tailieunhanh - Phsicochemical Treatment of Hazardous Wastes - Chapter 3

Công nghệ xử lý có thể được phân loại theo nhiều cách khác nhau. Ví dụ, để đạt được các tiêu chuẩn dọn dẹp, Đạo luật nước rõ ràng (CWA) phân loại các công nghệ xử lý như sau: • công nghệ điều khiển thực hiện (BPCT) áp dụng cho tất cả các chất gây ô nhiễm. • thông thường công nghệ (BCT) áp dụng đối với các chất ô nhiễm thông thường. • công nghệ có sẵn tốt nhất (BAT) áp dụng đối với các chất ô nhiễm độc hại và độc đáo. • chứng minh công nghệ có. | 3 Physicochemical Treatment Processes Introduction Treatment technologies can be classified many different ways. For example for achieving cleanup standards the Clear Water Act CWA classifies treatment technologies as follows Best practicable control technology BPCT applies to all pollutants. Best conventional technology BCT applies to conventional pollutants. Best available technology BAT applies to toxic and unconventional pollutants. Best available demonstrated technology BADT is used for new dischargers. According to treatment mechanisms however treatment technologies are classified as biological physicochemical and thermal processes. In terms of the place where the actual treatment takes place the issue of in situ vs. ex situ comes into play as far as selecting the most cost-effective remediation processes. For example most bioremediation processes are in situ while physicochemical processes may be implemented both in situ and ex situ according to the following In situ physical chemical treatment The advantage of in situ treatment is that it allows soil to be treated without being excavated and transported however it generally requires longer time periods and treatment uniformity is less certain because of the variability in soil and aquifer characteristics. Physical chemical treatment processes destroy separate or contain pollutants by using physicochemical approaches. Physical chemical technologies for volatile organic compounds VOCs include soil flushing soil vapor extraction and solidification stabilization in situ vitrification . 2004 by CRC Press LLC Ex situ physical chemical treatment Ex situ treatment generally requires excavation of soil or pumping of groundwater processes that may increase costs but which are less time consuming than in situ treatment. In addition ex situ treatment is more reliable due to being able to homogenize the contaminants. The available ex situ physicochemical technologies for VOCs .