摘要
本研究以净水污泥为原料,通过400℃、4 h煅烧制备了热改性净水污泥。探讨了其对水体中磷酸盐的吸附特性,以及在不同投加量(2.5%、5%、10%)下热改性净水污泥对底泥中磷的控释及形态影响。同时结合SEM、BET等表征手段,探究了WTS_(400-4)对底泥中磷的稳定机理。结果表明,WTS_(400-4)相比WTS具有更发达的孔隙结构及比表面积,增强了对磷酸盐的吸附能力。吸附过程符合准二级动力学模型,Freundlich模型更适用于描述WTS_(400-4)吸附磷酸盐的过程,其中参数n>1,说明WTS_(400-4)对磷酸盐的吸附容易进行。WTS_(400-4)的添加会使底泥中弱吸附态磷(NH4Cl-P)、氧化还原敏感态磷(BD-P)和有机磷(Org-P)等不稳定态磷向稳定的金属氧化物结合态磷(NaOH-rP)转变,且其转化量会随着WTS_(400-4)投加量的增加而增加,有助于抑制底泥磷向上覆水释放。此外,WTS_(400-4)的添加可降低底泥中WSP(水溶性磷)和Olsen-P(碳酸氢钠可提取磷)这2种生物有效磷含量。WTS_(400-4)添加入底泥,一方面可以降低底泥中潜在活性磷和生物有效磷含量,降低底泥内源磷向上覆水释放的风险,另一方面可以通过WTS_(400-4)的吸附作用直接去除间隙水中的磷,从而降低上覆水和间隙水之间的磷浓度梯度,进而抑制磷从间隙水向上覆水中释放。结果表明,WTS_(400-4)可作为底泥改良剂用以控制水体和底泥的磷含量。
In this study,the heat modified water purification sludge(WTS_(400-4))was prepared by 400℃and 4 h pyrolysis using water treatment sludge as raw material.The adsorption characteristics of phosphate in water and the effects of different dosage(2.5%,5%,10%)on the controlled release and the form of phosphate in the sediment were discussed.At the same time,combining with SEM,BET and other characterization methods,the stabilization mechanism of WTS_(400-4)on phosphorus in sediment was explored.The results showed that WTS_(400-4)had more developed pore structure and specific surface area than WTS,which strengthened the phosphate adsorption capacity.The adsorption process conformed to the quasi-second-order kinetic model.Freundlich model was more suitable to describe the phosphate adsorption process on WTS_(400-4),the parameter n higher than1 indicated that the WTS_(400-4)was easy to adsorb phosphate.The addition of WTS_(400-4)could cause the transformation of the weakly adsorbed phosphorus(NH4Cl-P),redox-sensitive phosphorus(BD-P),organophosphorus(Org-P)and other readily released phosphorus to stable metal oxide bound phosphorus(NaOH-rP)in sediment,and the conversion amount increased with the increase of WTS_(400-4)dosage,which could contribute to inhibiting the release of phosphorus from the sediment.In addition,the addition of WTS_(400-4)could reduce the contents of WSP(water-soluble phosphorus)and Olsen-P(sodium bicarbonate extractable phosphorus)in the sediment.Adding WTS_(400-4)to the sediment,on the one hand,could reduce the contents of potential active phosphorus and bioavailable phosphorus in the sediment and reduce the risk of endogenous phosphorus release from the sediment to the overlying water.On the other hand,the phosphorus in interstitial water could be directly removed through the adsorption on WTS_(400-4),so as to reduce the phosphorus concentration gradient between overlying water and interstitial water and inhibit the release of phosphorus from interstitial water to overlying water.The results showe
作者
张志鹏
陈钰
孙飞
何李文泽
李艳君
唐敬祥
ZHANG Zhipeng;CHEN Yu;SUN Fei;HE Liwenze;LI Yanjun;TANG Jingxiang(Chengdu Center of Hydrogeology and Engineering Geology,Sichuan Bureau of Geology&Mineral Resources,Chengdu 610081,China;School of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第1期34-47,共14页
Chinese Journal of Environmental Engineering
关键词
净水污泥
热改性
吸附
底泥
内源磷控释
water treatment sludge
thermal modification
adsorption
sediment
controlled release of endogenous phosphorus
