利用白云石回收污泥厌氧消化液中的磷

为经济有效地从污泥厌氧消化液中回收磷,构建了以白云石提供钙镁源的磷回收方法,探讨了磷回收的工艺条件与效果。通过盐酸酸化厌氧消化液以降低其碳酸盐含量,同时利用白云石溶于冷稀盐酸的特性使其钙镁缓慢释放到酸化的厌氧消化液中形成第一步磷回收体系,考察体系酸化pH、白云石与厌氧消化液的固液比以及反应pH对白云石的钙镁释放和磷回收效果的影响;第一步磷回收后的上清液为第二步厌氧消化液磷回收提供钙镁源,研究投加钙磷摩尔比对磷回收效果的影响。实验结果表明,当固液比为5.0时,在酸化pH为4.0～4.5且酸化溶出时间为10 h以及反应pH为9.0的条件下,第一步磷回收产物以磷酸钙盐沉淀为主,厌氧消化液磷回收率及回收产物含磷率（以P2O5计）分别达到99.43%和38.49%;第一步磷回收后的上清液按一定的钙磷摩尔比投加到酸化后的厌氧消化液中进行第二步磷回收,当投加钙磷摩尔比为0.20时,在反应pH为9.0的条件下,回收产物同时含有磷酸钙盐和磷酸铵镁,厌氧消化液中氮、磷回收率分别达到13.19%和90.90%,回收产物氮、磷含量（以P2O5计）分别为0.26%和39.58%;经XRD、XRF、ICP及SEM等分析表征,2步磷回收的产物以磷酸钙盐和磷酸铵镁为主要成分,杂质少。研究表明,利用白云石为钙镁源,通过分别构建不同的磷回收体系可以分步从污泥厌氧消化液中经济有效地回收磷,且磷回收率和回收产物含磷率高。     

Sources and Sinks of Phosphorus for a Perturbed Stream and the Effects of Mineral Deposits1

Effler, Steven W., Anthony R. Prestigiacomo, David A. Matthews, and Feng Peng, 2012. Sources and Sinks of Phosphorus for a Perturbed Stream and the Effects of Mineral Deposits. Journal of the American Water Resources Association (JAWRA) 48(2): 321‐335. DOI: 10.1111/j.1752‐1688.2011.00617.x Abstract: Patterns of concentrations and loading rates of multiple forms of phosphorus (P) are resolved and analyzed along Ninemile Creek, New York, a stream perturbed by a domestic waste discharge and residual effects of a closed industry. This analysis is based on biweekly monitoring of total, dissolved, and soluble reactive P (SRP) for 19 months at four sites that bracket each of these effects, and 15 years of biweekly measurements at the two sites that bound industrial deposits. The minerogenic particle populations of the stream and the surficial sediments along the reach with extensive CaCO₃ and clay mineral deposits are characterized with an individual particle analysis technique. Mass balance analyses depict: (1) increasing nonpoint inputs of particulate and dissolved organic P along the stream length; (2) input of P from a domestic waste facility, almost entirely in the form of SRP; and (3) a compensating downstream loss of SRP over the reach with the extensive industrial deposits of CaCO₃. The downstream sink process for SRP is attributed to sorption processes with minerogenic deposits. The domestic waste‐based source and the compensating industrial waste‐based sink are noteworthy fluxes relative to other prevailing loads received by downstream Onondaga Lake, for which a major rehabilitation program targeting cultural eutrophication is underway. The P source/sink conditions of this stream are considered in the context of this rehabilitation program.     

