The first project meeting was organized in University of Porto, Porto, Portugal in 8th of October 2015. Overall project objectives, progress of the project were discussed. The presentation from leading institution UPORTO is available HERE.
The project meeting called INNO Days was organized in Rome, Italy in 15-16th October 2015. Presentation from the meeting is available HERE.
Partnership agreement details, organizational questions and experimental setups were discussed.
RTU team performed an experiment in order to evaluate if phosphorus (and not carbon) is a limiting element of microbial growth. Experiments were performed in Baltezers groundwater treatment plant. A concentration of microbially assimilated phosphorus in water was decreased using three different techniques: biomass, adsorption on a sorbent and electrocoagulation in a model reactors (see image).
The second meeting of project partners was organized in RTU, Riga. CSMCRI presented water quality results from three study sites. Series of experiments were done in order to evaluate an effect of chlorination on bacteria in tested waters. It was found that some bacteria are chlorine resistant and these bacteria are responsible for membrane fouling.
CSIR-IICT also presented water quality results from study sites. The main problems are: fluoride, iron, nitrate, heavy metals.
RTU showed results from water pre-treatment experiments in order to limit phosphorus in water. Some additional tests should be done, but Indian partners showed interest in biofiltration technology.
TUBS reported on experiments with chemical pre-treatment methods. Tested coagulants were Al2(SO4)3, FeCl3, FeSO4. Use of FeSO4 resulted in poor sedimentation characteristics.
UPORTO showed results from experiments with biocides coatings immobilized on particles (as pre-treatment technology). Tested cores were: Zeolite powder, Zeolite B granular particles, Zeolite BF granular particles, Activated Charcoal, Cork, Sodium Alginate.
For investigating membrane fouling and coagulation effectiveness TU BS team developed a model raw water containing sodium chloride, humic acid sodium salt and Arizona dust. Coagulation experiments with aluminum sulfate, iron chloride and iron sulfate were carried out. Measurements of pH, electrical conductivity, spectral attenuation coefficient at 436nm and TOC content of raw water and pre-treated water (after coagulation and sedimentation) are used to evaluate the effectiveness of the pre-treatment. Aluminum sulfate and iron chloride showed very good results, but iron sulfate forms smaller flakes, therefor sedimentation is much slower.
In CSIR-CSMCRI (India) effect of chlorination on bacterial growth, on their physiological changes and on their potential to get attached to the membrane surface was studied. Nine chlorine resistant bacterial strains were isolated in local water body. These were identified primarily by biolog test and finally by 16s RNA sequencing. The bacterial strains were found to be live even after 30 minutes chlorine treatment following methods suggested by commercial membrane manufacturer [see image].
A team from the city based CSIR-Indian Institute of Chemical Technology led by Dr. S. Sridhar, Principal Scientist from Chemical Engineering Division designed and installed a Nanofiltration Pilot Plant of 30,000 L/day based on an indigenously developed hydrophilised polyamide membrane which provides high water recovery at low applied pressure (Fig. 1a). This work is funded by DBT, India and comes under POMACEA project scheme which is an Inno-Indigo based Indo-European collaboration. This societal welfare venture by CSIR-IICT aims to provide free drinking water to inpatients of the 1400 bed government hospital, 3000 outpatients per day, their attendants, doctors, nurses and staff. The plant was inaugurated on 21st December 2017 by Shri Laxma Reddy, the honorable health minister of Telangana State (Fig. 1b). The water consumption was 2000 L/day during the first week of plant installation, whereas, the quantity of consumption got increased to 5000 L/day from second week onwards, which ensures intake by 10,000 poor people each day.
Fig. 1. (a) Photograph of Nanofiltration pilot plant of 1000 L/h capacity (b) Demonstration to Shri Laxma Reddy, Honorable Health Minister, Telangana State (c) Photograph of CSIR-IICT Team Members at Gandhi Hospital, Hyderabad
The plant enables production of safe drinking water by lowering total dissolved solids from 300 ppm to 50 ppm with complete reduction in turbidity, bacteria and virus at an applied pressure of 7 atm and product water flow of 1500 Lit/hr. If necessary this plant which operates on a 3-phase power supply can be run @ 20 h per day to generate 30 kL/day. To increase membrane life, European partners from Portugal, Latvia and Germany will introduce pretreatment protocols based on new and safe antiscalant, antifoulant or novel chemicals for membrane cleaning to restore flux and rejection properties.
Details of publications:
(a) In Journal: B. Govardhan, S.S. Chandrasekhar, S. Sridhar. 2017. Purification of surface water using novel hollow fiber membranes prepared from polyetherimide/polyethersulfone blends. Journal of Environmental Chemical Engineering 5 (1), 1068-1078.
(b) Book Chapter
B. Govardhan, Y.V.L. Ravikumar, Sankaracharya Sutar, S. Sridhar. 2018. Design of highly compact and cost effective water purification systems for promoting rural and urban welfare. In Membrane Technology: An Approach towards Sustainable Solutions in Water, Health, Energy and the Environment, ed. S. Sridhar, Boca Raton: CRC press, Taylor & Francis., 2018 (Accepted for publication).