RESUMEN

Human urine, a highly saline solution rich in plant-available nutrients, leaves behind significant organic matter after nutrient recovery, necessitating additional treatment for environmental protection. While nutrient recovery from human urine is well-documented in the literature, research on the safe handling of the residual liquid phase is notably lacking. This study investigates nutrient recovery from source-separated human urine using clinoptilolite for the ion exchange/adsorption process and evaluates the safe management of the residual liquid through anaerobic granular sludge and a second-stage of sorption. The results indicated that the ion exchange/adsorption process, using an ammonium loading of 15 mg NH4+/g clinoptilolite, removed the majority of nutrients, achieving 82% ammonium removal and 100% phosphorus removal, along with 30% removal of organic matter. The residual liquid phase from the nutrient removal stage was treated separately with anaerobic digestion and a second-stage of sorption for further processing. Results showed that anaerobic processing removed 68%-84% of organic matter, with no additional nitrogen removal observed as expected, and produced 0.20-0.46 L CH4/L urine. The second-stage of sorption removed 59%-62% of organic matter and nearly all nitrogen. Both processes effectively removed organic matter, with sorption also eliminating nitrogen and anaerobic processing potentially generating biogas, making them recommended for improving the quality of the residual liquid phase before final disposal.

RESUMEN

Volatile fatty acids (VFAs) produced during anaerobic digestion (AD) of organic waste are a promising alternative carbon source for various biological processes; however, their applications are limited due to the presence of impurities such as ammonium (NH4+). This study investigates the potential for removal of ammonium using a naturally occurring zeolite (clinoptilolite) from chicken manure (CKM) derived VFA effluent recovered from an anaerobic membrane bioreactor (MBR). Experiments were conducted for both synthetic and actual VFA (AD-VFA) solutions, and the effects of different parameters were investigated with batch and continuous studies. It was observed that the Langmuir-type isotherm provided the best fit to the equilibrium data in the isotherm investigations carried out with the AD-VFA solution. The maximum adsorption capacity (qm) was found as 15.7 mg NH4+/g clinoptilolite. The effect of some operational parameters on process performance such as pH, initial NH4+ loading and potassium ion (K+) concentration was investigated. The pH had a negligible effect on ammonium removal for a pH range of 3-7, while the removal efficiency of ammonium decreased with the increase of initial NH4+ loading and K+ concentration. At the optimum conditions determined in batch experiments, the ammonium removal from synthetic and AD-VFA solutions were compared and average ammonium removal efficiencies of 93 and 94% were found in 12 h equilibrium time for synthetic and AD-VFA solutions, respectively. Overall findings indicated that clinoptilolite has excellent potential for ion exchange when combined with biological processes such as acidogenic fermentation of VFAs to purify the solution from high-ammonium content.

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RESUMEN

ECOSAN is a recent domestic wastewater management concept which suggests segregation at the source. One of these streams, yellow water (human urine) has the potential to be used as fertilizer, directly or indirectly, because of its rich content of plant nutrients. One physicochemical method for indirect use is adsorption/ion exchange using clinoptilolite. This paper aims to present the results of a scenario focusing on possible diversion of urine and self-sufficiency of nutrients recovered on site through the use of this process, using actual demographic and territorial information from an existing summer housing site. Specifically, this paper aims to answer the questions: (i) how much nitrogen can be recovered to be used as fertilizer by diverting urine? and (ii) is this sufficient or in surplus within the model housing site? This sets an example of resource-oriented sanitation using stream segregation as a wastewater management strategy in a small community. Nitrogen was taken as the basis of calculations/predictions and the focus was placed on whether nitrogen is self-sufficient or in excess as fertilizer for use within the premises. The results reveal that the proposed application makes sense and that urine coming from the housing site is self-sufficient as fertilizer within the housing site itself.

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