Study on algae removal by immobilized biosystem on sponge

In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake＇s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time （HRT） was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preyingby microcreatures were the two main modes of algal removal, which occurred in two steps： first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.     

纤维加筋市政污泥固结特性试验研究

城市内河环境整治及清淤过程中往往产生大量污泥, 安全高效处理和处置这类市政污泥并实现资源化利用对改善城市生态环境和经济可持续发展具有重要意义。污泥具有高含水率、高孔隙比和高压缩性等特点, 由于其含有较多有机质和细颗粒, 一般难以通过机械脱水达到减容的目的。因此, 提高污泥的脱水速率和改善其固结特性是实现污泥安全处置及资源化利用的首要任务, 也是目前该课题的研究难点。本文提出了一种离散短丝纤维加筋技术, 为了研究该技术对污泥固结特性的影响, 对不同纤维掺量(0, 0.05%, 0.1%, 0.2%, 0.4%和0.8%)的污泥进行了一系列固结压缩试验, 分析了固结过程中纤维掺量对固结系数和渗透系数的影响。结果表明:在相同的荷载条件下, 随着纤维掺量的增加, 试样的压缩量、孔隙比变化显著增加, 固结时间和压缩系数相对减小, 且当纤维掺入量为0.1%时变化最显著, 为最优掺量。此外, 研究结果表明, 纤维的掺入增大了污泥的固结系数和渗透系数, 固结效率和固结效果得到明显改善。     

投加海水化学沉淀法去除污泥脱水液中的磷酸盐

研究污水处理厂产生的污泥脱水液中的磷酸盐(PO43-)和铵盐(NH4 )的去除方法。依据化学沉淀法的原理,含有Ca2 和Mg2 的海水加入污泥脱水液后,可以使污水中的PO43-与金属离子发生化学沉淀反应,实现污水除磷的目的。采用正交试验优化得到这种方法处理污泥脱水液的工艺条件:水温20℃,海水与污水混合比例为2∶10,体系pH值为10.5,反应时间20min。经过静态处理,污泥脱水液中氨态氮(NH4 -N)的平均去除率为34%,无机磷(PO43--P)的平均去除率为95%,比不投加海水的处理提高26%,这表明投加海水有利于强化污泥脱水液的除磷效果。动态处理也有较好的效果,PO43--P和NH4 -N的去除率分别可达91%和18%。这种技术不仅除磷效果好,处理成本也较低,生成的沉淀物还可以作为肥料施用,因而是污泥脱水液除磷的有效途径,特别适用于沿海地区污水处理厂。     

改性污泥作填埋场覆盖材料室内试验研究

对采用不同石灰配比改性自来水厂污泥进行一系列室内土工试验，考察其改性后土性变化规律，研究改性后作为垃圾填埋场覆盖材料的可行性，探讨了合适的改性方案。初步认为按照一定泥灰比改性后的自来水厂污泥可作为覆盖材料的废弃物，并且能有效减少热收缩性。     

污水污泥对染料废水的吸附脱色性能研究

为探讨污泥的资源化利用和开发新型的染料废水吸附剂 ,在对污水污泥吸附处理染料废水的工艺条件进行优化的基础上 ,得到污水污泥对 3种染料 (中性橙、中性黑BL ,元青 )的最大吸附量及其吸附类型。结果表明 ,污泥焙烧温度、废水pH值和吸附时间对吸附效果有影响 ,而废水温度的变化则不会引起脱色率的较大改变。在最佳工艺条件 (污泥经 40 0℃焙烧 ,废水pH值为 1,吸附时间为 3 0min ,水温为 3 0℃ )下 ,3种染料废水的脱色率均达到 98% ,其最大吸附量都在 2 9mg·g-1左右 ,与活性炭的效果相当 ,而高于其它种类的吸附剂。焙烧后的污泥对中性黑BL的吸附符合Langmuir方程 ,对中性橙和元青的吸附符合Henry方程。焙烧污泥的优良脱色性能使其在染料废水处理方面具有较好的应用前景。     

改性污泥复合材料时间效应三轴力学特性试验研究

采用水玻璃、生石灰和絮状木质纤维作为污泥改性剂对城市污泥改性后,在不同养护龄期和不同改性剂配比下对改性污泥复合材料开展三轴固结不排水力学强度和破坏特征试验研究。改性剂设置3种配比5%、10%和15%,在相同围压下,养护5 d改性污泥复合材料破坏强度相对于原污泥相应地提高到1.25～1.426、1.12～1.33、1.2～1.5;养护10 d分别提高到1.33～1.45、1.154～1.35、1.56～1.67,改性剂配比5%和10%试验比15%硬化速度较快。养护10 d改性污泥在主应力差为20 kPa时,初始切线模量发生很大的突变,并且10%和15% 组有3%～5%应变延时期。养护10 d时5%和10%配比的试样内摩擦角 值大于15%配比的试样,而黏聚力 值明显小于15%配比的试样。基于Konder应力-应变双曲线方程,利用主应力差渐近值作为归一化因子,建立改性污泥在三轴固结不排水条件下的主应力差-应变关系方程     

