Direct Contact Membrane Distillation for Desalination of High Salinity Brines: Fundamentals and Application

Membrane distillation is a cost effective solution for the treatment of high salinity wastewater where reverse osmosis is not feasible, especially if waste heat is utilized for its operation. One such example of high salinity wastewater is produced water generated as a consequence of hydraulic fracturing used for natural gas extraction from unconventional onshore resources. The objective of this study was to evaluate the feasibility of treating such high salinity wastewaters by employing membrane distillation while using waste heat as a source of energy to drive the process and by using produced water as an example wastewater. When commercially available membranes were tested in a direct contact membrane distillation (DCMD) system, the membranes exhibited excellent rejections of ions with no flux degradation due to fouling. However, it was found that concentration polarization (CP) was significantly higher when treating high salinity feed water and the CP effect could not be accurately estimated using current methods of calculation. Based on lab scale studies, an ASPEN Plus simulation was developed to simulate the operation of large scale systems and estimate energy requirements of the DCMD process to treat produced water in the state of Pennsylvania by using exhaust stream of Natural Gas Compressor Station (NG CS) as the waste heat source. The results from this study suggested that the waste heat available from NG CS is sufficient to treat all the produced water generated in Pennsylvania regardless of its initial salinity. In an attempt to study the effect of concentration polarization that was found to be significant during DCMD tests with produced water, and has been neglected in most membrane distillation studies, a novel spatially resolved non-intrusive spectrophotometric method was developed to measure the concentration profile of solute near the membrane surface in a direct contact membrane distillation system. The objective was to probe the concentration profile of solute and analyze the impact of operating parameters, such as feed concentration, hydrodynamic conditions and feed temperature, on the solute concentration profile in the boundary layer. A key finding of this study is that the conventional approach of estimating the effect of concentration polarization severely under predicts the boundary layer thickness (BLT) and concentration polarization coefficient (CPC). The results of this study highlight the need to develop new methods to estimate the BLT and CPC as the conventional approach of mass transfer analogy of heat transfer does not agree with experimental observations obtained for a membrane distillation system

Qualitative analysis of pollen grains through honey samples collected from the different villages of Rahuri tehsil

Honey is one the oldest food of mankind and there have been references to it. Today honey is regarded as an important food and nutrient throughout the world.  Honey bees utilize certain natural raw materials that are identifiable in honey.  These raw materials are pollen and nectar from flowers of various plants major source of protein for bees.  Identification of pollen found in honey shows to give clear idea honey bees visit to particular plant to the nectar regarding and content into honey.  This study carried out to determine different types of pollen observed in honey sample by pollen analysis method with the help of Compound Microscope.  The samples were collected from different villages of Rahuri tehsil during months of October to January. Keywords- Pollen grains, honey, pollen analysis, Rahuri tehsi

Iridium complexes bearing a PNP ligand, favoring facile C(sp^3)–H bond cleavage

Hydrogen iodide is lost upon reaction of PNP with IrI_3, where PNP = 2,6-bis-(di-t-butylphosphinomethyl)pyridine to give crystallographically characterized Ir(PNP)*(I)_2, which reacts with H_2 to give Ir(PNP)(H)(I)_2. Ir(PNP)(Cl)_3 is relatively inert towards the intramolecular C–H activation of the tert-butyl's of the PNP ligand

Effective Microorganisms: Myth or reality?

Th e increase in population has lead to intensifi cation of agricultural systems. Due to the use of pesticides the productivity of agricultural systems has increased but environmental deterioration and unsustainable systems are the consequences of these ways of management. Th e environmentally friendly Eff ective Microorganisms (EM) technology claims an enormous amount of benefi ts (claimed by the companies). Th e use of EM as an addictive to manure or as a spray directly in the fi elds may increase the microfauna diversity of the soil and many benefi ts are derived from that increase. It seems that suffi cient information is available about this new technology. Th e aim of this project is to make an analysis of the literature about EM and answer the following questions: 1) how much is known about EM?, 2) how much research is done on EM?, 3) what are the principals of EM?, what are the socio-economic implications of EM?. We want to answer these questions in order to publish the facts about EM and its socio-economic implications.Th e increase in population has lead to intensifi cation of agricultural systems. Due to the use of pesticides the productivity of agricultural systems has increased but environmental deterioration and unsustainable systems are the consequences of these ways of management. Th e environmentally friendly Eff ective Microorganisms (EM) technology claims an enormous amount of benefi ts (claimed by the companies). Th e use of EM as an addictive to manure or as a spray directly in the fi elds may increase the microfauna diversity of the soil and many benefi ts are derived from that increase. It seems that suffi cient information is available about this new technology. Th e aim of this project is to make an analysis of the literature about EM and answer the following questions: 1) how much is known about EM?, 2) how much research is done on EM?, 3) what are the principals of EM?, what are the socio-economic implications of EM?. We want to answer these questions in order to publish the facts about EM and its socio-economic implications

