The potential impact of the addition of untreated sewage sludge from domestic waste and effluent from textile and tannery industries on agricultural soils is a common practice in this area of study. A proportion of he...The potential impact of the addition of untreated sewage sludge from domestic waste and effluent from textile and tannery industries on agricultural soils is a common practice in this area of study. A proportion of heavy metals in sewage sludge will be present in the soil solution. Soil samples from three Agricultural Site were collected at three depths （0-10 cm, 10-20 cm and 20-30 cm） from the months of June to September, 2007 （Rainy season）, February - May, 2008 （Dry season） for the determination of pH, electrical conductivity, organic matter, organic carbon, salinity, cation exchanged capacity, Ca, Na, K and heavy metals using standard procedures. Levels of the above parameters were higher in the dry season than in the rainy season. It was also observed from the result of this study that the levels of pH and organic carbon influenced the solubility and mobility of heavy metals. Generally, the levels of heavy metals, pH and organic carbon for the three agricultural sites increases significantly （P 〈 0.05） to a depth of 30 cm, while Conductivity, salinity, organic matter, CEC （Cation exchanged capacity）, Ca, Na and K decreased to a depth of 30 cm. The concentrations of heavy metals in the soil samples were higher than the Interim Canadian Environmental quality criteria and FAO （Food and Agriculture Organization） for contaminated site. Based on the above results, the study underscores the need for immediate remediation programme to control the use of untreated sewage sludge and waste water from tannery and textile industries by farmers in the study areas for crop production.展开更多
文摘The potential impact of the addition of untreated sewage sludge from domestic waste and effluent from textile and tannery industries on agricultural soils is a common practice in this area of study. A proportion of heavy metals in sewage sludge will be present in the soil solution. Soil samples from three Agricultural Site were collected at three depths （0-10 cm, 10-20 cm and 20-30 cm） from the months of June to September, 2007 （Rainy season）, February - May, 2008 （Dry season） for the determination of pH, electrical conductivity, organic matter, organic carbon, salinity, cation exchanged capacity, Ca, Na, K and heavy metals using standard procedures. Levels of the above parameters were higher in the dry season than in the rainy season. It was also observed from the result of this study that the levels of pH and organic carbon influenced the solubility and mobility of heavy metals. Generally, the levels of heavy metals, pH and organic carbon for the three agricultural sites increases significantly （P 〈 0.05） to a depth of 30 cm, while Conductivity, salinity, organic matter, CEC （Cation exchanged capacity）, Ca, Na and K decreased to a depth of 30 cm. The concentrations of heavy metals in the soil samples were higher than the Interim Canadian Environmental quality criteria and FAO （Food and Agriculture Organization） for contaminated site. Based on the above results, the study underscores the need for immediate remediation programme to control the use of untreated sewage sludge and waste water from tannery and textile industries by farmers in the study areas for crop production.
