The partial solution for the growing contamination of the environment is the implementation of new technologies. The most of the currently operated systems for surface and groundwaters treatment as well as for wastewater treatment characterize with complex technological arrangements based on a number of unit operations. In water-wastewater management membrane processes are more often applied, especially those in which the difference of pressure at both membrane sites is used as a driving force. As an example of such application is the use of nanofi ltration for groundwaters treatment at Water Treatment Plant Zawada near Dębica or the treatment of municipal landfi ll leachate and industrial wastewater at Eko Dolina Waste Utilization Plant in Łężyce near Gdynia (reverse osmosis unit capacity of 120 m /d). Municipal wastewater treatment based on membrane technologies has already been implemented at domestic wastewater treatment plant. It is especially profi table, when the load of contaminant present in a wastewater varies within a year. In the case of membrane systems use, this issue can be neglected. As an example of membrane based system may serve WWTP in Rowy n/Ustka started up in 2013 and modernized in 2017. The latest trends and developments of selected suppliers of membrane systems are also presented.

Compared to other European countries, Poland has scarce drinking water resources and exhibits

significant variation in annual runoff. On the other hand, the geothermal water resources present in sedimentary/structural basins, mostly in the Polish Lowlands and the Podhale geothermal system, not only provide a

valuable source of renewable energy, which is utilized, although only to a limited extent, but can also be used

for many other purposes. The paper presents the results of studies related to the desalination of low dissolved

mineral content geothermal waters from the Bańska IG-1 well using a dual hybrid system based on ultrafiltration and reverse osmosis. The desalination of geothermal waters may be considered a possible solution leading

to the decentralization of drinking water supply. In many cases, using cooled waters for drinking purposes may

be considered an alternative method of disposing of them, in particular for open drain arrangements, i.e. where

cooled water is dumped into surface waters.

Fresh water is essential for life. More and more countries around the world are facing scarcity of drinking water, which affects over 50% of the global population. Due to human activity such as industrial development and the increasing greenhouse effect, the amount of drinking water is drastically decreasing. To address this issue, various methods of sea and brackish water desalination are used. In this study, an energy analysis (specific energy consumption, SEC) of two laboratory membrane processes, reverse osmosis (RO) and pervaporation (PV), was conducted. A model feed system saline water at 0.8, and 3.5% wt. NaCl was used. The efficiency and selectivity of membranes used in PV and RO were examined, and power of the devices was measured. The desalination processes were found to have a high retention factor (over 99%) for both PV and RO. For PV, the permeate fluxes were small but they increased with increasing feed flow rate, process temperature and salt content in the feed. The calculated SEC values for both laboratory processes ranged from 2 to 70 MWh/m ³. Lowering the process temperature, which consumes 30 to 60% of the total energy used in the PV process, can be an important factor in reducing energy consumption.

The aim of the study was to develop an effective treatment of post-digestion liquors highly-loaded with biogenic and organic substances. The scope of the research project encompassed: mesophilic anaerobic digestion of waste activated sludge (WAS) as well as the treatment of post-digestion liquors, coming from the most appropriate HRT value of 25 days, in the process of ammonium magnesium phosphate (struvite) precipitation targeted at ammonia nitrogen binding and a subsequent reverse osmosis (RO) process. It was established that the method combining chemical precipitation and high-pressure filtration ensures a high degree of contaminants removal allowing for a direct release of treated liquors into the natural reservoir. However, in order to decrease the residual NH4+ concentration (6.1 mg NH4+/dm3) in the purified post-digestion liquors below the level allowing for a direct release to the natural reservoir, it turned out to be necessary to apply increased molar ratio of magnesium and phosphates (Mg:NH4+: PO43-= 1.5:1:1.5).

M embrane-based water desalination processes and hybrid technologies are often considered as a technologically and economically viable alternative for desalination of geothermal waters. This has been confirmed by the results of pilot studies concerning the UF-RO desalination of geothermal waters extracted from various geological structures in Poland. The assessment of the feasibility of implementing the water desalination process analysed on an industrial scale is largely dependent on the method and possibility of disposing or utilising the concentrate. The analyses conducted in this respect have demonstrated that it is possible to use the solution obtained as a balneological product owing to its elevated metasilicic acid, fluorides and iodides ions content. Due to environmental considerations, injecting the concentrate back into the formation is the preferable solution. The energy efficiency and economic analysis conducted demonstrated that the cost effectiveness of implementing the UF-RO process in a geothermal system on an industrial scale largely depends on the factors related to its operation, including without limitation the amount of geothermal water extracted, water salinity, the absorption parameters of the wells used to inject water back into the formation, the scale of problems related to the disposal of cooled water, local demand for drinking and household water, etc. The decrease in the pressure required to inject water into the formation as well as the reduction in the stream of the water injected are among the key cost-effectiveness factors. Ensuring favourable desalinated water sale terms (price/quantity) is also a very important consideration owing to the electrical power required to conduct the UF-RO process.