The effects of ammonium sulphate and urea upon egg hatching and miracidial survival of Schistosoma mansoni

Abstract

The effects of various concentrations of ammonium sulphate and urea on egg hatching and miracidial survival of S. mansoni were tested in order to determine if the use of these fertilizers in the ricelands of the Republic of Cameroon could affect the transmission of schistosomiasis. Results indicate that hatching of eggs and survival of miracidia varied with concentrations of tested chemicals and times of exposure. Exposure of S. mansoni eggs to 0.20%‐1.00% ammonium sulphate or to 0.50%‐4.00% urea reduced their ability to hatch and produce miracidia. A chemical concentration of 1.00% ammonium sulphate or 4.00% urea was found to be sufficient to produce complete inhibition of hatching. High concentrations of both chemicals not only inhibited miracidial emmergence but also may be ovocidal. Results obtained from miracidial survival tests indicated that LC₅, LC₅₀ and LC₉₅ values for ammonium sulphate were 0.07%, 0.80% and 10.61% after 2 hours of exposure; 0.03%, 0.16% and 0.90% after 4 hours of exposure; and 0.30%, 0.20% and 0.40% after 6 hours of exposure respectively. Similar statistical analyses revealed that the LC₅, LC₅₀ and LC₉₅ values for urea were 0.22%, 1.90% and 16.25% after 2 hours of exposure; 0.28%, 0.57% and 1.14% after 4 hours of exposure; and 0.13%, 0.27% and 0.57%” after 6 hours of exposure respectively. Although the two fertilizers exerted some adverse effects on S. mansoni eggs and miracidia at relatively high concentrations, neither of them was found to be of practical value. Ammonium sulphate and urea concentrations effective in killing S. mansoni eggs and miracidia were about one to two orders of magnitude greater than the actual field application rates.     

混凝吸附及化学氧化深度处理焦化废水

以蒙脱石、凹凸棒石、次氯酸钙和PAC、PAM为基本材料,对焦化废水二级生化出水进行深度处理。实验结果表明：蒙脱石与凹凸棒石以4：1的比例配合使用,可明显提高焦化废水中COD和色度去除率;采用次氯酸钙作为氧化剂,可进一步提高焦化废水的脱色率和COD去除率,处理间差异达到极显著和显著水平;去除COD的最优实验条件为：粘土矿物（蒙脱石：和凹凸棒石=4：1）添加量4．0g／L、氧化剂（次氯酸钙）添加量1．0g／L、絮凝剂（聚合氯化铝：聚丙烯酰胺=15／1）添加量0．15g／L,处理后色度去除率达到97．0％,COD去除率达到69．1％;脱色的最优实验条件为：粘土矿物添加量4．0g／L、氧化剂添加量1．0g／L、絮凝剂添加量0．2g／L,处理后色度去除率达到98．5％,COD去除率达到66．4％。     

过量生石灰对污泥含水率和有机物含量的影响

为了研究生石灰(氧化钙,CaO)处理活性污泥对污泥含水率和有机物含量的影响,通过向南京某城市污水处理厂出厂污泥投加过量CaO进行脱水实验,测定投加CaO后污泥的含水率;烘干后的脱水污泥进行热重实验,研究CaO投加量对污泥中有机组分含量的影响.脱水实验表明:随着CaO与污泥质量比的增大,污泥含水率迅速减小,当质量比达到1.5时,污泥达到完全脱水;投加过量CaO的脱水污泥呈干燥的粉末状,粒度均匀,可作为水泥生产的辅料。热重实验表明:投加CaO后单位干泥失重百分比随CaO与污泥质量比增大而逐渐减小,向污泥中投加CaO有利于污泥中有机组分的释放和去除,实现污泥的稳定化。     

水合改性对钙基吸收剂循环捕集CO2的影响

在钙基吸收剂捕集CO2的过程中,吸收剂转化率会随着循环次数的增加而迅速降低。钙基吸收剂的水合改性作为改善吸收剂循环转化率的主要方法之一受到了国内外学者的广泛关注。总结了目前国内外研究者对不同的吸收剂、循环捕集条件下的水合改性方法的研究成果。结果表明,在循环过程中的不同阶段对吸收剂进行水合处理后得到的效果不同。其中,在碳酸化阶段、煅烧阶段、循环捕集前预处理以及煅烧后对吸收剂水合改性．吸收剂捕集CO2的能力均得到了改善;碳酸化反应后对吸收剂进行水合处理是否对循环吸收有利还存在争议。目前,利用水合改性的方法提高钙基吸收剂循环捕集CO2能力的机理还存在争议,且水合改性后的吸收剂机械性能差以及此方法能耗高的问题尚待解决。     

