Laboratory examinations were carried out through the filtration stage, inoculation on the TBX Agar supplemented with Cefotaxime medium as well as species confirmation and ESBL with the indol test and double-disk test. The results showed that 87.08% (40-100%) of suspect colonies growing on TBX Agar supplemented with Cefotaxime medium were confirmed as E.coli and 82.51% (12-100%) were confirmed as ESBL-E.coli. However, there was no correlation between TBX Agar supplemented with Cefotaxime performance and sampling locations. Based on the results of the study, it can be concluded that the TBX supplemented with Cefotaxime medium can be used for ESBL-E.coli screening in the environment, but further confirmation is needed using the indole and double-disk tests. Keywords: Escherichia coli, ESBL, TBX Agar suplemented with Cefotaxime Abstrak Identifikasi ESBL-E.coli tanpa medium selektif akan sangat sulit dilakukan pada sampel lingkungan mengingat ESBL-E.coli bercampur dengan berbagai mikroorganisme lainnya. Tujuan penelitian ini yaitu untuk mengetahui performa TBX Agar yang disuplementasi Cefotaxime sebagai medium selektif untuk skrining ESBL-E.coli. Sampel penelitian sebanyak 138 sampel air lingkungan yang diambil dari sungai, saluran pembuangan terbuka di pasar, rumah pemotongan hewan unggas (RPHU) serta inlet dan outlet limbah rumah sakit di sekitar Jakarta. Pemeriksaan laboratorium melalui tahapan filtrasi, inokulasi pada medium TBX Agar dengan suplementasi Cefotaxime serta konfirmasi spesies dan ESBL dengan uji indol dan double-disk test. Hasil menunjukkan bahwa koloni tersangka yang tumbuh pada medium TBX Agar dengan suplementasi Cefotaxime sebanyak 87,08% (40-100%) terkonfirmasi sebagai E.coli dan 82,51% (12-100%) terkonfirmasi sebagai ESBL-E.coli. Namun, tidak ada hubungan antara performa TBX Agar dengan suplementasi Cefotaxime dengan lokasi pengambilan sampel. Berdasarkan hasil penelitian dapat disimpulkan bahwa medium TBX Agar dengan suplementasi Cefotaxime cocok digunakan untuk skrining ESBL-E.coli di lingkungan namun tetap diperlukan konfirmasi lanjut menggunakan uji indol dan double disk test. Kata kunci: Escherichia coli, ESBL, TBX Agar suplemented with Cefotaxime

Application of synthetic and grafted polymeric flocculants in agricultural wastewater treatment

Due to the large amounts of freshwater consumed in Egypt by the agricultural sector that is more than 85% of Egypt share of freshwater in addition to the high concentrations of salts, chemicals and nutrients produced from fertilizers. Reduction of these pollutants concentrations to an acceptable level and breaking the sedimentation stability of colloidal substances and organic particles for reuse for irrigation purposes was associated with the application of biological treatment with coagulants addition. The flocculation process was performed by using polydiallyldimethylammonium chloride (polyDADMAC) and polyacrylamide grafted oatmeal (OAT-g-PAM). The scale-pilot consists of an aeration tank equipped with an air blower, sedimentation tank followed by a filtration stage through 20 cm of pottery scrubs media. To study the performance of synthetic and grafted polymeric flocculants, 3 trials were performed. Activated sludge process without adding any polymeric flocculants was the control trial. In the second trial, polyDADMAC was added with a dose of 5 mg/l. Finally, OAT-g-PAM with a dose of 1.25 mg/l was used in the third trial. The physicochemical properties of agricultural wastewater were measured at the national research center in Cairo. It was found that OAT-g-PAM incorporated with activated sludge process was the most effective in treating agricultural wastewater as it achieved COD, BOD,TKN, TP, and TSS removal efficiency up to 92.29%, 93.13%, 90.64%, 90.46%, and 92.5%, respectively which made it suitable to reuse for agricultural purposes, in addition to its ability to biodegrade, environmentally friendly, and low dosage required compared to polyDADMAC.

