Cationic content effects of biodegradable amphoteric chitosan-based flocculants on the flocculation properties

A series of biodegradable amphoteric chitosan-based flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified carboxymethyl chitosan, denoted as CMC-CTA) with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.     

厌氧折流板调节池预处理垃圾转运站压滤液的中试研究

建立了中试规模的厌氧折流板调节池,用于转运站垃圾压滤液的现场预处理。转运站垃圾压滤液具有高有机污染物浓度、水质变化剧烈和pH值较低等特点,当进水COD浓度为50 000 mg/L～80 000 mg/L,厌氧折流板反应器能稳定实现出水COD=25 000 mg/L左右,总氮去除率30%～40%,总磷去除率70%,抗冲击能力和低pH值进水运行稳定性良好。厌氧折流板调节池发生酸化后,综合采用了多种措施加以调控。     

工业废弃场地再开发的环境评估：Ⅱ健康风险评估

工业废弃场地往往受到严重的土壤地下水污染,再开发往往会给公众带来潜在健康风险。对河南某城市一工业废弃污染场地进行了健康风险评估。根据未来土地利用状况,分剐对居住场景和建筑场景的健康风险进行了评估。在居住场景下,总石油烃会引起较高的非致癌风险,而苯会通过口腔摄入和呼吸摄入导致较高的致癌风险。假如长期饮用MW—1附近区域的地下水时,苯和总石油烃会给居民带来不可接受的非致癌风险。同时苯还会带来较高的致癌风险。在建筑场景下,由于较短的暴露周期,场地污染不会带来不可接受的风险。为保护未来居民的健康,应当在场地开发为住宅小区前进行污染区域的修复。     

Synthesis of tributyl citrate using acid ionic liquid as catalyst

Synthesis of tributyl citrate (TBC) has been studied by using acid functionalized ionic liquid as catalyst. The results indicated that acidic ionic liquids show good catalytic and reusable performance. Under the optimum conditions, using 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate as catalyst, the conversion of citric acid was 97%. After easily separated from the products the ionic liquid could be reused 13 times without any disposal, and the conversion of citric acid was not less than 93%. Therefore, an environmental friendly approach for the synthesis of tributyl citrate is provided.     

基于雷达估算降雨的湖北漳河流域径流模拟研究

本文以湖北省漳河流域为研究对象,从2008-2017年中选取了16次洪水过程(10次过程用于率定参数,6次过程用于检验),分别采用了4种方法进行雷达降雨估算,并将估算结果输入到TOPMODEL和新安江模型进行了径流模拟计算。结果表明:4种雷达降雨估算方法中动态Z-I的平均相对误差最小为8.16%,其次是分组Z-I为20.1%,最优Z-I和经典Z-I分别为29.7%和29.02%;从径流模拟结果来看,动态Z-I效果最佳,分组Z-I次之,最优Z-I和经典Z-I模拟效果相对较差,且TOPMODEL模型的洪峰相对误差和峰现时差比新安江模型的模拟结果要小,新安江模型模拟结果的确定性系数与TOPMODEL模型接近。     

天津经济技术开发区(TEDA)社会发展预警系统建立的研究

本文根据社会发展的统计指标体系,结合评价可持续发展的社会指标体系构成,得出社会发展警情、警兆指标体系,然后根据统计数据,采用实证和理论分析相结合的方法,给出社会发展警情预报的警情警限值,并利用其研究ＴＥＤＡ的社会发展态势,最终给出ＴＥＤＡ警源形成因素及排警对策。     

一种新型聚四氟乙烯膜在油田采出水的试验研究

本实验装置原水为大庆油田采出水,经过0.1μm聚四氟乙烯膜处理后要求达到SS≤1.0 mg/L、粒径中值≤1μm和0il≤5.0 mg/L的标准,然后再回注。实验结果表明:在预处理出水稳定在0il≤15.0 mg/L、SS≤5.0 mg/L、粒径中值≤3μm条件下,该水质作为膜系统的进水时,膜的出水水质中粒径中值不达标,SS和oil含量能达到设计要求。在预处理出水水质超出设计范围时,膜的出水水质中SS超标,而oil和粒径中值能达标。     

染料行业节水减污措施探讨

染料行业发展迅速,但随着节能减排要求的提高,问题也愈暴露,甚至影响到染料工业的生存。针对染料行业水耗高、废水产生量大的严峻环境问题,提出节水减污的工作思路。通过推行清洁生产,找出水耗高、污染物产生量大的环节,结合企业实际生产情况,从染料生产的技术工艺、设备、水回收利用、加强管理、结合一定的末端治理5个方面,探讨节水减污的措施,争取做到源头节水,将污染物最大程度地消灭在生产过程中,做到废水的回收利用,使染料行业能够可持续发展下去。     

Assessment of source water contamination by estrogenic disrupting compounds in China

Detection of estrogenic disrupting compounds (EDCs) in drinking waters around China has led to rising concerns about health risks associated with these compounds. There is, however, a paucity of studies on the occurrence and identification of the main compounds responsible for this pollution in the source waters. To fill this void, we screened estrogenic activities of 23 source water samples from six main river systems in China, using a recombinant two-hybrid yeast assay. All sample extracts induced significant estrogenic activity, with E2 equivalents (EEQ) of raw water ranging from 0.08 to 2.40 ng/L. Additionally, 16 samples were selected for chemical analysis by gas chromatography-mass spectrometry. The EDCs of most concern, including estrone (E1), 17βup-estradiol (E2), 17αup-ethinylestradiol (EE2), estriol (E3), diethylstilbestrol (DES), estradiol valerate (EV), 4-t-octylphenol (4-t-OP), 4-nonylphenols (4-NP) and bisphenol A (BPA), were determined at concentrations of up to 2.98, 1.07, 2.67, 4.37, 2.52, 1.96, 89.52, 280.19 and 710.65 ng/L, respectively. Causality analysis, involving comparison of EEQ values from yeast assay and chemical analysis identified E2, EE2 and 4-NP as the main responsible compounds, accounting for the whole estrogenic activities (39.74% to 96.68%). The proposed approach using both chemical analysis and yeast assay could be used for the identification and evaluation of EDCs in source waters of China.