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

农业活动产生的污染是一个严重的全球性环境问题，包括杀虫剂和营养物质等几种污染物。农药是特别重要的污染物，因为它们具有毒性、生物蓄积性和通常在环境中持久性。它们在饮用水中的存在是一种潜在的公共健康危害，因为这些化学物质被认为是神经毒性、致癌物和内分泌干扰物，即使是微量的。它们也对几种水生生物构成严重威胁，最近被认为是蜜蜂数量减少的原因。在加拿大，所有省份的地表水和地下水中都检测到杀虫剂。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。

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.