Accelerated Metolachlor Degradation in Soil by Zerovalent Iron and Compost Amendments

Abstract

Soil incubation and germination tests were conducted to assess zerovalent iron (ZVI), organic compost, moisture and their combinations on metolachlor degradation in soil. The ZVI alone degraded 91% of metolachlor in soil within 40 days following bi-phasic kinetics. Organic amendment alone facilitated metolachlor degradation in soil up to 60% after 40 days depending on the amendment rate. However, the combination of ZVI with compost amendment at 30 ton ha(-1) and 30% moisture content accelerated metolachlor degradation to 90% after 3 days and 98% after 40 days. The half life (t (1/2)) of metolachlor degradation with ZVI, compost at 30 ton ha(-1), and 30% moisture was about 1 day, which was faster than ZVI treatment alone and 98% faster than controls. Germination and growth of lettuce (Lactuca sativa) and crabgrass (Digitaria sanguinalis L. Scop.) were severely inhibited in unamended metolachlor-contaminated soils but when these soils were amended with ZVI, germination and growth was comparable to controls (metolachlor free soil). Metolachlor degradation was greatest when ZVI, compost and moisture were used together, suggesting that these treatments will maximize in situ remediation of metolachlor-contaminated soils in the field.

Ameliorants to immobilize Cd in rice paddy soils contaminated by abandoned metal mines in Korea

“…The uptake index was (Kim et al 2010). Even with decreased uptake for Cd and other metals, as well as potential concomitant decreases in the uptake of other nutrients, no significant decrease in estimated rice yields occurred in the greenhouse experiment due to these chemical changes in the soil (Fig.…”

Commercial versus synthesized polymers for soil erosion control and growth of Chinese cabbage

“…Three replicates were employed. During germination test, the incubation temperature was maintained at 25±2°C (ISTA 1996 ; Kim et al 2010 ).…”

Physico-chemical and agronomic results of soil remediation by In Situ Chemical Reduction applied to a chlordecone-contaminated nitisol at plot scale in a French Caribbean banana plantation

“…Despite the fact that ISCR clearly relies on reducing conditions, most papers published on the use of Daramend ® or ZVI for the remediation of soil polluted by chlorinated contaminants do not include data on soil redox potential (Abbey et al, 2003;Kim et al, 2010;Phillips et al, 2005;Zhuang et al, 2014). In a clayey soil with a water content set in laboratory conditions to 80 % of the water-holding capacity (Dalgren et al, 2009), the lowest, transitory, redox potential of -300 mV (relative to the standard hydrogen electrode) was obtained by the 20 th week of treatment after the addition of 2% Daramend ® and an additional 1.5 % of ZVI (w/w).…”