Sea salt bittern-driven forward osmosis for nutrient recovery from black water: A dual waste-to-resource innovation via the osmotic membrane process

• A dual “waste-to-resource” application of FO was proposed. • Performance of sea salt bittern as an economic FO draw solution was evaluated. • High quality struvite recovery from black water using FO was demonstrated. • Feed pH is a key factor to control the form of recovered phosphorous. A dual “waste-to-resource” innovation in nutrient enrichment and recovery from domestic black water using a sea salt bittern (SSB)-driven forward osmosis (FO) process is proposed and demonstrated. The performance of SSB as a “waste-to-resource” draw solution for FO was first evaluated. A synthetic SSB-driven FO provided a water flux of 25.67±3.36 L/m²⋅h, which was 1.5‒1.7 times compared with synthetic seawater, 1 M NaCl, and 1 M MgCl₂. Slightly compromised performance regarding reverse solute selectivity was observed. In compensation, the enhanced reverse diffusion of Mg²⁺ suggested superior potential in terms of recovering nutrients in the form of struvite precipitation. The nutrient enrichment was performed using both the pre-filtered influent and effluent of a domestic septic tank. Over 80% of phosphate-P recovery was achieved from both low- and high-strength black water at a feed volume reduction up to 80%‒90%. With an elevated feed pH (~9), approximately 60%‒85% enriched phosphate-P was able to be recovered in the form of precipitated stuvite. Whereas the enrichment performance of total Kjeldahl nitrogen (TKN) largely differed depending on the strength of black water. Improved concentration factor (i.e., 3-folds) and retention (>60%) of TKN was obtained in the high-nutrient-strength black water at a feed volume reduction of 80%, in comparison with a weak TKN enrichment observed in low-strength black water. The results suggested a good potential for nutrient recovery based on this dual “waste-to-resource” FO system with proper management of membrane cleaning.     

Returning to normalcy in the short term: a preliminary examination of recovery from Hurricane Harvey among individuals with home damage

This study focuses on coastal counties in Texas, United States, affected by Hurricane Harvey in 2017 to gauge the influence of individual and contextual characteristics on people's ability to return to normalcy in the short term. Data from a survey conducted by the Kaiser Family Foundation and the Episcopal Health Foundation between October and November 2017 were utilised in the analysis. The paper observes, based on the results of an ordered logistic regression, and contrary to previous work, that age, gender, levels of poverty, and social capital are not significant predictors of a return to normalcy. However, indicators such as whether a person evacuated, if he/she identified as Hispanic/Latino, the extent of damage sustained to one's home, and if one's automobile was damaged or destroyed are shown to affect recovery. A discussion of the potential reasons for these findings is provided as a means of informing future research on disaster recovery.     

组合方法去除新型采油污水中有机污染物的研究

含聚丙烯酰胺采油污水的有效处理是近年来困扰油田三次采油生产的一个难题。研究采用移动床生物膜技术与O3/UV/H2O2高级氧化技术的组合方法来处理含聚丙烯酰胺采油污水。实验结果表明,移动床生物膜技术可以有效去除污水中的石油类有机物,但对聚丙烯酰胺几乎无效果。O3/UV/H2O2高级氧化技术可以降解污水中的聚丙烯酰胺。组合方法处理后的含聚丙烯酰胺采油污水水质可以达到污水综合排放标准中的一级要求。     

转炉渣诱导磷酸钙结晶法去除和回收废水中磷的研究

以转炉渣为晶种材料,利用批次结晶沉淀实验,研究不同的反应条件对诱导磷酸钙结晶法去除和回收废水中磷的影响。结果表明,最优反应条件为:pH=9.5,Ca/P摩尔比2∶1,转炉渣用量1.7 g/L,反应时间3 h,在此条件下,碳酸根对反应的影响甚小,对养猪场废水和污泥浓缩池上清液的处理,最高去除率分别达到95.36%和96.54%;转炉渣循环利用10次,回收磷的效果仍然很好。运用扫描电子显微镜(SEM)、X射线能谱仪(EDS)和X射线衍射仪(XRD)等测试手段对在最优工艺条件下重复使用10次的转炉渣进行了表征,证明回收的磷主要以羟基磷灰石(HAP)形态存在。     

