Multicomponent systems are representative of the most common real situations as many industrial discharges contain a mixture of several pollutants. This study examines the concurrent adsorption of phenol (PHE) and ciprofloxacin (CIP) onto three types of polyethylene terephthalate microplastics (PET MPs): pristine, acid-modified, and thermal-oxidatively aged. Using extended Langmuir (EL), extended Freundlich (EF) isotherms, and a new artificial neural network (ANN) model, equilibrium adsorption capacities were predicted. The EL isotherm fit for pristine and aged PET MPs, while EF fit for modified PET MPs. Monolayer adsorption capacities ranged from 342.10–3715.73 mg/g for PHE and 2518.23–14498.79 mg/g for CIP, exceeding single-component adsorption. The ANN model used one hidden layer with 3 neurons for pristine and aged PET MPs, and 2 hidden layers with five neurons for modified PET MPs, with a hyperbolic tangent activation function. Models showed excellent performance metrics, including R2 values of 0.989–0.999, RMSE of 0.001–0.413, and AAE of 0.009–0.327. Synergistic interactions were observed in the binary system, with PET MPs showing higher selectivity toward CIP. The study demonstrates the effectiveness of PET MPs for binary adsorption of PHE and CIP in aqueous solutions, highlighting their potential for multicomponent pollutant removal.

The ultrasound technique was applied to the synthesis of layered double hydroxides. The use of ultrasound in the synthesis of these compounds was studied in terms of its effect on their crystal qualities and surface properties. The crystal qualities of the compounds synthesized with ultrasound were compared with those of compounds synthesized without ultrasound to elucidate the effect of the ultrasound on the synthesis. The effect of crystal quality (crystallite size) on the adsorption behavior of humic substances was examined. The compounds synthesized under ultrasonic conditions showed a larger crystallite size and a larger adsorption capacity for humic substances than those synthesized without ultrasonic treatment. The degree of adsorption correlated well with crystal quality.

Organic pollutants are widespread and a known problem for the environment. p-nitrophenol (PNP) is one such pollutant found in effluents from various industries involved with pesticides, pharmaceuticals, petrochemicals, plastic, paper, and other materials. The objective of this research was to prepare and test organically modified clays using four different surfactants and to evaluate the removal efficiency of PNP from aqueous solutions. Organically modified clays have attracted great interest due to their wide applications in industry and environmental protection as sorbents for organic pollutants. Two natural smectite-dominated clay types from outcrops in Latvia and Lithuania as well as industrially manufactured montmorillonite (Mt) clay were modified using different nonionic (4-methylmorpholine N-oxide (NMO) and dimethyldodecylamine N-oxide (DDAO)) and cationic (benzyltrimethyl ammonium chloride (BTMAC) and dodecyltrimethyl ammonium chloride (DTAC)) surfactants. Modified clay materials were characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller method (BET) for surface area analysis. Sorption of PNP was investigated under various conditions, e.g. surfactant loading, initial PNP concentration, contact time, and pH. The novelty of the present study was to prepare innovative organo-sorbents based on manufactured as well as natural clay samples using cationic surfactants and nonconventional nonionic surfactants as modifiers. The sorption data combined with FTIR and XRD supplementary results suggests that nonionic organo-clay (Mt-DDAO_2) is the most effective sorbent and may serve as a low-toxicity immobilizer of pollutants such as phenols.

Montmorillonite (Mnt), a clay mineral with a nanolayered structure, was combined with an Fe-based metal–organic framework (MOF; MIL-53(Fe)) using an in situ growth technique that yielded a novel eco-friendly clay-based adsorbent (MIL-53(Fe)@Mnt). The adsorbent was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and N2 gas adsorption. The MIL-53(Fe) particles grew on the surface of the nanolayered Mnt and the MIL-53(Fe) particle size became smaller. The adsorption performance of MIL-53(Fe)@Mnt was investigated by removing methylene blue (MB), and optimization experiments were carried out to study the effects of contact time, pH, initial dye concentration and adsorbent mass on the adsorption processes. The MIL-53(Fe)@Mnt exhibited excellent adsorption capacity for MB, namely 313.7 mg g−1, which was 3.02 times and 3.54 times greater than that of pure Mnt and MIL-53(Fe), respectively. Adsorption was fitted with the Langmuir isotherm model and followed a pseudo-second order kinetic model. The MIL-53(Fe)@Mnt obtained is a low-cost and eco-friendly adsorbing material and might be a candidate for removing dyes during water treatment.