CPC/CaO2氧缓释复合材料的制备及其释氧性能探讨

利用过氧化钙（CaO2）遇水释放氧气的特性,采用混合法将CaO2载入到磷酸钙骨水泥（CPC）中,并通过挤出-滚圆造粒方法制备出CPC/CaO2氧缓释复合材料,旨在为污染地下水的好氧生物修复技术提供一种长期、高效的供氧源。由X射线衍射（XRD）分析可知,通过固相反应制取的CPC主要成分为Ca5（PO4）3（OH）和Ca10（PO4）6（OH）2,具有较快的固化时间和固化效果;CPC/CaO2氧缓释复合材料分3个阶段进行释氧,其中2、3阶段分别符合一级和零级释氧动力学特征,且其释氧速率和释氧周期得到明显改善。本研究成果可用于实际地下水修复工程,解决污染地下水原位生物修复过程中溶解氧（DO）的输送问题。     

丙烯酸/烯丙基壬基酚聚醚硫酸铵无磷阻垢剂制备及性能

以过硫酸铵为引发剂,丙烯酸(AA)和烯丙基壬基酚聚醚硫酸铵(TS-10,10为乙烯基重复单元数)为单体合成了TS-10/AA聚合物阻垢剂。利用红外光谱对共聚物结构进行了表征。采用静态阻垢方法探讨了单体配比、阻垢剂用量以及溶液中Fe2+、Ca2+、PO43-、杀生剂和溶液pH值对共聚物阻磷酸钙垢性能的影响,结果表明单体TS-10与AA质量比为3∶1合成的TS-10/AA阻垢剂阻磷酸钙效果最佳。阻垢剂TS-10/AA在高Fe2+、高Ca2+、高pH值条件下具有优异的阻磷酸钙垢性能,与异噻唑啉酮杀生剂有很好的配伍性。阻垢剂TS-10/AA用量存在临界值效应,在8 mg/L时,阻磷酸钙垢为99.3%。扫描电镜表明,阻垢剂TS-10/AA改变磷酸钙的晶型和松散度。TS-10/AA的高效阻磷酸钙垢性能是源于其侧链上含有强亲水性的聚醚结构以及大量的—COO-离子且易与循环水系统中存在的钙离子发生作用。实验结果表明,TS-10/AA是一种性能优异的循环冷却水用阻垢剂。     

Mechanochemical degradation of chlorinated contaminants in fly ash with a calcium-based degradation reagent

This report presents our results in a low-temperature mechanochemical hydrodechlorination process applied to fly ash coming from a municipal waste incinerator in order to efficiently remove all traces of PCDDs, PCDFs and PCBs. We found that the most suitable degradation agent is a mixture of metallic calcium and calcium oxide. A sample of fly ash presenting a TEQ of 5200 pg g⁻¹ was completely detoxified (no traces of PCDDs, PCDFs and PCBs detected) after ball-milling at 400 rpm over night.     

亚磷酸钙工业废渣制取亚磷酸

研究了以亚磷酸钙工业废渣为原料制取亚磷酸的工艺条件.实验确定最佳工艺条件为:在1 500 mL去离子水中加入亚磷酸钙工业废渣500.0 g和碳酸钠350.0 g,80℃反应8h,得亚磷酸钠溶液;向亚磷酸钠溶液中加入163.3 g硫酸得到亚磷酸粗产品;加入300 mL无水乙酸萃取亚磷酸粗产品后,在蒸馏温度100℃、蒸馏真...