Nature based solutions for contaminated land remediation and brownfield redevelopment in cities: A review

Urban industrialization has caused severe land contamination at hundreds of thousands of sites in cities all around the world, posing a serious health risk to millions of people. Many contaminated brownfield sites are being left abandoned due to the high cost of remediation. Traditional physical and chemical remediation technologies also require high energy and resource input, and can result in loss of land functionality and cause secondary pollution. Nature-based solutions (NBS) including phytoremediation and conversion of brownfield sites to public greenspaces, holds much promise in maximizing a sustainable urban renaissance. NBS is an umbrella concept that can be used to capture nature based, cost effective and eco-friendly treatment technologies, as well as redevelopment strategies that are socially inclusive, economically viable, and with good public acceptance. The NBS concept is novel and in urgent need of new research to better understand the pros and cons, and to enhance its practicality. This review article summarizes NBS's main features, key technology choices, case studies, limitations, and future trends for urban contaminated land remediation and brownfield redevelopment.

Photochemical sample treatment: a greener approach to chlorobenzene determination in sediments

Due to worker׳s exposure, solvent and stationary phases׳ consumption, sample purification is one of the most polluting steps in analytical procedures for determination of organic pollutants in real samples. The use of photochemical sample treatment represents a valid alternative methodology for extracts clean up allowing for a reduction of the used amount of organic solvents. In this paper we report the first application on the photolytic destruction of organic substances to eliminate some of the interferences in the analysis of Chlorobenzenes in sediment samples. The method׳s efficiency and robustness were compared with classic silica column purification process currently used in clean up procedures in sediment analysis. Quality parameters such as recovery, linearity and reproducibility were studied. The entire procedure was validated by three replicate analysis of spiked real sediment sample. The quantification limits (LOQ) obtained by us ranged from 1.0 to 2.3 ng g(-1), while the detection limits (LOD) were of 1.0 ng g(-1). The RSD for each congener was below 10% and recoveries were in the range 95-130%. Results based on the analysis of real samples showed similar or improved detection thresholds and pointed out the advantages of the photochemical methodology in terms of costs, use of chemical substances and operator׳s safety according to Green Analytical Chemistry principles.