Development of photocatalytic adsorbents for removal and degradation of pesticides in water and wastewaters

农业活动造成的污染是一个严重的世界性环境问题，包括几种类型的污染物，如农药和营养素。杀虫剂是特别重要的污染物，因为它们有毒、生物累积，通常在环境中持久存在。它们在饮用水中的存在是一个潜在的公共健康威胁，因为这些化学物质被认为是神经毒性、致癌物质和内分泌干扰物，即使在微量水平上也是如此。它们也是对几种水生生物的严重威胁，最近被确认为蜜蜂数量下降的原因。在加拿大，所有省份的地表水和地下水中都检测到了杀虫剂。因此，有必要开发有效的修复技术来去除水和废水中的农药。 目前DG提案的目标是利用创新的合理设计的光催化吸附材料开发一种综合处理农业废水中农药的吸附去除和氧化光催化降解，重点是吸附能力和催化反应活性和选择性。具体目标是：(1)催化剂的合成；(2)实现农药完全降解的工艺条件的优化；(3)暗吸附的研究；(4)光催化反应的动力学研究；(5)催化剂稳定性的研究和工业化配方的概念论证。 这项研究可能带来的好处包括可持续地解决农业和农业食品活动对环境的严重负面影响。这项研究计划将使加拿大的几个工业和市政领域受益，如供水、废水处理厂和农业。此外，该研究计划将有助于在农业污染控制以及水和废水处理的绿色工艺的重要领域培训高素质的人员(2名博士、1名硕士、2名美国国家海洋局和1名PDF)。

Pollution arising from agricultural activities is a serious environmental worldwide problem encompassing several types of pollutants such as pesticides and nutrients. Pesticides are particularly important pollutants as they are toxic, bioaccumulative and generally persistent in the environment. Their presence in drinking water is a potential public health hazard as these chemicals are reputed to be neurotoxic, carcinogen and endocrine disruptors even at trace levels. They represent also a serious threat to several aquatic organisms and identified recently as responsible of the decline of bees. In Canada, pesticides were detected in surface and ground waters throughout all provinces. Therefore, there is a necessity to develop efficient remediation techniques to get rid of the pesticides in water and wastewaters. The objective pursued in the present DG proposal is to develop an integrated treatment for the adsorptive removal and oxidative photocatalytic degradation of pesticides occurring in agricultural aqueous effluents using innovative rationally-designed photocatalytic adsorbent materials with emphasis on both adsorption capacity and catalytic reaction activity and selectivity. The specific objectives are: (1) Catalysts synthesis; (2) Optimization of process conditions to achieve total pesticide degradation; (3) Investigation of the dark adsorption; (4) Kinetic investigation of the photocatalytic reaction and (5) Study of the stability of the catalysts and proof of concept on commercial formulation. The benefits that could accrue from this research include sustainable solution for the acute negative repercussions of agricultural and agri-food activities on the environment. This research program will benefit several industrial and municipal fields in Canada such as water supplies, wastewater treatment plants and agriculture. Moreover, this research program will contribute to the training of highly qualified personnel (2 Ph.D., 1 MsC., 2 USRA and 1 PDF) in the important area of agricultural pollution control and green processes for water and wastewater treatment.