In the present work, the dried biomass of soil isolated fungus Eurotium cristatum was used for synthesizing silver na-noparticles (AgNPs). The synthesized AgNPs were spherical in shape with average diameter of 16.56 nm and displayed maximum absorbance at 418. Fourier transform infrared (FTIR) study indicated the presence and binding of proteins with myco-produced silver nanoparticles. The optimum conditions for AgNPs biosynthesis were found to be at temperature of 40°C, pH of 8.0, substrate concentration of 500 ppm and fungal biomass wt. of 0.8 g. The AgNPs showed antibacterial ac-tivity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Shigella flexneri. AgNPs was built-in thin film nanocomposite (TFNC) membrane and the impacts of nanomaterial composition on membrane properties and de-salination process were studied. The AgNPs produced membrane TFNC had better filtration performances than pure thin film composite membrane TFC. The TFNC membrane had enhanced water flux (32.0 vs. 16.5 dm3∙m–2∙h–1) and advanced NaCl rejection (91.7 vs. 89%) compared to the TFC membrane. A pot experiment was conducted to evaluate the effect of the irrigation with desalinated water on yield and productivity of essential oil of the sweet basil (Ocimum basilicum L.) and lavender (Lavandula multifida L.). The irrigation with desalinated water reduced significantly the soil reaction, soil electri-cal conductivity (EC), sodium adsorption ratio and exchangeable sodium percent in rhizospheric soil, it also enhanced the growth and oil yield of both plants compared with those irrigated with salt water.

A number of inorganic compounds, including anions such as nitrate(V), chlorate(VII), bromate (V),

arsenate(III) and (V), borate and fluoride as well as metals forming anions under certain conditions, have been

found in potentially harmful concentrations in numerous water sources. The maximum allowed levels of these

compounds in drinking water set by the WHO and a number of countries are very low (in the range of µg/l to a

few mg/l), thus the majority of them can be referred to as charged micropollutants. Several common treatment

technologies which are nowadays used for removal of inorganic contaminants from natural water supplies, represent serious exploitation problems. Membrane processes such as reverse osmosis (RO), nanofiltration (NF),

ultrafiltration (UF) and microfiltration (MF) in hybrid systems, Donnan dialysis (DD) and electrodialysis (ED)

as well as membrane bioreactors (MBR), if properly selected, offer the advantage of producing high quality

drinking water without inorganic anions.

I

The post-processes coke wastewater treatment was carried out using flat ultrafiltration membranes

with a variable polysulfone concentration in membrane solution (15 wt% - 17% wt.) and variable evaporation

time of the solvent from the polymer film surface (0s, 2s, 5s). The ultrafiltration process was carried out with the

transmembrane pressure of 0.4 MPa and the linear speed of water flow over the surface of the membrane at 2

m / s. For all the membranes transport characteristic of de-ionized water describing the dependence of the volumetric flow on the transmembrane pressure was done. Since none of the ultrafiltration membranes prepared had

provided a sufficiently high degree of pollutants removal from wastewater, it was post-treated by RO method.

The wastewater treated this way can be used as technical water for coke quenching. The calculations based on

the assumptions of the hydraulic model of filtration resistance allowed to predict the efficiency of ultrafiltration membranes used in the process. To that end, for each of the membranes, the following parameters were

determined experimentally: the alterations of effluent stream volume over the time of the low-pressure filtration,

the total hydraulic resistance and the resistance constituents such as „new” membrane resistance, the resistance

generated by polarization layer and the resistance caused by fouling - reversible and irreversible.

In recent years, the increasing threat to ground water quality due to human activities has become a matter of great con-cern. The ground water quality problems present today are caused by contamination and by over exploitation or by combination of both. Reverse osmosis (RO) desalination is one of the main technologies for producing fresh water from sea water and brackish ground water.

Algeria is one of the countries which suffer from the water shortage since many years, so desalination technology becomes inevitable solution to this matter.

In this study, a comparison is provided of results of reverse osmosis desalination for three different qualities of brack-ish water from the central-east region of Algeria (Bouira and Setif Prefectures), wherein they cannot use it as human drink-ing or in irrigation systems. The main objective of our study is to establish a comparison of the reverse osmosis membrane TW30-2540 performances in the term of (permeate flow, recovery rate, permeate total dissolved solids – TDS and salts re-jection) under different operation pressures (each one takes a time of 720 second for pilot scaling). In order to make an overview comparison between the experimental and the simulated results we used ROSA (Reverse Osmosis System Analy-sis) software.

At the end of this study we noted that, the simulated results are lower than the pilot scaling values and the most re-moved salts are the sodium chlorides with 99.05% of rejection rate.