Germination of fruit of common lambsquarters (Chenopodium album L.) from three out of four sources was enhanced by 9 to 41% by removal of the fruit coat, and by 21% by washing the fruit for 70 h. Brown-black seed germinated more rapidly than the black and brown seed after washing for 70 h. The washing treatment appeared to remove some unknown inhibitors. After washing, seed germination was found to be positively correlated with seed size.

This paper analyses the steady-state operation of a generalized bioreactor model that encompasses a continuous-flow bioreactor and an idealized continuous-flow membrane bioreactor as limiting cases. A biodegradation of organic materials is modelled using Contois growth kinetics. The bioreactor performance is analysed by finding the steady-state solutions of the model and determining their stability as a function of the dimensionless residence time. We show that an effective recycle parameter improves the performance of the bioreactor at moderate values of the dimensionless residence time. However, at sufficiently large values of the dimensionless residence time, the performance of the bioreactor is independent of the recycle ratio.

Cryptosporidium and Giardia are intestinal parasites of humans and of many other species of animals. Water constitutes an important route of transmission for human infections in both developed and developing countries. In Poland, contamination of water sources with oocysts/cysts is not routinely monitored and scientific research in this field is scarce. Our aim was to compare the contamination of surface and treated water and thus the success of water treatment processes. Water samples (n=94) of between 30 l (surface water) to over 1000 l for tap water, were taken in the period of 2008–2009 using specially constructed equipment with cartridge filtration (Filta-Max; IDEXX, USA). Immunofluorescent assay, and nested polymerase chain reaction were used for the detection of parasites. Cryptosporidium oocysts were found in 85% of surface water and in 59% of raw (intake) water samples. Oocysts were also detected in treated water (16%) but were absent in samples of swimming pool water. The highest mean number of Cryptosporidium oocysts [geometric mean (GM)=61/10 l] was found in samples of rinsing water. Giardia cysts were observed in 61% of surface water samples, in 6% of raw water and in 19% of treated water, with the highest number of cysts noted in rinsing water samples (GM=70 cysts/10 l). Our study highlights the frequent occurrence of parasites in surface waters in Poland and the effectiveness of water treatment for the removal of parasites from drinking water.

This paper shows that natural materials such as barks can successfully replace syntheticresins for industrial purposes. Evaluated in batch conditions, biosorption of uranium onsuitably prepared Douglas fir barks took place in less than 10 min and appeared to beoptimum at pH>4. The biosorption process of uranium (uranyl formUO\hbox{$_{\mathrm{\mathbf{2}}}^{\mathrm{\mathbf{2+}}}$}$\begin{array}{}{2}\mathrm{+}\\ {2}\end{array}$)was characterized in the optimal physico-chemical conditions and could be mathematicallymodeled as a Langmuir isotherm. With a maximum uranium specific uptakeqmaxvalue of 1.16 meq.g-1 (138mgU.g-1) it was found that the sorption capability of Douglas fir barks wasat least five times higher for uranium than for other heavy metals such as lead.Adsorption of uranium contained in water leached from a former uranium mine was thenmonitored over a one-month period in a laboratory-scale chromatography column. Thefixation capacity remained fairly constant throughout the whole testing period. Waterradioactivity decreased from 1500 mBq.L-1 (0.12 mgU.L-1) to <5 mBq.L-1(0.4 μ gU.L-1) at the columnexit. This technology was successfully transferred and tested through a pilot projectunder industrial conditions with the support of AREVA NC.

