Enhanced ozonation degradation of atrazine in the presence of nano-ZnO: Performance, kinetics and effects

Enhanced ozonation degradation of atrazine (ATZ) with nano-ZnO (nZnO) as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone (O₃) and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O₃/nZnO process after 5 min of reaction compared to O₃ alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5 mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated that OH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO, which could promote the utilization of O₃, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O₂-.     

华南南亚热带不同演替阶段植被的环境效应

研究华南南亚热带不同演替阶段植被对养分保护、碳氧平衡和对酸雨的缓冲作用的结果表明 :①100年生季风常绿阔叶林植物 N、P、K贮量是草地和芒萁群落的 12～ 39倍 ,灌木林的 12～16倍 ;死地被物 N、P、K贮量是草地和芒萁群落的 11～ 36倍 ,灌木林的 3.1～ 5.2倍 .30年生季风常绿阔叶林净初级生产量的 N、P、K贮量是草地、芒萁、灌木群落的 1.9～ 5.1倍 .②100年生季风常绿阔叶林植物碳贮量是草地、芒萁、灌木群落的 13～ 49倍 .30年生季风常绿阔叶林植物碳净固定量是草地、芒萁、灌木群落的 2.3～3.4倍 ,前者的氧释放量也明显大于后者 . ③芒萁、灌木群落和季风常绿阔叶林穿透雨的平均 p H值比降雨p H值分别高 1.13、1.03和 1.90个单位 ,季风常绿阔叶林对酸雨的缓冲能力明显高于芒萁、灌木群落 . ④正向演替可加强植被的环境效应 ,让草地、芒萁、灌木群落演替成为季风常绿阔叶林 ,有利于区域生态环境的改善 .     

胶莱平原大气降水氢氧稳定同位素特征研究

区域大气降水稳定同位素组成是利用同位素技术研究区域水循环所必须的前提,对于深入了解水循环过程具有重要意义。本研究基于降水样品,分析了胶莱平原及周边地区降水氢氧稳定同位素特征,探讨了降水同位素的环境效应,并通过对比分析不同水汽输送路径站点的降水同位素季节变化趋势,揭示了胶莱平原大气降水水汽来源。结果显示：胶莱平原大气降水线LMWL为δ²H=6.38δ¹⁸O+0.72,胶莱平原大气降水δ¹⁸O存在较显著的温度效应和降水量效应,高程效应不显著。6—9月,胶莱平原降水水汽主要受控于东亚季风,水汽主要来自相邻太平洋海域蒸发水汽;10月—次年5月,胶莱平原降水水汽主要受控于西风,水汽来源于局地蒸发,受极地水汽影响较小。本研究结果将为胶莱平原地表水—地下水—海水之间的相互转化及水循环研究提供基础。     

铜、镍、铅、锌4种重金属对水田土壤藻类的综合效应

为确定污水、污泥的农田施用标准,使用正交试验表L₉（3⁴）研究了4种重金属铜、镍、铅和锌在低、中、高3种浓度下对土壤藻类的数量和种类的影响。混合重金属使土壤藻类的种群结构发生改变,使蓝藻数量减少,硅藻数量或减少或增加,视条件而定,裸藻成为优势种。在土壤－藻类体系中重金属临界值铜为50mg/kg,镍为50mg/kg,铅为150mg/kg,锌为300mg/kg。     

混凝强化除磷的模拟实验研究

以模拟污水为研究对象,考察了不同絮凝剂(聚合氯化铝、三氯化铁及硫酸亚铁)对污水中磷的去除效果及其影响因素,并对氢氧化铁的吸附除磷规律,以及氢氧化铁与絮凝剂复配除磷的效果进行了探讨,提出了聚合氯化铝、三氯化铁及硫酸亚铁可行的投加量.     

聚铝及其加载粘土矿物高效絮凝沉降铜绿微囊藻的研究

考察了4种聚铝絮凝剂絮凝沉降铜绿微囊藻的效果，发现编号为HPACS02的聚铝絮凝剂除藻效果最好，并进一步研究得知HPACS02在pH7．5时絮凝除藻的效率最高。在采用HPACS02作为絮凝剂时，如果少量投加滑石、海泡石或高岭土等粘土矿物会对铜绿微囊藻的絮凝沉降产生增效作用，其中滑石的助凝效果最好。     

新疆工业固体废物状况及对策与建议

根据新疆工业固体废物的产生特点及工业固体废物处理处置现状,提出适用于本地的对策与建议。     

福州青年运动会环境空气质量状况及原因分析

利用2015年10月福州市国控点位空气质量常规6项参数(SO_2、NO_2、CO、O_3、PM_(10)、PM_(2.5))、NCEP/NCAR再分析逐日高度场、风场资料、温度场资料(垂直方向为17层,分辨率为2.5°×2.5°),对10月及福州第一届青年运动会(以下简称"青运会")期间空气质量进行分析与评价,并结合采取的相关管控措施和气象条件情况,分析福州市空气质量变化原因。结果表明,2015年10月福州市空气质量达到优良水平,各项污染物指标均达到一级标准,浓度较2014年同期明显下降,同时青运会期间污染物浓度较10月显著降低,这与对重点工业源、流动源、扬尘源等采取的管控措施密不可分,而且青运会前期受台风"巨爵"外围气流影响,福州温度较常年偏高,有利于空气垂直湍流运动,青运会后期的降水清洁过程,易于污染物清除。     

环境污染对生态危害经济损失评估模式的研究

定量评估环境污染对生态环境危害的经济损失,是环境科学研究的课题。本文从风险评价和环境经济学角度,提出环境污染对生态环境危害经济损失的评估模式。     

Effects of operational factors on soluble microbial products in a carrier anaerobic baffled reactor treating dilute wastewater

The effects of feed strength,hydraulic residence time(HRT),and operational temperatures on soluble microbial product(SMP) production were investigated,to gain insights into the production mechanism.A carrier anaerobic batfled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions,namely,feed strengths of 300-600 mg/L,HRTs of 9-18 h,and temperatures of 10-28℃.Generally, SMP production increased with increasing feed strength and decreasing temperature.At high temperature (28℃),SMP production increased with decreasing HRT. As the temperature Was decreased to 18 and 10℃.the SMP production was at its peak for 12 h HRT Therefore,temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio Was found at high temperature and long HRT because of complete volatile fatty acid degradation.SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR.As a secondary metabolite.some SMP could be consumed at lower feed strength.