Availability of heavy metals for Brassica chinensis grown in an acidic loamy soil amended with a domestic and an industrial sewage sludge

• Published in: Water, air, and soil pollution air, and soil pollution, 2001-06, Vol.128 (3-4), p.339-353
• Main Authors: WONG, I. W. C, LAI, K. M, SU, D. S, FANG, M
• Format: Article
• Language: English
• Subjects: Acidic soils; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Brassica chinensis; China, People's Rep., Hong Kong; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Environmental monitoring; Feasibility studies; Fundamental and applied biological sciences. Psychology; Heavy metals; Hong Kong; Industrial wastes; Iron; Lime; Lime treatment; Liming; Loamy soils; Non agrochemicals pollutants; Phytopathology. Animal pests. Plant and forest protection; Plant extracts; Plant tissues; Pollution effects and side effects of agrochemicals on crop plants and forest trees. Other anthropogenic factors; Pollution effects. Side effects of agrochemicals; Sewage disposal; Sewage sludge; Sludge; Sludge disposal; Soil (material); Soil amendment; Vegetables
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1023/A:1010353107240

The use of sewage sludge on agriculture provides an alternativefor sewage sludge disposal. Therefore, it was the aim of thepresent study to evaluate the feasibility of using a domestic(Tai Po sludge) and an industrial (Yuen Long sludge) sewagesludge produced in Hong Kong for the growth of vegetable crops.The acidic loamy soil with or without lime treatment was amendedseparately with each sludge at application rates of 0, 5, 10, 25and 50% (v/v) for the growth of a common local vegetable crop,Brassica chinensis. The plant available metal contents, asindicated by the DTPA extraction, increased with an increase insludge amendment, but decreased with lime amendment at eachsludge application rate due to the reduced metal availabilityat a higher pH. Sludge amendment enhanced the dry weight yieldof B. chinensis and the increase was more obvious for thesoil with lime treatment. The industrial sludge caused a loweryield than that of the domestic sludge amendment and asignificant reduction in yield at high application rates of YuenLong sludge was also noted. Tissue heavy metal contents, exceptfor Fe, increased as the sludge amendment rate increased whileplant grown in Yuen Long sludge amended soil contained higher Crand Zn contents at each sludge application rate. Liming the soilreduced the heavy metal contents in the plant tissues, exceptfor Fe, which were all below the allowable levels for vegetablecrops. The present experiment demonstrates that liming wasimportant in facilitating the growth of B. chinensis in sludge amended soil. The optimal sludge amendment rate for thesoil with lime amendment was 25% Tai Po sludge and 10% YuenLong sludge, while for the soil without lime amendment was 10% and5%, respectively.[PUBLICATION ABSTRACT]