Abstract

This study evaluates the bio-treatability performance and kinetic models of full-scale horizontal subsurface flow constructed wetland used for the tertiary treatment of composite industrial effluent characterized by high-salt content ranging from 5830 to 10,400 µS/cm and biochemical oxygen demand (BOD₅): chemical oxygen demand (COD) ratio below 0.2. The wetland vegetated with Phragmites australis was operated in a semi-arid climate under an average hydraulic loading rate of 63 mm/d. The results of a 4-year operation calculated based on the concentration of pollutants showed that the average removal efficiency of COD, BOD_5, and total suspended solids (TSS) were 17.5, 5.1, and 11.2%, respectively. The system reduced up to 6.5 ± 0.7% of electrical conductivity presenting poor phyto-desalination potential without considering the contribution of evapotranspiration in water balance in contrast to satisfying performance for heavy metals reduction. The comparison of the kinetics of organic matter removal obtained by the first-order and Monod models paired with continuous stirred-tank reactor and plug flow regime showed that Monod-plug flow model provided the best fit with the constants of 2.01 g COD/m²·d and 0.3014 g BOD₅/m²·d with the best correlation coefficient of 0.610 and 0.968 between the predicted and measured concentrations, respectively. The low kinetic rates indicate that the process is capable of effluent polishing instead of purification due to the presence of organic compounds recalcitrant to biodegradation and a high level of salinity.

摘要

这项研究评估了全水平水平地下流动人工湿地的生物处理性能和动力学模型，该湿地用于高盐含量为5830至10,400 µS / cm和生化需氧量（BOD _5）的复合工业废水的三级处理。）：化学需氧量（COD）比率低于0.2。在半干旱气候下，以芦苇为生的湿地在平均水力负荷为63 mm / d的条件下运行。根据污染物浓度计算的4年运行结果表明，COD，BOD ₅的平均去除效率为_5。和总悬浮固体（TSS）分别为17.5％，5.1和11.2％。该系统降低了高达6.5±0.7％的电导率，这意味着较差的植物脱盐潜力，而没有考虑蒸散作用对水平衡的影响，这与令人满意的重金属还原性能形成了对比。通过一阶模型和Monod模型与连续搅拌釜反应器和活塞流方案配对获得的有机物去除动力学的比较表明，Monod-plug流动模型以2.01 g COD / m ²的常数提供了最佳拟合。·d和0.3014 g BOD ₅ / m ²·d在预测浓度和测量浓度之间的最佳相关系数分别为0.610和0.968。低动力学速率表明，由于存在对生物降解不利的有机化合物和高盐度，该方法能够进行废水精制而不是纯化。