垃圾填埋场污泥灰改性黏土衬垫的强度特性及微观结构

为评价污泥灰改性黏土作为填埋场衬垫防渗材料的可行性,分析污泥灰改性黏土强度特性及孔隙结构,针对受垃圾渗沥液腐蚀的纯黏土与污泥灰掺量为1%～5%的改性黏土,采用直接剪切试验分析其抗剪强度变化规律,采用低温氮气吸附试验分析剪切变形后试样的孔隙结构组成。结果表明,改性黏土属于VI型等温线,并存在H3型滞后环,且2～6 nm介孔的数量占比较大。受垃圾渗沥液腐蚀后,黏土抗剪强度大幅下降,黏聚力与内摩擦角分别下降60.12%和19.17%;黏土的最大氮气吸附量降低16.19%,且孔隙分布双肩峰发育不完全;随污泥灰添加量的增加,改性黏土抗剪强度增大,且孔隙分布逐渐恢复双肩峰形式,总孔容增大。     

污泥吸附剂制备的研究

为探索城市污泥资源化的途径,以城市污水处理厂的剩余污泥为原料,采用氯化锌活化法制备污泥吸附剂,考察了活化剂浓度、固液比、活化温度、活化时间4种因素对制备污泥吸附剂碘吸附值的影响,并对吸附剂进行了表征分析。实验结果表明:氯化锌浓度3mol/L、固液比1:2、活化温度550℃和活化时间40min为最佳制备条件,此条件下制得的污泥吸附剂碘吸附值为408.94mg/g,比表面积199.196m2/g,总孔体积为0.481cm3/g,微孔体积为0.089cm3/g,平均孔径为4.83nm。与商品活性炭相比,污泥吸附剂的碘吸附值和比表面积较小,孔径较宽,微孔所占比例较小,主要以过渡结构为主。     

Heavy metal retention by soil mineral phases during a potential soil contamination by sewage sludge

The immobilization conditions of heavy metals （Ni, Cu, Zn, Pb） potentially released from sewage sludge to soils were examined. Competitive adsorption experiments, sequential extraction and analytical electron microscopic studies were performed on soils with different compositional characteristics to gain information about the interaction and association of metals with soil minerals. The results showed that Cu and Pb can be characterized by a preferred adsorption in contrast to Zn and Ni independent of initial metal concentrations, ratios, and soil composition. Precipitation is the dominating retardation process in the sample containing carbonates, but it is also characteristic of metals with inhibited adsorption in samples free of carbonate. Both Cu and Pb show high affinity towards organic matter. Differences in metal affinities towards different clay minerals show the immobilization of Cu rather by specific adsorption and that of Pb rather by ion exchange. According to the sequential extraction studies the role of ion exchange is the most important process for the retardation of Zn, and in the sample containing montmorillonite. The specific adsorption is significant mostly for Cu and Pb, and primarily in samples rich in organic matter and containing vermiculite. The co-precipitation of metals with Fe-Mn oxides is significant primarily for Cu, but in some cases Pb and Zn can be also found in this fraction. In general, the strength of immobilization for the studied metals is as follows： Cu〉Pb〉Zn〉Ni. Significantly higher metal adsorption was found by the phases in the sample containing carbonates, as well as in samples characterized by the close association of clay minerals and iron oxides. Smectite and vermiculite are the most important adsorbents in soils for all of the metals. Additionally, iron-oxides immboilize significant amounts of Cu and Zn, too.     

城镇污水处理厂污泥处理处置及污染防治技术政策（试行）

关于印发《城镇污水处理厂污泥处理处置及污染防治技术政策（试行）》的通知建城[2009]23号 各省、自治区、直辖市建设厅（建委,市政管委、水务局）、环保局、科技厅（委）,计划单列市建委（建设局）、环保局、科技局。新疆生产建设兵团建设局、环保局、科技局：为推动城镇污水处理厂污泥处理处置技术进步,明确城镇污水处理厂污泥处理处置技术发展方向和技术原则,指导各地开展城镇污水处理厂污泥处理处置技术研发和推广应用,促进工程建设和运行管理,避免二次污染,保护和改善生态环境,促进节能减排和污泥资源化利用,住房和城乡建设部、环境保护部和、、科学技术部联合制定了《城镇污水处理厂污泥处理处置及污染防治技术政策（试行）》。现印发给你们,请结合本地区实际认真执行。