Investigation of copper and zinc contaminations in bioponic systems using chicken manure fertilizer

Abstract

The bioponic system is a system that utilizes biological waste as a nutrient-rich source such as chicken manure fertilizer for plant growth integrated with aquaponic. At present, chicken manure fertilizer is contaminated with�Cu and Zn may have the potential health effects�through vegetable consumption. The objective of this study was to evaluate nitrogen transformation, nitrogen recovery, and plant growth in chicken manure-based bioponics at Cu (50–150 mg/kg) and Zn (200–600 mg/kg) supplementation and�investigate the effects of Cu and Zn supplementations on plant bioaccumulation, root microbial community, and dietary health risk. Cu and Zn concentrations�were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The result found that the average TKN was ranged from 11.2 ? 0.5 to 19.4 ? 1.8, TAN was 1.1 ? 0.8 to�1.5 ? 1.8 and�NO3?�was 11.6 ? 4.0 to�14.9 ? 4.7 mgN/L for lettuce�cultivated, while pak choi�cultivated TKN was ranged from 16.3 ? 0.1 to�19.4 ? 1.8, TAN was �0.7 ? 0.4 to�0.9 ? 0.5 and�NO3?�was 8.8 ? 6.8 to�10.1 ? 6.8 mgN/L respectively. These studies have shown that heavy metal contamination in chicken manure does not significantly affect nitrogen concentration and nitrogen use efficiency by plants ( significant level p < 0.05). The concentrations of Cu and Zn were�found in lettuce shoot and root ranged� 5.6 ? 0.1 to 7.2 ? 1.0 mg/kg and 64.8 ? 13.8 to 89.9 ? 2.6 mg/kg, while in pak choi was ranged�1.3 ? 0.3 to 4.1 ? 2.9 mg/kg and 43.3 ? 1.5 to 119.8 ? 34.1 mg/kg, respectively. Furthermore, the relative abundance of bacterial communities of lettuce�and pak choi�roots-based bioponics at phylum level was found Proteobacteria�and�Planctomycetes�are dominant highest relative abundance respectively.�However, the result of the health risk assessment was showed that HQ and HI < 1, which does not exceed the acceptable level. This study indicated that consuming lettuce and pak choi-based bioponic systems did not cause any human health effects or health risks to children and adults.