The Application Of Excess Sludge Extract Of Sewage Treatment Plant In Landscaping

The excess sludge was used as the material,and the amino acid was hydrolyzed by potassium hydroxide to prepare the sludge extract as the research object in this paper.The fertilizer effect of the excess sludge extract was evaluated and its influence on the growth of landscaping plants and soil physical and chemical properties were studied through pot experiments.Three species of flower: Tagetes erecta L.,Zinnia elegans and Impatiens balsamina,and five species of turfgrass: Zoysiamatrella,Festuca arundinacea,Zoysia tenuifoli var,Cynodondactylon(L.)Pers.and Lolium perenne L.were selected as the test materials.In the pot experiment,six treatment groups were set up,which were 800 times(S1),700 times(S2),600 times(S3),500 times(S4),400 times(S5)of excess sludge extract dilution,respectively,and SS of commercial foliar fertilizer.The control group was clear water(CK).Each treatment was set up with three repetitions.The effects of plant height,stem thickness,flower diameter,flower yield,plant weight of three species of flower,plant height,growth rate,biomass,chlorophyll of five species of turfgrass,and the physical and chemical properties of soil of the plants under different application concentrations of excess sludge extract were explored.The main conclusions of the study were as follows:1.The initial solution content of amino acid in sludge extract was 3.6%,and the total amount of trace elements was 66.46 ppm.It was fully soluble,slightly alkaline,and the harmful elements As,Cd,and Pb did not exceed the content of the standard.Although the total amount of amino acids and trace elements was lower than the standards of amino acid-containing foliar fertilizers in China,it can meet the requirement of foliar fertilizer dilution in the market and can be used as amino acid foliar fertilizer after dilution.2.The sludge extract had a significant promotion effect on the plant height,stem thickness,flower diameter,flower yield,and plant weight of the three species of flower,and the growth indexes were significantly higher than that of the control group.The optimal application concentration of Tagetes erecta L.and Zinnia elegans was 600 times of excess sludge extract dilution.All the growth indexes of Tagetes erecta L.and the flower yield,stem thickness and plant weight of Zinnia elegans were better than the commercial foliar fertilizer.The optimal application concentration of Impatiens balsamina was 500 times of excess sludge extract dilution,and the effect of stem thickness and plant weight application was better than the commercial foliar fertilizer.3.The sludge extract had a significant promotion effect on the plant height,growth rate,biomass and chlorophyll of five species of turfgrasse.The optimal application concentration of Cynodondactylon(L.)Pers.and Zoysia tenuifoli var was 600 times of excess sludge extract dilution.All the growth indexes of Cynodondactylon(L.)Pers.and Zoysia tenuifoli var were better than the commercial foliar fertilizer.The best application concentration of Lolium perenne L.was 500 times of excess sludge extract dilution,and all the growth indexes were better than the commercial foliar fertilizer.The best application concentration of Festuca arundinacea and Zoysiamatrella was 700 times of excess sludge extract dilution.The plant height and growth rate of Festuca arundinacea and all the growth indexes of Zoysiamatrella were better than the commercial foliar fertilizer.4.The application concentration of the sludge extract shouldn't be too large.When the application concentration continued to increase to 400 times of excess sludge extract dilution,the growth indexes of the flowers and turfgrass had a downward trend.5.The sludge extract as a foliar fertilizer could provide organic matter and N,P,K content for the plants.Except Tagetes erecta L.,planted other plants could increase the K content in the soil.For Zinnia elegans,Impatiens balsamina and Lolium perenne L.,it could also increase the N content in the soil,so the sludge extract could improve the soil fertility.