Ultrasonic treatment, a relatively less explored technology in water disinfection, was used to quantify the energy required for the destruction of larvae of barnacle Balanus amphitrite, which is a major marine fouling and a potential invasive organism. Since the power used and treatment time for disinfection are economically, and practically, the most important parameters, the energy required to pulverize the larvae into pieces ≤30 µm was determined as a function of the acoustic power density. The present investigation suggests that an ultrasonic system operating at 20 kHz and 0.0975 W/cm3 can effectively pulverize barnacle larvae having length (~440 µm) and breadth (~350 µm) within 45 seconds using 0.1 mJ/larva of pulverization energy. It was also observed that following pulverization of the larvae, the bacterial abundance increased and the rate of release of bacteria was dependent on power level and treatment time, which in turn decided the pulverization rate and hence the rate of release of bacteria.

The purpose of this paper was to describe a method of preparing Fe-TiO2 supported on sepiolite fibers with sol-gel method and to discuss the feasibility of photocatalytic degradation of paper-making waste water with chemical oxygen depletion (CODcr) (Potassium dichromate method) as evaluation criterion of catalytic activity. As-fabricated catalysts consisted of TiO2 particles impregnated with iron and dispersed on the sepiolite fibers (S.F.s). The novel Fe-TiO2-sepiolite was characterized by specific surface area and pore size distribution measurements, scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD) and Fourier transform Infrared spectrometer (FT-IR) etc. The effects of parameters such as the amount of Ti/sepiolite fibers, initial pH, H2O2, Fe-doped, concentration of waste water, etc. were studied in detail. The results indicated that the presence of sepiolite in the support preparation and its role as a matrix over which TiO2 particles were dispersed seem to play an important effect in the migration process of oxygen species through the support vacancies. On the basis of these properties, the most promising carriers to be used in a waste water treatment process were selected.

Marine land-based fish farms located in coastal wetlands (salt-pond zones, lagoon banks, etc.), whether extensive or intensive, send farm effluents directly to the sea or after short periods of stocking in retention reservoirs. The aims of our investigation have been to compare the efficiency of current and potential water treatment procedures in open-air. Wastewater retention ponds in commercial farms (Atlantic coasts of France) are efficient in removing up to 1 metric ton of particulate material (dry weight) per hectare and per day (faeces and unconsumed feed), but are inefficient in reducing dissolved wastes, both organic (urea, amino acids, protein) and inorganic (total ammonia nitrogen, phosphates). Forthcoming outdoor technology to treat these forms of waste were examined by trials at different sites: treatment by foam fractionation in extensive systems (Italian fish pond culture), treatment by microalgae production (Skeletonema costatum) and oyster filtration (Crassostrea gigas) in intensive systems (sea bass farm, Dicentrarchus labrax). It can be concluded that foam fractionation coupled with aeration and water circulation is a good way to treat and recirculate wastewaters in extensive systems, but that a multiple treatment combining a retention pond, foam fractionation and microalgae-bivalve filtration, is the best solution to treat all these forms of wastes from intensive systems.

Intensive coniferous afforestation of many water supply catchments is taking place in Strathclyde Region. The current concern over the impact of this significant change in land use on the quantity and quality of water supplies is discussed. Some effects, such as high sediment run-off associated with ploughing and road development, may be of dramatic short-term effect, while others, such as reduction in quantitative yield, the development of eutrophication or acidification with aluminium leaching from soils, may take longer to materialise. Selective routine water quality monitoring work commenced in 1984 in a number of water supply catchments aimed at identifying forestry-related water quality trends. The initial results of this work are presented. Against the background of catchment land use changes, new European Community water supply standards were imposed in 1985 committing the Region to a substantial capital expenditure programme over a ten-year period in order to upgrade water treatment works. Any significant long-term changes in water quality associated with forestry activity will make this programme more costly to achieve. It is considered that the water supplies most susceptible to forestry related quantity or quality problems are the small supplies in areas of Argyll, Ayrshire and the Islands. It is suggested that the way forward is for improved advance consultation and planning on a site specific basis to protect public water supply interests.