Environmental management of pesticidal POPs in China: past, present and future

China, the largest developing country in the world, has been undergoing rapid economic growth in the past two decades. Synchronously, large quantities of persistent organic chlorinated pesticides have been used in agriculture and non-agriculture areas. Accompanying with incomplete management framework, the improper use and disposal of pesticides have caused serious pollution problems. In this study, we discussed: (1) ten persistent organochlorine pesticides in terms of historical production, consumption and number of manufacturers, import and export; (2) the current management framework of pesticidal persistent organic pollutants (POPs) with respect to legal system and government administrative system; (3) the existing problems in the management of pesticidal POPs; and proposed recommendations for countermeasures. Based on the available information, it can be concluded that records on the historical production and consumption quantities of pesticidal POPs are incomplete which makes a difficulty in the management. Although China has come a long way in developing a modern legal system, the current system is still considered weak and inefficient; and many challenges are ahead. The government administrative system has also been reformed and improved, but over-lapping jurisdictions still exist and are ineffective in managing pesticidal POPs program. To address these existing problems in pesticidal POPs management, it was suggested that more investigations should be conducted to collect information on pollution sources of pesticidal POPs, to evaluate their environmental risks, to identify new alternative chemicals and to complete management framework of pesticidal POPs in China. Furthermore, the public should be encouraged to participate in managing hazardous pesticidal POPs in China, and international cooperation and communication should be established and strengthened imperatively as well.     

Solid-state anaerobic co-digestion of food waste,rice straw,and rice husk supplemented with cattle digesta under thermophilic conditions

Journal of Material Cycles and Waste Management - Improving the solid-state digestion of food waste (FW) is important for recovering energy and utilizing the digested residue as fertilizer. Herein,...     

PnET-CN模型对东亚森林生态系统碳通量模拟的适用性和不确定性分析

东亚地区森林类型多样,开展区域生态系统碳循环模拟时应考虑森林类型的差异。论文利用基于叶氮浓度-最大净光合作用速率关系的PnET-CN模型,对东亚地区8 个森林生态系统通量观测站点的总生态系统碳交换（GEE）和生态系统呼吸（RE）进行模拟,以探讨模型的适用性并对不确定性来源进行分析。研究结果表明：①PnET-CN模型能较为准确地模拟东亚地区大部分森林生态系统站点的GEE和RE;②模型的适用性排序依次为温带、寒温带、亚热带、 热带,模型未能很好地模拟热带湿地森林GEE和RE 的季节与年际变异;③在同一气候区中,PnET-CN模型更加适用于针叶林碳交换的模拟;④PnET-CN模型比较准确地反映了东亚森林生态系统GEE、RE对气候因子（例如,温度或辐射）的响应,但在低温、较弱辐射条件下模型低估了GEE,在高温或较强辐射条件下高估了GEE;在低温条件下模型低估了RE,在高温条件下模型高估了RE。针对东亚多个森林通量站点的模拟情况,论文提出模型应在以下方面进行改进：①PnET-CN模型计算物候时除了考虑温度之外还应加入土壤湿度的影响,并对不同气候区森林生态系统赋予不同叶片凋落时长;②PnET-CN模型中温度对GEE的限制以及光合最适温度应该根据不同站点设置;③PnET-CN模型应该考虑森林生态系统对环境胁迫的适应性,加强对干旱等干扰的模拟;④同时对于拥有复杂水文条件的森林生态系统应该改进土壤含水量的算法,以准确反映该类型森林生态系统GEE和RE的季节变化。