1,2,3-Trichloropropane (TCP) is a groundwater contaminant in the drinking water aquifers in Hawaii and some other states. Granular activated carbon (GAC) has been used for 30 years to treat approximately 60 million gallons per day of TCP-contaminated groundwater in Hawaii. The State of Hawaii's current maximum contaminant level (MCL) for TCP is 600 ng/L (ppt), and consideration is being given to lower the MCL to 5 ppt. There is no EPA MCL for TCP. A study was conducted to determine if any GAC could meet a 5 ppt MCL for TCP, and if so, how many bedvolumes (BVs) could be treated prior to breakthrough. Constant Diffusivity-Rapid Small-Scale Column Tests (CD-RSSCTs) were performed to evaluate GAC adsorption of TCP. Three different groundwaters and six different GACs were utilized. The RSSCTs with the currently-utilized GAC were predictive of the performance of the GAC contactors (50,000 BVs to breakthrough). Any of the six GACs could meet a MCL of 5 ppt and some could do so for 150,000 or more BVs. No single GAC was optimal for all three well sites, indicating effects of subtle undefined differences in the water matrix and/or GAC physiochemical properties. The coal-based direct-activated carbon currently being used is the least optimal for all three well sites with respect to meeting a potential new TCP MCL of 5 ppt. The most effective GACs for Kunia were the Calgon coal-based GAC and the Siemens enhanced coconut shell GAC, while the most effective for Waipahu were the Siemens regular and enhanced coconut shell GACs, and the most effective for Mililani was the Calgon coal-based GAC. Choosing just one GAC for use at all three well sites (rather than the optimal for each site) would result in a reduction of treatment run time of 1 year at one well site (63% reduction).

1,2,3-三氯丙烷（TCP）是夏威夷和其他一些州的饮用水含水层中的地下水污染物。夏威夷使用粒状活性炭（GAC）已有30年的历史，每天可处理约6000万加仑的被TCP污染的地下水。夏威夷州目前对TCP的最大污染物水平（MCL）为600 ng / L（ppt），并且正在考虑将MCL降至5 ppt。没有用于TCP的EPA MCL。进行了一项研究，以确定是否有任何GAC可以满足TCP的5 ppt MCL，如果可以，在突破之前可以处理多少床体积（BV）。进行了恒定扩散-快速小规模柱测试（CD-RSSCT），以评估TCP的GAC吸附。利用了三种不同的地下水和六种不同的GAC。具有当前使用的GAC的RSSCT可以预测GAC接触器的性能（突破50,000个BV）。六个GAC中的任何一个都可以达到5 ppt的MCL，有些可以达到150,000个或更多BV。没有一个单一的GAC对所有三个井位都是最佳的，表明水基质和/或GAC的理化性质存在细微的不确定差异。就满足潜在的5 ppt的新TCP MCL而言，当前正在使用的基于煤的直接活性炭对于所有三个井场都是最不理想的。对Kunia最有效的GAC是Calgon煤基GAC和西门子增强型椰子壳GAC，而对Waipahu最有效的是Siemens常规和增强型椰子壳GAC，对Mililani最有效的是Calgon煤基GAC。 。