A Second-Generation Voltage-Conveyor-Based Interface for Ultrasonic PVDF Sensors

Exploiting the transmission and reception of low frequency ultrasounds in air is often associated with the innate echolocating abilities of some mammals, later emulated with sophisticated electronic systems, to obtain information about unstructured environments. Here, we present a novel approach for the reception of ultrasounds in air, which exploits a piezopolymer broadband sensor and an electronic interface based on a second-generation voltage conveyor (VCII). Taking advantage of its capability to manipulate both voltage and current signals, in this paper, we propose an extremely simple interface that presents a sensitivity level of about −100 dB, which is in line with commercially available references. The presented results are obtained without any filtration stage. The second-generation voltage conveyor active device is implemented through a commercially available AD844, with a supply voltage of ±15 V.

Purification and Characterization of Resistant Dextrin

In this study, an efficient method for the purification of resistant dextrin (RD) using membrane filtration and anion exchange resin decolorization was developed, then the purified RD was characterized. In the membrane filtration stage, suspended solids in RD were completely removed, and the resulting product had a negligible turbidity of 2.70 ± 0.18 NTU. Furthermore, approximately half of the pigments were removed. Static decolorization experiments revealed that the D285 anion exchange resin exhibited the best decolorization ratio (D%), 84.5 ± 2.03%, and recovery ratio (R%), 82.8 ± 1.41%, among all the tested resins. Under optimal dynamic decolorization conditions, the D% and R% of RD were 86.26 ± 0.63% and 85.23 ± 0.42%, respectively. The decolorization efficiency of the D285 resin was superior to those of activated carbon and H2O2. Moreover, the chemical characteristics and molecular weight of RD did not change significantly after purification. The nuclear magnetic resonance spectroscopy of RD showed the formation of new glycosidic linkages that are resistant to digestive enzymes. The superior water solubility (99.14%), thermal stability (up to 200 °C), and rheological properties of RD make it possible to be widely used in food industry.

Behavior of PBTC, HEDP, and Aminophosphonates in the Process of Wastewater Treatment

Ten times at intervals of 1–2 months, individual treatment stages of two wastewater treatment plants (WWTPs) were analyzed for the five quantitatively most widely used phosphonates. The total dissolved concentration of the investigated phosphonates in the influents was between 131 µg/L and 384 µg/L. The nitrogen-free phosphonates 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) and 1-hydroxyethylidene(1,1-diphosphonic acid) (HEDP) accounted for an average proportion of 83–85%. Diethylenetriaminepenta(methylene phosphonic acid) (DTPMP) contributed with 13–14%, whereas aminotris(methylphosphonic acid) (ATMP) (≤15 µg/L) and ethylenediaminetetra(methylene phosphonic acid) (EDTMP) (≤11 µg/L) contents detected in the WWTP influents were comparatively low. The application of new analytical methods allowed the quantification of phosphonates in the solid fraction of the WWTP influents for the first time. High loads of phosphonates were determined (223–2555 mg/kg), indicating that 20%–80% of the phosphonates are present in the adsorbed state. The removal of total dissolved phosphonate by secondary clarification was between 69.7% and 92.4% (medians: 90.7% and 87.7%). In both WWTPs, HEDP (medians: 89.2% and 86.4%) was slightly better eliminated than PBTC (medians: 87.2% and 82.5%). In the sand filtration stage of a WWTP, the average removal was not further improved. In contrast, an additional removal of dissolved phosphonates could be achieved by activated carbon treatment (median: 96.4%). The proportion of phosphonate-P in the dissolved unreactive phosphorus fraction was consistently between 10% and 40% throughout all treatment stages.

Sistema de tratamiento de aguas superficiales para consumo humano en la microcuenca del Río Carrizal, Ecuador

