造纸污泥土地利用的资源价值与潜在风险

Value and potential contamination risk of paper mill sludge land application:a review

随着造纸工业的发展，造纸污泥产生的环境问题日益显露出来。造纸污泥含水量高达75％-80％，有机物含量高，易腐烂、有恶臭、不便于运输和施用，必须对污泥进行稳定化、无害化处理。造纸污泥经过堆肥无害化处理后可以作为一种价廉优质的有机肥料，造纸污泥不仅含有丰富的有机质，且含有N、P、K等其他营养元素，土地利用不会导致重金属、有机污染物、硝酸盐淋失等污染风险。大量的研究表明，施用造纸污泥及其堆肥，可以增加土壤的有机质含量，降低土壤容重，促进团粒结构形成，改善土壤结构，提高土壤孔隙度和保水、保肥能力，增强土壤酶活性。施用造纸污泥还可改善土壤的养分状况，且具有一定的增产效果和后效。造纸污泥经过堆肥后制成有机肥或有机复混肥是解决造纸污泥出路的主要途径。

The pulp and paper industry generates a considerable amount of sludges from the paper making processes. With the development of paper making industry, the environment concerns about paper sludge have increased. Paper sludge has high water content from 75% to 80% and high organic matter. It is easily to be rotten and has odor, and also isn＇t inconvenient to transport and land application. Therefore, paper sludge should be stabilized and used non-hazardous treatment. Composting can be an effective strategy to stabilize the sludge and reduce its environmental risk prior to land application. The composting process biologically stabilizes heterogeneous raw paper sludge and reduces mass and volume and thus hauling costs. Paper sludge is rich in organic matter and other nutrients and its land application don＇t lead to the heavy metal contamination, the organic chemicals and nitrate leaching risk. Many studies involving paper sludge and compost land application highlight the effects on soil chemical and physical properties. Application of paper sludge can increase soil C, water holding properties and aggregation, also can improve soil structure, decrease soil bulk density, and promote the soil enzyme activity. Paper sludge and compost can also improve soil nutrients status, and increase crop production and has residual effect. It is a main avenue to dispose paper sludge that paper sludge after composting process mixes with chemical fertilizer as compound organic fertilizer.