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[Objectives] This paper was aimed to study the remediation effects of phosphate-solubilizing fungi and bone char in different soils. [Methods] Three different types of lead-contaminated soils (neutral yellow brown soil, alkaline sand soil and acidic red soil)were mixed with the bone char sintered at different temperatures. We measured the contents of phosphorus and lead, and the remediation differences of different soils. The Pb bioavailability of lead-contaminated soil was then determined by planting non-heading Chinese cabbage. The application potential of compound remediation materials was confirmed by adding compound remediation agents to the soil with the best remediation effect. [Results] The bone char had the best effect of promoting the release of phosphorus in yellow brown soil, and the available phosphorus content was 64 times higher than that of the control, showing a high potential of lead remediation. The pH of yellow brown soil was neutral, and the available P in the soil would not be fixed by Ca, Fe, Al, etc., thus increasing the probability of its reaction with Pb. When bone char was solely used, the material treated at 200-300 ℃ had qualified remediation effect. We planted non-heading Chinese cabbage to verify the bioavailability of lead in yellow brown soil after bone char application. It was observed that addition of a certain proportion of bone char to yellow brown soil (the initial mass ratio of bone char to lead was over 0.5:1) could not only increase the absorption of phosphorus by 2.0 to 3.5 times, but also reduce the absorption of lead by non-heading Chinese cabbage(content of lead in pakchoi leaves was reduced by 70% to 80% compared with blank treatment). A composite of bone char and Aspergillus niger was further applied to yellow brown soil, and the effective lead was reduced to 14.36 mg·kg-1. In particular, the growth of the A. niger proved the remediation potential of the composite. [Conclusions] The composite of bone char and A. niger was suitable for lead remediation in neutral soils, and the suitable heating temperature for preparing bone char was 200-300 ℃. [ABSTRACT FROM AUTHOR]

[Objectives]This paper aimed to evaluate the validity of pesticides application strategy in rice, and analyse the risk of dietary exposure and ecological impact. [Methods] This study implemented long-term investigation on usage and residual details of pesticides using for pest control in single-season and double-season rice of Jiangsu and Jiangxi provinces. Investigation of pesticides residues in rice and soil had been conducted in the period of tillering, heading and harvesting stage, and the results had been compared between the pesticide reduction strategies adopted area and the regular integrated pest management (IPM) adopted area. Acute and chronic dietary exposed risk and ecological impact risks had been evaluated by using the dietary exposure risk assessment model and the ecology relative risk model (EcoRR). [Results] The results revealed that.4 of total 51 pesticides used in rice for pest control, had been found in the harvest brown rice. Pymetrozine and hexaconazole were the most frequently found pesticides in all rice samples with the frequency up to 93.00% and 28.75%, followed by 14.29% and 7.14% for chlorpyrifos and pentazolidol, respectively. However, the risk assessment of acute and chronic toxicity that may be caused by these 4 pesticides through dietary exposure, was finalized to be negligible for all populations divided by age. Adopting pesticide reduction strategies could further low the risk of dietary exposure. As for the soil sampled from the period of tillering, heading, and harvesting stages of rice, 13 different kinds of pesticides were found, tricy clazole, hexaconazole and propiconazole with 100% detection rates in particular. It could be explained by the long half-life periods of these pesticides and the remains of previous residue. The ecological risk assessment showed that the reduction use of pesticides could decrease the ecological risks significantly, even down to low level from medium level risk. It was found that the most effective effort of reducing the ecological impact was to decrease the use of pymetrozine, as this pesticide played a key role to the contribution of ecological risks in the period of tillering, heading, and harvesting ( 54.16% -83.68%, 19.07%-84.39%, and 0.00%-82.32% respec tively). Secondly, the use of pretilachlor at tillering stage, difenoconazole at the heading stage and propiconazole at the harvest stage was considered to be alternative key elements for the cause of ecological risk, with contributions of the risk ratios of 0.00%-71.50%. 0.00%-68.95% and 1.12%-62.24%,respectively. [Conclusions] Reducing the use of specific pesticides in the particular growth period of rice could reduce ecological impact and dietary exposure significantly. Pymetrozine plays a key role for ecological impact, followed by difenoconazole, propiconazole and pretilachlor, which should be used appropriately. [ABSTRACT FROM AUTHOR]