Surface water treatment system for human consumption in the micro-basin of the Carrizal River, Ecuador Resumen Con el objetivo de implementar un sistema de tratamiento del agua del tipo filtración de múltiples etapas para el consumo humano en las comunidades Balsa en Medio, Julián y Severino, Ecuador, a nivel de laboratorio se desarrolló un sistema a escala, estructurado por filtrado en arenas+gravas, seguido de filtración con las zeolitas clinoptilolita y mordenita y finalmente se realizó el proceso de cloración. Se empleó el diseño experimental completamente aleatorizado con cuatro repeticiones para los tratamientos. Los resultados indican que en la etapa de filtración en arenas+gravas las variables DBO5; sólidos totales; coliformes fecales y turbiedad, alcanzaron niveles permitidos de acuerdo a las normas establecidas para el agua de consumo humano. El uso de zeolitas del tipo clinoptilolita y/o mordenita como procedimiento para complementar el proceso de filtración, redujo significativamente los tenores de cobre, plomo, hierro, aluminio, cobalto y cromo. El uso del tratamiento con cloro después del filtrado redujo en 87% la presencia de coliformes fecales reduciendo los valores dentro de los rangos permitidos. El sistema de tratamiento de aguas propuesto para las comunidades estudiadas es de fácil operación y mantenimiento, sus costos son aceptables y los insumos requeridos para su implantación están disponibles en el Ecuador. Palabras clave: calidad de agua; filtros de arenas y gravas; zeolita, cloración. Abstract With the objective of implementing a multi-stage filtration system for water treatment to human consumption in the communities of Balsa en Medio, Julián and Severino, Ecuador, at the laboratory level a scale system was developed, initially structured by filtering in sands + gravels, followed by filtration whit clinoptilolite and mordenite zeolites. Finally the water chlorination process was carried out. The essay was developed with a completely randomized experimental design with four repetitions. According to the results, it was evidenced that in the filtration stage in sands + gravels the variables: BOD5; total solids; fecal coliforms and turbidity, reached permitted levels according to the norms established for water for human consumption. The use of clinoptilolite and/or mordenite zeolites as a method to complement the filtration process significantly reduced the copper, lead, iron, aluminum, cobalt and chromium levels. The use of the chlorine treatment after filtering reduced the presence of fecal coliforms in water in 87% leading the values ​​within the permitted ranges. The proposed system for the treatment of the dammed water in the studied communities is easy to operate and maintain, its costs are acceptable and the inputs required for its implementation are available in Ecuador. Keywords: water quality; sand and gravel filters; zeolite; chlorination.

Rancang Bangun Sistem Pengolah Air Bersih Standar WHO dan Kemenkes Bagi Warga Dusun Sinan - Desa Gawerejo - Kecamatan Karangbinangun - Kabupaten Lamongan Jawa Timur

Sinan Village is located in Karangbinangun Subdistrict, Lamongan city, which is experiencing a shortage of clean water. The main source of water for the people in that village is originated from river water of Bengawan Solo branches which is mixed with pond water and is collected in a pond. The results of the pH, turbidity and TDS tests that have been carried out show that the Bengawan Solo water does not meet WHO's clean water standards and the standard from Ministry of Health. In this study, the design of the river and pond water filtration control system in the reservoir was carried out. The designed filtration system consists of the deposition stage and filtering stage. Deposition stage is carried out by using alum as a purifying medium and aims to simplify the screening phase. While the screening stage is carried out using stone, sand, charcoal and palm fiber which aims to increase the pH value and reduce the value of turbidity and TDS. The system is designed in a modular manner between each filtration stage to fascillitate the maintenance process of the system and flushing the remaining deposits produced by the filtration process. Testing result of this system is done by varying the variables of volume and height of sand used and it is known that the difference in sand volume used has a significant effect on the levels of TDS, Turbidity, and pH of the resulting clean water.

Leachate Treatment with a combined Fenton/filtration/adsorption processes

Fenton and adsorption are two of the most widely used physicochemical processes for leachates treatment. Each one separately has shown limited treatment capabilities, reaching COD removals up to 60-70%. The Fenton process oxidizes both organic and inorganic matter; nevertheless, low-density sludges are produced and hard to decant. To remove them, the filtration process could be an efficient alternative to eliminate these solids the remaining substances could be removed by means of the adsorption process. This study presents the results of a Fenton/filtration/adsorption treatment train, under the following conditions: a) Fenton: pH = 4, contact time= 60 minutes, [Fe2+]/[H2O2] = 0.6, [COD]/[H2O2] = 9; b) leachate filtered through 4 µm pore filter paper; c) adsorption was performed in a packed column with macroporous granular activated carbon. The COD removals reached 99.9%, where 90.8% was achieved with the Fenton/filtration process and 9.1% was removed by adsorption. The 95.7% of color was removed in the Fenton/filtration stage and 4.3% by adsorption. Although, the COD, BOD5, color and TSS removals from the adsorption process were lower than the Fenton/filtration process, the additional removal allows to the effluent reach the values required to meet the current Mexican Norms