Reduced graphene oxide-nano zero value iron (rGO-nZVI) micro-electrolysis accelerating Cr(VI) removal in aquifer

Nanoscale zero-valent iron (nZVI) assembled on graphene oxide (GO) (rGO-nZVI) composites were synthesized by reduction of GO and ferrous ions with potassium borohydride, for use in Cr(VI) removal from aqueous solution. The results showed that the two-dimensional structure of GO could provide a skeleton support for Fe⁰, thus overcoming the bottleneck of aggregation for nZVI. Also, rGO-nZVI would form a ferric-carbon micro-electrolysis system in Cr(VI)-contaminated aquifers, enhancing and accelerating electron transfer, exhibiting high rate and capacity for Cr(VI) removal. The optimum dosage of the applied rGO-nZVI was linearly correlated with the initial Cr(VI) concentration. Characterization of rGO-nZVI before and after reaction with Cr(VI) revealed the process of Cr(VI) removal: rGO-nZVI firstly transferred electrons from Fe⁰ cores via their Fe(II)/Fe(III) shells to the GO sheet; there, negatively charged Cr(VI) received electrons and changed into positively charged Cr(III), which was adsorbed by the negatively charged GO sheet, avoiding the capping and passivating of nZVI. rGO-nZVI formed a good electrically conductive network, and thus had long-term electron releasing properties, which was important for groundwater remediation.     

Effects of adding bulking agents on the biodrying of kitchen waste and the odor emissions produced

The effects of adding a bulking agent on the performance and odor emissions(ammonia and eight sulfur-containing odorous compounds) when biodrying kitchen waste were investigated. Three treatments were considered: the addition of either cornstalks(CS) or wood peat(WP) to kitchen waste as a bulking agent before biodrying, and a control treatment(CK). The water-removal rates for CK, CS, and WP treatments were 0.35, 0.56, and0.43 kg/kg, respectively. Addition of bulking agents to kitchen waste produced less leachate,higher moisture-removal rates, and lower consumption of volatile solids. The CS treatment had the highest biodrying index(4.07), and those for the WP and CK treatments were 3.67 and 1.97, respectively. Adding cornstalks or wood peat decreased NH3 emissions by 55.8%and 71.7%, respectively. Total sulfur losses were 3.6%–21.6% after 21 days biodrying, and H2 S and Me2 SS were the main( 95%) sulfur compounds released. The smallest amounts of sulfur-containing odorous compounds were emitted when cornstalks were added, and adding cornstalks and wood peat decreased total sulfur losses by 50.6%–64.8%.     

不锈钢厂废水减排回用及提标工艺技术研究

国务院环保部近年来出台了多项环保政策和排放标准,根据最新的钢铁工业水污染物排放标准,某不锈钢厂首先对废酸水处理站排水进行生物脱氮预处理,然后与循环水站排污水混合后,采用混凝沉淀-砂滤-超滤-反渗透组合工艺进行减排回用处理,出水达到工业水标准后回用,对反渗透浓水采用生物脱氮-混凝沉淀-电催化氧化-砂滤工艺进行处理,处理后出水达到《钢铁工业水污染物排放标准》(GB 13456-2012)直接排放标准后外排.     

In situ combined chemical and biological assessment of estrogenic pollution in a water recycling system

Estrogenic pollution and its control in aquatic systems have drawn substantial attention around the world. The chemical and biological assessment approaches currently utilized in the laboratory or field cannot give an integrated assessment of the pollution when used separately. In this study, in situ chemical and biological methods were combined to detect pollution in a water recycling system. Data for the water quality index(WQI) demonstrated that the water treatment resulted in the decline of pollution from upstream to downstream.Wild male Nile tilapia, Oreochromis niloticus, was sampled in June and September. The concentrations of four common endocrine disrupting chemicals(EDCs) were determined in the tilapia liver by chromatographic analysis methods. The level of 17β-estradiol(E2) declined from upstream to downstream in both months. In contrast, the levels of bisphenol A(BPA),di-(2-ethylhcxyl) phthalate(DEHP), and perfluorooctane sulfonate(PFOS) did not display this declining tendency. The highest relative expression of vitellogenin 1(VTG1) was observed in tilapia from upstream, then the level significantly decreased along the water system. The relative expression levels of CYP1A1 in the water system were also significantly higher than that of the control. However, no declining trend could be observed along the water system. The change of VTG1 expression corresponded well with that of E2 levels in the tilapia liver. Overall,our study assessed the pollution by endocrine disruptors using chemical and biological data with good correspondence. This study also demonstrated the effectiveness of the water recycling system in eliminating estrogen pollution in municipal sewage.     

