Environmental Safety Risks in Agricultural Application of Effluents From Sugar Molasses-based Fermentation Industries
WANG XiaoBin, YAN Xiang, LI XiuYing*, TU Cheng, SUN zhaokaia
Sugar molasses is a by-product from sugar industries. The sugar molasses-based fermentation industries mainly refer to the fermentation industries using molasses from sugar mills as raw materials for alcohol or yeast fermentation. A large volume of effluents can be produced in the process of sugar molasses-based alcohol or yeast fermentation. Considering the possibility of resource utilization with such effluents, many sugar-producing countries use the effluents for crop irrigation and fertilization or soil remediation directly into the farmlands by waste disposal methods. Because the effluents from sugar molasses-based fermentation industries are both high concentration organic wastewater, and heavy metal-polluted wastewater, which are difficult to be treated, With the long-term disposal of such effluents into the farmlands in some sugar-producing countries (such as Brazil, India, and China), the problems about ecological environment pollution in soil-crop-water systems are increasingly exposed. At present, some fertilizer production enterprises in China use such effluents as raw materials to produce organic water-soluble fertilizers (accounting for 32%), but the long-term research and monitoring data about environmental safety risks for agricultural application of the effluents from sugar molasses-based fermentation industries are still lack. This paper collects the relevant scientific research literatures since 1980 on the pollution characteristics of the effluents from sugar molasses-based fermentation industries, and their environmental impacts on agricultural application. Through the investigation and review on the relevant research data, this paper evaluates the environmental safety risks for agricultural application of the effluents from sugar molasses-based fermentation industries: (1) Such effluents were at a risk of seriously exceeding the limits for water quality standards, and a risk of ecotoxicity to plants. For example, such effluents have strong acidity, and high salinity, and contain not only high load organic pollutants, but also several heavy metals and other pollutants (including 5 heavy metals (As, Hg, Cd, Pb and Cr), but also other pollutants (such as Mn, Cu, Zn, Ni and Se, etc.). The concentrations of these pollutants mostly exceeded the limits of the Standards for Irrigation Water Quality (GB 5084—2021). (2) Such effluents for agricultural application were at a risk of farmland pollution. The concentrations of pollutants (such as Cu, Cd, Cr, Zn, Ni, Mn, Pb and Cl) detected from the soil samples irrigated with such effluents were about 10-641 times higher than those in the control soil. (3) Such effluents for agricultural application were at a safety risk of agricultural products. The concentrations of pollutants (such as Cu, Cd, Cr, Zn, Ni, Mn and Pb) detected in the grains of crops (wheat and mustard) irrigated with such effluents were about 3-12 times higher than those in the control crops, in which all the pollutants detected in the crops irrigated with such effluents exceeded both the allowable limits specified by FAO/WHO, but also the Maximum Levels of Contaminants in Food (GB 2762—2017) specified by China. In view of the issue of environmental safety risks for agricultural application of such effluents, therefore, it is necessary to strengthen the quality detection and risk control on the organic water-soluble fertilizer products with such effluents as raw material, to enable the safety of effluent utilization in agriculture.
WANG XiaoBin, YAN Xiang, LI XiuYing, TU Cheng, SUN zhaokaia. Environmental Safety Risks in Agricultural Application of Effluents From Sugar Molasses-based Fermentation Industries[J].Scientia Agricultura Sinica, 0, (): 1-.
