HCB与γ-HCH在辽河沉积物中的缺氧降解动力学

Kinetics of the anaerobic degradation of HCB and γ-HCH in Liaohe River sediment.

为全面认识多氯有机物在天然水沉积物中的转化行为,利用超声波发生仪萃取沉积物样品,采用气相色谱仪(Ni63-ECD)定量分析,在缺氧条件下,测定了辽河沉积物中六氯苯(HCB)、γ-HCH的微生物降解速率.在单个培养体系中,测定出不外加有机碳源,外加葡萄糖和乙酸钠3种条件下HCB、γ-HCH的缺氧降解符合准一级动力学方程,动力学常数分别为HCB:k(不外加有机碳源)=0.0014d-1,k(葡萄糖)=0.0033d-1,k(乙酸钠)=0.0052d-1;γ-HCH:k(不外加有机碳源)=0.0454d-1,k(葡萄糖)=0.1143d-1,k(乙酸钠)=0.1451d-1.在2种氯代物混合培养体系中,HCB、γ-HCH的降解速率均有所下降.经GC-MS测定,三氯苯、二氯苯分别是HCB、γ-HCH的主要降解产物.

In order to know entirely the transformation behavior of polychloro organic substances in the sediment of natural water, under anaerobic condition, the microorganism degradation rates of hexachlorobenzene (HCB) and γ-HCH in Liaohe River sediment were determined utilizing ultrasonic wave generator to extract sediment samples and GC(Ni63-ECD) to analyze quantitatively. Determined in single cultivation system under 3 kinds of conditions: without organic carbon source added (WOSA) glucose added (GA) and sodium acetate added (SAA), the anaerobic degradation of HCB, γ-HCH fitted pesudo-first-order kinetics equation, with kinetic constant of HCB; k(WOSA)=0.0014d-1, k(GA)=0.0033d-1, k(SAA)=0.0052d-1;γ-HCH: k(WOSA)=0.0454d-1, k(GA)=0.1143d-1, k(SAA)=0.1451d-1. The degradation rates of HCB and γ-HCH all decressed a little in two kinds of chloro compounds mixed cultivation system. The main degradation products of HCB and γ-HCH determined with GC-MS were trichlorobenzene and dichlorobenzene respectively.