Sorbent

The effect of the nature and concentration of coagulants on the effectiveness of reducing the colour intensity with varying the concentration of sorbent from 1 to 3 g/l and coagulants Al2(SO4)3 and FeCl3, respectively 0.5; 0.75 mg/l. It has been shown that from the mentioned reagents the optimal option is the use of aluminium sulfate and iron chloride as a coagulant, as a flocculant - anionic polyacrylamide in concentrations of 0.5 mg/l, 0.75 mg/l and 0.5 mg/l respectively. It is determined that application of coagulants and flocculant for treatment of wastewater of silkworm production makes it possible to achieve required parameters of quality of treatment, at that efficiency of treatment on suspended substances makes 94.0-97.0%, on COD 87.0-91.0%, on dyes 91.0-94.0%.

Present study was conducted to investigate the removal of manganese from aqueous solution by using eco-friendly biosorbent of Banana peels activated carbon (BPAC). Batch experiments have been carried out to determine the influence of parameters such as pH, biosorbent dose, initial metal ion concentrations and contact times on the biosorption process. From these investigations, a significant increase in percentage removal of manganese 97.4 % is observed at pH value 5.0, biosorbent dose 0.8 g, initial concentration 20 ppm, temperature 25 ± 2 °C, stirring rate 200 rpm and contact time 2h. The equilibrium concentration and the adsorption capacity at equilibrium of the experimental results were fitted to the Langmuir, Freundlich and DubininRadushkevich (D–R) isotherm models; the Langmuir isotherm was found to well represent the measured adsorption data implying BPAC had heterogeneous surface. The predicated maximum monolayer adsorption capacity of manganese for BPAC are found to be 11.806 mg/g. Pseudo- firstorder, pseudo-second-order kinetic and intraparticle diffusion model were used to analyze the biosorption data; it was observed that the pseudo-secondorder model best represented the relationship. The calculated thermodynamic parameters showed that the biosorption of manganese onto BPAC is spontaneous and endothermic in nature. A raw groundwater samples were collected from Baharmos groundwater treatment plant network at Embaba and Manshiet Elkanater City/District-Giza, Egypt, for treatment at the best conditions that reached at first phase by BPAC. The treatment with BPAC could reduce iron and manganese value of raw groundwater by 91.4% and 97.1 %, respectively and the effect of the treatment process on the microbiological properties of groundwater sample showed decrease of total bacterial count either at 22°C or at 37°C to 85.7 % and 82.4 %, respectively. Also, BPAC was characterized using SEM and FTIR spectroscopy.

The headspace of common dairy products, including cheese and milk, was analyzed utilizing a new sample preparation technique called Vacuum Assisted Sorbent Extraction (VASE). VASE improves the recovery of heavier and more polar volatile compounds in nearly any matrix by GCMS. After introducing a sample into a 20-40mL vial, a cartridge containing 70mg of Tenax is placed into the headspace of the vial using a vacuum tight interface that allows the vial headspace to be evacuated to less than 0.01atm, or at least until the pressure needed to boil an aqueous mixture at 25°C is reached. This results in faster diffusion from the sample/ headspace boundary layer to the adsorbent, enhancing the rate of sample extraction. In particular, heavy volatile compounds with low vapor pressures that have little to no response by classical SPME are extracted 10-50x more efficiently. Unlike Dynamic Headspace, which uses an inert gas to sweep the volatiles of a sample through the adsorbent bed to concentrate and trap analytes, VASE is performed statically. VASE allows the sample and headspace to come to an equilibrium in a closed system, causing analytes to diffuse onto and collect at the very front of the adsorbent bed. Consequently, VASE achieves a much better recovery of heavier compounds while reducing the common carryover issues affecting other adsorbent techniques that use flow to push compounds far up into a trap. Once placed under vacuum, the analyst determines the length of extraction time, ranging from minutes to hours, until equilibrium between the sample and headspace is reached to produce complete, reproducible extractions. Dairy products generally have low levels of headspace volatiles. In this study, VASE proceeded for 4-24 hours, with many Sorbent Pens extracting samples simultaneously to simulate conditions of a production laboratory. The increase in sample extraction duration combined with a large phase to sample ratio allows more accurate determination of headspace composition, with reduced matrix affects. Data is presented showing milk and cheese analysis, with recovery of compounds well into the semi-volatiles range.

The standard groundwater treatment technology is a simple, non-chemical reagent technology based on aeration and filtration processes. This treatment technology is resulted in the formation of groundwater treatment sludge (GWTS). Because one of the elements of sustainable development is the possibility of their reuse, that water treatment plant operators are looking for new ways of managing these sludges. At present, not all factors determining the adsorptive capacity of water treatment sludge are known. The explanation why the adsorption capacity of sludge with a similar structure and chemical composition may differ significantly will allow for their wider use as adsorbents. The information which must be known to ensure proper sludge management are the quality, chemical composition and texture characteristics of the GWTS. The sludges were characterized by X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy and N 2 adsorption/desorption isotherms. The results showed that the composition and properties of the GWTS depend primarily on the quality parameters of the raw water and the processes and reagents used in its treatment technology. GWTS contains mainly amorphous iron oxides. Sludges are characterized by a large specific surface area (145 m 2 /g). Due to composition and textural parameters, GWTS demonstrates good adsorption properties toward different compounds such as heavy metals and metalloids. In this article, the authors describe the relationship between properties of resulting sludge and the properties of groundwater, the treatment technology and backwash water treatment from rapid filters.

