Current use of ion exchange unit process in water treatment for food industry is mainly for boiler feed water softening. However, potentials of ion exchange in water treatment process are of greater significance, which is exactly the matter researched in this paper. After a short review of ion exchange unit process basics, and ion exchangers as an equipment (in scope of that, a suggestions for investitor about techno-econommic analysis of offered solutions for ion exchanger line design is given, in order to minimize errors in plan and design, which might be harmful for investitor), options of using ion exchange in some phases of water treatment process for food industry are discussed, like removing of: mineral matter (softening, decarbonization, demineralization), natural organic matter, and some other constituents (nitrate, ammonia, heavy metals).

Perchlorate (ClO4−) is a strong oxidizer and has gained significant attention due to its reactivity, occurrence, and persistence in surface water, groundwater, soil and food. Stable isotope techniques (i.e., (18O/16O and 17O/16O) and 37Cl/35Cl) facilitate the differentiation of naturally occurring perchlorate from anthropogenic perchlorate. At high enough concentrations, perchlorate can inhibit proper function of the thyroid gland. Dietary reference dose (RfD) for perchlorate exposure from both food and water is set at 0.7 μg kg−1 body weight/day which translates to a drinking water level of 24.5 μg L−1. Chromatographic techniques (i.e., ion chromatography and liquid chromatography mass spectrometry) can be successfully used to detect trace level of perchlorate in environmental samples. Perchlorate can be effectively removed by wide variety of remediation techniques such as bio-reduction, chemical reduction, adsorption, membrane filtration, ion exchange and electro-reduction. Bio-reduction is appropriate for large scale treatment plants whereas ion exchange is suitable for removing trace level of perchlorate in aqueous medium. The environmental occurrence of perchlorate, toxicity, analytical techniques, removal technologies are presented.

Land application of food-processing waste water occurs throughout California's Central Valley and may be degrading local ground water quality, primarily by increasing salinity and nitrogen levels. Natural attenuation is considered a treatment strategy for the waste, which often contains elevated levels of easily degradable organic carbon. Several key biogeochemical processes in the vadose zone alter the characteristics of the waste water before it reaches the ground water table, including microbial degradation, crop nutrient uptake, mineral precipitation, and ion exchange. This study used a process-based, multi-component reactive flow and transport model (MIN3P) to numerically simulate waste water migration in the vadose zone and to estimate its attenuation capacity. To address the high variability in site conditions and waste–stream characteristics, four food-processing industries were coupled with three site scenarios to simulate a range of land application outcomes. The simulations estimated that typically between 30 and 150% of the salt loading to the land surface reaches the ground water, resulting in dissolved solids concentrations up to sixteen times larger than the 500 mg L⁻¹ water quality objective. Site conditions, namely the ratio of hydraulic conductivity to the application rate, strongly influenced the amount of nitrate reaching the ground water, which ranged from zero to nine times the total loading applied. Rock–water interaction and nitrification explain salt and nitrate concentrations that exceed the levels present in the waste water. While source control remains the only method to prevent ground water degradation from saline wastes, proper site selection and waste application methods can reduce the risk of ground water degradation from nitrogen compounds.

Wastewater from a food-manufacturing plant with a low concentration of organic matter below 100 mg/l TOC was first treated at 37 degrees C in an anaerobic fluidized-bed reactor (AFBR) or in an upflow anaerobic sludge blanket (UASB). The TOC removal efficiency in both reactors decreased from 85% to 65% as the influent TOC concentration decreased from 100 to 35 mg/l at a hydraulic retention time (HRT) of 6 h. Treatment at an HRT of 4 h resulted in an effluent TOC concentration of 11 to 15 mg/l. The concentration of suspended solids in the effluent could be reduced to 20 mg/l, which corresponded to 7% of that of the influent. The effluent from both reactors was then treated anaerobically in a fixed-bed reactor system. The TOC concentration and optical density (OD) of the effluent from the aerobic treatment were reduced to 5 mg/l and 0.005, respectively, at an HRT of 2 h. When anaerobically or aerobically treated effluent was pressed over an activated carbon column, the effluent TOC concentration was reduced to 2 to 3 mg/l. The conductivity of 1.3 mS/cm in raw wastewater, which was not removed through the above treatments, was reduced to 0.001 mS/cm on an ion-exchange resin column. An effluent quality corresponding to that of ultra-pure water for industrial use was finally attained by the treatment in this multi-step system.

A new and practical sample enrichment method termed ionic liquid-based ultrasound-assisted in situ solvent formation microextraction (IL-UA-ISFME) was combined with electrothermal atomic absorption spectrometry (ETAAS) for preconcentration and trace determination of vanadium in real samples. In this sample enrichment methodology, a hydrophilic ionic liquid (IL) ([Hmim][BF₄]) was added to the aqueous media containing an ion-exchange reagent (NaPF₆), in order to obtain a hydrophobic IL ([Hmim][PF₆]) as the microextraction solvent. The hydrophobic extraction solvent formed under these conditions was completely dispersed into the sample solution using ultrasonic radiation. Vanadium was complexed with N-benzoyl-N-phenylhydroxylamine (BPHA), and extracted into the IL phase during the dispersion of the hydrophobic IL. Main variables affecting the recommended method was studied in details and optimized. Under the optimum conditions, the combined methodology provided a linear dynamic range of 15–2,500 ng l⁻¹, a limit of detection (LOD) of 4.7 ng l⁻¹ and a relative standard deviation (RSD) of 4.0 %. The accuracy and validity of the method was checked by analyzing a certified standard reference material of water (SRM-1643e). Finally, the developed method was utilized for quantitation of vanadium in real water and milk samples.