ELEMENTAL PROBLEMS OF PROJECT APPRAISAL OF DISASTER RESISTANT ENGINEERING

Introduction　Disasterresistantengineeringprojectmeansaprojectwhichaimsatpreventingandre ducingvariouskindsofdisasterswhicharehappeningorwillprobablyhappen ,anditcanalsobecalleddisasterreductionproject.Itcanbeanewly builtproject ,suchasanewly builttidalbarrageincoastalareaetc .,adampprooffloodgate dam ;oraenlarging scaleonoriginalpro jects,suchasfixingpresentconstructionswithanti earthquakeequipmentorimprovingfloodcontrolfacilities.　Constructingdisasterresistantengineeringprojectisanimportant…     

可逆配仓带式输送机除尘方法分析及应用

叙述了可逆配仓带式输送机扬尘污染的特点，以及目前常用的几种除尘方法，介绍了移动式通风口装置技术在这方面的应用实例。     

我国城镇可持续发展实验区建设的理论与实践

可持续发展综合实验区是我国实施可持续发展战略的重要行动。本文在分析、总结我国城镇可持续发展实验区实践的基础上,提出了建设城镇可持续发展实验区的基本思路     

ZnFe_2O_4/TiO_2光催化剂制备及乙酰甲胺磷降解性能研究

分别采用共沉淀法和溶胶-凝胶法制备了ZnFe2O4和掺杂ZnFe2O4的纳米级TiO2光催化剂,进行了XRD、TEM和UV visDRS表征,以卤素灯为光源对纳米TiO2降解水溶液中乙酰甲胺磷农药进行了研究。考察了反应液初始pH值、催化剂用量、H2O2用量对降解率的影响。实验结果表明,焙烧温度为400℃、掺杂量为0.5%的ZnFe2O4/TiO2纳米粉体降解效果最佳,在相同条件下,反应2h后农药降解率可比纯TiO2提高20%左右。正交实验优化了降解反应条件,在常温常压下,起始pH值为12、H2O2浓度为12mmol/L、催化剂浓度为0.5g/L、反应3h后,初始浓度为1.0×10-4mol/L的乙酰甲胺磷农药降解率可达61.2%。     

氯对医疗废物处置厂废水处理的影响

分析了医疗废物处置厂废水处理中如何消减氯对后续活性污泥处理工艺负面影响的问题。结合山西省某医疗废物高温蒸汽灭菌厂的废水处理实例,提出了一种利用生活污水中的氨氮来消减余氯对后续活性污泥处理影响的有效方法。     

代表性二级处理、三级处理和湿地生态修复技术对城镇污水人源干细胞毒性的削减

污水中的难降解污染物往往具有浓度低但毒性强的特点,可以通过多种暴露途径直接或间接对人体健康产生有害影响,因此有必要评估污水处理技术对健康效应的削减效果.本研究选择人骨髓间充质干细胞(human bone marrow mesenchy-mal stem cells,hBMSCs)体外模型,评估典型二级处理、三级处理和湿地修复技术进水、主要工艺排水的综合毒性,并与发光菌急性毒性测试结果进行比较.水样萃取物对hBMSCs的细胞毒性呈剂量依赖性关系,进水毒性单位(toxicity unit,TU)在0.03～ 0.22范围内,出水TU为0.02 ～ 0.03.二级处理技术对细胞毒性的削减率为59.8％.三级处理过程中经混凝、微滤和反渗透处理后,出水无显著细胞毒性,但经臭氧消毒后最终排水的细胞毒性较进水无显著变化.湿地修复技术对细胞毒性的削减率为49.9％.66.7％ (14/21)水样品对于hBMSCs细胞毒性的TU值高于发光菌急性毒性的TU值.在相对富集倍数(related fold enrichment,REF)20％效应浓度(EC20)下,二级处理和三级处理技术对污水hBMSCs细胞毒性的削减率低于发光菌急性毒性,但湿地修复技术对细胞毒性的削减率高于发光菌急性毒性.结果 提示污水处理厂排水中残留的难降解有机污染物对人源干细胞具有较强的有害效应,为再生水水质安全性评价以及城镇污水资源化技术研发提供参考依据和方法.