污泥厌氧消化液中碳酸盐对回收磷的影响

为探讨污泥厌氧消化液中碳酸盐对以磷酸钙盐形式回收磷的影响,以粉煤灰浸出液为钙源,考察了消化液中的碳酸盐对磷回收过程和磷回收产物性质的影响。实验结果表明,在反应pH为10、反应钙磷摩尔比为1.67、反应时间为10 m in的条件下,消化液碳酸盐浓度为2 400 mg/L(以CaCO3计)时,磷的回收率为78.53%,回收产物中磷含量(以P2O5计)为28.93%;对消化液进行盐酸预酸化使pH达到4及以下时,磷回收率接近100%,回收产物中磷含量(以P2O5计)达到43.08%。消化液中碳酸盐的存在易形成碳酸钙沉淀,从而降低了磷回收率、回收产物中磷含量以及回收产品的纯度;预酸化能够有效地去除消化液中的碳酸盐并降低了其对磷回收的不利影响。     

水蒸气对改性椰壳活性炭吸附VOCs的影响

选取甲苯、甲基丙烯酸甲酯、吡啶3种不同极性的有机物作为吸附质,改性椰壳活性炭作为吸附剂,使用穿透曲线法研究了水蒸气对这3种VOCs在活性炭上吸附行为的影响,并同时讨论了水蒸气预处理对活性炭吸附的影响。结果表明,改性椰壳活性炭对3种有机废气均具有良好的吸附性能,但水蒸气的存在对极性小的甲苯吸附影响较大,尤其当甲苯浓度较低时,水分子易与甲苯产生竞争吸附。在对活性炭吸湿预处理后发现,吡啶、甲基丙烯酸甲酯分子可以置换出活性炭预先吸附的水分子,并且通过低温水蒸气加热再生法可以方便地完成活性炭再生过程,重复再生率可以维持在85%。     

膜电解法从模拟酸性蚀刻废液中回收铜粉

酸性蚀刻废液是一种印制电路板制作过程中产生的强酸、高铜的工业废水,对其回收利用具有较高的经济价值。采用膜电解法处理模拟酸性蚀刻废液,在阴极区回收铜粉。研究了铜粉的形成条件,考察了阴极液铜浓度、温度和电流密度对阴极电流效率的影响。结果表明,阴极液的铜浓度在20~25 g/L,温度为45~50℃,电流密度在11~12 A/dm2,阴极的电流效率最高。随着阴极液酸度的增加,铜粉的纯度提高,但阴极电效会降低。为保证较高的铜粉纯度及阴极电效,阴极液的酸度在0.32~0.36 mol/L为宜。     

黄浦江上游原水强化处理选炭试验研究

以黄浦江上游水源为原水,通过煤质炭、竹质炭、椰壳炭等炭种筛选小试和中试试验,研究了黄浦江上游原水中有机污染物强化去除的最佳炭种及其最佳投加量。结果表明黄浦江上游原水中投加PAC能够改善处理后水质,提高原水中有机物的去除效果;并且随着PAC投加量的增加,原水中有机物去除效果增强;综合性价比、碳源等因素确定竹质炭较为经济合理;当竹质炭投加量为10～15mg/L时,处理后出水CODMn可达到3mg/L或以下。     

政府支持垃圾焚烧发电的公共利益分析

阐述了垃圾焚烧发电的公共利益性质,政府支持垃圾焚烧发电是增进公共利益的必然要求,政府应构建支持垃圾焚烧发电常态机制,整合与垃圾焚烧发电相关各方力量,制定科学合理的正负激励政策,以期相关各方为垃圾焚烧发电的贡献最大化,有效增进公共利益。     

Falcon离心分选机回收废弃电路板金属的灰色模型研究

电子废弃物的资源化既能实现资源的二次利用,又能防止环境污染,具有重要的理论意义和应用价值。论述了Falcon离心分选机分选电路板的机制,并对小于0.5mm废弃电路板中金属富集体进行了分选试验。运用GM(0,N)模型对离心复合力场中回收废弃电路板建立了分选灰色模型,与实际分选结果比较表明,该模型精度很高。该模型可以对离心复合力场中回收废弃电路板金属的分选试验结果进行预测。