Shervin Hashemi

Optimization of fertilization characteristics of urine by addition of Nitrosomonas europaea bio-seed.

BACKGROUND Because of the high concentration of nutrients in human urine, its utilization as an organic fertilizer has been notable throughout history. However, the nitrogen compounds in urine are not stable. Therefore, to convert urine into a suitable fertilizer, it is important to stabilize and adjust unstable nitrogen compounds such as ammonia. Because nitrification can influence the nitrogen profile, the use of nitrifying microorganisms can be useful for stabilizing the nitrogen profile of urine. This study investigated the changes in nitrogen compounds in pure urine and examined the effect of adding Nitrosomonas europaea bio-seed solution on these changes. RESULTS It was found that the addition of bio-seed could reduce nitrogen loss as well as the time required to stabilize the nitrogen profile. Furthermore, the optimum concentration of bio-seed (6 × 10(5) N. europaea cells L(-1) ) that not only leads to the least nutrient loss but also results in an adequate nitrate/ammonium ratio and regulates the amount of nitrate produced, thereby preventing over-fertilization, was determined. CONCLUSION At this concentration, no dilution or dewatering is required, thus minimizing water and energy consumption. Usage of the optimum of concentration of bio-seed will also eliminate the need for inorganic chemical additives.

The Waterless Portable Private Toilet: An Innovative Sanitation Solution in Disaster Zones.

Catastrophes can occur without warning and inevitably cause short-term and long-term problems. In disaster zones, having an action plan to alleviate difficulties can reduce or prevent many long-lasting complications. One of the most critical and urgent issues is sanitation. Water, energy, personnel, transportation, and the allocation of resources in disaster areas tend to become very limited during emergencies. Sanitation systems suffer in the process, potentially leading to crises due to unsafe and unhygienic surroundings. This article explores the problems of current sanitation practices in disaster areas and identifies the essential characteristics of sustainable sanitation systems. This study also presents a plan for an innovative and sustainable sanitation system using a waterless, portable, private toilet, in addition to a procedure for collecting and disposing waste. The system is agronomic, is socially acceptable, prevents contact with human waste, and can be used for individuals or families. Environmental pollution and social problems (such as sexual harassment) can be reduced both during and after restoration.

The effect of material and flushing water type on urine scale formation.

One of the important challenges with current sanitation practices is pipe blockage in urinals caused by urine scale formation. Urinal material and flushing water type are the two most important factors affecting scale formation. This paper examines the scale formation process on different materials which are commonly used in urinal manufacturing and exposed to different urine-based aqua cultures. This study shows that urine scale formation is the greatest for carbon steel material, and the least for PVC. Additionally, material exposure to the urine-rainwater mixture resulted in the smallest amount of scale formation. Based on these results, two new methods for improving sanitation practices are proposed: (1) using PVC as production material for urinals and pipelines; and (2) using rainwater for flushing systems.

Harvesting nutrients from source-separated urine using powdered rice straw

ABSTRACT As a principle of resource-oriented sanitation practice, urine should be separated from the source and utilized for other purposes such as producing fertilizer. This is because urine is rich in nutrients; therefore, sending it directly to wastewater treatment plants causes problems in the regular treatment process. The addition of solid additives such as powdered rice straw can help with harvesting nutrients from urine. In this study, the procedure and efficiency of using powdered rice straw for nutrient harvesting were investigated by tracking the reductions in ammonia, phosphate, magnesium, and calcium ions, and the harvested nutrients were identified using crystallography methods. Results show that the ammonia, phosphate, and magnesium ions showed similar reduction trends. However, the reduction process was limited by the magnesium and phosphate availability, which reduced the nutrient harvesting efficiency. The nutrients harvested with the rice straw were identified to be mostly struvite. Balancing the phosphate and magnesium ions with ammonia is recommended to improve the efficiency of nutrient harvesting. The treated powdered rice straw can serve as a good solid fertilizer, while the remaining urine, which includes fewer nutrients, can be utilized for irrigation or sent to wastewater treatment plants.

Fate of Fecal Indicators in Resource-Oriented Sanitation Systems Using Nitrifying Bio-Treatment

Hygienic fecal treatment in resource-oriented sanitation (ROS) systems is an important concern. Although the addition of nitrifying microorganisms is a sustainable fecal treatment method in ROS systems, it is essential to examine the cleanliness of this method. In this study, we investigated the fate of fecal indicators in source-separated fecal samples through tracking Escherichia coli and total coliforms. The effects of adding different amounts of Nitrosomonas europaea bio-seed, along with a constant amount of Nitrobacter winogradskyi bio-seed, were studied. In intact feces samples, the pathogen population underwent an initial increase, followed by a slight decrease, and eventually became constant. Although the addition of nitrifying microorganisms initially enhanced the pathogen growth rate, it caused the reduction process to become more efficient in the long-term. In addition to a constant concentration of 10,000 cells of N. winogradskyi per 1 g feces, a minimum amount of 3000 and 7000 cells of N. europaea per 1 g feces could completely remove E. coli and total coliforms, respectively, in less than 25 days. Increasing the amount of bio-seeds added can further reduce the time required for total pathogen removal.

Field evaluation of the fertilizing potential of biologically treated sanitation products

Among different approaches of treating source-separated urine and feces for agronomic utilization, the treatment by addition of nitrifying bio-seeds seems to be useful in increasing the fertilizing potential of these sanitation products by modifying and stabilizing the nitrogen profile. In this study, biological treatment was applied to an onsite resource-oriented sanitation system by adding nitrifying microorganism bio-seeds. Further, the potential of the sanitation products to be utilized as fertilizer for white radish (Raphanus sativus var. longipinnatus) cultivation was examined and compared with that of a commercial fertilizer. This was done through the measurement of nutrients released in soil samples as well as measurements of root mass, root length, and the measurement of accumulated nitrogen, sugar, and water content in plant tissues. Our results show that soil fertilized with a mixture of biologically treated urine and feces exhibits a statistically similar nutrient release trend to soil fertilized using a commercial fertilizer. Moreover, soil fertilized with a mixture of biologically treated urine and feces yielded larger white radishes with a higher sugar and water content, as well as a higher accumulation of nutrients in the plant tissues, than soil fertilized with a commercial fertilizer.