Endosulfan insecticide removal planning with bioaugmentation-landfarming bioremediation method

Endosulfan is a toxic organochlorine insecticide and is persistent in the environment. Endosulfan residue can be accumulated underground and lower soil quality, pollute water sources, and create bioaugmentation. This research aims to gather required information and study the potential of bacteria consortium consists of Bordetella sp., Bordetella petrii, and Achromobactery xylosoxidans to remediate endosulfan polluted soil. Bioremediation on laboratory scale conducted in a soil reactor, the pH level of 7, 20% humidity, and adjusted temperature to field temperature. Endosulfan was added into a reactor with a concentration of 2mg/g. The bacteria consortium utilized endosulfan as a nutrient source to decently grow up until this research was finished on the 30th day. Maximum removal occurred on upper layer soil with 99% of alpha-endosulfan and beta-endosulfan removal rates. Pilot-scale removal can be implemented with landfarming bioremediation. Two (2) processing beds were prepared with 15m of length, 7.5m of width, and 0.5m of height. This method was able to remove 99% of endosulfan in just 457.75 hours. This research can be implemented to remediate endosulfan polluted soil through the bioremediation method by utilizing bacteria consortium.

EXPRESS: T1 difficulty does not modulate the magnitude of the attentional blink

When the visual system is busy processing one stimulus it has problems processing a subsequent stimulus if it arrives soon after the first. Laboratory studies of this second-stimulus impairment – known as ¬attentional blink (AB) – have employed two targets (T1, T2) presented in rapid sequence, and have found identification accuracy to be nearly perfect for T1 but impaired for T2. It is commonly believed that the magnitude of the AB is related directly to the difficulty of T1: the greater the T1 difficulty, the larger the AB. A survey of the experimental literature disconfirms that belief showing it to have arisen from artificial constraints imposed by the 100% limit of the response scale. Removal of that constraint, either by using reaction time (RT) instead of accuracy as the dependent measure, or in experiments in which the functions of T2 accuracy over lags do not converge to the limit of the response scale, reveals parallel functions for the easy-T1 and the hard-T1 conditions, consistent with the idea that T1 difficulty does not modulate AB magnitude. This finding is problematic for all but the Boost-and-Bounce and the Locus Coeruleus-Norepinephrine theories in which T1 acts merely as a trigger for an eventual refractory period that leads to the failure to process T2, rendering T1 difficulty and its relationship to the AB an irrelevant consideration.

Scale Removal In A Deepwater Oil Production Well Using Fresh Water

The aim of this paper is to present the results obtained by the use of fresh water in order to remove inorganic scale deposited inside production tubing from carbonate reservoir deepwater production wells with high salinity and low BS&W. The paper covers the entire process from the identification of production loss, the investigation of its main causes, treatment propositions and discussion of obtained results. One of the hypotheses regarding the scale deposition mechanism in the studied wells is that the precipitation of salts is due to the evaporation of produced water. This phenomenon occurs through the contact of water with dry gas applied in the artificial elevation method (gas lift). The proposed and tested scale removal procedure consists of a soaking of the production tubing with fresh water in order to dissolve the deposition or at least part of it that is soluble in water. Preventive care actions in relation to flow assurance were taken, since the suggested method uses a high volume of fresh water, increasing the hydrate risks. Scaling in wells with those characteristics was systematically removed through remote acidification (with specialized vessel assistance). That approach has shown to be always effective. On the other hand, remote acidification was always costly and dependent on the availability of critical resources. The technique depicted in this paper requires neither a vessel nor acid and, therefore, incurs significantly lower costs. The results obtained in the first tests were substantially positive since the wells’ productivity was fully restored. In this sense, the hypothesis of water solubility of the scale deposition was confirmed, and the method validated. Since its validation, the method has been applied a number of times, confirming its repeatability, and extending its use to other wells with similar scaling occurrences, reducing costs and restoring the production in a short time. Nevertheless, new challenges arise in relation to the full comprehension of the deposited material and the prevention of its deposition.

Laboratory-Scale Investigation of the Utilisation of Multiple Flat-Fan Nozzles in Descaling Petroleum Production Tubing

Despite the recent wide embrace of mechanical descaling approaches for cleaning scales in petroleum production tubings and similar conduits with the use of high-pressure (HP) water jets, the process is still associated with downhole backpressure and well integrity challenges. While the introduction of sterling beads to replace sand particles in the water recorded high successes in maintaining well completion integrity after scale removal in some recent applications of this technique, it is, unfortunately, still not without questions of environmental degradation. Furthermore, the single nozzle, solids-free, aerated jetting descaling technique – recently published widely – is categorized with low scale surface area of contact, low descaling efficiency and subsequent high descaling rig time. The modifications to mechanical descaling techniques proposed in this work involve the use of three high-pressure flat fan nozzles of varying nozzles arrangements, standoff distances and injection pressures to remove soft scale deposits in oil and gas production tubings and similar circular conduits. This experiment provides further insights into the removal of paraffin scales of various shapes at different descaling conditions of injection pressures, stand-off distances and nozzle arrangements with the use of freshwater. The results obtained from this study also show consistency with findings from earlier works on the same subject.

Influence of the hydraulic pump unit on the quality of the rolled surface

To ensure the competitiveness of rolled metal in the modern market, the decisive factor is the quality of the rolled surface (defects with a depth of no more than 0.2 mm are allowed without stripping). Rolling processing is a source of formation of small surface defects, most of which are obtained in the process of deformation of a continuously cast billet (hereinafter referred to as CCB, billet) at hot rolling mills in the presence of areas with non-removed furnace scale. This is the main reason for the formation of such types of surface defects as rolled scale, ripple, scale shells, which reduces the quality of the rolled surface and increases the sorting of metal with surface defects. In addition, the scale not removed from the surface of the CCB has a negative impact not only on the quality of metal products, but also on the operation of rolling equipment.One of the directions that allows to achieve high quality of the surface of long products in production conditions is the effective removal of scale from the surface of the initial billet before hot deformation. Scale removal from the surface of the workpiece is carried out on the installation of a hydraulic descaling unit, but not always a satisfactory (complete) scale removal occurs.To determine the cause of poor – quality scale removal before hot deformation, the efficiency of the hydraulic descaling unit and the state of the metal – scale interface surface were investigated.

Enzyme-catalyzed biodegradation of penicillin fermentation residues by β-lactamase OtLac from Ochrobactrum tritici

Background Biodegradation of antibiotics is a promising method for the large-scale removal of antibiotic residues in the environment. However, the enzyme that is involved in the biodegradation process is the key information to be revealed. Results In this study, the beta-lactamase from Ochrobactrumtritici that mediates the biodegradation of penicillin V was identified and characterized. When searching the proteins of Ochrobactrumtritici, the β-lactamase (OtLac) was identified. OtLac consists of 347 amino acids, and predicted isoelectric point is 7.0. It is a class C β-lactamase according to BLAST analysis. The coding gene of OtLac was amplified from the genomic DNA of Ochrobactrumtritici. The OtLac was overexpressed in E. coli BL21 (DE3) and purified with Ni2+ column affinity chromatography. The biodegradation ability of penicillin V by OtLac was identified in an in vitro study and analyzed by HPLC. The optimal temperature for OtLac is 32 ℃ and the optimal pH is 7.0. Steady-state kinetics showed that OtLac was highly active against penicillin V with a Km value of 17.86 μM and a kcat value of 25.28 s−1 respectively. Conclusions OtLac demonstrated biodegradation activity towards penicillin V potassium, indicating that OtLac is expected to degrade penicillin V in the future.