Regulating the aqueous phase monomer balance for flux improvement in polyamide thin film composite membranes

Polyamide thin film composite (PA TFC) membranes are synthesized from interfacial polymerization using two amines in the aqueous phase. The conventional monomer, mphenelynediamine (MPD), is partially replaced by a linear monomer, 1,3–diamino-2- hydroxypropane (DAHP). The water permeability of the membranes improves by around 22 % (to 2.67 ± 0.09 L.m-2.h-1.bar-1) while keeping the same high salt rejection (96-98%) at an optimum DAHP/MPD ratio of 12.8 %. While developing the control PA TFC membrane we introduce a washing step and show that the support surface should be free from surface protective coatings to achieve high water flux (2.18 ± 0.08 L.m-2.h-1.bar-1). Incorporating DAHP units into the polyamide network improves the water flux through the membranes fabricated on both original and washed supports. The surface morphologies of polyamide films change significantly with introduction of DAHP, from large ridge-and-valley structure to enlarged nodular structures. High resolution SEM images show an ultrathin polyamide thin film with a thickness that is reduced with addition of DAHP. These influences of DAHP, namely a reduction in the selective layer thickness, an alteration in surface morphology, changes in internal molecular packing and hydrophilicity, are suggested as factors behind the improved water permeability.We would like to thank EPSRC grant, Schlumberger Faculty for the Future (FFTF) foundation and the Qatar National Research Fund for the research financial support.This is the accepted manuscript. The final version is available at http://www.sciencedirect.com/science/article/pii/S0376738815002161

Landscape-Scale Mining and Water Management in a Hyper-Arid Catchment: The Cuajone Mine, Moquegua, Southern Peru

The expansion of copper mining on the hyper-arid pacific slope of Southern Peru has precipitated growing concern for scarce water resources in the region. Located in the headwaters of the Torata river, in the department of Moquegua, the Cuajone mine, owned by Southern Copper, provides a unique opportunity in a little-studied region to examine the relative impact of the landscape-scale mining on water resources in the region. Principal component and cluster analyses of the water chemistry data from 16 sites, collected over three seasons during 2017 and 2018, show distinct statistical groupings indicating that, above the settlement of Torata, water geochemistry is a function of chemical weathering processes acting upon underlying geological units, and confirming that the Cuajone mine does not significantly affect water quality in the Torata river. Impact mitigation strategies that firstly divert channel flow around the mine and secondly divert mine waste to the Toquepala river and tailings dam at Quebrada Honda remove the direct effects on the water quality in the Torata river for the foreseeable future. In the study area, our results further suggest that water quality has been more significantly impacted by urban effluents and agricultural runoff than the Cuajone mine. The increase in total dissolved solids in the waters of the lower catchment reflects the cumulative addition of dissolved ions through chemical weathering of the underlying geological units, supplemented by rapid recharge of surface waters contaminated by residues associated with agricultural and urban runoff through the porous alluvial aquifer. Concentrations in some of the major ions exceeded internationally recommended maxima for agricultural use, especially in the coastal region. Occasionally, arsenic and manganese contamination also reached unsafe levels for domestic consumption. In the lower catchment, below the Cuajone mine, data and multivariate analyses point to urban effluents and agricultural runoff rather than weathering of exposed rock units, natural or otherwise, as the main cause of contamination

Food nano-biotechnology roadmap for Sri Lanka

Nanotechnology is a major ernergmg technology, which can revolutionize food industry by employing special nanoscale properties of matter. It can he applied to food processing and packaging in order to improve quality, safety, varieties and health effects of food products. Sri Lanka. as a country based on an agricultural economy, has the potential to use this new technology for its socio-econornical development. The changing lifestyles and consumption patterns and the increasing global nano food market highlights the opportunities. while the government's support on nanotechnology R&D. positive industrial growth rates and established research facilities for food industrial research being the major strengths for applying this technology to the SLPPI. The Food Nano-biotcchnolcgy roadmap proposes mechanisms to eliminate weaknesses such as lack of technological awareness and innovativeness. The Food Nano-hioteehnology Roadmap is developed to lead the industry. academia and the government towards a nano-based food industry. Thus. National frameworks used in other countries arc reviewed and their strengths arc absorbed to develop the food nano-biotechnology roadmap for Sri Lanka. The proposed \ mechanism under the National Nano Center (NNC) is to be supported by the cxi ting university system. government departments and the industry. The IO-ycar time frame reveals the ability to move towards health, beauty and safety based food processing industry using nanoscale additives and ingredients, nanoencapsulation, nanocmulsions and nanopackaging. The Food Nano-biotechnology roadmap introduces the use of Blue Ocean strategy to enter the global nano food market for success of the business

