The Benefits and Risks of Using River Sediment for Vietnamese Agriculture: A Case Study of the Nhieu Loc Canal in Ho Chi Minh City

Abstract

This study was conducted to assess the potential of river sediment for amendment of agricultural land with respect to heavy metal mobilization. The mobility and concentration of bioavailable heavy metal containing in the sediment were evaluated with the use of DTPA (diethylenetriamine pentaacetic acid) extraction techniques. Sum of metals in exchangeable and carbonate fractions obtained from sequential extraction scheme was used to evaluate the potential plant available. Four land blocks of size (1 m x 5.8 m) were prepared for cabbage field experiment and applied with different loading rates of sediment (approximately 28 and 42 ton/ha or equivalent to 100 kgN/ha and 150 kgN/ha). In parallel test, land blocks treated with fertilizer at similar nitrogen loading rates were also conducted for comparisons. Pure soil plot was used as a control system. Results show that both plant available and total heavy metal concentration were found higher in those plots treated with higher loading rates of sediment (42 ton/ha). The concentrations of heavy metals (Cu,Zn,Pb) in soil were decreased with time after crop harvesting and the residues remain in the soil were well below those of the UK, USA and Germany standards. Simple linear regression was used to show the correlation between the DTPA extractable metals and the plant metals fractions (root and shoot) resulting from fertilizer and sediment applications in the amended soils. In most cases, plant available metal concentrations showed positively correlated with plant metal uptake concentrations (R2 = 0.01-0.95, n = 3). Concentration of metals in the cabbage tissue detected: Zn at 131.53+/-10.43 mg kg(-1) DM, Cu at 20.84+/-1.62 mg kg(-1) DM, Pb at 0.09+/-0.01 mg kg(-1) DM, Cd at 0.21+/-0.09 mg kg(-1) DM and Ni at 0.44+/-0.05 mg kg(-1) DM. None of these metals concentration exceeded the tolerable limits of plant. One-way analysis of variance (ANOVA) was applied to find out the effect of different soil amendments on cabbage yield in term of fresh and dry weights. The sequence of crop yields in this field studies for amended soils is chemical fertilizer > sediment > control soil.

The EDTA effect on phytoextraction of single and combined metals-contaminated soils using rainbow pink (Dianthus chinensis)

“…Even through 0.005 M DTPA is not suitable in assessing the EDTA effect on phytoextraction of heavy metals-contaminated soils by rainbow pink in this study. The DTPA extractable soil Cd, Cu, Pb, and Zn concentration is useful to predict that concentration in plants (Parkpian et al, 2002). The 0.05 M EDTA (pH 7.0) extractable Cd, Zn, and Pb concentration results were similar to the 0.005 M DTPA (pH 5.3) results (Fig.…”

Distribution of triclosan-resistant genes in major pathogenic microorganisms revealed by metagenome and genome-wide analysis

“…These common human-associated pathogenic and few non-pathogenic bacteria include bacteria of the oral cavity, skin-associated bacteria, food and water-borne bacterial pathogens, zoonotic bacterial pathogens, nosocomial bacteria, emerging pathogens, and some beneficial resident flora ( S4 Table ). Along with reports of TCS accumulation from wastewater, wastewater treatment plants, sewage sludge [ 49 – 50 ] and sediments [ 51 ], in some Asian countries such as Vietnam, the use of sediment as fertilizer was also reported [ 52 ]. Therefore, we hypothesized that the sewage sludge from wastewater treatment plants and sediment containing TCS may selectively enrich soil-borne plant pathogens as pathogens may carry TCS resistance determinants.…”

Effects of EDTA on solubility of cadmium, zinc, and lead and their uptake by rainbow pink and vetiver grass

“…The concentrations of heavy metals in the soil solution extracted by different extractors or directly sampled by RSMS can predict the concentrations in the shoot of plants (Kabata-Pendias et al, 1993;Parkpian et al, 2002). The analysis of data in this study yields correlation coefficients (R 2 ) between the concentrations of three metals in the soil solution and those in the shoots of rainbow pink of 0.23 (Cd, p > 0:05), 0.50 (Zn, p < 0:01) and 0.91 (Pb, p < 0:001) (Fig.…”