Pharmacognostic Study of Leaves of Kigelia pinnata (Lam) Benth

The  Kigelia pinnata (Lam) Benth is a species of the Bignoniaceae family commonly known as Kigelia africana is locally known as waghul phul.  The adult sausage tree has spectabular fruits these can weigh several kilogram hence the tree English common name worsboom.  Wherever the trees grows it is usually evergreen especially places where rainfall occurs throughout the year but deciduous in places of long dry season. Kigelia pinnata is renowned for its traditional application as anti-inflammatory, anti-diabetic, anti-oxidant, anti –microbial, and anti-cancer effects.  It contains chemical constituent like kigenol, kigelinone7, kigenol12, iso-kigenolls. In the present work pharmacognostic studies are carried out to investigate its medicinal properties.  The study consists of macroscopic character of the plant Kigelia pinnata physico-chemical parameters like total ash, acid insoluble ash, thin layer chromatography etc.  Keywords-  Kigelia pinnata,  pharmacognostic studies,  total ash, acid insoluble ash, thin layer chromatograph

Android Application for Password less Login to Web Application

Passwordless Login for Web Application? is an android application, will be used to access online internet accounts of distinct web applications and web services. The user would register with pre-requisite credentials primarily like, an email id, primary mobile number, and a unique username and a secondary mobile number. After successful registration, the user would be required to enter its registered username only. After submitting the registered username, a unique QR code will be popped up on the website. The user would scan the QR code using his/her android mobile phone. After successful scanning of QR code, the authentication and authorization procedure will be performed thereby granting secure access

Rhodium complexes bearing tetradentate diamine-bis(phenolate) ligands

Using tetradentate, dianionic ligands, several new rhodium complexes have been prepared. Some of these diamine-bis(phenolate) compounds, are active for C–H activation of benzene. These complexes are air and thermally stable. All four complexes were characterized by X-ray diffraction

Cause of death and associated conditions of stillbirths

Background: Fetal death is a psychological trauma for the expecting mother and their family. Most of the countries worldwide lack data on stillbirths. Simply counting stillbirths is the first step in analysis and prevention and hence stillbirths need to count. Purpose of the study is to know the incidence, cause of stillbirths and to plan cause specific interventions to reduce stillbirths.Methods: This is a prospective cross-sectional study of patients with stillbirths from September 2014 to August 2015 in Karnataka Institute of Medical Sciences, Karnataka.  All the cases who delivered stillbirths  of  weight more than 1kg, were  grouped into  the following CODAC (causes of death and associated conditions)  simplified classification and were analysed.Results: The total number of births during the study period was 9,863.  Total number of stillbirths in our study period was 563. In the study period, the stillbirth rate was 57.9 per 1000 births, out of which 56.3% were in preterm pregnancy and 43.69% in term pregnancies. The three common causes of stillbirths were hypertensive disorders (34.63%), intrapartum fetal loss (27.17%) and abruptio placenta (11.54%).  In 7.9% of cases the cause of stillbirth was unknown. Nutritional anaemia, teenage pregnancy and intrauterine growth restriction were the most common associated conditions of stillbirths.Conclusions: Anaemia and teenage pregnancy are the two important risk factors associated with stillbirths. Adolescent health education, folic acid and iron supplementation in schools has to be planned as a primary prevention of stillbirth. Early detection and treatment of hypertensive disorders and good intrapartum care, will help us in reducing the stillbirth rate to a large extent, as these are the two important causes of stillbirth

Fouling in direct contact membrane distillation during treatment of produced water from unconventional (shale) gas production

Hydraulic fracturing used for natural gas extraction from unconventional onshore resources (i.e., shale plays) generates large quantities of produced water. This water needs to be managed efficiently and economically to ensure further development of this industry. The most common solution for produced water management is disposal by deep well injection. This approach is being scrutinized by public and regulatory agencies due to increasing number of seismic events associated with this practice. The industry is now striving to reuse the produced water for hydraulic fracturing, which is feasible only as long as there are sufficient number of new gas wells being developed. The total dissolved solids (TDS) content of produced water can be in excess of 300,000 mg/l with sodium and chloride being the primary ions, followed by calcium, barium, strontium and magnesium. This water also contains some organics and heavy metals at low concentrations. Most membrane-based technologies employed today for seawater desalination are not feasible in this industry due to extremely high TDS of produced water. Membrane distillation (MD) can achieve complete rejection of ions and non-volatile organics as long as the membrane pores are not wetted. MD may be a cost effective method to treat produced water due to its reasonably high permeate flux and ability to operate using low-quality heat (i.e., it operates at temperatures well below the boiling point of water). This study focuses on the potential for membrane wetting and/or fouling by inorganic salts present in produced water in the case of direct contact membrane distillation (DCMD) treatment of actual produced water from unconventional gas wells in Pennsylvania. The produced water was concentrated to near halite saturation limit to evaluate potential scaling and its impact on DCMD performance. Initial experiments showed that no membrane wetting occurred as evidenced by extremely low conductivity of the permeate stream. Iron-based scale accumulated on the membrane surface along with embedded islands of barium chloride and sodium chloride. The inorganic scale that formed on PTFE membranes during several hours of operation had negligible effect on MD performance in terms of permeate flux and thermal efficiency. Inspection of these inorganic scales suggests that they are typically very thin (i.e., several microns) and highly porous, which may explain the lack of observable impact on the transport of water vapor in DCMD module. Initial results suggest that DCMD has great potential for desalination of highly concentrated wastewaters generated by the unconventional gas industry. However, inorganic scale that may form on the feed side could potentially impact the performance of this technology. Further insights into the composition and morphology of inorganic scales that may form under realistic operating conditions will be presented at the conference together with pretreatment options and scale mitigation approaches to minimize the effect of scaling on DCMD performance when treating produced water from the most productive shale plays in the U.S