实验室废液与脱硫石膏配施对碱土化学性质及苜蓿生长的影响

Effects of combined application of laboratory waste liquids and gypsum on chemical properties of alkali soils and alfalfa growth

为研究实验室废液资源化利用途径,将实验室废液进行无害化处理后与脱硫石膏配施,进行碱土改良与栽培苜蓿的盆栽试验。通过比较各处理土壤pH、碱化度、电导率、全盐量、八大离子、有效氮磷钾和有机质含量及苜蓿出苗率、株高和地上部生物量,评价实验室废液与脱硫石膏配施对碱土化学性质的改善效果及其对苜蓿生长的效应。结果表明:实验室废液呈强酸性,通常pH<2,其主要污染物是汞(Hg)、镉(Cd)、铜(Cu)、锌(Zn)、镍(Ni)、铅(Pb)和六价铬(Cr^(6+))等重金属,其中六价铬超标,可以用活性炭(添加量0.8 g/200 mL)吸附(48 h)法进行无害化处理,使废液的六价铬含量达到灌溉水质标准,从而加以资源化利用。实验室废液与脱硫石膏适当配施对碱土化学性质有显著的改良作用,对苜蓿苗期的生长有显著的促进作用,其中w(脱硫石膏)=1.3%配施φ(实验室废液)=30%和w(脱硫石膏)=2.0%配施φ(实验室废液)=30%这2个处理的效果最为显著。

In order to explore the resource utilization of laboratory waste liquid,the laboratory liquid waste harmlessly treated was applied together with gypsum to carry out the pot experiment of alkali soil improvement and alfalfa cultivation.By comparing soil pH,alkalinity,conductivity,total salt content,eight major ions,available nitrogen,phosphorus and potassium,organic matter contents,alfalfa seedling rate,plant height and aboveground biomass,the improvement effect of laboratory liquid waste and gypsum combined application on alkali soil chemical properties and growth of alfalfa was evaluated.The results show that the laboratory waste liquid is strongly acidic with pH<2,and the main pollutants are mercury(Hg),cadmium(Cd),copper(Cu),zinc(Zn),nickel(Ni),lead(Pb)and hexavalent chromium(Cr^(6+))and other heavy metals.The Cr^(6+) exceeds the standard,but can be harmlessly treated by activated carbon(0.8 g/200 mL)adsorption for 48h.The content of Cr^(6+) in the treated liquid meets the water quality standard of irrigation water and can be used as resources.Proper combination of laboratory waste liquid and gypsum can significantly improve the chemical properties of alkaline soils and promote the growth of alfalfa,among which the two treatments of 1.3%gypsum with a 30%concentration of laboratory wastes and 2.0%gypsum with a 30%concentration of laboratory wastes have the most significant effects.