以河道水为原水的高速过滤过程及其性能分析

针对平原城市缓流河道普遍存在的季节性水质恶化问题,采用预氧化、微絮凝+高速过滤对天津市某缓流河道水体进行中试规模实验。结果表明,该处理技术具有处理周期长(>24 h)、过滤滤速高(平均为43.26 m·h-1)和出水效果好(出水水质优于地表水Ⅳ类水质标准)的特点。同时发现：单位面积滤柱的产水率呈“阶梯”下降趋势;高速过滤的堵塞特征曲线服从三次多项式分布;系统过滤历经增长期、稳定期和衰减期,其中增长期为3~4 h,稳定期约14 h,过滤系数λ为(0.020 1±0.001 3) cm-1(置信度P=95%),其可作为系统基本属性的定量参数。     

灰霾的健康效应

灰霾是颗粒物和气体污染物导致的可察觉到的能见度降低的污染天气现象.近年来,随着城市化进程的快速发展,城市大气污染加剧,灰霾天气也随之增多.总结了灰霾这一污染型天气的特征,介绍了灰霾的化学成分、污染机制等,并从影响机制和流行病学角度出发,对国内外灰霾对人体的健康效应研究成果进行了综合评述,提出目前急需解决的科学问题和今后的研究方向.     

浓磷酸预处理废弃棉织物回收葡萄糖和涤纶的优化

为了实现废弃棉织物的高效资源化利用,采用浓磷酸预处理,将棉纤维转化为葡萄糖,并回收高纯度涤纶.以磷酸浓度、磷酸与原料液固比、预处理温度和时间为研究对象,以涤纶回收纯度、葡萄糖收率为考察指标,采用中心组合设计(CCD),建立响应面模型对预处理工艺参数进行优化.并确定了最佳的浓磷酸预处理工艺条件为:磷酸质量分数85%,液固比15:1,预处理时间7 h,预处理温度50℃.在此条件下涤纶回收纯度可达100%,葡萄糖收率可达79.0%,且实验验证值与模型预测值较为接近,模型精度较高.此外,再生纤维素不经干燥直接酶水解,葡萄糖收率可被进一步提高至83.0%.     

Composting of municipal solid waste by different methods improved the growth of vegetables and reduced the health risks of cadmium and lead

Environmental Science and Pollution Research - Reutilization of putrescible municipal solid wastes (MSW) in agriculture can provide valuable plant nutrients. However, it may pose serious...     

农业源水污染物削减技术探讨

农业面源污染是水体中COD、氮、磷等指标的主要来源。它包括农药化肥施用、畜禽养殖和农村生活污水排放。对农业源水污染物进行削减是实现污染物总量控制的重要手段。通过详细总结国内外现有农业源水污染物削减技术方法,分析对比其优缺点和实用性,筛选出适用于不同农业污染来源的污水处理技术。结果表明,畜禽养殖废水的适宜处理技术有厌氧/缺氧/好氧(A/A/O)、序批式活性污泥法(SBR)、膜生物反应器(MBR)、升流式厌氧污泥床(UASB)、厌氧沼气池;农地施肥污水的适宜处理技术有SBR、MBR、UASB;农村生活污水的适宜处理技术有厌氧沼气池、生物滴滤池、人工湿地、稳定塘。     

剩余污泥发酵液对黏性膨胀污泥特性的影响

为了解决剩余污泥碱性发酵液作为低碳氮比生活污水外加碳源时引发的黏性污泥膨胀问题,采用序批式反应器(SBR),以剩余污泥碱性发酵液为进水碳源,对黏性膨胀污泥的沉降性能及其影响因素之间的相关性进行了系统研究。结果表明：当进水COD值为300~350 mg·L⁻¹时,随着运行时间的推移,污泥容积指数(SVI)逐渐升高,最终达到540 mL·g⁻¹,此时发生污泥黏性膨胀现象;黏性膨胀污泥表面负电荷由0.62 mV累积到29.49 mV,相对疏水性(RH)从44%下降至19%,污泥容积指数(SVI)与Zeta电位、相对疏水性(RH)呈负相关(R²分别为0.837 71和0.678 54),与污泥粒径不相关;胞外聚合物总量从31 mg·g⁻¹提高至39 mg·g⁻¹,但LB-EPS/TB-EPS的比例从0.92增加至2.92;与TB-EPS相比较,LB-EPS与污泥容积指数(SVI)、Zeta电位、相对疏水性(RH)具有显著相关性(R²分别为0.892 88、0.885 29和0.776 68)。以上结果揭示了以发酵液为碳源引发的黏性膨胀污泥特性的变化规律,可为实际工程中以发酵液为碳源的黏性污泥膨胀问题提供借鉴。     

