Increasing the Knowledge on the Management of Cu‐Contaminated Agricultural Soils by Cropping Tomato (Solanum Lycopersicum L.)

This paper increases the knowledge on the potential use of Cu‐contaminated agricultural soils with tomato (Solanum lycopersicum L.). The effect of Cu and its interaction with soil properties on plant biomass production and on the accumulation of this metal in plant tissues were evaluated by conducting biomass assays in four representative Mediterranean agricultural soils contaminated by Cu. Copper toxicity on plant biomass production, evaluated through the effective concentrations of Cu added to soil that reduce the biomass production by 50% (EC₅₀) and by 10% (EC₁₀), was higher in soils having less soil organic matter and clay content and even in soils with favourable properties but having salinity. For the cases in which tomato was collected, Cu concentrations in them were similar for all soils and doses and never exceed the maximum Cu concentration allowed by the Codex Alimentarius Commission Regulation (10 mg_Cu kg⁻¹ in fresh weight basis). According to our results, tomato could be cropped in Cu‐contaminated Mediterranean agricultural soils when concentrations of Cu determined in them rely between their respective EC₅₀ and EC₁₀, because production and quality of fruits, the latter understood as the Cu concentration in them, would not be compromised. For the soils assayed, these values would range between 32·9 and 1696·5 mg kg⁻¹, depending on soil properties. Because the baseline value considered is similar to those established in other parts of the European Mediterranean region, these results can be used as guidance for this region to establish adequate phytoremediation strategies and prevent land degradation processes. Copyright © 2014 John Wiley & Sons, Ltd.     

Cu2+对新农药噻虫嗪水解的影响

通过模拟试验研究了Cu2 对噻虫嗪水解的影响。结果表明,噻虫嗪的水解符合一级动力学方程,Cu2 (包括Cu(OH) 、Cu(OH)-3等)对噻虫嗪的水解具有明显的催化作用,且其催化作用基本不受温度和pH的影响,Cu(OH)2对噻虫嗪的水解无催化作用。根据GC-MS对水解产物的鉴定,发现噻虫嗪的主要水解产物为3-(2-氯-噻唑-5-亚甲基)-5-甲基-4-氧代-(1,3,5)恶二嗪,从而推测了Cu2 对其水解的催化机理,这对于了解噻虫嗪在环境中的迁移、转化具有重要意义。     

我国主要麦区土壤有效铁锰铜锌丰缺状况评价及影响因素

明确我国主要麦区土壤有效铁锰铜锌含量分布和影响因素，对了解麦田土壤微量元素供应能力、指导小麦丰产与优质生产至关重要。于2016—2021年连续6年，在我国17个小麦主产省/市采集1 314份耕层土壤样品，参考中国土壤有效微量元素分级标准，评价了我国麦田土壤有效铁锰铜锌丰缺状况，并采用随机森林方法定量分析了主要土壤化学性质对铁锰铜锌有效性的贡献。结果表明，我国主要麦区土壤有效铁含量介于1.8~612 mg?kg-1，平均为49.1 mg?kg-1，8.9%的样本未达到缺铁临界值4.5 mg?kg-1，且主要集中在北方、西北麦区的山西、陕西、甘肃等地，西南和长江中下游麦区有效铁较高。土壤有效锰介于0.1~176 mg?kg-1，平均为22.1 mg?kg-1，低于缺锰临界值5 mg?kg-1的样本占6.9%，缺锰土壤分布在西北、北方麦区的山西、陕西、甘肃、内蒙古等地，西南、长江中下游麦区土壤有效锰含量较高。土壤有效铜介于0.1~10.8 mg?kg-1，平均为1.9 mg?kg-1，仅1.8%样本未达到缺铜临界值0.5 mg?kg-1。土壤有效锌介于0.1~26.0 mg?kg-1，平均为1.4 mg?kg-1，14.3%的样本低于缺锌临界值0.5 mg?kg-1，主要分布在西北和北方麦区的山西、陕西、甘肃、内蒙古等省份，云南、贵州等西南麦区的有效锌较高。土壤基本化学性质中，pH对有效铁、有效锰含量影响最大，有效铁是铜有效性的重要因素，影响有效锌的主要因素是有效磷和有效铜。我国麦田土壤有效铁锰铜锌含量存在较大的区域变异，铁、锰、锌不足主要发生在北方石灰性土壤，南方麦田供应充足，几乎所有麦田土壤有效铜可满足作物铜需求。     

Optimal bandwidth selection for retrieving Cu content in rock based on hyperspectral remote sensing

Hyperspectral remote sensing technology is widely used to detect element contents because of its multiple bands,high resolution,and abundant information.Although researchers have paid considerable attention to selecting the optimal bandwidth for the hyperspectral inversion of metal element contents in rocks,the influence of bandwidth on the inversion accuracy are ignored.In this study,we collected 258 rock samples in and near the Kalatage polymetallic ore concentration area in the southwestern part of Hami City,Xinjiang Uygur Autonomous Region,China and measured the ground spectra of these samples.The original spectra were resampled with different bandwidths.A Partial Least Squares Regression(PLSR)model was used to invert Cu contents of rock samples and then the influence of different bandwidths on Cu content inversion accuracy was explored.According to the results,the PLSR model obtains the highest Cu content inversion accuracy at a bandwidth of 35 nm,with the model determination coefficient(R²)of 0.5907.The PLSR inversion accuracy is relatively unaffected by the bandwidth within 5-80 nm,but the accuracy decreases significantly at 85 nm bandwidth(R²=0.5473),and the accuracy gradually decreased at bandwidths beyond 85 nm.Hence,bandwidth has a certain impact on the inversion accuracy of Cu content in rocks using the PLSR model.This study provides an indicator argument and theoretical basis for the future design of hyperspectral sensors for rock geochemistry.     

冶炼废渣中有价值金属的综合回收

首先采用硝酸与添加剂湿法分离产台炼废渣中的铜，铋和银等金属，然后用火法收集浸渣中的金，从而高效而又综合地回收了渣中各种有价值的金属。