A solution to the problems associated with low efficiency of purification of arsenic-contaminated water and/or high installation costs may be the use of adsorption process and application of bog iron ores (RD) as an adsorbent. The aim of this study is to determine the sorption efficiency of RD with regards to arsenic and zinc, to verify the obtained results in flow systems and to investigate the chemical stability of the adsorbent. Based on the obtained results, it was found that granular bog iron ores (gRD) are able to efficiently purification of arsenic contaminated waters, and the adsorption column module enables reduction of arsenic content in waters of less than 100 μg/L. This paper demonstrates that gRD have high application potential and can be successfully used in technologies dedicated to the removal of heavy metals and arsenic from contaminated waters.

The main objective of the study was to evaluate the applicability of two solid sorbent media (Anasorb 708 and Strata X), the impinger filled with distilled water and PTFE filters for determination of airborne cyclophosphamide (CP) in the hospital working environment. For this purpose, air contamination of Masaryk Memorial Cancer Institute (Czech Republic) was monitored using the sampling apparatus containing the samplers described above. In addition, the surface contamination was also determined using the wipe sampling technique. During the monitoring, contamination of three different workplaces (storage room, preparation room and outpatient clinic) was studied. Using Strata X solid sorbent tubes, airborne CP was determined in all (n = 5) samples collected at the outpatient clinic over a 5 day monitoring period (concentration range: 0.3-4.3 ng m(-3)). Other samplers (including PTFE filters) did not collect any detectable amount of CP (the limit of detection, LOD ≤ 0.1 ng m(-3)). Negative results detected at filter samples indicate that CP determined at Strata X samples was most probably of gaseous origin. Surface contamination ranged from <2 to 19, <8 to 418 and 133-15,500 pg cm(-2) at the storage room, preparation room and outpatient clinic, respectively. The study showed that evaporation of antineoplastic drugs should not be neglected, albeit the concentrations determined in our study are relatively low. Therefore, proper monitoring of airborne contamination should involve simultaneous sampling of both particle-bonded and gaseous phases. In this way, Strata X sorbent tubes seem to be an effective tool for the sampling of gaseous CP in the indoor air.

Abstract: This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80±10 nm and specific ...

The aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) into two groups. This is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. In this process mixture of PAHs and PCBs divide in two groups and simultaneously other interferences like lipids and aliphatic compounds are removed. So the sample is prepared to be analyzed and quantified by HPLC. The main purpose of the research was to find a combination of sorbents for the column chromatography method that would permit the determination of many types of pollutants (PAHs, PCBs and aliphatic compounds) in a single run. Elution profiles for both the analytes and the interfering components were determined for several types of column chromatography sorbents (alumina, silica) and combination of them . The silica: alumina (5:5 g) column is suitable for the separati...

... Recently the US Environmental Protection Agency announced a three-year phase-out of diazinon for indoor use, because it is one of the leading causes of acute insecticide poisoning of humans and wildlife [7]. Since diazinon can also affect the nervous system of humans ...

Arsenic in water bodies has increased to toxic levels and become a major issue worldwide. Among various treatment methods, the removal of As from polluted water with low-cost and environmental-friendly sorbents such as biochar is considered a promising technique nowadays. In a recent experiment, the treatment of As-contaminated water using egg shell biochar was studied. Various parameters affecting the sorption, such as pH, contact time, sorbent dose, As(V) concentration and the effects of anions, were also examined. The results revealed that at a pH of 4.5, a maximum sorption of 6.3 mg g−1 was observed, and the As(V) removal was 96% with an As concentration of 0.6 mg L−1 and a sorbent dose of 0.9 g L−1. At a contact time of 2 h (120 min), a maximum sorption of 6.3 mg g−1 was noted with a removal percentage of 96%. The sorption of As(V) was obtained at an optimal sorbent dose of 0.9 g L−1. The SEM-EDS data illustrated that biochar consisted of a large number of active sites for As(V...

Anticancer drugs pose a potential risk to the environment due to their significant consumption and biological effect even at low concentrations. They can leach into soils and sediments, wastewater, and eventually into drinking water supplies. Many conventional technologies with more effective advanced oxidation processes such as photocatalysis are being extensively studied to find an economical and environmentally friendly solution for the removal of impurities from wastewater as the main source of these pharmaceuticals. Since it is impossible to treat water by photocatalysis if there is no sorption of a contaminant on the photocatalyst, this work investigated the amount of imatinib and crizotinib sorbed from an aqueous medium to different forms of photocatalyst. In addition, based on the sorption affinity studied, the applicability of sorption as a simpler and less costly process was tested in general as a potential route to remove imatinib and crizotinib from water. Their sorption...