Study On The Long-term Effects Of Organo-neutralization On The Availability Of Copper, Zinc And Arsenic In A Smeltery-contaminated Soil

A long-term field experiment at a heavy-metal contaminated field in the suburb of Xinluo County, Fujian Province was conducted to evaluate the feasibility of organo-neutralization in remediating heavy-metal contaminated soils. Lime, calcium magnesium phosphate, manure and peat were applied into the soils both separately or assembly as remediation materials. Nine treatments, control (CK), lime (L), calcium magnesium phosphate (G), peat (P), hog manure (M), lime with peat (LP), lime with hog manure (LM), calcium magnesium phosphate with peat (GP) and calcium magnesium phosphate with hog manure (GM), are included in this experiment. The main results are as follows:1 , On the polluted soil, the remediation materials increased the yields of rice, peanut, sweet potato, celery, water spinach and cauliflower except the P treatment, but the yield of rice was lower than the comparison in 05/07. After the neutral remediation materials or the neutral remediation materials with organic materials added to the polluted soil, soil pH was increased.2, Soil pH played an important role in controlling the availabilities of As, Cu and Zn. The content of available As increased while that of available Zn decreased with soil pH. The effects of soil pH on the Cu availability seemed more complicated. The available As decreased with the increase in available P and free Fe because phosphorous competed the adsorption sites with arsenate and iron oxides fixed the arsenate strongly. Most of the treatments increased the content of available As whereas decreased that of available Zn. The treatments of LP and GP showed better effects in lowering available Zn than the others, compared with the comparison their contents superlatively reduced 59.3%. The LP treatment decreased available Cu more effectively than the others, compared with the comparison its content superlatively reduced 27.2%, although the GP treatment also reduced it to some extents. Contrary to expection, the LM treatment increased the available Cu.3, The concentrations of As, Cu and Zn in the edible parts of the crops significantly correlated with the contents of soil available As, Cu and Zn, respectively. Of those, the concentrations of As, Zn in rice grains, water spinach with the soil available contents had achieved 1% side significance level, respectively; the concentration of Cu in the sweet potato with the soil available content had also achieved 1% side significance level. The treatments...