水厂污泥制备可吸附污染物的生态透水砖

污泥制砖是现阶段污泥资源化、稳定无害化、产业化途径之一。采用黏土作为黏结材料添加到给水厂污泥中烧结透水砖;并对制备的烧结砖吸附水体中污染物的性能进行了试验。用黏土作为添加剂加入到水厂污泥中制备透水砖的最佳条件是给水厂污泥、黏土和石英砂的比例分别为40%、30%、30%,在30 MPa的压力下压制成砖坯,烧成温度为1 100℃,保温时间为3 h,制成品抗压强度达到32. 7 MPa,透水系数为1. 06×10~(-2)cm/s,满足透水砖标准的要求。在实际生产中,为了尽量多地利用给水厂污泥,可将污泥的比例控制在45%左右,粗骨料标准砂的粒径控制在0. 8～1. 2 mm之间,水厂污泥筛分至0. 3 mm左右,黏土筛分至0. 125 mm左右。烧结砖吸附水中污染物试验表明,震荡吸附60 h后,其对初始浓度分别为158 mg/L、6. 17 mg/L和10. 86 mg/L的COD、NH_4~+-N和TP的去除率分别为25%、30%和57%。

Preparation of Permeable Bricks Using Water Treatment Residual and Its Adsorption Capacity for Pollutants

Making bricks using water treatment residual (WTR) is one of the feasible methods for municipal sludge recycling and reclamation. The preparation conditions of permeable bricks using WTR and clay, as a binding material, were investigated and the adsorption performance for contaminants in water by the sintered bricks was tested. The optimal preparing conditions were as follows: the proportions of the WTR, clay and quartz sand were 40%, 30%, and 30%, respectively; the unfired bricks were pressed at a pressure of 30 Mpa; sintering temperature was 1100°C and that temperature was kept for 3h. The compressive strength and the water permeability coefficient of the finished bricks were 32.7Mpa and 1.06×10_-2cm/s, both of which met the demand of the permeable brick standard. The proportion of the WTR can be adjusted to about 45%. The particle size of the quartz sand was controlled at 0.8-1.2 mm, and about 0.3mm and 0.125mm for WTR and clay respectively. The adsorption tests of contaminants in water by the sintered brick showed when the initial concentrations of COD, NH₄₊-N and TP were 158mg/L, 6.17mg/L and 10.86 mg/L in water solution, the removal rates of COD, NH₄₊-N and TP were 25%, 30% and 57% after 60h, respectively,