硫化亚铁活化过一硫酸盐降解含表面活性剂水溶液中三氯乙烯的效果与机制

采用硫化亚铁(FeS)活化过一硫酸盐(PMS)降解含表面活性剂吐温-80(TW-80)水溶液中的三氯乙烯(TCE),考察了PMS和FeS投加量、TW-80浓度、溶液初始pH、无机阴离子(Cl^–和HCO₃^–)对TCE降解的影响,确定了PMS/FeS体系中的主导自由基及TCE降解机理,验证了PMS/FeS体系处理实际地下水中含TW-80的TCE效果。结果表明：增加PMS或FeS投加量有利于TCE的降解,但当其投加剂量分别超过0.8 mmol·L^–1和0.6 g·L^–1时,TCE降解反而受到抑制,且TCE的降解率随TW-80浓度的增加而下降;PMS/FeS体系对pH有较宽的适用范围,在pH=11时受到抑制,Cl^–和HCO₃^–对TCE降解有抑制作用;通过自由基淬灭实验和电子顺磁共振实验确定了SO₄^–·、HO·和O₂^–·是PMS/FeS体系中的主导自由基;相比于其他氯代烃,该体系对四氯乙烯和四氯化碳也有较好的降解效果;实际地下水的处理结果证实PMS/FeS体系在实际应用中具有潜力和优势。     

厚覆盖区1：25万区域地质调查工作方法研究

通过1：25万杭州市幅厚覆盖区第四纪研究和填图实践，初步总结出“以气候旋回及基准面旋回等时性理论为基础，从古气候旋回宏观识别标志研究人手，以标准孔为基准点外延扩展，在反复认识与验证的基础上，进行层序地层划分，建立剖面等时格架，制作高精度对比的剖面图及准瞬时岩相古地理图”的研究方法，以及“从古岸线沉积物研究人手，充分运用非正式岩石地层单位的表示方法，结合考古及地方志，填绘出具岩石空间分布、海平面升降信息、古文化遗址、浅表含水层展布及河流与海岸线变迁”的非常规填图方法。提高了本区第四纪地层研究精度，使地质图具有强烈的地区特色。拓宽了区调工作的服务领域。并为沿海厚覆盖区的区域地质调查另辟了一条新思路。     

Lead adsorption capacities of different components in natural surface coatings

Pb adsorption capacities of Fe oxide, Mn oxide and organic materials in natural surface coatings (biofilms and associated minerals) collected in three lakes, two ponds and a river in Jilin Province, China and Cayuga Lake in US were studied. A novel extraction technique was employed to remove one or more component(s) from the surface coatings. Pb adsorption to surface coatings before and after extraction was performed to determine the adsorptive properties of the extracted component(s). The statistical analysis of observed Pb adsorption was carried out using nonlinear least squares fitting (NLSF) to estimate the Pb adsorption capacity of each component of surface coatings. For each body of water, the estimated Pb adsorption capacity of Mn oxide( mol Pb/mol Mn) was significantly higher than that of Fe oxide( mol Pb/ mol Fe). The value of estimated adsorption capacities of organic materials with the unit mol Pb per kg COD was similar to or less than that of Fe oxides with the unit mol Pb per mol Fe. Comparison of components of surface coatings in different waters showed that the estimated Pb adsorption capacities of components in surface coatings developed in different natural waters were different,especially for Mn oxides.     

Heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province, China

The heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province was investigated. 97 feed and manure samples were sampled from 31 farming plants in 10 major cities of Jiangsu. 14 metals, including Zn, Cu, Pb, Cd, Cr, Ni, Mo, Mn, Ba, Co, Sr, Ti, As and Hg, were analyzed after samples acid digestion. The results showed that the most feed samples contained high concentration of metals exceeding National Hygienical Standard for Feeds. Meanwhile, it was found that Cu, Zn, Pb, Cd and Cr concentrations in animal manures were also high, for example, Cu concentration in a manure sample reached to as much as 1726.3 mg/kg. Heavy metals loading quantities in soil per year were then calculated when metals contaminated organic fertilizers were applied, and its effects on soil environmental qualitv were further evaluated.