Industrial wastewater treatment for fertilizer industry—A case study

Abstract

Wastewaters from chemical fertilizer industry mainly contain organics, alcohols, ammonia, nitrates, phosphorous, heavy metals such as cadmium and suspended solids. The nature of effluent streams varies in terms of its constituents and complexity. The present work attempts to fill the void in the literature that mostly reports synthetic wastewater treatment studies; by evaluating effluent treatment solutions and comparison of different methods for real wastewaters from the fertilizer industry. An attempt has been made to devise suitable methodology mainly using a new device in the form of vortex diode for hydrodynamic cavitation and also using adsorption, for several real wastewater streams from different locations in one major fertilizer industry of Maharashtra, India. The strategy involved characterization of wastewaters, studies on the effective removal of Chemical Oxygen Demand(COD) and devising solutions for effective reduction in ammoniacal nitrogen-a more serious issue in the fertilizer industry. The characterization of wastewaters from different streams revealed huge variation in COD from 50 to 140,000 ppm and ammoniacal nitrogen from 6 to 1700 ppm. Some effluent streams contained alcohol up to 5 %. Hydrodynamic cavitation using vortex diode and adsorption with modified carbons were used to treat these streams. Cavitation studies were carried out on a pilot plant and the effect of pressure drop, cavitating device and process intensification were studied. It was observed that the effluent treatment strategy requires careful identification and application of suitable treatment method on the basis of the nature of the effluent. Also, hydrodynamic cavitation, using vortex diode appears to be techno-economically attractive option in treating fertilizer wastewaters giving a very high reduction in COD and ammoniacal nitrogen (up to 85%), similar to adsorption. The results clearly identify potential of newer methodologies in the treatment of effluents in the fertilizer industry.

Solvent degradation studies using hydrodynamic cavitation

“…generate secondary waste. Hydrodynamic cavitation is an emerging technology, especially for industrial wastewater treatment and is capable of destruction of the pollutants through complete mineralization [1,2]. Cavitation is easy to operate variant of advanced oxidation process without requiring a complex catalyst, high temperature, and pressure.…”

Developing techno-economically sustainable methodologies for deep desulfurization using hydrodynamic cavitation

“…Hydrodynamic cavitation works through the generation of hydroxyl radicals through cleaving of water molecules-an active oxidant. The in situ generation of oxidising agent participates in the oxidation of organics effecting their removal/degradation [36,37]. Though the mechanism for degradation of pollutants from water using cavitation is well discussed in the literature, there have not been any reports on the two phase/multiphase systems such as the one used in the present study.…”

Modelling of hydrodynamic cavitation with orifice: Influence of different orifice designs

“…For wastewater in particular, HC could potentially play a critical role in future treatment strategies (Ranade and Bhandari [1]). Numerous bench scale studies have highlighted the promise of HC to treat a range of pollutants, including organics [2,3], pharmaceutical compounds [4,5] and common fertilizers and pesticides [6][7][8]. HC has also been studied as a potential mechanism to inactivate micro-organisms such as E-coli [9].…”