Minimizing loss of Ethanol with non-condensable gases in distilleries

In a distillery where concentrated ethanol is manufactured, a large amount of ethanol vapour is lost during distillation. It was hypothesized that reduction of reflux at the fi nal disti llation column where non-condensable gases are vented reduces loss of ethanol vapour. This hypothesis was tested and verified using computer aided process simulation with application to a working distillery in Sri Lanka. It reduced the loss of ethanol vapour at a rate of 6.8 kg/h. The associated net financial saving was Rs. 400 000 per month

Manufacture and Usage of Fuel Ethanol in Sri Lanka- A Feasibility Study

A 10 volume % blend of ethanol in petrol is the optimum product to introduce ethanol onto Sri Lankan fuel market. Ethanol in such a blend can also serve as an octane-enhancing additive. As a result, the value of ethanol is always higher than that of petrol. Even with no subsidies from the government, it is profitable for Sri Lankan distilleries to manufacture dehydrated fuel ethanol in the place of potable quality spirit, which they currently manufacture

Improvement of efficiency of bio-ethanol manufacturing process

Many distilleries where potable-quality ethanol spirit is manufactured contain a hydro-extractive distillation column. Addition of water as the extractive agent here results in a large dilution of ethanol, and subsequently, a higher energy consumption at the rectification column. By means of computer-aided simulation, it was found that the hydro-extractive distillation step could be effectively replaced with a high-reflux distillation step. It was also found that application of this result to a working distillery in Sri Lanka would result in an energy saving of 251 kW

Development an efficient process for the manufacture of anhydrous fuel ethanol

Ethanol is a renewable alternative for petrol which can be manufactured with raw materials in Sri Lanka. A 10 % v/v blend of ethanol in petrol is the optimum product to introduce ethanol onto Sri Lankan fuel market. Ethanol in such a blend can also serve as an octane-enhancing additive. As a result, the value of ethanol is always higher than that of petrol. At the initial stage, it would be suitable to replace the 95-octane petrol with the 10 % v/v blend. Even with no subsidies from the government, it is profitable for Sri Lankan distilleries to manufacture dehydrated fuel ethanol in the place of potable quality spirit, which they currently manufacture

Developing a food nano-bio technology roadmap for Sri Lanka

Nanotechnology, the next revolution in the 21" century has many applications in several fields. Sri Lanka as a country based on the agricultural economy can benefit from this technology by enhancing the quality, safety and variety of food products. The food nano-bio technology roadmap opens a pathway to identify the available techniques, their applicability to the food industry and the required facilities. Commercially available applications are discussed with their applicability to the Sri Lankan food industry

Manufacture of fuel ethanol from vegetable and fruit market waste

In Sri Lanka, due to inappropriate packing, handling, transport, storage and poor, marketing strategies adopted by farmers, distributors and sellers, more than 40% of vegetables and fruits get spoilt and are thrown out as Vegetable and Fruit Market Waste (VFMW), Local authorities dispose the VFMW on valuable commercial land, which are converted into open dumps, causing soil, water and air pollution, as well as, bad smell, spread of disease, breeding of insects and pests

Landscape-Scale Mining and Water Management in a Hyper-Arid Catchment: The Cuajone Mine, Moquegua, Southern Peru

The expansion of copper mining on the hyper-arid pacific slope of Southern Peru has precipitated growing concern for scarce water resources in the region. Located in the headwaters of the Torata river, in the department of Moquegua, the Cuajone mine, owned by Southern Copper, provides a unique opportunity in a little-studied region to examine the relative impact of the landscape-scale mining on water resources in the region. Principal component and cluster analyses of the water chemistry data from 16 sites, collected over three seasons during 2017 and 2018, show distinct statistical groupings indicating that, above the settlement of Torata, water geochemistry is a function of chemical weathering processes acting upon underlying geological units, and confirming that the Cuajone mine does not significantly affect water quality in the Torata river. Impact mitigation strategies that firstly divert channel flow around the mine and secondly divert mine waste to the Toquepala river and tailings dam at Quebrada Honda remove the direct effects on the water quality in the Torata river for the foreseeable future. In the study area, our results further suggest that water quality has been more significantly impacted by urban effluents and agricultural runoff than the Cuajone mine. The increase in total dissolved solids in the waters of the lower catchment reflects the cumulative addition of dissolved ions through chemical weathering of the underlying geological units, supplemented by rapid recharge of surface waters contaminated by residues associated with agricultural and urban runoff through the porous alluvial aquifer. Concentrations in some of the major ions exceeded internationally recommended maxima for agricultural use, especially in the coastal region. Occasionally, arsenic and manganese contamination also reached unsafe levels for domestic consumption. In the lower catchment, below the Cuajone mine, data and multivariate analyses point to urban effluents and agricultural runoff rather than weathering of exposed rock units, natural or otherwise, as the main cause of contamination.This research is supported through a collaborative agreement between the National University of Moquegua (UNAM) and the University of Cambridge (grant RG85120)