**4. Conclusion**

The present study used bubble column reactor which simple and efficient. Removal of P via struvite-K showed 98.5% with the precipitates Mg:P of 0.7 and K:P of 1. The yields of 11.28 gram. Compost and struvite-K have positive impact on crop growth of (radish and komatsuna) were compared than control. Which might be caused supplied nutrient source on soil and uptake on crop. However, the struvite-K is more effective than compost may cause contains higher macro nutrient such as magnesium, potassium and phosphate. This is indicated that the recovery process of P and K via struvite-K using bubble column reactor was very effective and efficient to utilization as a fertilizer.

## **Acknowledgements**

The author (E.H) would like to thanks to Japanese Government (MEXT Scholarship) for financial support during studying in Prefectural University of Hiroshima.

### **Conflict of interest**

The authors declare no conflict of interest.

## **Author details**

Endar Hidayat\* and Hiroyuki Harada Department of Environmental Science, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan

\*Address all correspondence to: hidayatendar1@gmail.com

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