Our planet earth is endowed with the perfect environmental balance for sustenance of living beings. however, more than three fourth of it is covered by marine water whereas the potable surface water reserves are limited. hence besides exploiting the natural reserves gifted to us, it is one of our prime responsibilities to protect the water sources from being polluted. as we are living in the age of modern science and technology where rapid proliferation of industries are endlessly taking place, the water requirement is proportionately enhanced, resulting in the release of polluted effluents thereby causing environmental nuisance. the present inventions are based on membrane technology for industrial progress, societal benefit and environmental safety. in our research, synthesis of novel cost effective membranes is one of the primary objectives. in this project report, a novel, indigenious, inexpensive spinning process for hollow fiber membrane casting has been reported. this inexpensive membrane can bring down the cost of suface water treatment for rural welfare and industrial application due to high surafce area/unit volume. the inventions based on membrane technology have been bifurcated in two aspects, rural welfare and industrial development. for rural welfare, installation of several plants for defluoridation of ground water in villages were taken up to cater to the drinking water needs of a population of 1 lakh in fluorosis affected districts. a model compact reverse osmosis (ro)/ nanofiltration (nf) system has also been designed, fabricated and installed at iict campus for the production of purified drinking water and cooking. the product water also helps to reduce the boiler corrosion. the water flux was found to be 45 l/m2h at 17 bar using compact ro membrane. this system can be installed at interior villages for removing harmful contaminants such as fluoride, arsenic, nitrate, iron from drinking water. novel hand pump and piston operated ultrafiltration (uf) systems has been design, fabricated and installed for flood affected regions. hand operated uf can also be installed in the villages, where electriciy is not available to provide drinking water from surface water. this system is capable of providing 220 l m-2 h-1, sufficient to meet the daily drinking water requirement of 500 people. piston operated portable uf module is also helpful for the individuals such as mountaineers, travellers for getting purified drinking water. for industrial development two different inventions have been reported. lab scale compact, indigenous submerged membrane bioreactor with low cost inoculums has been developed using polyacrylonitrile (pan) hollow fiber membrane module to treat dairy industrial effluents. the observed optimum permeability of the membrane was approximately 115 lmh bar-1 with high extent of impurity removal. the rejection of cod was found to be as high as 91% whereas corresponding rejection of bod was observed to be 86%. computational fluid dynamics (cfd) study has been performed to investigate the flow profile within the smbr process. based on the experimental and modeling result a pilot smbr set up has been installed for treating iict kitchen wastewater. this set up with novel low cost inoculums can also be installed for the treatment of municipal, tannery, textile, distillery industry effluents. in the next work, novel polyphenylene oxide (ppo) membranes were subjected to pervaporation-based dehydration of the highly hazardous and hypergolic monomethyl hydrazine (mmh) and unsymmetrical dimethyl hydrazine (udmh) liquid propellants. molecular dynamics (md) simulation and cfd were used for optimization of process parameters. high separation factors (3570) and reasonable water fluxes (0.1−0.2 kg/m2.h) were observed for separation of the aqueous azeotropes of mmh (35 wt %) and udmh (20 wt %) and their further enrichment to > 90 % purity.