人造景观水体的污染与处理技术

人工营造的亲水景观,由于缺少天然水系的自我净化功能和生物动态平衡体系,易产生发"绿"、发"臭"等现象,不仅影响了景观水域的视觉效果,更影响了周围居住环境。文章通过对人造景观水质的研究,针对人造景观用水的水质的特点,探讨了行之有效的景观水处理技术方案。

改进的SWAT模型在强人类活动地区的应用

针对中国人类活动强烈的流域水循环特点,在二元水循环理论的指导下,以SWAT分布式水文模型为基础,进行了灌溉和人工耗、用水模块的开发和改进,构建了适用于此类区域的二元水循环模型。利用改进后的模型对天津市的水循环过程进行了模拟。结果表明,改进后的模型模拟的NASH效率系数从0.62提高到0.89,相关系数从0.79提高到0.91,比改进前有明显的提高。模型的构建和改进,对分布式水文模型在高强度人类活动影响流域的水资源、水环境研究和管理将起到积极的作用。

A hydrated amorphous iron oxide nanoparticle as active water oxidation catalyst

Developing efficient water oxidation catalysts(WOCs)with earth‐abundant elements still remains a challenging task for artificial photosynthesis.Iron‐based WOC is a promising candidate because it is economically cheap,little toxic and environmentally friendly.In this study,we found that the catalytic water oxidation activity on amorphous iron‐based oxide/hydroxide(FeOx)can be decreased by an order of magnitude after the dehydration process at room temperature.Thermogravimetric analysis,XRD and Raman results indicated that the dehydration process of FeOx at room temperature causes the almost completely loss of water molecule with no bulk structural changes.Based on this finding,we prepared hydrated ultrasmall(ca.2.2 nm)FeOx nanoparticles of amorphous feature,which turns out to be extremely active as WOC with turnover frequency(TOF)up to 9.3 s^-1 in the photocatalytic Ru(bpy)3^2+‐Na2S2O8 system.Our findings suggest that future design of active iron‐based oxides as WOCs requires the consideration of their hydration status.

Buffer anion effects on water oxidation catalysis: The case of Cu(Ⅲ) complex

Water oxidation is the bottleneck of artificial photosynthesis.Since the first ruthenium-based molecular water oxidation catalyst,the blue dimer,was reported by Meyer’ s group in 1982,catalysts based on transition metals have been widely employed to explore the mechanism of water oxidation.Because the oxidation of water requires harsh oxidative conditions,the stability of transition complexes under the relevant catalytic conditions has always been a challenge.In this work,we report the redox properties of a CuⅢ complex(TAML-CuⅢ] with a redox-active macrocyclic ligand(TAML) and its reactivity toward catalytic water oxidation.TAML-CuⅢ displayed a completely different electrochemical behavior from that of the TAML-CoⅢ complex previously reported by our group.TAML-CuⅢ can only be oxidized by one-electron oxidation of the ligand to form TAML·+-CuⅢand cannot achieve water activation through the ligand-centered proton-coupled electron transfer that takes place in the case of TAML-CoⅢ.The generated TAML·+-CuⅢ intermediate can undergo further oxidation and ligand hydrolysis with the assistance of borate anions,triggering the formation of a heterogeneous B/CuOx nanocatalyst Therefore,the choice of the buffer solution has a significant influence on the electrochemical behavior and stability of molecular water oxidation catalysts.

Role of transition-metal electrocatalysts for oxygen evolution with Si-based photoanodes

A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOOH,M=Fe,Co,Ni)as a model system,we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction(OER).Among the photoanodes with the three different electrocatalysts,the best OER activity,with a low-onset potential of∼1.01 VRHE,a high photocurrent density of 24.10 mA cm^(-2)at 1.23 VRHE,and a remarkable saturation photocurrent density of 38.82 mA cm^(-2),was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight(100 mW cm^(-2))in 1 M KOH electrolyte.The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport,provides a larger number of surface active sites,and results in higher OER activity,compared to other electrocatalysts.This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.

A Preliminary Study on Cactus as Flocculants in Water Recycling from Moroccan Phosphates Schlamms

In this work we used a new organic biodegradable flocculants which is the cactus cladodes juice in order to recycle water from phosphate schlamms. This flocculants has enabled us to increase the settling velocity of the schlamms so consequently the water recycled degree. The study was conducted on an industrial sample of phosphates schlamms from Khouribga phosphates washing plant. The study was about the influence of concentration, pH, and velocity gradient with cactus extract leads to satisfactory results in term of settling decantation, and in water recycling degree which is 93%.

Rain Water Utilizing System Combing Artificial Wetland and Urban Drainage System

The method of utilizing rain water has been well developed in foreign countries to realize the sustainable development of water recourse while the method is still at the initial level in China. When considering the increasing of water shortage and urban flood, the awareness of utilizing rain water, as an inevitable trend, has been applied to various engineering technologies. This article has analyzed the principle of conventional road drainage system and the application of artificial wetland technology, also proposed to combine the road drainage system and artificial wetland, as a complex drainage system, to utilize the urban rain water, decrease urban flood pressure, and improve urban micro environment. The calculation principle and method for the complex drainage system are included as well.